@misc{gusmini_wehner_2008, title={Fifty-five years of yield improvement for cucumber, melon, and watermelon in the United States}, volume={18}, number={1}, journal={HortTechnology}, author={Gusmini, G. and Wehner, T. C.}, year={2008}, pages={9–12} }
 @article{gusmini_wehner_2007, title={Heritability and genetic variance estimates for fruit weight in watermelon}, volume={42}, number={6}, journal={HortScience}, author={Gusmini, G. and Wehner, T. C.}, year={2007}, pages={1332–1336} }
 @article{gusmini_wehner_donaghy_2007, title={SASQuant: A SAS software program to estimate genetic effects and heritabilities of quantitative traits in Populations consisting of 6 related generations}, volume={98}, ISSN={["1465-7333"]}, DOI={10.1093/jhered/esm033}, abstractNote={Plant breeders are interested in the analysis of phenotypic data to measure genetic effects and heritability of quantitative traits and predict gain from selection. Measurement of phenotypic values of 6 related generations (parents, F(1), F(2), and backcrosses) allows for the simultaneous analysis of both Mendelian and quantitative traits. In 1997, Liu et al. released a SAS software based program (SASGENE) for the analysis of inheritance and linkage of qualitative traits. We have developed a new program (SASQuant) that estimates gene effects (Hayman's model), genetic variances, heritability, predicted gain from selection (Wright's and Warner's models), and number of effective factors (Wright's, Mather's, and Lande's models). SASQuant makes use of traditional genetic models and allows for their easy application to complex data sets. SASQuant is freely available and is intended for scientists studying quantitative traits in plant populations.}, number={4}, journal={JOURNAL OF HEREDITY}, author={Gusmini, Gabriele and Wehner, Todd C. and Donaghy, Sandra B.}, year={2007}, pages={345–350} }
 @article{gusmini_wehner_2006, title={Qualitative inheritance of rind pattern and flesh color in watermelon}, volume={97}, ISSN={["1465-7333"]}, DOI={10.1093/jhered/esj023}, abstractNote={Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus] is a diverse species, with fruits of different sizes, shapes, rind patterns, and flesh colors. This study measured the inheritance of novel rind phenotypes and verified the genetics of white, red, salmon yellow, and canary yellow flesh colors. For each of the 11 crosses, six generations (P(a)S1, P(b)S1, F1, F2, BC1P(a), and BC1P(b)) were produced to form 11 families. Three new genes were identified and designated as follows: Scr for the scarlet red flesh color of Dixielee and Red-N-Sweet, Yb for the yellow belly (ground spot) of Black Diamond Yellow Belly, and ins for the intermittent stripes of Navajo Sweet. The inheritance of the C gene for the canary yellow flesh color was verified as single dominant, and a new inbred type line was developed possessing that gene. Aberrations in the segregation of red, white, and salmon yellow flesh colors were recorded, raising questions on the inheritance of these traits. Finally, the spotted phenotype from Moon and Stars was combined with light green and gray rind patterns for the development of novel cultivars with distinctive rind patterns.}, number={2}, journal={JOURNAL OF HEREDITY}, author={Gusmini, G and Wehner, TC}, year={2006}, month={Mar}, pages={177–185} }
 @article{gusmini_wehner_2005, title={Foundations of yield improvement in watermelon (vol 45, pg 141, 2003)}, volume={45}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2005.0810}, abstractNote={High yield is a major goal for watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] breeders. The objective of this study was to measure yield in a diverse set of watermelon cultivars to identify high-yielding germplasm for use in breeding programs. Phenotypic variation for fruit yield in a diverse set of 80 watermelon cultivars was studied in the field in North Carolina. Yield was evaluated in replicated experiments of three environments (combinations of 2 yr and two locations), and two to four replications per environment. Plots were harvested one to two times, depending on the average maturity of the fruits at the first harvest. The highest yield overall was obtained from 'Mountain Hoosier' and 'Starbrite'. Some of the new, elite hybrid cultivars were in the top-yielding group, but there were old, inbred cultivars in the top group as well. Consistent and significant yield differences among the 80 cultivars across environments indicates genetic variation for the trait. In addition, high-yielding cultivars for use in breeding programs were identified. Watermelon breeders interested in developing new, high-yielding cultivars should make use of top performers in this study in their breeding programs.}, number={2}, journal={CROP SCIENCE}, author={Gusmini, G and Wehner, TC}, year={2005}, pages={810–810} }
 @article{gusmini_wehner_2005, title={Genes determining rind pattern inheritance in watermelon: A review}, volume={40}, number={6}, journal={HortScience}, author={Gusmini, G. and Wehner, T. C.}, year={2005}, pages={1928–1930} }
 @article{gusmini_song_wehner_2005, title={New sources of resistance to gummy stem blight in watermelon}, volume={45}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2005.0582}, abstractNote={Gummy stem blight, caused by Didymella bryoniae (Auersw.) Rehm, is a major disease of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]. Plant breeders need sources of resistance that can be incorporated into adapted breeding lines to help control the disease. We tested all the available accessions from the USDA‐ARS watermelon germplasm collection, including C. lanatus var citroides (L.H. Bailey) Mansf., for resistance to gummy stem blight. The experiment was a randomized complete block with 1332 cultigens, two sites (field and greenhouse), two or four replications, and two to six plants per plot. The resistant check was PI 189225 and the susceptible check was ‘Charleston Gray’. PI 279461, PI 482379, PI 254744, PI 526233, PI 482276, PI 271771, PI 164248, PI 244019, PI 296332, and PI 490383 were selected as the most resistant cultigens to be used in future breeding efforts. The most susceptible cultigens were PI 183398, PI 169286, PI 223764, PI 226445, PI 525084, PI 534597, and PI 278041.}, number={2}, journal={CROP SCIENCE}, author={Gusmini, G and Song, RH and Wehner, TC}, year={2005}, pages={582–588} }
 @article{gusmini_wehner_2004, title={Cultivars suitable for watermelon rind pickles}, ISBN={1064-5594}, number={27}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Wehner, T. C.}, year={2004}, pages={41} }
 @article{gusmini_wehner_2004, title={Estimates of variance components and broad-sense heritability for yield in watermelon}, ISBN={1064-5594}, number={27}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Wehner, T. C.}, year={2004}, pages={45} }
 @article{gusmini_wehner_2004, title={Heterosis for yield in a watermelon hybrid}, ISBN={1064-5594}, number={27}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Wehner, T. C.}, year={2004}, pages={43} }
 @article{gusmini_wehner_jarret_2004, title={Inheritance of egusi seed type in watermelon}, volume={95}, DOI={10.1093/jhered/esh031}, abstractNote={An unusual seed mutant in watermelon (Citrullus lanatus var. lanatus) has seeds with a fleshy pericarp, commonly called egusi seeds. The origin of the phenotype is unknown, but it is widely cultivated in Nigeria for the high protein and carbohydrate content of the edible seeds. Egusi seeds have a thick, fleshy pericarp that appears during the second to third week of fruit development. We studied the inheritance of this phenotype in crosses of normal seeded Charleston Gray and Calhoun Gray with two plant introduction accessions, PI 490383w and PI 560006, having the egusi seed type. We found that the egusi seed type is controlled by a single recessive gene, and the symbol eg was assigned.}, number={3}, journal={Journal of Heredity}, author={Gusmini, G. and Wehner, Todd and Jarret, R. L.}, year={2004}, pages={268–270} }
 @article{gusmini_wehner_joobeur_dean_levi_2004, title={Protocol for DNA extraction from watermelon leaves for SSR marker studies}, ISBN={1064-5594}, number={27}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Wehner, T. C. and Joobeur, T. and Dean, R. A. and Levi, A.}, year={2004}, pages={25} }
 @article{gusmini_schultheis_wehner_2004, title={Rind thickness of watermelon cultivars for use in pickle production}, volume={14}, number={4}, journal={HortTechnology}, author={Gusmini, G. and Schultheis, J. R. and Wehner, T. C.}, year={2004}, pages={540–545} }
 @article{song_gusmini_wehner_2004, title={Screening the watermelon germplasm collection for resistance to gummy stem blight}, ISBN={["90-6605-667-3"]}, ISSN={["2406-6168"]}, DOI={10.17660/actahortic.2004.637.6}, abstractNote={All available accessions from the USDA watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) germplasm collection, including C. lanatus var. citroides, were screened for resistance to gummy stem blight (Didymella bryoniae, anamorph Phoma cucurbitacearum). The experiment was a randomized complete block with 1,325 cultigens (elite cultivars, obsolete cultivars, breeding lines, and PI accessions), two locations (field and greenhouse), and two or four replications. Isolates used were collected from cucurbits and verified for virulence on watermelon. The most resistant cultigens were significantly better than the check, ‘Charleston Gray’, and the most susceptible cultigens were significantly worse. The most resistant and most susceptible cultigens were retested, along with check cultivars (including a set of cucumber cultigens with known characteristics of resistance and susceptibility), to verify their reaction. The retest was a randomized complete block with 75 (38 in 2000) cultigens, two locations (field and greenhouse), and three or four replications. The most resistant cultigens were PI 279461, PI 254744, PI 482379, PI 244019, PI 526233, PI 482276, PI 164248, PI 482284, PI 296332, PI 490383, PI 271771, and PI 379243. The most susceptible cultigens were PI 226445, PI 534597, PI 525084, PI 223764, PI 169286, and PI 183398. INTRODUCTION Gummy stem blight (Didymella bryoniae (Auersw.) Rehm) is one of the most destructive diseases of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai), a major vegetable crop in the U.S. (Schenck, 1962; Keinath, 1995). Gummy stem blight causes crown blight, extensive defoliation and fruit rot, and can cause severe losses in the field. For example, in 1991 over 15% of the watermelon crop in South Carolina was abandoned before harvest (Power, 1992). The disease also causes loss of fruit during storage and transportation (Leupschen, 1961; Sowell and Pointer, 1962; Norton, 1978). Didymella bryoniae is seed-borne (Lee et al., 1984), air-borne (Van Steekelenburg, 1983), and soil-borne (Keinath, 1996; Bruton, 1998). The fungus persists in crop residue even at extreme temperatures, such as –9°C for 14 days (Van Steekelenburg, 1983). D. bryoniae is a facultatively necrotrophic fungus (Svedelius, 1990); thus, wounding the leaves, particularly the old ones (Van Steekelenburg, 1985a), helps disease initiation because the production of exudates from the lesions favors the fungus in its growth and infection. High relative humidity and the presence of free water on the plants are required for the fungus to induce large lesions on leaves and stems (Van Steekelenburg, 1981, 1984, 1985a, b). Finally, there is no evidence of race specialization for this pathogen (St. Amand and Wehner, 1995). Genetic resistance has received attention in the last 50 years. Differences in resistance to gummy stem blight have been demonstrated among cultivars of watermelon. ‘Congo’ was the least susceptible, ‘Fairfax’ was intermediate, and ‘Charleston Gray’ was the most susceptible (Schenck, 1962). PI 189225 was the most resistant accession of 439 evaluated from the USDA watermelon germplasm collection (Sowell and Pointer, 1962). Proc. XXVI IHC – Advances in Vegetable Breeding Eds. J.D. McCreight and E.J. Ryder Acta Hort. 637, ISHS 2004 Publication supported by Can. Int. Dev. Agency (CIDA) 64 Several years later, PI 271778 was identified as an additional source of resistance (Sowell, 1975). It had a disease response that was intermediate between PI 189225 and ‘Charleston Gray’. A later screening effort of 138 watermelon accessions showed that PI 500335, PI 505590, PI 512373, PI 164247, and PI 500334 were resistant to gummy stem blight (Boyhan et al., 1994). Resistant cultivars were developed from two crosses (‘Jubilee’ x PI 271778 and ‘Crimson Sweet’ x PI 189225) by selecting disease-resistant seedlings from backcrossed families that produced high yield of excellent quality fruit (Norton et al., 1986). ‘AU-Jubilant’ and ‘AU-Producer’ (Norton et al., 1986), ‘AUGolden Producer’ (Norton et al., 1993), and ‘AU-Sweet Scarlet’ (Norton et al., 1995) were released with moderate to high resistance to anthracnose, fusarium wilt, and gummy stem blight in greenhouse screening tests. Seedling screening methods are the most commonly used among breeders to test new cultivars and lines for resistance to gummy stem blight in cucurbits (Zhang et al., 1995; Dias et al., 1996; Zhang et al., 1997; Wehner and Shetty, 2000). Tests involve spraying seedlings with a water suspension of spores collected from in vitro cultures of the pathogen. However, in field tests the gummy stem blight resistance of these cultivars has not proven useful. So far, no cultivars of watermelon (Sumner and Hall, 1993) have been released that have high resistance to gummy stem blight. The objective of this study was to identify new and useful sources of resistance to gummy stem blight by screening the USDA watermelon germplasm collection. The ultimate objective was to develop resistant and adapted cultivars. MATERIALS AND METHODS Locations and Seed Sources All experiments were run at the Plant Pathology greenhouses in Raleigh, N.C., and at the Horticultural Crops Research Station, Clinton, N.C. All Citrullus Plant Introduction (PI) accessions were obtained from the Southern Regional Plant Introduction Station, Griffin, Ga. The accessions originated from 66 different countries. The checks were 51 watermelon cultivars, along with a set of seven cucumber cultivars, to provide reference points for gummy stem blight resistance. The checks were obtained from public and private plant breeders in the U.S. Inoculum Preparation For all tests, D. bryoniae was increased on petri plates containing 15 ml potato dextrose agar (PDA). Inoculated plates were incubated for 2 to 3 weeks at 24 ± 2°C under alternating periods of 12 h fluorescent light (40 to 90 μmol.m.sec PPFD) and 12 h darkness until sporulating pycnidia formed. For all inoculations, a spore suspension was prepared by flooding the culture plates with 5 to 10 ml of sterile, distilled water and scraping the surface of the agar using a finger. The liquid from each plate was filtered through 4 layers of cheese-cloth to remove mycelia, pycnidia and dislodged agar. The final pH of the inoculum was unadjusted. Spore concentration was measured with a hemacytometer and adjusted to a concentration of 5x10 spores/ml adding deionized water. Immediately before inoculation, Tween 80 (2 drops/L) was added to the inoculum. Inoculation Procedure In the greenhouse test, plants were inoculated at the second true leaf stage, after the leaf surface was damaged by brushing it with a wooden stake. Inoculum was applied using a hand-pumped spray bottle (EcoLogical, Sprayco, Mich.). Immediately after inoculation, plants were placed in a humidity chamber with clear-plastic walls (top open during the summer, top closed during the winter). Humidifiers were used in the chamber (Model 500, Trion, Sanford, N.C.) running continuously for the treatment time (1 day before inoculation through 3 days after inoculation) to keep the relative humidity close to 100% day and night. Plants in all treatments were watered daily using overhead sprinklers, except when humidifiers were running.}, number={637}, journal={ADVANCES IN VEGETABLE BREEDING}, publisher={Leuven, Belgium : International Society for Horticultural Science}, author={Song, R and Gusmini, G and Wehner, TC}, year={2004}, pages={63–68} }
 @article{gusmini_schultheis_wehner_2004, title={Some considerations on speed of weighing watermelon fruit in yield trials}, ISBN={1064-5594}, number={27}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Schultheis, J. R. and Wehner, T. C.}, year={2004}, pages={49} }
 @article{gusmini_ellington_wehner_2003, title={Mass production of gummy stem blight spores for resistance screening}, ISBN={1064-5594}, number={26}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Ellington, T. L. and Wehner, T. C.}, year={2003}, pages={26} }
 @article{gusmini_wehner_2003, title={Polygenic inheritance of some vine traits in two segregating watermelon families}, ISBN={1064-5594}, number={26}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Wehner, T. C.}, year={2003}, pages={32} }
 @article{gusmini_wehner_holmes_2002, title={Disease assessment scales for seedling screening and detached leaf assay for gummy stem blight in watermelon}, ISBN={1064-5594}, number={25}, journal={Report (Cucurbit Genetics Cooperative)}, author={Gusmini, G. and Wehner, T. C. and Holmes, G. J.}, year={2002}, pages={36} }