小麦不同世代群体轮回选择效应(英文)

EFFECTS OF RECURRENT SELECTION ON POPULATIONS OF VARIOUS GENERATIONS IN WHEAT

由10个高蛋白和4个高产小麦亲本的太谷核雄性不育株(经6～10代转育)等量种子混合组成基础群体B_1;由4个高产小麦亲本的太谷核雄性不育株等量种子混合组成基础群体B_2。对B_1进行混合选择(MS)和单性状集团选择(CS),对B_2进行回交混合选择(BS),各进行3轮选择,研究了6个性状的直接遗传进度。结果表明,利用太谷核雄性不育基因进行小麦轮回选择是有效的。对于单个性状的改良,CS是最有效的方法,且第一轮(C_1)选择进度最大,但多元方差分析表明CS不利于群体的变异。MS在第2轮(C_2)效应最大,BS到第3轮才显示出最大效应,而且MS和BS均有利于群体的变异。从3轮选择的平均效应看,MS是3种轮选方法中最好的一种方法。

Mass selection (MS) and bulk selection of a single character (CS) were used for the improvement of a base population B_1, which was composed of Taigu male-sterile progenies of ten high protein content and four high yielding parental lines of wheat (Triticum aestivm L. ), transfered by 6 to 10 hackcrossing generations, with equal numbers of plants from each line. Backcross mass selection (BS) was used for the improvement of a second base population, B_2, which was formed by Taigu male-sterile plants of four high yielding parental lines ,again with equal numbers of plants from each line. Three cycles of selection were conducted for both population B_1 and B_2. Direct genetic advances of sterile plants for six traits were studied. The results indicated that use of the Taigu male-sterile single dominant gene is effective fot recurrent selection of wheat. For improvement of a single character, CS was the most effective method, of which the selective effect in the first cycle (C_1) was greater than that in the second cycle (C_2) and the third cycle (C_3), although multivariate analysis showed that CS method was not favourable to maintaing variation in the population. The greatest effect of selection was found in C_2 with MS method, multivariate analysis also indicated that both MS and BS method increased the variation in the population, but from the mean selective effect of three of three cycles, MS was found to be the best selective method studied in this paper.