矮败小麦利用的研究Ⅲ．株高遗传评价

Studies on the Dwarfing-Sterile Wheat and its Application Ⅲ Genetic evaluation on plant height

以矮败小麦为母本经姊妹交，测交、回交以及轮回群体中开放授粉获得有关分离世代群体。通过计算其群体株高平均数、方差和遗传力，以及亲子间株高相关系数，对矮败小麦株高遗传特性进行研究。结果表明：矮败小麦株高表现出较高的遗传力，但不育株、可育株间株高差异显著，不育株一般４０ｃｍ左右，且株高遗传变异相对较小。不同遗传背景对可育株株高影响显著，而对不育株影响甚微。对可育株株高选择，早代进行效果较好。矮败小麦不育株与不同株高的父本杂交，后代可育株株高呈现偏父正态分布，且半矮秆植株的分离频率相对较高。回交世代中，回交父本对后代可育株影响较大，而对不育株影响较小。随着回交世代增加，可育株株高越来越接近父本。经４～５代回交后，两者之间几乎无甚差别。由于矮败不育株有利于接受群体中较矮植株的花粉，在轮回选择中，应用矮败小麦能够有效地控制群体株高。

Different segregating pop'ulations of progenies derived from dwarfing -sterile wheat (DSW) as female through sib mating,testcrosses,backcrosses and open--pollination in recurrent selection were studied for their genetic characteristics of plant height. Plant height of DSW showed high heritability, while the difference of performance between sterile plant and fertile plant was significant. Usually,the sterile plant is about 40cm high and its genetic variation was relatively low,but genetic background was obviously related to the performance of fertiile plant on plant height. Selection for plant height of fertile plant in early generations performed very well. As sterile plants of DSW crossed male parents diversified in plant height respectively,fertile plants of progenies showed normal distribution for plant height,but proportion of semidwarfing plants was relatively high. In generations of backcrosses, male parent affected plant height performance of fertile plant more greatly than that of sterile plant,and plant height of fertile plant was more and more toward the male parent generation by generation. After backcrossed 4-5 times,there was little difference in plant height performance between fertile offsprings and their male parents. because the dwarfing male sterile plants have more opportunities to accept pollen from low male plant,a satisfactory result on plant height controlling of population can be reached when DSW was used in recurrent selection.