TY - JOUR TI - Volumetric treatment efficiencies of some commercial clay stabilizers AU - Hesterberg, Dean AU - Reed, M.G. T2 - SPE Production Engineering AB - Summary Volumetric treatment efficiencies of three commercially available clay-stabilizer treatments were evaluated in the laboratory. Rock volume treated per unit chemical volume varied up to three-fold between stabilizers and depended on sandstone mineral properties. The results are valuable for designing clay-stabilizer treatments and maximizing stabilizer cost-effectiveness. DA - 1991/// PY - 1991/// DO - 10.2118/18466-PA VL - 6 IS - 1 SP - 57-62 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0026108455&partnerID=MN8TOARS ER - TY - JOUR TI - Effects of perennial forage legume living mulches on no-till winter wheat and rye AU - White, J.G. AU - Scott, T.W. T2 - Field Crops Research AB - No-till winter cereals sown in narrow rows may compete successfully with perennial forage-legume living mulches that can fix nitrogen (N), conserve soil, increase dry-matter production, and suppress weeds. The effects of small-grain species, mulch species, and top-dress N on grain and mulch yield and the grain N concentration of winter cereals direct-drilled into legume living mulches were examined in a two-year field study in New York, U.S.A., on soils of the Lima and Kendaia series: fine-loamy, mixed, mesic Glossoboric and Aeric Hapludalfs. Wheat (Triticum aestivum L.) or rye (Secale cereale L.) were grown in monoculture or drilled into summer-established plots of alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), crownvetch (Coronilla varia L.), ladino clover (Trifolium repens L. forma lodigense Hort ex. Gams), red clover (T. pratense L.), or white clover (T. repens L.). Spring top-dress N was applied at 0 or 56 kg N ha−1. Cereals were reseeded for a second season. Mulches generally interfered more and yielded more with wheat than with rye. Birdsfoot trefoil, crownvetch, and white clover had little effect on grain-yield the first year; birdsfoot trefoil and crownvetch interfered strongly with cereals the second year. Red clover did not affect rye grain-yield in the absence of top-dress N, but did tend to reduce wheat yield. Top-dress N increased cereal grain-yield and decreased mulch yield. In general, legume mulches did not appear to enhance cereal N nutrition the first year; red and white clovers appeared to contribute N to rye the second year. Second-year grain-yields were generally lower than first-year yields, due to increased interference from living mulches and broadleaf weeds. All living mulches except crownvetch suppressed weeds the second year. The results indicate that some species of perennial forage legumes may be suitable for use as living mulches for direct-drilled small grains, especially tall early winter cereals. DA - 1991/// PY - 1991/// DO - 10.1016/0378-4290(91)90079-b VL - 28 IS - 1-2 SP - 135–148 ER - TY - JOUR TI - CHARACTERIZATION OF POTATO VIRUS-Y RESISTANCE FROM GAMETOCLONAL VARIATION IN FLUE-CURED TOBACCO AU - YUNG, CH AU - WERNSMAN, EA AU - GOODING, GV T2 - PHYTOPATHOLOGY AB - A previously identified gametoclonal tobacco variant, NC 602, exhibits resistance to certain potato virus Y (PVY) strains. NC 602 was subjected to a second cycle of anther culture and colchicine treatment. The resulting doubled haploid lines were evaluated for back mutation to susceptibility and any additional mutation that might provide resistance to tobacco etch virus (TEV). The PVY resistance was stable in anther culture, and although no TEV resistance was found, three lines were identified with delayed symptom onset (...) DA - 1991/8// PY - 1991/8// DO - 10.1094/Phyto-81-887 VL - 81 IS - 8 SP - 887-891 SN - 0031-949X ER - TY - JOUR TI - Registration of 'NC-V11' peanut AU - Wynne, J. C. AU - Coffelt, T. A. AU - Mozingo, R. W. AU - Anderson, W. F. T2 - Crop Science AB - Crop ScienceVolume 31, Issue 2 cropsci1991.0011183X003100020062x p. 484-485 Registration of Cultivars Registration of ‘NC-VII’ Peanut J. C. Wynne, J. C. Wynne Dep. of Crop Sci., Box 7629, North Carolina State Univ., Raleigh, NC, 27695Search for more papers by this authorT. A. Coffelt, T. A. Coffelt Tidewater Agric. Exp. Stn. Suffolk, North Carolina State Univ., Raleigh, NC, 27695Search for more papers by this authorR. W. Mozingo, R. W. Mozingo USDA-ARS, Suffolk, VA, 23437Search for more papers by this authorW. F. Anderson, W. F. Anderson Dep. of Crop Sci., Box 7629, North Carolina State Univ., Raleigh, NC, 27695Search for more papers by this author J. C. Wynne, J. C. Wynne Dep. of Crop Sci., Box 7629, North Carolina State Univ., Raleigh, NC, 27695Search for more papers by this authorT. A. Coffelt, T. A. Coffelt Tidewater Agric. Exp. Stn. Suffolk, North Carolina State Univ., Raleigh, NC, 27695Search for more papers by this authorR. W. Mozingo, R. W. Mozingo USDA-ARS, Suffolk, VA, 23437Search for more papers by this authorW. F. Anderson, W. F. Anderson Dep. of Crop Sci., Box 7629, North Carolina State Univ., Raleigh, NC, 27695Search for more papers by this author First published: 01 March 1991 https://doi.org/10.2135/cropsci1991.0011183X003100020062xCitations: 24 Corresponding author. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume31, Issue2March-April 1991Pages 484-485 RelatedInformation DA - 1991/// PY - 1991/// DO - 10.2135/cropsci1991.0011183x003100020062x VL - 31 IS - 2 SP - 484 ER - TY - JOUR TI - Registration of 'NC 10C' peanut AU - Wynne, J. C. AU - Beute, M. K. AU - Bailey, J. AU - Mozingo, R. W. T2 - Crop Science AB - Crop ScienceVolume 31, Issue 2 cropsci1991.0011183X003100020061x p. 484-484 Registration of Cultivars Registration of ‘NC 10C’ Peanut J. C. Wynne, J. C. Wynne Dep. of Crop Sci. Tidewater Agric. Exp. Stn., Suffolk, VA, 23437Search for more papers by this authorM. K. Beute, M. K. Beute Dep. of Crop Sci.Search for more papers by this authorJ. Bailey, J. Bailey Dep. of Crop Sci.Search for more papers by this authorR. W. Mozingo, R. W. Mozingo Dep. of Plant Pathology, North Carolian State Univ., Raleigh, NC, 23769Search for more papers by this author J. C. Wynne, J. C. Wynne Dep. of Crop Sci. Tidewater Agric. Exp. Stn., Suffolk, VA, 23437Search for more papers by this authorM. K. Beute, M. K. Beute Dep. of Crop Sci.Search for more papers by this authorJ. Bailey, J. Bailey Dep. of Crop Sci.Search for more papers by this authorR. W. Mozingo, R. W. Mozingo Dep. of Plant Pathology, North Carolian State Univ., Raleigh, NC, 23769Search for more papers by this author First published: 01 March 1991 https://doi.org/10.2135/cropsci1991.0011183X003100020061xCitations: 22 Corresponding author. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume31, Issue2March-April 1991Pages 484-484 RelatedInformation DA - 1991/// PY - 1991/// DO - 10.2135/cropsci1991.0011183x003100020061x VL - 31 IS - 2 SP - 484 ER - TY - JOUR TI - EFFECT OF MICROSPORE STAGE AND MEDIA ON ANTHER CULTURE OF PEANUT (ARACHIS-HYPOGAEA-L) AU - WILLCOX, MC AU - REED, SM AU - BURNS, JA AU - WYNNE, JC T2 - PLANT CELL TISSUE AND ORGAN CULTURE DA - 1991/1// PY - 1991/1// DO - 10.1007/BF00044261 VL - 24 IS - 1 SP - 25-28 SN - 0167-6857 KW - ANTHER CULTURE KW - ARACHIS KW - MEDIA KW - MICROSPORE DEVELOPMENT KW - PEANUT ER - TY - JOUR TI - BREEDING FOR DISEASE RESISTANCE IN PEANUT (ARACHIS-HYPOGAEA L) AU - WYNNE, JC AU - BEUTE, MK AU - NIGAM, SN T2 - ANNUAL REVIEW OF PHYTOPATHOLOGY AB - Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth–promoting bacteria and fungi in the rhizosphere prime the whole plant body for ...Read More DA - 1991/// PY - 1991/// DO - 10.1146/annurev.py.29.090191.001431 VL - 29 SP - 279-303 SN - 1545-2107 KW - GROUNDNUT KW - GENETICS OF PEANUT KW - OILSEED CROP KW - PATHOGEN VARIABILITY KW - FOOD LEGUME ER - TY - JOUR TI - SOYBEAN GROWTH-RESPONSE TO PLANT-DENSITY - RELATIONSHIPS AMONG CANOPY PHOTOSYNTHESIS, LEAF-AREA, AND LIGHT INTERCEPTION AU - WELLS, R T2 - CROP SCIENCE AB - Plant spacing greatly affects leaf area, light interception, and canopy apparent photosynthesis (CAP) in soybean [ GLycine max (L.) Merr.]. This study examined relationships among these variables in four population‐density and row‐width treatment combinations for two seasons. Wide‐row (0.96 m) treatments were 3,11, and 18 plants m −2 in 1988 and 3, 15, and 24 in 1989; narrow‐row (0.43 m) treatments were 12 plants m −2 in 1988 and 13 in 1989. Narrow‐row treatments tended to have greater CAP rates during early growth in 1988, but not 1989, when rates lagged behind the wide‐row, high population. The reduction in CAP by the narrow‐row treatment in 1989 corresponded to its reduced light interception as measured parallel to the row base. Both total radiation (300‐2500 nm wavelengths) interception measured in 1988, and average photosynthetically active radiation (400‐700 nm) interception measured in 1989, were linearly related to CAP prior to, but not after, canopy closure. Similarly, leaf area indices (LAI) were curvilinearly related to percent light interception until canopy closure. After canopy closure, light interception did not decline at a rate commensurate with the loss of leaf area, indicating abscission of leaves not involved in light interception. Canopy photosynthesis was not different for any treatment after Reproductive Stage R5 in either year; however, significant differences were evident between Rl and R5 in 1989. These differences corresponded to the significantly lower yield of the low population in that year. Yield differences between the medium populations of the wide and narrow rows were not explained by CAP during reproductive growth. The data indicate that when LAI is above critical levels in post‐anthesis soybean canopies, factors other than photosynthesis may be involved in the response of seed yield to variation in plant density. DA - 1991/// PY - 1991/// DO - 10.2135/cropsci1991.0011183X003100030044x VL - 31 IS - 3 SP - 755-761 SN - 0011-183X KW - CAP KW - CANOPY-APPARENT PHOTOSYNTHESIS KW - DAP KW - DAYS AFTER PLANTING KW - LAI KW - LEAF AREA INDEX KW - LP KW - MP KW - HP KW - = LOW KW - MEDIUM KW - AND HIGH POPULATION DENSITY KW - NR KW - WR = NARROW ROW KW - WIDE ROW KW - PAR KW - PHOTOSYNTHETICALLY ACTIVE RADIATION KW - PPFD KW - PHOTOSYNTHETIC PHOTON FLUX DENSITY KW - SLW KW - SPECIFIC LEAF WEIGHT ER - TY - JOUR TI - PEANUT YIELD AS A RESULT OF 50 YEARS OF BREEDING AU - WELLS, R AU - BI, T AU - ANDERSON, WF AU - WYNNE, JC T2 - AGRONOMY JOURNAL AB - Abstract Breeding for increased yield is known to indirectly alter other plant characteristics in many crop species, including peanut ( Arachis hypogaea L.). This 2‐yr, field study examined growth and dry matter allocation to various plant organs of 10 Virginia‐type peanut genotypes bred for increased yield in North Carolina, Genotypes representing the period from 1944 to the present were grown in 1988 and 1989. Growth was measured on five dates in each year. Genotypes expressed as the minimum number of breeding cycles from an indigenous germplasm exhibited a yield increase of 30 g m 2 per breeding cycle. Genotypes developed from a greater number of breeding cycles tended to have smaller vegetative mass and shorter main stem lengths. However, concurrent increases in reproductive allocation, measured as pod mass and reproductive‐to‐vegetative ratios (RVR), were evident. Correlation analysis at 133 d after planting (DAP) between the number of breeding cycles and measurements of main stem length, total dry weight (DW), vegetative DW, stem DW, leaf area index (LAI) and RVR resulted in significant correlation coefficients of −0.67,0.38, −0.67, −0.71, −0.42, and 0.74 respectively. At 71 DAP, reproductive growth, measured as peg number, pod number, pod mass, and RVR was correlated with the number of breeding cycles, with significant correlation coefficients of 0.53, 0.52, 0.46, and 0.46, respectively. Reproductive to vegetative ratio continued to be positively related to both breeding cycle number and year of cultivar release throughout reproductive growth. The data indicate greater reproductive dry matter allocation by more recently released genotypes. Further, the allocation in reproductive growth appears related to an earlier transition from vegetative to reproductive development DA - 1991/// PY - 1991/// DO - 10.2134/agronj1991.00021962008300060007x VL - 83 IS - 6 SP - 957-961 SN - 0002-1962 ER - TY - JOUR TI - Modeling competition for light between soyabean and broadleaf weeds AU - Wiles, L. J. AU - Wilkerson, G. G. T2 - Agricultural Systems AB - Crop yield reductions due to weed competition can vary with both environmental and cultural conditions. Models of resource use by crops and weeds will likely be necessary to accurately simulate crop losses from weed competition. Many broadleaf weeds cause losses in soybean (Glycine max (L.) Merr.) through competition for light. A simple model of canopy structure and light interception by soybean and broadleaf weeds within a weed area of influence has been developed and incorporated into SOYWEED, a dynamic soybean-weed competition model. Daily photosynthetic rates per unit ground area are calculated according to interception of direct light by the weed and crop. Interception is approximated from the simple exponential extinction of light by a plant canopy. For competing plants, interception depends on both the amount and arrangement of leaf area. Arrangement of that leaf area is described by extinction coefficients, the plant height, and the vertical distribution of leaf area. Preliminary testing with cocklebur (Xanthium strumarium L.) competition data indicates an improved simulation of weed and crop growth and crop yield with the incorporation of this model into SOYWEED, but highlights the lack of data on weed and soybean canopy structure. Simulated crop response to changes in weed emergence date and time before weed removal is consistent with general observations reported in the literature. Simulation results indicate that several weed canopy characteristics may contribute to the differential ability of weed species to compete with soybean. DA - 1991/// PY - 1991/// DO - 10.1016/0308-521X(91)90145-Z VL - 35 IS - 1 SP - 37 ER - TY - JOUR TI - Influence of safeners on the in vivo and in vitro metabolism of bentazon and metolachlor by grain sorghum shoots: A preliminary report AU - Moreland, D. E. AU - Corbin, F. T. T2 - Zeitschrift fur Naturforschung. C, Biosciences AB - Abstract Metabolism of bentazon and metolachlor by excised shoots and a microsomal fraction iso­lated from the shoots, of 3-day-old, dark-grown, grain sorghum (Sorghum bicolor cv. Funk G 522 DR) seedlings was studied. The effects of seed treatments, on the subsequent metabo­lism of the herbicides, with the safeners naphthalic anhydride, oxabetrinil, and CGA 133205 were compared against surface-sterilization and Captan-treatments. Bentazon was aryl hydroxylated in both in vivo and in vitro studies with the hydroxylated derivative undergoing glycosylation only under in vivo conditions. Both shoots and microsomes isolated from shoots of safener-treated seed showed enhanced metabolism of bentazon relative to the controls. In­ hibition by tetcyclacis, a potent inhibitor of plant cytochrome P-450 monooxygenases, in both the in vivo and in vitro studies, and a requirement for NADPH in the in vitro studies suggested that the formation of hydroxybentazon was mediated by a cytochrome P-450 monooxygenase. Metolachlor was metabolized to polar material and O-desmethylmetolachlor under in vivo conditions. Only the demethylated product was formed in vitro. Shoots isolated from safener-treated seed showed enhanced formation of polar com pounds which were assumed to have arisen from conjugation with glutathione. Tetcyclacis did not affect the formation of the polar components. However, the formation of O-desmethylmetolachlor was depressed in the shoots excised from safener-treated seed under both in vivo and in vitro conditions. Tetcyclacis completely prevented formation of the demethylated metabolite. Hence, formation of this meta­bolite is considered to be P-450 mediated. The differential response obtained with the safeners, i.e., stimulation of aryl hydroxylation of bentazon and depression of metolachlor demethylation, suggests that the reactions are probably catalyzed by different cytochrome P-450 mono­oxygenases. DA - 1991/// PY - 1991/// DO - 10.1515/znc-1991-9-1031 VL - 46 IS - 9-10 SP - 906 ER - TY - JOUR TI - Growth regulator and axillary bud position effects on in vitro establishment of Vitis rotundifolia AU - Sudarsono, AU - Goldy, R. G. T2 - HortScience DA - 1991/// PY - 1991/// VL - 26 IS - 3 SP - 304 ER - TY - JOUR TI - Nitrogen supplied to corn by legumes in a central Amazon Oxisol AU - Smyth, T. J. AU - Cravo, M. S. AU - Melgar, R. J. T2 - Tropical Agriculture DA - 1991/// PY - 1991/// VL - 68 IS - 4 SP - 366 ER - TY - JOUR TI - HIGHER-PLANT RESPONSES TO ENVIRONMENTAL NITRATE AU - REDINBAUGH, MG AU - CAMPBELL, WH T2 - PHYSIOLOGIA PLANTARUM DA - 1991/8// PY - 1991/8// DO - 10.1034/j.1399-3054.1991.820423.x VL - 82 IS - 4 SP - 640-650 SN - 1399-3054 KW - GENE EXPRESSION KW - NITRATE ASSIMILATION KW - NITRATE REDUCTASE KW - NITRATE TRANSPORT KW - NITRITE REDUCTASE KW - ROOT MORPHOLOGY KW - ROOT RESPIRATION ER - TY - JOUR TI - GENETIC-ENGINEERING OF WOOD AU - WHETTEN, R AU - SEDEROFF, R T2 - FOREST ECOLOGY AND MANAGEMENT AB - The technology of genetic engineering provides an opportunity to accelerate tree improvement and to make directed modifications in the physical and chemical properties of wood. Modifications that lead to more efficient pulping of wood for paper may be among the earliest applications because of the information available on the pathway for lignin bisosynthesis. Other potential areas of application include fiber morphology, wood density, extractive content, biomass-utilization efficiency and dimensional stability. Widespread application of this technology awaits two developments: better methods of gene transfer, and a fundamental understanding of the development process of wood formation. If it can be successfully applied, genetic engineering will help to meet the projected demand for wood and paper products in the next century. DA - 1991/10/15/ PY - 1991/10/15/ DO - 10.1016/0378-1127(91)90133-G VL - 43 IS - 3-4 SP - 301-316 SN - 0378-1127 ER - TY - JOUR TI - Efficacy of early-season fluridone treatment for management of watermeal, Wolffia columbiana Karst AU - H., Kay. S. T2 - Journal of Aquatic Plant Management DA - 1991/// PY - 1991/// VL - 29 SP - 42 ER - TY - JOUR TI - Fate and behaviour of herbicides in soils AU - Weber, J. B. T2 - Applied Plant Science DA - 1991/// PY - 1991/// VL - 5 IS - 1 SP - 28 ER - TY - JOUR TI - DUPLICATIONS COMPLICATE GENETIC-MAPPING OF RF4, A RESTORER GENE FOR CMS-C CYTOPLASMIC MALE-STERILITY IN CORN AU - SISCO, PH T2 - CROP SCIENCE AB - Previous studies of the genetics of fertility restoration for C‐type cytoplasmic male sterility (cms‐C) in corn ( Zea mays L.) have produced conflicting results. The objective of this study was to localize the restorer gene(s) for cms‐C using restriction fragment length polymorphism (RFLP) analysis. Rf4 , a single dominant restorer gene for cms‐C found in inbred A619, was localized to Chromosome 8, ≈2 centimorgans from an RFLP marker locus, NPI114A . The presence in corn of extensive nucleotide duplication complicated the analysis. Because the region of Chromosome 8 near Rf4 is duplicated on Chromosome 3, an additional restorer gene for cms‐C may eventually be found on Chromosome 3. DA - 1991/// PY - 1991/// DO - 10.2135/cropsci1991.0011183X003100050036x VL - 31 IS - 5 SP - 1263-1266 SN - 0011-183X ER - TY - JOUR TI - CYTOLOGICAL AND INTERFERTILITY RELATIONSHIPS OF ARACHIS SECTION ARACHIS AU - STALKER, HT AU - DHESI, JS AU - PARRY, DC AU - HAHN, JH T2 - AMERICAN JOURNAL OF BOTANY AB - Twenty-nine recently introduced diploid (2n = 2x = 20) accessions of section Arachis plus an A. correntina (Burk) Krap. et Greg. nom. nud. control were hybridized to the diploid A-genome species A. duranensis Krap. et Greg. nom. nud. (ace. 7988), the diploid B-genome species A. batizocoi Krap. et Greg. (acc. 9484), and with two subspecies of the A-B genome (2n = 4x = 40) A. hypogaea cultivars NC 4 and Argentine. Most attempted crosses were successful and the resulting plants were vigorous. However, A. batizocoi × accession 30008 hybrids died as seedlings and A. batizocoi × accession 30017 produced only dwarf plants. The 710 diploid F1s from A. batizocoi were generally sterile, while those from A. duranensis had fertility ranges from 5% to 84%. Meiotic chromosome relationships in diploid crosses were cytologically evaluated in 185 plants plus tester accessions. Most taxa in section Arachis have an A genome, only A. batizocoi accessions have a B genome, a D genome is represented by accessions 30091 and 30099, and two other genomic groups, represented by accessions 30011 and 30033, may be present in the section. Most cytological differentiation was found among species originally collected in southern and eastern Bolivia. On the other hand, species collected at the extremes of the distribution of section Arachis species (northern Argentina to north-central Brazil) were cytologically very similar. Evidence is presented for speciation in Arachis being associated with both genetic differentiation and with translocated chromosomes. All taxa in the section except the D-genome species are believed to be cross-compatible with A. hypogaea, so germplasm introgression from most Arachis species should be possible. DA - 1991/2// PY - 1991/2// DO - 10.2307/2445247 VL - 78 IS - 2 SP - 238-246 SN - 1537-2197 ER - TY - JOUR TI - AN ANALYSIS OF THE B-GENOME SPECIES ARACHIS-BATIZOCOI (FABACEAE) AU - STALKER, HT AU - DHESI, JS AU - PARRY, DC T2 - PLANT SYSTEMATICS AND EVOLUTION DA - 1991/// PY - 1991/// DO - 10.1007/BF00940337 VL - 174 IS - 3-4 SP - 159-169 SN - 0378-2697 KW - ANGIOSPERMS, FABACEAE, ARACHIS-BATIZOCOI, A-HYPOGAEA KW - GENOME ANALYSIS, PHYLOGENETIC RELATIONSHIPS ER - TY - JOUR TI - Plant breeding in the 1990s: A summary AU - Stalker, H. T. T2 - AgBioTech News and Information DA - 1991/// PY - 1991/// VL - 3 IS - 3 SP - 425 ER - TY - JOUR TI - IMAGE-ANALYSIS AND NONLINEAR MODELING TO DETERMINE DIMENSIONS OF WET-SIEVED, MASTICATED FORAGE PARTICLES AU - LUGINBUHL, JM AU - FISHER, DS AU - POND, KR AU - BURNS, JC T2 - JOURNAL OF ANIMAL SCIENCE AB - A procedure to estimate dimensions of digesta particles was developed and evaluated. After wet sieving, particles of masticated switchgrass and bermudagrass hays retained on sieves with apertures of 1.0 mm2 or larger were placed on moist white filter paper, separated manually, and photographed. Photographs were scanned with a flat-bed scanner, scaled to size, and digitized. Projected area, perimeter, length, and width of particles were determined by a microcomputer system. Variables derived for each particle included the form factor, which was defined as (4 x pi x area)/perimeter2, and each particle's length: width ratio. Ninety-three percent of data from two trials with steers had significant lack of fit (P less than .05 to P less than .0001) to normal, lognormal, Weibull, or gamma distributions. As an alternative, individual particle measurements were summed on a cumulative percentage basis for each variable and were fit to an inverted Gompertz function to estimate median, mode, and mean dimensions of scanned particles. Estimates from the equation fit the distribution well; asymptotic SE averaged 3.5 and 1.4% of parameter means for dimensions of masticated switchgrass and bermudagrass hay particles, respectively. No analytic solution exists for the mean, which must be estimated numerically, but analytic solutions are available for the median and mode. Use of this equation will prevent bias caused by lack of fit to a particular distribution and yield more accurate estimates of mean particle dimensions than arithmetic means. DA - 1991/9// PY - 1991/9// DO - 10.2527/1991.6993807x VL - 69 IS - 9 SP - 3807-3816 SN - 0021-8812 KW - DIMENSIONAL ANALYSIS KW - MASTICATION KW - FORAGE KW - CATTLE ER - TY - JOUR TI - A NEW SPECIES IN SECTION ARACHIS OF PEANUTS WITH A D-GENOME AU - STALKER, HT T2 - AMERICAN JOURNAL OF BOTANY AB - Arachis glandulifera Stalker is a diploid (2n = 2x = 20) taxon in section Arachis native to eastern Bolivia. Plants of A. glandulifera have longer lateral branches than other taxa of section Arachis, an upright mainstem, prostrate lateral branches, and larger flowers and seeds than other wild species in the section. The pods are greatly reticulated. Glandular trichomes are present on vegetative plant parts and the peg. Intraspecific hybrids among four accessions are fertile and uniformly have ten bivalents in pollen mother cells. Three accessions had nearly identical karyotypes, while a fourth had subtelocentric chromosomes 6 and 9. Hybrids between A. glandulifera and two other diploid species of section Arachis were male-sterile, and chiasmata frequencies ranged between 5.8 and 12.1 per cell. Attempts to hybridize the species with A. hypogaea failed. A new species description and D genomic classification are proposed for A. glandulifera, which is different from previously described A and B genomes of section Arachis. DA - 1991/5// PY - 1991/5// DO - 10.2307/2445084 VL - 78 IS - 5 SP - 630-637 SN - 0002-9122 ER - TY - JOUR TI - RESPONSE OF SOYBEAN PHOTOSYNTHESIS AND CHLOROPLAST MEMBRANE-FUNCTION TO CANOPY DEVELOPMENT AND MUTUAL SHADING AU - BURKEY, KO AU - WELLS, R T2 - PLANT PHYSIOLOGY AB - The effect of natural shading on photosynthetic capacity and chloroplast thylakoid membrane function was examined in soybean (Glycine max. cv Young) under field conditions using a randomized complete block design. Seedlings were thinned to 15 plants per square meter at 20 days after planting. Leaves destined to function in the shaded regions of the canopy were tagged during early expansion at 40 days after planting. To investigate the response of shaded leaves to an increase in available light, plants were removed from certain plots at 29 or 37 days after tagging to reduce the population from 15 to three plants per square meter and alter the irradiance and spectral quality of light. During the transition from a sun to a shade environment, maximum photosynthesis and chloroplast electron transport of control leaves decreased by two- to threefold over a period of 40 days followed by rapid senescence and abscission. Senescence and abscission of tagged leaves were delayed by more than 4 weeks in plots where plant populations were reduced to three plants per square meter. Maximum photosynthesis and chloroplast electron transport activity were stabilized or elevated in response to increased light when plant populations were reduced from 15 to three plants per square meter. Several chloroplast thylakoid membrane components were affected by light environment. Cytochrome f and coupling factor protein decreased by 40% and 80%, respectively, as control leaves became shaded and then increased when shaded leaves acclimated to high light. The concentrations of photosystem I (PSI) and photosystem II (PSII) reaction centers were not affected by light environment or leaf age in field grown plants, resulting in a constant PSII/PSI ratio of 1.6 +/- 0.3. Analysis of the chlorophyll-protein composition revealed a shift in chlorophyll from PSI to PSII as leaves became shaded and a reversal of this process when shaded leaves were provided with increased light. These results were in contrast to those of soybeans grown in a growth chamber where the PSII/PSI ratio as well as cytochrome f and coupling factor protein levels were dependent on growth irradiance. To summarize, light environment regulated both the photosynthetic characteristics and the timing of senescence in soybean leaves grown under field conditions. DA - 1991/9// PY - 1991/9// DO - 10.1104/pp.97.1.245 VL - 97 IS - 1 SP - 245-252 SN - 0032-0889 ER - TY - JOUR TI - Effects of grass species on growing steers: II. Dry matter intake and digesta kinetics AU - Burns, J. C. AU - Pond, K. R. AU - Fisher, D. S. T2 - Journal of Animal Science AB - Animal responses to treatments in grazing experiments frequently remain unexplained because of inadequate pasture and(or) animal measurements. This 2-yr study examined DMI, gastrointestinal tract fill of undigested DM (FILL), rate of digesta passage (ROP), and digesta mean retention time (MRT) for steers grazing tall fescue (Festuca arundinacea Schreb.), switchgrass (Panicum virgatum L.), flaccidgrass (Pennisetum flaccidum Griseb.), and bermudagrass (Cynodon dactylon [L.] Pers.). A randomized complete block design was used with two agronomic replicates. Comparisons in June (yr 1) among continuously grazed switchgrass (SG), flaccidgrass (FG), and bermudagrass (BG) or in May (yr 2) among tall fescue (TF), SG, and FG showed similar digesta kinetics, but different DMI (kg.d-1.100 kg BW-1), among these forages within each sampling. In the June evaluation, the DMI of SG and FG were similar (means = 3.09), DMI of bermudagrass (BG) was lowest (2.23), and fecal DM output (FO) was similar among forages. In the May evaluation, DMI by steers grazing SG (3.90) was higher than that by steers grazing FG (2.97); DMI of tall fescue (TF) was intermediate (3.41) but similar to DMI of FG. Differences in DMI were due to differences in diet in vitro DM disappearance (IVDMD) rather than to differences in digesta kinetics. In July (yr 2), the MRT was highest for BG (84 h) and similar for SG and FG (57 h). Steers grazing different forages exhibited similar ROP and FILL, but FO (kg.d-1.100 kg BW-1) among steers varied (.37 for steers fed BG; .74 for steers fed SG and FG).(ABSTRACT TRUNCATED AT 250 WORDS) DA - 1991/// PY - 1991/// DO - 10.2527/1991.6931199x VL - 69 IS - 3 SP - 1199 ER - TY - JOUR TI - SAPROLITE SOIL TRANSFORMATIONS IN THE PIEDMONT AND MOUNTAINS OF NORTH-CAROLINA AU - BUOL, SW AU - WEED, SB T2 - GEODERMA AB - In the Piedmont and Mountain Provinces of North Carolina average annual precipitation exceeds evapotranspiration. Soil solum thickness is usually 1 to 2 m. Saprolite thickness is variable but related to rock type and geomorphic position. Slow hydraulic conductivity in the zone between the soil and the saprolite appears to restrict vertical percolation of water, thus slowing saprolite weathering on convex slopes. In saprolite zones immediately above granitic gneiss, often about 5 m below the surface, halloysite, gibbsite and X-ray amorphous aluminosilicate clay are the initial secondary minerals formed. Halloysite contents increase upward in the saprolite, apparently from resilication of gibbsite and the amorphous aluminosilicates. In the upper zones of the saprolite the halloysite is recrystallized into kaolinite which is the predominant clay-sized mineral in the soil. Over gabbro and metagabbro rocks, the lower zones of the saprolite contain appreciable quantities of smectite, vermiculite, and where chlorite is present, regularly interstratified chlorite-smectite. Although these smectite minerals become partially interlayered with hydroxy aluminum in the overlying soil, they p persist as a substantial component of the clay-sized fraction. Saprolite thickness is less than over the granitic rocks. Increased run-off and lateral through-flow produced by low hydraulic conductives of smectite-rich argillic horizons and convex hill slopes are believed to be responsible for the thin saprolite above mafic bedrock. Soils and saprolites from biotitic gneiss on upper sideslopes in the Mountain physiographic province have mineralogical trends with depth similar to those found over the granitic gneisses of the Piedmont. Gibbsite often constitutes as much as 30% of the clay, and contents tend to increase in the deeper saprolite zones. Biotite sand, which is common throughout the soil and saprolite, alters to kaolinite sand under the acidic conditions of the saprolite. Sand-sized mica appears resistant to weathering except where there is evidence of physical transport. DA - 1991/11// PY - 1991/11// DO - 10.1016/0016-7061(91)90064-Z VL - 51 IS - 1-4 SP - 15-28 SN - 1872-6259 ER - TY - JOUR TI - Recurrent selection progress in a population derived from an interspecific peanut cross AU - Halward, T. M. AU - Wynne, J. C. AU - Stalker, H. T. T2 - Euphytica DA - 1991/// PY - 1991/// VL - 52 IS - 2 SP - 79 ER - TY - JOUR TI - RECENT DEVELOPMENTS IN BREEDING SOYBEANS FOR IMPROVED OIL QUALITY AU - BURTON, JW T2 - FETT WISSENSCHAFT TECHNOLOGIE-FAT SCIENCE TECHNOLOGY AB - Abstract Soybean breeding has traditionally focused on improving crop productivity. While this is still the main objective of soybean breeding programs, there is increased emphasis on improving the intrinsic characteristics of the seeds. Breeding goals with respect to oil quality improvement have been threefold: (1) reducing lipoxygenase activity, (2) decreasing linolenic acid concentrations in soybean oil and more recently (3) reducing the saturated fatty acid, palmitate, in soybean oil. The first two are aimed at improving oil flavor and shelf life. The third has been added as a result of medical concerns about excess saturated fats in the human diet. Considerable progress has been made toward achieving all three objectives. Improved soybean germplasm has been released and is being used to develop high yielding cultivars improved oil quality. Null alleles for three lipoxygenase isozymes have been transferred into the cultivar ‘Century’ through backcrossing. Three different germplasm sources have been developed through mutagenesis and selection with low concentrations of linolenic acid (3.0 to 3.5%). This material has been released and is being widely used by public and private breeders to incorporate the low linolenic acid trait into high yielding cultivars. Cultivars with 2% germplasm with lower concentrations of palmitic acid in soybean oil by as much as 50%. In the U.S., soybean oil accounts for about 50% of the palmitic acid in diets. Therefore, reducing palmitic acid in soybean oil could significantly decrease saturated fat consumption without dietary change. Other research in progress includes studies of the genetic inheritance and control oil quality traits and efforts to use molecular genetics to improve oil quality. DA - 1991/4// PY - 1991/4// DO - 10.1002/lipi.19910930402 VL - 93 IS - 4 SP - 121-128 SN - 0931-5985 ER - TY - JOUR TI - Interpretive summary of Part 1: factors affecting the availability of phosphorus in soils of the semi-arid tropics AU - Cox, F. R. T2 - Phosphorous nutrition of grain legumes in the semi-arid tropics DA - 1991/// PY - 1991/// SP - 43 ER - TY - JOUR TI - HERITABILITY AND EARLY-GENERATION SELECTION FOR RESISTANCE TO EARLY AND LATE LEAFSPOT IN PEANUT AU - ANDERSON, WF AU - HOLBROOK, CC AU - WYNNE, JC T2 - CROP SCIENCE AB - The genetic nature of resistance to early ( Cercospora arachidicola Hod) and late [ Cercosporidium personatum (Berk. & Curt.) Deighton] leafspot of peanut ( Arachis hypogaea L.) is quantitative, making selection for resistance difficult in segregating populations. In many areas of peanut production, without fungicide application one or both diseases may significantly reduce yields. A study was conducted to obtain heritability estimates, responses to selection, and relationship of resistance of two peanut populations for early and late leafspot resistance. Selection based on F 2 family means in the F 3 generation via defoliation, infection, and sporulation was performed for early and late leafspot in North Carolina and Georgia, respectively, within populations of PI 314817/[TG3/EC 76446 (292)] and (PI 314817/ICGS 4). Divergent selections for each disease were evaluated in the F 4 generation at the same locations the following year for resistance by visual rating of infection and defoliation. Broad‐sense heritability estimates ranged from low to high (0.12–0.88) for components of resistance to each leaf‐spot disease. Narrow‐sense heritability estimates from parent‐offspring regression (0.18–0.74) and realized heritability (0.60–1.41) were significant for late leafspot resistance and early leafspot resistance in the PI 314817/[TG3/EC 76446 (292)] population. Results indicated that selection based family means would be successful. Selection of individual plants within families did not significantly improve genetic progress. Moderate to high correlations (0.41–0.86) existed between early and late leafspot disease components indicating possible genetic linkage or host‐plant physiology that conferred resistance to both diseases in one population. DA - 1991/// PY - 1991/// DO - 10.2135/cropsci1991.0011183X003100030008x VL - 31 IS - 3 SP - 588-593 SN - 0011-183X ER - TY - JOUR TI - GENERATION MEANS ANALYSIS FOR PRODUCTIVITY IN 2 DIVERSE PEANUT CROSSES AU - HALWARD, TM AU - WYNNE, JC T2 - THEORETICAL AND APPLIED GENETICS DA - 1991/// PY - 1991/// DO - 10.1007/bf00227326 VL - 82 IS - 6 SP - 784-792 SN - 0040-5752 KW - GERMPLASM KW - GENETIC DIVERSITY ER - TY - JOUR TI - COTTON RESPONSE TO STARTER FERTILIZER PLACEMENT AND PLANTING DATES AU - GUTHRIE, DS T2 - AGRONOMY JOURNAL AB - Abstract Effect of planting date on cotton ( Gossypium hirsutum L.) response to side‐banded starter fertilizer has not been well documented. Consequently, field studies were conducted in four North Carolina environments to examine the response of cotton to placement of starter fertilier at three planting dates. Cotton planted prior to 5 May (Early), mid‐May (Mid), and late‐May (Late) on a Norfolk loamy sand (fine‐loamy, siliceous, and thermic Typic Kandiudults) and Craven fine sandy loam (clayey, mixed, thermic Aquic Hapludults) received broadcast or side‐banded applications of ammonium polyphosphate at the rate of 17 and 57 kg ha −1 of N and P 2 O 5 respectively. Fertilizer placement had minor effects on plant population. Planting period effects on plant population could not be attributed to heat unit accumulations. Flower production during the first 3 wk of bloom varied with planting period and environment Mid‐ and late‐planting decreased average lint yields across the four environments by 31 and SO%, respectively. Lint yield was increased 9% by side‐banded fertilizer placement. Significant planting period ✕ fertilizer placement interactions were not observed for plant population, flower production, and lint yield. This indicates that applying side‐banded starter fertilizer can benefit producers irrespective of planting date. DA - 1991/// PY - 1991/// DO - 10.2134/agronj1991.00021962008300050013x VL - 83 IS - 5 SP - 836-839 SN - 0002-1962 ER - TY - JOUR TI - CHIMERIC MITOCHONDRIAL GENES EXPRESSED IN THE C-MALE-STERILE CYTOPLASM OF MAIZE AU - DEWEY, RE AU - TIMOTHY, DH AU - LEVINGS, CS T2 - CURRENT GENETICS DA - 1991/// PY - 1991/// DO - 10.1007/BF00334775 VL - 20 IS - 6 SP - 475-482 SN - 0172-8083 KW - CYTOPLASMIC MALE STERILITY KW - ATP9 KW - ATP6 KW - COXII KW - RECOMBINATION KW - MITOCHONDRIAL DNA ER - TY - JOUR TI - STABILITY OF ALKALOID PRODUCTION IN FLUE-CURED TOBACCO AU - BOWMAN, DT AU - WEEKS, WW AU - WILKINSON, CA T2 - CROP SCIENCE AB - Alkaloid production in flue‐cared tobacco ( Nicotiana tabacum L.) genotypes must be within an established acceptable level for the genotypes to be released as cultivars. The objectives of this study were to examine the stability of alkaloid production in cultivars and advanced breeding lines relative to standards set in the Regional Minimum Standards Program. Stability of alkaloid production was examined using data from the Regional Farm Test entries (1986– 1988) and the North Carolina Official Variety Tests (1979–1983). Averaged across 55 environments, the two check cultivars did not differ in nicotine or nornicotine production; however, ‘NC 95’ produced higher levels of anabasine and anatabine and had a higher ratio of total secondary alkaloids to total alkaloids (TSA/TA) than ‘NC 2326’. As indicated by the coefficients of variation, there were stability differences for nornicotine, anabasine, and anatabine production as well as TSA/TA in the Regional Farm Tests but none for nicotine production. In the North Carolina Official Variety Tests, there was a significant cultivar ✕ year interaction for nicotine production and a significant location effect for nornicotine production. The unstable production of secondary alkaloids suggests that TSA/TA should be examined across both years in which the entries are in the program before rejection or acceptance. DA - 1991/// PY - 1991/// DO - 10.2135/cropsci1991.0011183x003100050006x VL - 31 IS - 5 SP - 1121-1124 SN - 0011-183X ER - TY - JOUR TI - POTENTIAL USE OF VISUAL MOLD RATINGS TO PREDICT MYCOTOXIN CONTAMINATION OF GRAIN-SORGHUM AU - BOWMAN, DT AU - HAGLER, WM T2 - JOURNAL OF PRODUCTION AGRICULTURE AB - The suggested association between zearalenone contamination and Fusarium grain mold, along with documented cases of zearalenone and deoxynivalenol contamination in sorghum [Sorghum bicolor (L.) Moench], prompted an investigation into a determination if field scouting could be used to predict contamination level. Several sorghum hybrids were examined for bird damage and visible grain mold prior to harvest at seven locations in 1986 and 1987. Zearalenone and deoxynivalenol levels were analyzed in the harvested samples. Bird damage, Fusarium grain mold, zearalenone, and deoxynivalenol were detected in 68, 87, 67, and 88% of all samples, respectively. There appeared to be no correlation between bird damage and mycotoxin levels; however, highly significant correlation coefficients of 0.38** and 0.39** were found between grain mold and zearalenone and deoxynivalenol levels, respectively. Of the 13% of the samples with no visible grain mold, all were contaminated with one or both of these mycotoxins. With 96% of the samples showing signs of mold and later revealing detectable levels of zearalenone or deoxynivalenol, it would appear that visible grain mold can indicate possible mycotoxin contamination; however, absence of any grain mold does not necessarily assure the grain is free from contamination. DA - 1991/// PY - 1991/// DO - 10.2134/jpa1991.0132 VL - 4 IS - 1 SP - 132-134 SN - 0890-8524 ER - TY - JOUR TI - PLOT CONFIGURATION IN LATE-PLANTED DETERMINANT SOYBEAN YIELD TRIALS IN NORTH-CAROLINA AU - BOWMAN, DT T2 - JOURNAL OF PRODUCTION AGRICULTURE AB - Competition has been shown to be significant in soybean [Glycine max (L.) Merrill] yield trials in the past, and consequently the use of bordered plots is a standard practice in the Southern USA. The earlier studies, however, did not involve late-planted determinant soybeans which constitute a major portion of the soybeans planted in this region. A field study was conducted to determine if competition were great enough in late-planted determinant soybean yield trials planted at conventional row widths (i.e., 30–38 in.) to require bordered plots. The study involved four environments, three maturity groups, and from nine to 26 entries within each group. Each plot consisted of four rows with the center two rows considered a bordered plot and the two outside rows considered an unbordered, two-row plot. The average error variance of the unbordered plots was 1.26 times as great as the error variance of the bordered plots, but the entry by border interaction was significant in only two of the 12 data sets. Correlations between border treatments for entry mean yield and entry rank were all highly significant. The relative efficiency of two-row unbordered plots with six replicates averaged 2.02, while harvesting all four rows vs. only the center two rows resulted in an average relative efficiency of 1.40. The need for border rows on each side of a two-row plot in late-planted determinant soybeans at conventional row widths does not seem justified. DA - 1991/// PY - 1991/// DO - 10.2134/jpa1991.0256 VL - 4 IS - 2 SP - 256-259 SN - 0890-8524 ER - TY - JOUR TI - Latin America maize collections: A case for urgent action AU - Goodman, M. M. AU - Hernandez, J. M. T2 - Diversity DA - 1991/// PY - 1991/// VL - 7 IS - 1-2 SP - 87 ER - TY - JOUR TI - JASMONIC ACID-DEPENDENT INCREASE IN VEGETATIVE STORAGE PROTEIN IN SOYBEAN TISSUE-CULTURES AU - ANDERSON, JM T2 - JOURNAL OF PLANT GROWTH REGULATION DA - 1991/// PY - 1991/// DO - 10.1007/BF02279304 VL - 10 IS - 1 SP - 5-10 SN - 0721-7595 ER - TY - JOUR TI - SALT ACTIVATION OF SUCROSE-PHOSPHATE SYNTHASE FROM DARKENED LEAVES OF MAIZE AND OTHER C-4 PLANTS AU - HUBER, SC AU - HUBER, JL T2 - PLANT AND CELL PHYSIOLOGY AB - Maize leaf sucrose-phosphate synthase (SPS) has been shown to be inactivated by protein phosphorylation in vitro, which appears to be the mechanism of light modulation in situ [Huber and Huber (1991) Plant Cell Physiol. 32: 319–326]. The catalytic activity of the inactivated enzyme (dark form or in vitro inactivated form) was strongly stimulated by high ionic strength in the assay mixture and at 0.4 M KC1 reached activities similar to those obtained from illuminated leaves. Numerous salts were effective, but for most studies, 0.3 M KC1 was used. The salt-stimulation of enzyme activity was rapid and readily reversible and was antagonized by the presence of ethylene glycol in the assay. The presence of salt was also found to reduce the IC50 (concentration required for 50% inhibition) for p-chloromercuribenzenesulfonic acid. We postulate that phosphorylation of maize SPS induces a conformational change in the protein (that affects both maximum catalytic activity and sensitivity to Pi either through electrostatic or hydrophobic interactions which are affected by high ionic strength. Salt stimulation of the deactivated enzyme extracted from darkened leaves was observed for a variety of C-4 plants, but not for any of the C-3 species tested. DA - 1991/4// PY - 1991/4// DO - 10.1093/oxfordjournals.pcp.a078084 VL - 32 IS - 3 SP - 327-333 SN - 0032-0781 KW - MAIZE KW - PROTEIN CONFORMATION KW - SUCROSE BIOSYNTHESIS KW - SUCROSE-PHOSPHATE SYNTHASE, SALT ACTIVATION ER - TY - JOUR TI - REGULATION OF MAIZE LEAF SUCROSE-PHOSPHATE SYNTHASE BY PROTEIN-PHOSPHORYLATION AU - HUBER, SC AU - HUBER, JL T2 - PLANT AND CELL PHYSIOLOGY AB - Studies were conducted to determine the potential for regulation of maize leaf sucrose-phosphate synthase (SPS) by protein phosphorylation. Highly activated enzyme, in desalted crude leaf extracts prepared from illuminated leaves, was inactivated in vitro in a time- and ATP-de-pendent manner. Partial purification of SPS by polyethylene glycol fractionation and Mono Q chromatography yielded enzyme that was not ATP-inactivated, possibly due to elimination of contaminating protein kinase. We used the partially purified SPS as substrate to identify an endogenous protein kinase. The protein kinase catalyzed the time- and ATP-dependent inacti-vation of SPS, and the apparent Km for Mg-ATP was estimated to be approximately 10μM. The partially purified maize SPS protein was phosphorylated in vitro using [y-32P]ATP and either the endogenous protein kinase or the catalytic subunit of cAMP-dependent protein kinase. The incorporation of radiolabel was closely paralleled by inactivation of the enzyme. These results provide the first evidence for regulation of maize leaf SPS by protein phosphorylation, which we postulate is the mechanism of light-dark regulation in vivo. DA - 1991/4// PY - 1991/4// DO - 10.1093/oxfordjournals.pcp.a078083 VL - 32 IS - 3 SP - 319-326 SN - 0032-0781 KW - MAIZE KW - PROTEIN KINASE KW - PROTEIN PHOSPHORYLATION KW - SUCROSE BIOSYNTHESIS KW - SUCROSE-PHOSPHATE SYNTHASE ER - TY - JOUR TI - INVITRO PHOSPHORYLATION AND INACTIVATION OF SPINACH LEAF SUCROSE-PHOSPHATE SYNTHASE BY AN ENDOGENOUS PROTEIN-KINASE AU - HUBER, SC AU - HUBER, JL T2 - BIOCHIMICA ET BIOPHYSICA ACTA AB - (1) Partially purified preparations of spinach (Spinacia oleracea L.) leaf sucrose-phosphate synthase (SPS) contain an endogenous protein kinase that phosphorylates and inactivates the enzyme with [gamma-32P]ATP. (2) The kinetic effect of phosphorylation is to alter affinities for substrates and the effector inorganic phosphate without affecting maximum velocity. (3) Two-dimensional peptide mapping of tryptic digests of in vitro labeled SPS yielded two phosphopeptides (designated sites 5 and 7). Labeling of the two sites occurred equally with time, and both correlated with inactivation. Maximum inactivation was associated with incorporation of 1.5 to 2.0 mol P/mol SPS tetramer, and about 70% of the phosphoryl groups were incorporated into one of the sites (phosphopeptide 7). (4) Phosphorylation and inactivation were strongly inhibited by NaCl, and the presence of salt alters some characteristics of the kinase reaction. In the absence of salt, the apparent Km for Mg.ATP was estimated to be 5 microM. (5) The dependence of the rate of phosphorylation on SPS concentration suggested that SPS and the protein kinase are distinct enzymes, but have some tendency to associate especially in the presence of ethylene glycol. (6) Ca2+/EGTA and polyamines have no effect on the rate of phosphorylation, whereas polycations (polylysine, polybrene and protamine) are inhibitory. (7) Of the metabolic intermediates tested, Glc 6-P inhibited phosphorylation and inactivation of the enzyme. The inhibition was not antagonized by inorganic phosphate, which suggests that Glc 6-P may be an effector of the kinase, rather than the target protein. Regulation by Glc 6-P may be of physiological significance. DA - 1991/2/19/ PY - 1991/2/19/ DO - 10.1016/0167-4889(91)90205-c VL - 1091 IS - 3 SP - 393-400 SN - 0006-3002 KW - PROTEIN PHOSPHORYLATION KW - ENZYME INACTIVATION KW - SUCROSE-PHOSPHATE SYNTHASE KW - PROTEIN KINASE KW - (SPINACH LEAF) ER - TY - JOUR TI - FRACTIONAL INTEGRATED STOMATAL OPENING TO CONTROL WATER-STRESS IN THE FIELD AU - FISCUS, EL AU - ALAM, ANMM AU - HIRASAWA, T T2 - CROP SCIENCE AB - The usefulness of totally automated irrigation control systems is well established. Mass‐flow porometers can be used as the sensing and feedback elements to implement such a system for the experimental control of water stress in the field. This study was conducted to determine if consistent relationships could be established between the mass‐flow readings and other water‐related physiological parameters. A range of stress conditions were imposed on plots of corn ( Zea mays L.) by the system during the 1986 and 1987 field seasons in Greeley, CO. Midday leaf xylem water potential, leaf diffusive conductance, and year‐end grain yields were measure during both years. In 1987, additional measurements were made of the infrared canopy temperature for calculating the Crop Water Stress Index (CWSI), and individual kernel weights and numbers, to determine the components of the grain yield predictions observed in 1986. Reductions in the number of kernels produced per unit land area were associated with stress‐induced delays of silking relative to pollen shed. Additional yield reductions in some treatments were attributable to reduced weight per kernel. Significant correlations were found between the mass‐flow sensors and grain yield and CWSI. The relationship between grain yield and stomatal conductance was consistent over both years, suggesting that the cumulative mean conductance may be useful as a yield predictor. DA - 1991/// PY - 1991/// DO - 10.2135/cropsci1991.0011183X003100040032x VL - 31 IS - 4 SP - 1001-1008 SN - 1435-0653 ER - TY - JOUR TI - Effects of grass species on grazing steers: 1. Diet composition and ingestive mastication AU - Fisher, D. S. AU - Burns, J. C. AU - Pond, K. R. AU - Mochrie, R. D. AU - Timothy, D. H. T2 - Journal of Animal Science AB - In traditional grazing trials, per animal and per hectare productivity are determined, but pasture and animal measurements are generally inadequate to address reasons for different treatment responses. This 2-yr study examined the diet and diet characteristics of steers grazing tall fescue (Festuca arundinacea Schreb.), switchgrass (Panicum virgatum L.), flaccidgrass (Pennisetum flaccidum Griseb.), and bermudagrass (Cynodon dactylon [L.] Pers.) pastures. A randomized complete block design was used with two agronomic replicates. In vitro DM disappearance (IVDMD) of masticates from tall fescue (TF), switchgrass (SG), and flaccidgrass (FG) generally were similar; all exceeded 70% (70.3 to 79.9%), except for bermudagrass (BG), which was lowest (63.5 to 65.0%). Sieving the masticate DM showed BG to contain the highest proportion (20 to 29%) of particles passing a .5-mm sieve and the lowest proportion (6 to 8%) of particles retained on a 2.8-mm sieve. This resulted in BG having the smallest mean (1.29 mm) and median (1.08 mm) particle sizes in yr 1 and a mean (1.10 mm) and median (.91 mm) particle size smaller than SG in yr 2. Except for BG, the IVDMD of the masticate DM was lowest for small particles. Canopies showed BG and SG to have the highest proportion of stem (47 and 52%, respectively); the BG canopy was composed of fractions that were consistently lowest in IVDMD. In general, BG offered the grazing animal a canopy inferior in IVDMD concentration and had canopy characteristics that limited the animals' selection of a diet with quality as high as that of TF, SG, or FG. DA - 1991/// PY - 1991/// DO - 10.2527/1991.6931188x VL - 69 IS - 3 SP - 1188 ER - TY - JOUR TI - EFFECT OF SOYBEAN THRIPS (THYSANOPTERA, THRIPIDAE) FEEDING INJURY ON PENETRATION OF ACIFLUORFEN IN SOYBEAN AU - HUCKABA, RM AU - COBLE, HD T2 - JOURNAL OF ECONOMIC ENTOMOLOGY AB - Greenhouse and laboratory studies were conducted to determine the effect of the physical injury inflicted by feeding soybean thrips, Sericothrips variabilis (Beach), on penetration of acifluorfen in soybean, Glycine max (L.) Merrill. In these studies, S. variabilis feeding injury was observed to have a minimal effect on 14C-acifluorfen penetration while attempts to simulate rasping type feeding injury increased 14C-acifluorfen penetration two to three fold. Scrutiny of the soybean leaflet tissues damaged by feeding S. variabilis , using both light and scanning electron microscopy, revealed that epidermal cells were collapsed and many mesophyll cells destroyed. There were no gashes on the leaf surface to indicate a rasping-sucking feeding behavior as described in the early literature. The primary damage on the surface of the leaves was holes, indicating S. variabilis has a piercing-sucking type feeding action. These observations on S. variabilts feeding support recent findings made for other thrips species. Based on these findings, we concluded that the piercing type feeding injury caused by S. variabilis does not produce wounds on the leaf surface of sufficient quantity or size-compared with wounds that were predicted for a rasping-sucking action-to allow a significant increase of 14C-acifluorfen into the soybean leaf. DA - 1991/2// PY - 1991/2// DO - 10.1093/jee/84.1.300 VL - 84 IS - 1 SP - 300-305 SN - 0022-0493 KW - INSECTA KW - SERICOTHRIPS-VARIABILIS KW - FEEDING INJURY KW - ACIFLUORFEN ER - TY - JOUR TI - CULTURED OVULES AS MODELS FOR COTTON FIBER DEVELOPMENT UNDER LOW-TEMPERATURES AU - HAIGLER, CH AU - RAO, NR AU - ROBERTS, EM AU - HUANG, JY AU - UPCHURCH, DR AU - TROLINDER, NL T2 - PLANT PHYSIOLOGY AB - Cotton fibers (Gossypium hirsutum L.) developing in vitro responded to cyclic temperature change similarly to those of field-grown plants under diumal temperature fluctuations. Absolute temperatures and rates of temperature change were similar under both conditions. In vitro fibers exhibited a "growth ring" for each time the temperature cycled to 22 or 15 degrees C. Rings were rarely detected when the low point was 28 degrees C. The rings seemed to correspond to alternating regions of high and low cellulose accumulation. Fibers developed in vitro under 34 degrees C/22 degrees C cycling developed similarly to constant 34 degrees C controls, but 34 degrees C/22 degrees C and 34 degrees C/15 degrees C cycling caused delayed onset and prolonged periods of elongation and secondary wall thickening. Control fiber length and weight were finally achieved under 34 degrees C/22 degrees C cycling, but both parameters were reduced at the end of the experiment under 34 degrees C/15 degrees C cycling. Fibers developed under all conditions had equal bundle tensile strength. These results demonstrate that: (a) cool temperature effects on fiber development are at least partly fiber/ovule-specific events; they do not depend on whole-plant physiology; and (b) cultured ovules are valid models for research on the regulation of the field cool temperature response. DA - 1991/1// PY - 1991/1// DO - 10.1104/pp.95.1.88 VL - 95 IS - 1 SP - 88-96 SN - 0032-0889 ER - TY - JOUR TI - Buffer capacity of cotton cells and effects of extracellular pH on growth and somatic embryogenesis in cotton cell suspensions AU - Shang, X. M. AU - Huang, J. Y. AU - Haigler, Candace H. AU - Trolinder, N. L. T2 - In Vitro Cellular & Developmental Biology. Plant DA - 1991/// PY - 1991/// DO - 10.1007/bf02632199 VL - 27P SP - 147–152 ER - TY - CHAP TI - The relationship between polymerization and crystallization in cellulose biogenesis AU - Haigler, C. H. T2 - Biosynthesis and biodegradation of cellulose A2 - Haigler, C. H. A2 - Weimer, P. PY - 1991/// SP - 99-124 PB - New York: Marcel Dekker SN - 0824783875 ER -