摘要
使用单株植物C-带核型鉴定技术,研究了小麦和黑麦染色体在八倍体小黑麦×普通小麦的F_1,BC_1,F_2和F_3代中的遗传行为。黑麦染色体通过花粉和卵细胞的传递率显著不同,通过卵细胞丢失的染色体较多。黑麦染色体在F_2和F_3的传递率为36.0—38.8%,显著低于通过配子的平均传递率。不同的黑麦染色体通过配子的传递是随机的,而在F_2和F_3中却存在着显著的差异,1R的传递率最高,6R、7R最低。发生上述差异的原因可能是黑麦染色体的丢失不仅发生在配子形成和受精阶段,还受具有不同核型的受精卵在发育过程中夭亡的影响。受黑麦染色体的影响,小麦染色体也有不同程度的丢失。在不同的世代群体中,约有7.3—28.1%的植株丢失了小麦染色体。6R、5R和7R对小麦染色体丢失的作用较大。根据本研究的结果,在使用八倍体小黑麦×小麦的杂交方式利用黑麦遗传物质于小麦育种的工作中,F_2和F_3是有效选择的关键世代。本文建议的单株植物C-带核型鉴定技术是实现这一选择目标的有效方法。
The F1,. BC1, F2 and F3 populations of two octoploid triticale X common wheat hybrids were cytologically analyzed on a plant-by-plant basis using a Giemsa C-banding technique for the transmission patterns of rye and wheat chromosomes. The data indicated that the rye chromosomes exhibited an intensive tendency to lose. The mean transmission rates of rye chromosomes ranged from 36.0% to 38.8% in the F2 and F2 populations, which were significantly lower than those through the gametes of the F1. The transmission rates of individual rye chromosomes appeared no significant difference through both the eggs and pollen, but they deviated significantly from the random pattern in the F2 and F2 populations. 1R is the most frequent and 6R, 7R the least to be observed. The reason for the difference may be partly accounted for the selection effect of endosperm against rye chromosomes. The endosperm with more rye chromosomes under aneuploid condition would die in the development stage more easily than those with less rye chromosomes. Wheat chromosomes were capable of being lost owing to the disturbance of rye chromosomes. 7.3-28.1% of the plants from the BC1, F2 and F3 were detected, in which the loss of the wheat chromosomes was observed. Elimination of the wheat chromosomes was caused more frequently by 6R, 5R and 7R than by the other rye chromosomes. The results indicated that the F2 and F3 should be the most important generations to select in wheat breeding with octoploid triticale × wheat.
关键词
小麦
黑麦
小黑麦
染色体传递
Transmission of chromosomes, Wheat, Triticale.
