二棱大麦产量性状的遗传分析

Genetic Analysis of Yield Traits in Two-Rowed Barley:

以甘木二条等７个二棱大麦（ＨｏｒｄｅｕｍｄｉｓｔｉｃｈｕｍＬ．）品种进行７×７半双列杂交，对亲本、Ｆ１和Ｆ２的单株产量、单株穗数、每穗粒数、千粒重、收获指数５个性状，采用加性－显性－上位性（ＡＤＡＡ）模型进行遗传分析。遗传方差分量占表现型方差比率的估算表明，只有收获指数有加×加上位性效应，其余均受加性－显性效应的作用，其中单株穗数、千粒重以加性效应为主，单株产量、每穗粒数则以显性效应为主。产量性状中，千粒重有较高的广义和狭义遗传力。基因效应预测值表明，选用Ｒｉｓ１５０８较易获得多穗的后代；６７１１－２８、浙农大３号的后代每穗粒数较多；Ｓ－０９６、紫皮大麦、６７１１－２８的后代千粒重较高。杂种优势预测表明，二棱大麦多数杂交组合的高产杂种优势主要表现在千粒重增加、每穗粒数增多的杂种优势。

A half-diallel analysis of grain yield per plant, spikes per plant, grains per spike, 1000-grain weight and harvest indeX was carried out with F 1, F 2 and parents of 7 two-rowed barley varietis by using additive-dominance-epistatic model. The estimation of the ratio between components of genetic variance and phenotypic variance indicats that only harvest index is conditioned with additive by additive epistatic effect, while other characters are conditioned with additive and dominance effect, where spikes per plant and 1000-grain weight are mainly controlled by additive effect, grain yield per plant and grains per spike by dominance effect. Among the yield traits 1000-grain weight has high broad-sense and narrow-sense inheritability. Estimation of gene effect value shows that in the progenies of cross with Ris 1508 as parent, plants with more spikes are much more likely to be isolated, whereas more plants with more grains per spike will segerate from crosses with 6711-28, zhenongda 3 as parents, and more plants with higher 1000-weight from crosses with s-096, zipidamai, 6711-28 as parents. Heterosis prediction reveals that heterosis expresses mainly in 1000-grain weight and grains per spike which contribute to yield heterosis.