系谱重建在日本落叶松自由授粉子代测定中的应用

摘要

[Objective] The genetic parameters of growth traits and wood chemical properties of Japanese larch (Larix kaempferi (Lamb.) Carr.) were compared before and after pedigree reconstruction,aiming at providing a more effective method for the genetic evaluation of open-pollination progeny testing in China.[Method] In this study,the complete pedigree information of 601 progenies from 66 pollination families of Japanese larch was obtained through pedigree reconstruction technique.The changes of genetic parameters (e.g.additive genetic variance,heritability,breeding value),breeding value accuracy and the realized genetic gains of growth traits (tree height,diameter at breast height,volume) and wood properties (α-cellulose,lignin and holocellulose) were compared.[Result] The additive genetic variances and heritabilities of all the traits decreased after genetic reconstruction.The dominant effect significantly affected the tree height,α-cellulose and lignin content.The estimated accuracy of breeding value and realized genetic gain were higher than that before pedigree reconstruction,while the realized genetic gain declined due to the decrease of additive variance.The genetic gain decreased by 26％,40％,56％,42％ and 51％ for DBH,volume,α-cellulose,lignin (low content is superior) and holocellulose when forward selection (progeny selection) was made at 5％ selection intensity.[Conclusion] In order to improve the estimation accuracy and breeding efficiency of the genetic parameters of the current open-pollinated progeny testing materials,it is suggested to adopt the pedigree reconstruction method based on individual mixed model to replace the conventional analysis method based on parental model.%[目的]比较研究日本落叶松系谱重建前后生长和化学材性性状遗传参数的变化,以期为国内以自由授粉子代测定林为主的遗传测定提供更为科学有效的评价方法.[方法]采用系谱重建技术获取了来自66个日本落叶松自由授粉家系的601个子代的完整系谱信息,并利用单株混合线性模型比较了系谱重建前后生长(树高、胸径、材积)和材性(α-纤维素、木质素、综纤维素)性状的遗传参数(加性遗传方差、遗传力、育种值)、育种值准确度和现实遗传增益的变化.[结果]系谱重建后各性状的加性遗传方差和遗传力均有所下降;胸径和材积主要受加性效应控制,树高主要受显性效应控制,化学性状除了受加性效应控制外,也受显性效应控制;系谱重建后育种值和现实遗传增益的估算准确度高于系谱重建前,现实遗传增益由于加性方差的降低而减少,当以5％的强度进行子代的前向选择时,胸径、材积、α-纤维素、木质素(负选择)及综纤维素的遗传增益较重建前下降了26％、40％、56％、42％和51％,分别为2.72％、5.38％、8.06％、3.48％和8.75％.[结论]系谱重建能够提高自由授粉家系子代测定材料遗传参数、育种值和遗传增益估算的准确性,建议以基于系谱重建的单株模型方法取代基于亲本模型的自由授粉家系常规方法.