Estimates of genetic parameters between and within black oat populations

ABSTRACT The aims of this study were to characterize black oat populations by estimating between- and within-populations variance components and genetic parameters, as well as to distinguish the populations using multivariable statistics. The experiment was carried out in randomized blocks design with three repetitions, with 14 black oat populations collected in several municipalities of Rio Grande do Sul state. Agronomic important traits were assessed at physiological maturation stage. Variance components and genetic parameters were estimated considering within-block information. In addition, Mahalanobis distance, relative contribution of traits, and canonical variables were used to distinguish the populations. Selection based on panicle length, number of grains per panicle, panicle weight and panicle grain weight may result in higher selection gains. Panicle grain weight presents a greater contribution to genetic divergence between studied populations. The formation of distinct groups indicated the presence of genetic variability among black oat populations in the northwestern of the Rio Grande do Sul state. Directed crosses between individual plants of populations from (i) Alto Alegre and Salvador das Missões, Chapada, or Santa Rosa or (ii) between plants of populations from Salvador das Missões and Campos Borges or Santa Rosa can generate segregating populations with great genetic variability. The predominance of between-phenotypic variance and a within-genetic variance indicate prospects for success in selection gain and possible selection of a new cultivar with fewer efforts compared to a cross-based method. This is supported by the high values of within-population heritability.

摘要 本研究旨在通过估算群体间与群体内方差组分及遗传参数，对黑燕麦群体进行特征表征，并借助多变量统计学方法区分各群体。试验采用随机区组设计，设置3次重复，供试材料为从南里奥格兰德州多个市镇采集的14份黑燕麦群体。在生理成熟阶段对重要农艺性状进行测定。基于区组内信息估算方差组分与遗传参数。此外，采用马氏距离（Mahalanobis distance）、性状相对贡献率及典范变量（canonical variables）对各群体进行区分。基于穗长、每穗粒数、穗重及穗粒重进行选择，可获得更高的选择增益。穗粒重对供试群体间的遗传分化贡献更大。类群的形成表明，南里奥格兰德州西北部的黑燕麦群体间存在遗传变异。（i）阿尔托阿莱格雷（Alto Alegre）与萨尔瓦多达斯米绍斯（Salvador das Missões）、查帕达（Chapada）或圣罗萨（Santa Rosa）的群体个体植株间，或（ii）萨尔瓦多达斯米绍斯与坎普斯博尔赫斯（Campos Borges）或圣罗萨的群体个体植株间进行定向杂交，可产生具有丰富遗传变异的分离群体。群体间表型变异占主导地位，且群体内存在遗传变异，这表明相较于基于杂交的育种方法，通过选择即可获得更高的选择增益，且培育新品种所需投入更少。群体内遗传力较高的结果进一步佐证了这一结论。