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通过对北京地区1949 年以来不同时期冬小麦品种生物产量若干性状的演变规律、遗传相关、环境相关和遗传变异系数的比较得出:①目前推广品种的收获指数比解放初推广品种增加了11-72 个百分点,但是单位茎叶重所负担的子粒重( 克草粒重) 却增加了83-9 % ,说明库源器官的比例变化较大,光合产物输出增多。②随着品种的遗传改良,单个茎秆特别是单个穗子的生产能力强化了,但群体成穗数有所下降,茎秆矮化、粗壮,穗子也变得粗大,小穗勾数增加。③生产品种在系统演化过程中,有些性状间的遗传相关为负值,但这些性状之间的环境相关却几乎全部为正值,说明品种在系统改良的过程中,性状的遗传相关与个体发育中的纯生物学相关不尽一致;一些性状的负向选择( 植株矮化等) 可能要牺牲一些其它性状。④相对于环境变异系数来说,株高、穗子大小和千粒重的遗传变异系数较大,选择的把握性较大。要改良品种的生物产量应该强化源器官的发育、光合生产及输出效率,以总生物产量做指标选择的可靠性较小,如要选择准确则应增加重复数。
By comparing the evolution law, genetic correlation, environmental correlation and genetic coefficient of variation of several biological characteristics of winter wheat cultivars at different periods in Beijing since 1949, the results showed that: (1) The harvest index of the current varieties increased 11-72 However, the weight of stems and leaves per unit weight of seeds (Kg) increased by 83-9%, which indicated that the proportion of source and sink organs changed greatly and the output of photosynthate increased. With the genetic improvement of varieties, the productivity of individual stalks, especially single ones, was enhanced. However, the number of stalks decreased, the stalks dwarfed, stout, and the ears became coarse, and the number of spikelets increased. (3) The genetic correlation of some traits in the process of system evolution was negative, but the correlation between these traits was almost all positive, indicating the genetic correlation and individual development of traits in the process of system improvement The purely biological correlations are not consistent; some negative traits (plant dwarfing, etc.) may sacrifice some of the other traits. ④ Relative to the coefficient of environmental variation, the genetic variation coefficient of plant height, ear size and 1000-grain weight are larger, and the selection is more certain. To improve the biological yield of varieties should strengthen the development of source organs, photosynthetic production and output efficiency, the overall biological yield index to choose less reliable, if you want to select accurate, you should increase the number of repeats.