蒙农杂种冰草退化群体农艺性状变异分析

Analysis on Agronomic Characters Variation of Degraded Population of Hycrest-Mengnong Wheatgrass

为冰草属牧草以及其他禾本科牧草的遗传改良和新品种选育提供依据,以蒙农杂种冰草为研究材料,采用田间观察与室内分析方法连续两年(2018年、2019年)对15个农艺性状(株高、叶长、叶宽、穗长、穗宽、小穗长、小穗宽、每穗节数、每节小穗数、每小穗小花数、株丛茎、第一旗叶长、第一节间长、干重、鲜重)进行鉴定。结果表明,蒙农杂种冰草连续生长利用多年后,群体退化明显,15个农艺性状平均变异系数为25.49%,以第一节间长的变异系数最大(42.55%),其次是地上生物量及叶部和穗部的性状,株高的变异系数亦较大;性状间相关性显著,株高与旗叶及地上生物量呈正相关;株高、叶长、叶宽、穗长、穗宽、地上生物量是变异的主要性状,且营养生长有关性状的变异显著大于生殖生长的性状变异。因此,在群体遗传改良或提纯复壮时可从株型、叶型、地上生物量等几个方面考虑。

15 agronomic characters(plant height,leaf length,leaf width,panicle length,panicle width,spikelet length,spikelet width,number of nodes per panicle,number of spikelet per spikelet,number of florets per spikelet,cluster stem,first flag leaf length,first internode length,dry weight,fresh weight)of A.cristatum×A.desertorum cv.‘Hycrest-Mengnong’were identified by field observation and laboratory analysis for two years(2018,2019),the aim was to provide basis for genetic improvement and new variety breeding of wheatgrass and other grasses.The results showed that after continuous growth and utilization for many years,the population degraded obviously,the average coefficient of variation of 15 agronomic characters was 25.49%,and the coefficient of variation of the first internode length was the largest,42.55%,then was the above-ground biomass and the leaf and panicle traits,the variation coefficient of plant height was also large;the correlation between characters was significant.the plant height and flag leaf had positive correlation with the above-ground biomass;Plant Height,leaf length,leaf width,ear length,ear width and above ground biomass were the main variation characters,and the variation of vegetative growth traits were significantly greater than that of reproductive growth.Therefore,plant type,leaf type and above ground biomass can be improved(or selected)in the process of population genetic improvement or purification and rejuvenation.