@article{wu_grissom_mckeand_o'malley_2004, title={Phenotypic plasticity of fine roots increases plant productivity in pine seedlings}, volume={4}, journal={BMC Ecology}, author={Wu, R. and Grissom, J. E. and McKeand, S. E. and O'Malley, D. M.}, year={2004}, pages={14} } @article{wu_hu jianjun_yifan_2002, title={How phenotypic plasticity affects crown architecture and development in woody plants}, volume={38}, ISBN={1001-7488}, number={4}, journal={Scientia Silvae Sinicae}, author={Wu, R. L. and Hu JianJun, Liu HongXia and YiFan, Han}, year={2002}, pages={141} } @article{wu_ma_painter_zeng_2002, title={Simultaneous maximum likelihood estimation of linkage and linkage phases in outcrossing species}, volume={61}, ISSN={["1096-0325"]}, DOI={10.1006/tpbi.2002.1577}, abstractNote={With the advent of new molecular marker technologies, it is now feasible to initiate genome projects for outcrossing plant species, which have not received much attention in genetic research, despite their great agricultural and environmental value. Because outcrossing species typically have heterogeneous genomes, data structure for molecular markers representing an entire genome is complex: some markers may have more alleles than others, some markers are codominant whereas others are dominant, and some markers are heterozygous in one parent but fixed in the other parent whereas the opposite can be true for other markers. A major difficulty in analyzing these different types of marker at the same time arises from uncertainty about parental linkage phases over markers. In this paper, we present a general maximum-likelihood-based algorithm for simultaneously estimating linkage and linkage phases for a mixed set of different marker types containing fully informative markers (segregating 1:1:1:1) and partially informative markers (or missing markers, segregating 1:2:1, 3:1, and 1:1) in a full-sib family derived from two outbred parent plants. The characterization of linkage phases is based on the posterior probability distribution of the assignment of alternative alleles at given markers to two homologous chromosomes of each parent, conditional on the observed phenotypes of the markers. Two- and multi-point analyses are performed to estimate the recombination fraction and determine the most likely linkage phase between different types of markers. A numerical example is presented to demonstrate the statistical properties of the model for characterizing the linkage phase between markers.}, number={3}, journal={THEORETICAL POPULATION BIOLOGY}, author={Wu, RL and Ma, CX and Painter, I and Zeng, ZB}, year={2002}, month={May}, pages={349–363} } @article{wu_gallo-meagher_littell_zeng_2001, title={A general polyploid model for analyzing gene segregation in outcrossing tetraploid species}, volume={159}, number={2}, journal={Genetics}, author={Wu, R. L. and Gallo-Meagher, M. and Littell, R. C. and Zeng, Z. B.}, year={2001}, pages={869–882} } @article{wu_li_wu_casella_2001, title={A maximum likelihood-based method for mining major genes affecting a quantitative character}, volume={57}, ISSN={["0006-341X"]}, DOI={10.1111/j.0006-341X.2001.00764.x}, abstractNote={Summary. In this article, we present a maximum likelihood‐based analytical approach for detecting a major gene of large effect on a quantitative trait in a progeny population derived from a mating design. Our analysis is based on a mixed genetic model specifying both major gene and background polygenic inheritance. The likelihood of the data is formulated by combining the information about population behaviors of the major gene during hybridization and its phenotypic distribution densities. The EM algorithm is implemented to obtain maximum likelihood estimates for population and quantitative genetic parameters of the major locus. This approach is applied to detect an overdominant gene governing stem volume growth in a factorial mating design of aspen trees. It is suggested that further molecular genetic research toward mapping single genes affecting aspen growth and production based on the same experimental data has a high probability of success.}, number={3}, journal={BIOMETRICS}, author={Wu, RL and Li, BL and Wu, SS and Casella, G}, year={2001}, month={Sep}, pages={764–768} } @article{wu_wu_ma_zeng_yang_casella_2001, title={A multivalent pairing model of linkage analysis in autotetraploids}, volume={159}, number={3}, journal={Genetics}, author={Wu, S. S. and Wu, R. L. and Ma, C. X. and Zeng, Z. B. and Yang, M. C. and Casella, G.}, year={2001}, pages={1339–1350} } @article{wu_zeng_2001, title={Joint linkage and linkage disequilibrium mapping in natural populations}, volume={157}, number={2}, journal={Genetics}, author={Wu, R. L. and Zeng, Z. B.}, year={2001}, pages={899–909} } @article{yin_huang_wang_zhu_zeng_wu_2001, title={Preliminary interspecific genetic maps of the Populus genome constructed from RAPD markers}, volume={44}, ISSN={["0831-2796"]}, DOI={10.1139/gen-44-4-602}, number={4}, journal={GENOME}, author={Yin, TM and Huang, MR and Wang, MX and Zhu, LH and Zeng, ZB and Wu, RL}, year={2001}, month={Aug}, pages={602–609} } @article{wu_grissom_o'malley_mckeand_2000, title={Root architectural plasticity to nutrient stress in two contrasting ecotypes of loblolly pine}, volume={10}, ISBN={1054-9811}, DOI={10.1300/j091v10n03_13}, number={3}, journal={Journal of Sustainable Forestry}, author={Wu, R. L. and Grissom, J. E. and O'Malley, D. M. and McKeand, Steven}, year={2000}, pages={307} } @article{wu_li_2000, title={A quantitative genetic model for analyzing species differences in outcrossing species}, volume={56}, ISSN={["0006-341X"]}, DOI={10.1111/j.0006-341X.2000.01098.x}, abstractNote={Summary.A genetic model based on a two‐level intra‐ and interspecific mating design is proposed to estimate the genetic architecture of species differences and heterosis for outcrossing species. The underlying genetic analyses make use of classical quantitative genetic theories and recent results from molecular genetic studies. Gene effects across different quantitative trait loci (QTL) can be approximated by a geometric series. Under natural selection, gene effects are often associated with allele frequencies in a particular way, which can be approximated by the gamma distribution. By incorporating these approximations into family structural analyses in the mating design, we are able to estimate a number of genetic parameters that contribute to quantitative genetic variation based on a nonlinear optimization approach. These parameters include the number of QTL, their gene effects, and their allele frequencies in the parental populations. We perform simulation studies and illustrate an example to demonstrate the statistical property and procedure of the method.}, number={4}, journal={BIOMETRICS}, author={Wu, RL and Li, BL}, year={2000}, month={Dec}, pages={1098–1104} } @article{wu_han_hu_fang_li_li_zeng_2000, title={An integrated genetic map of Populus deltoides based on amplified fragment length polymorphisms}, volume={100}, ISSN={["0040-5752"]}, DOI={10.1007/s001220051431}, number={8}, journal={THEORETICAL AND APPLIED GENETICS}, author={Wu, RL and Han, YF and Hu, JJ and Fang, JJ and Li, L and Li, ML and Zeng, ZB}, year={2000}, month={Jun}, pages={1249–1256} } @article{han_yin_li_huang_wu_2000, title={Host effect on genetic variation of Marssonina brunnea pathogenic to poplars}, volume={100}, ISSN={["1432-2242"]}, DOI={10.1007/s001229900082}, number={3-4}, journal={THEORETICAL AND APPLIED GENETICS}, author={Han, ZM and Yin, TM and Li, CD and Huang, MR and Wu, RL}, year={2000}, month={Feb}, pages={614–620} } @inbook{wu_li_zeng_2000, title={Molecular dissection of quantitative traits: new perspectives from populus}, volume={1}, booktitle={Molecular biology of woody plants}, publisher={Dordrecht; Boston: Kluwer Academic}, author={Wu, R. and Li, B. and Zeng, Z.-B.}, editor={Jain, S. M. and Minocha, S. C.Editors}, year={2000}, pages={475–490} } @misc{wu_hu_han_2000, title={Molecular genetics and developmental physiology: Implications for designing better forest crops}, volume={19}, ISSN={["1549-7836"]}, DOI={10.1016/S0735-2689(00)80024-6}, abstractNote={ABSTRACT Current tree biology related to tree genetics and breeding has two important developments that have not well been integrated in the literature. The first is the physiological and biochemical dissection of plant yield, whereas the second is the genetic mapping based on molecular markers, such as RFLPs, RAPDs, AFLPs, and microsatellites. Genetic mapping has revolutionized traditional quantitative genetic analysis by which the genetic variation of a character is described in terms of its mean and (co)variance without the knowledge of the underlying genes. By integrating physiological and developmental studies of yield traits, genetic mapping can provide a unique means for detecting key QTL that play important roles in affecting tree growth and metabolism. The incorporation of these QTL into commercial populations through gene transformation or marker-assisted selection will move current breeding programs strictly based on an empirism to an approach that is mechanistically oriented. In this review, we discuss how plant physiology and development are merged with genetic mapping to formulate the strategy of molecular breeding in which superior forest crops are selected at the gene level. It is anticipated that this novel breeding strategy can potentially provide major breakthroughs for tree breeding.}, number={5}, journal={CRITICAL REVIEWS IN PLANT SCIENCES}, author={Wu, RL and Hu, XS and Han, YF}, year={2000}, pages={377–393} } @article{wu_2000, title={Partitioning of population genetic variance under multiplicative-epistatic gene action}, volume={100}, ISSN={["0040-5752"]}, DOI={10.1007/s001220051347}, number={5}, journal={THEORETICAL AND APPLIED GENETICS}, author={Wu, RL}, year={2000}, month={Mar}, pages={743–749} } @article{wu_2000, title={Quantitative genetic variation of leaf size and shape in a mixed diploid and triploid population of Populus}, volume={75}, ISSN={["0016-6723"]}, DOI={10.1017/S0016672399004279}, abstractNote={In the interspecific cross of Populus trichocarpa × P. deltoides, unexpected simultaneous occurrence of diploid hybrids and triploid hybrids (with two alleles from the female parent and one from the male parent at each locus) led us to examine the evolutionary genetic significance of this phenomenon. As expected, leaf size and shape of the triploid progeny are closer to the female P. trichocarpa than male P. deltoides parent. Although the pure triploid progeny population did not have higher genetic variance in leaf traits than the pure diploid population, the former appears to hide much non-additive genetic variance and display strong genetic control over the phenotypic plasticity of leaf traits. It is suggested that the cryptic non-additive variance, especially epistasis, can be released when a population is disturbed by changes in the environment. A mixed diploid and triploid progeny population combines phenotypic and genetic characteristics of both pure hybrids and is considered to be of adaptive significance for poplars to survive and evolve in a fluctuating environment. The significant effect due to general and specific combining ability differences at the population level suggests that the population divergence of these two species is under additive and non-additive genetic control.}, number={2}, journal={GENETICAL RESEARCH}, author={Wu, RL}, year={2000}, month={Apr}, pages={215–222} } @article{wu rongling_huang minren_mingxiu_2000, title={The application of marker-assisted selection to tree breeding}, volume={36}, ISBN={1001-7488}, number={1}, journal={Scientia Silvae Sinicae}, author={Wu RongLing, Yin TongMing and Huang MinRen and MingXiu, Wang}, year={2000}, pages={103} } @article{wu_li_1999, title={A multiplicative-epistatic model for analyzing interspecific differences in outcrossing species}, volume={55}, DOI={10.1111/j.0006-341x.1999.00355.x}, abstractNote={Summary.Epistasis may play an important role in evolution and speciation. Under multiplicative interactions between different loci, an analytical model is proposed to estimate genetic parameters at the individual locus level that contribute to interspecific differences in outcrossing species. The multiplicative epistasis model, inferred from a number of animal and plant experiments, suggests that genotypes at a pair of loci have genotypic values equal to the product of genotypic values at the two different loci. By considering the genetic property of outcrossing species (i.e., high polymorphisms) in the multilevel family structure analysis for an intra‐ and interspecific factorial mating design, a method is developed to provide estimates for allele frequencies and additive and dominant effects at individual loci in each of the two parental populations, the genotypic values of newly formed heterozygotes through species combination each with one allele from a parental population and the second from the other parental population, and the numbers of genetic factors that lead to species differentiation. Use of clones offers a tremendous power to test the adequacy of the model. However, the utilization of the model with species that cannot be cloned is also discussed. An example with interspecific hybrids of two forest tree species is used to demonstrate the model.}, number={2}, journal={Biometrics}, author={Wu, R. L. and Li, B. L.}, year={1999}, pages={355–365} } @article{wu_han_1999, title={Genetic mapping of quantitative trait loci underlying complex genotype-phenotype relationships in forest trees}, volume={48}, number={3-4}, journal={Silvae Genetica}, author={Wu, R. and Han, Y.}, year={1999}, pages={133–146} } @article{wu_1999, title={Mapping quantitative trait loci by genotyping haploid tissues}, volume={152}, number={4}, journal={Genetics}, author={Wu, R. L.}, year={1999}, pages={1741–1752} } @article{kim_duan_wu_seok_boston_jang_eun_nahm_1999, title={Molecular and genetic analysis of transgenic rice plants expressing the maize ribosome-inactivating protein b-32 gene and the herbicide resistance bar gene}, volume={5}, ISSN={["1380-3743"]}, DOI={10.1023/A:1009692230725}, number={2}, journal={MOLECULAR BREEDING}, author={Kim, JK and Duan, XL and Wu, R and Seok, SJ and Boston, RS and Jang, IC and Eun, MY and Nahm, BH}, year={1999}, pages={85–94} } @article{wu rongling_liu hongxia_1999, title={Statistical methods for mapping quantitative trait loci in forest trees}, volume={35}, number={2}, journal={Scientia Silvae Sinicae}, author={Wu RongLing and Liu HongXia, Han YiFan}, year={1999}, pages={100} } @article{wu_dm o'malley_mckeand_1999, title={Understanding the genetic architecture of a quantitative trait in gymnosperms by genotyping haploid megagametophytes}, volume={99}, ISSN={["0040-5752"]}, DOI={10.1007/s001220051411}, number={6}, journal={THEORETICAL AND APPLIED GENETICS}, author={Wu, RL and DM O'Malley and McKeand, SE}, year={1999}, month={Oct}, pages={1031–1038} } @article{li_howe_wu_1998, title={Developmental factors responsible for heterosis in aspen hybrids (Populus tremuloides x P-tremula)}, volume={18}, DOI={10.1093/treephys/18.1.29}, abstractNote={Juvenile growth and bud set phenology were analyzed to study the biological basis of heterosis (hybrid vigor) in interspecific hybrids of Populus tremuloides Michx. (T) and P. tremula L. (Ta). Growth, measured as seedling volume index, was significantly higher for each of the two reciprocal interspecific crosses, T x Ta and Ta x T, than for the T x T intraspecific cross. Broad-sense heritabilities were 2-6 times larger than narrow-sense heritabilities for growth and shoot components in the T x T intraspecific cross, suggesting an important role for dominance or overdominance in aspen growth. Previous genetic analyses have indicated that hybrid vigor may be the result of overdominance at several key loci each with an allele inherited from each of parental species. Internode length and leaf number contributed substantially to the heterosis of stem volume, but their effects on heterosis differed between the T x Ta and Ta x T hybrids. In T x Ta seedlings, heterosis of stem volume was attributed to a high diameter growth rate, whereas in Ta x T seedlings heterosis of stem volume was probably the result of delayed bud set resulting in a longer duration of height growth. In addition to internode number and length and leaf number, other morphological or physiological components might affect heterosis, for example, extended leaf retention.}, number={1}, journal={Tree Physiology}, author={Li, B. L. and Howe, G. T. and Wu, R. L.}, year={1998}, pages={29–36} } @article{wu_bradshaw_stettler_1998, title={Developmental quantitative genetics of growth in Populus}, volume={97}, ISSN={["0040-5752"]}, DOI={10.1007/s001220050998}, number={7}, journal={THEORETICAL AND APPLIED GENETICS}, author={Wu, R and Bradshaw, HD and Stettler, RF}, year={1998}, month={Nov}, pages={1110–1119} } @article{wu_1998, title={Genetic mapping of QTLs affecting tree growth and architecture in Populus: implication for ideotype breeding}, volume={96}, ISSN={["1432-2242"]}, DOI={10.1007/s001220050761}, abstractNote={A segregated F2 progeny derived from two highly divergent poplar species, Populus trichocarpa and P. deltoides, was used to evaluate the genetic basis of canopy structure and function in a clonally replicated plantation. The QTLs of large effect on growth, branch, and leaf traits were identified using the Populus linkage map constructed by 343 molecular markers. Stem height and harvest index appeared to be under the control of few QTLs with major effects, whereas variation in stem basal area, volume, and dry weight might be due to many more QTLs. Branch and leaf traits on sylleptics tended to include more QTLs with major effects than those on proleptics. In the environment where the pedigree was tested, sylleptics were very frequent in the P. trichocarpa parent but rare in the P. deltoides parent. For sylleptic traits for which two or more QTLs were identified, however, increases in the trait values were conditioned not only by the P. trichocarpa alleles, but also by the P. deltoides alleles. Similar findings were found for traits on proleptics that were differently expressed between the two parents. For both sylleptic and proleptic branch types, dominance (ranging from partial to over) was observed. The QTLs on specific linkage groups were found to be responsible for relationships between stem growth and its developmental components. Similar QTL clustering was also observed for morphological or developmental integration in poplar, i.e., traits with similar developmental origins are more strongly correlated with one another than traits with different developmental origins. The implications of these molecular genetic results for ideotype breeding of poplars are discussed.}, number={3-4}, journal={THEORETICAL AND APPLIED GENETICS}, author={Wu, RL}, year={1998}, month={Mar}, pages={447–457} } @article{wu_dm o'malley_1998, title={Nonlinear genotypic response to macro- and microenvironments}, volume={96}, ISSN={["1432-2242"]}, DOI={10.1007/s001220050787}, number={5}, journal={THEORETICAL AND APPLIED GENETICS}, author={Wu, RL and DM O'Malley}, year={1998}, month={Apr}, pages={669–675} } @article{wu_1998, title={The detection of plasticity genes in heterogeneous environments}, volume={52}, ISSN={["1558-5646"]}, DOI={10.1111/j.1558-5646.1998.tb01826.x}, abstractNote={The molecular genetic mechanisms for phenotypic plasticity across heterogeneous macro‐ and microenvironments were examined using the Populus genomic map constructed by DNA‐based markers. Three hypotheses have been suggested to explain genetic variation in phenotypic response to varying environments (i.e., reaction norm): Lerner's homeostasis, allelic sensitivity, and gene regulation. The homeostasis hypothesis, which predicts that heterozygotes are less sensitive to the environment than homozygotes, was supported for phenotypic plasticity to unpredictable environments (microenvironmental plasticity) at the whole‐genome level, but for phenotypic plasticity to predictable environments (macroenvironmental plasticity) the hypothesis was supported only at functioning quantitative trait loci (QTLs). For all growth traits studied, gene regulation was suggested to play a prevailing role in determining the norms of reaction to environments. Indirect evidence for gene regulation is that there tend to be more QTLs with larger effects on the phenotype in optimal growing conditions than suboptimal growing conditions because the expression of these QTLs identified is mediated by regulatory genes. Direct evidence for gene regulation is the identification of some loci that differ from QTLs for trait values within environments and exert an environmentally dependent control over structural gene expression. In this study, fewer environmentally sensitive QTLs were detected that display unparalleled allelic effects across environments. For stem height, there were more regulatory loci and more structural loci (whose expression is determined by gene regulation) affecting phenotypic plasticity than for basal area. It was found that microenvironmental plasticity was likely controlled by different genetic systems than those for macroenvironmental plasticity.}, number={4}, journal={EVOLUTION}, author={Wu, RL}, year={1998}, month={Aug}, pages={967–977} } @article{li_wu_1997, title={Heterosis and genotype x environment interactions of juvenile aspens in two contrasting sites}, volume={27}, DOI={10.1139/97-110}, number={10}, journal={Canadian Journal of Forest Research}, author={Li, B.-L. and Wu, R.-L.}, year={1997}, pages={1525–1537} } @article{wu_bradshaw_stettler_1997, title={Molecular genetics of growth and development in Populus (Salicaceae) .5. Mapping quantitative trait loci affecting leaf variation}, volume={84}, ISSN={["1537-2197"]}, DOI={10.2307/2446076}, abstractNote={We examined the genetic variation of leaf morphology and development in the 2‐yr‐old replicated plantation of an interspecific hybrid pedigree of Populus trichocarpa T. & G. and P. deltoides Marsh. via both molecular and quantitative genetic methods. Leaf traits chosen were those that show pronounced differences between the original parents, including leaf size, shape, orientation, color, structure, petiole size, and petiole cross section. Leaves were sampled from the current terminal, proleptic, and sylleptic branches. In the F2 generation, leaf traits were all significantly different among genotypes, but with significant effects due to genotype × crown‐position interaction. Variation in leaf pigmentation, petiole length, and petiole length proportion appeared to be under the control of few quantitative trait loci (QTLs). More QTLs were associated with single leaf area, leaf shape, lamina angle, abaxial color, and petiole flatness, and in these traits the number of QTLs varied among crown positions. In general, the estimates of QTL numbers from Wright's biometric method were close to those derived from molecular markers. For those traits with few underlying QTLs, a single marker interval could explain from 30 to 60% of the observed phenotypic variance. For multigenic traits, certain markers contributed more substantially to the observed variation than others. Genetic cluster analysis showed developmentally related traits to be more strongly associated with each other than with unrelated traits. This finding was also supported by the QTL mapping. For example, the same chromosomal segment of linkage group L seemed to account for 20% of the phenotypic variation of all dimension‐related traits, leaf size, petiole length, and midrib angle. In both traits, the P. deltoides alleles had positive effects and were dominant to the P. trichocarpa alleles. Similar relationships were also found for lamina angle, abaxial greenness, and petiole flatness.}, number={2}, journal={AMERICAN JOURNAL OF BOTANY}, author={Wu, R and Bradshaw, HD and Stettler, RF}, year={1997}, month={Feb}, pages={143–153} }