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本文对携带有黑麦B组染色体的四倍体小麦(Triticum durum Desf)的细胞遗传效应进行了研究,并与六倍体小麦(T.aestivum)相同数量的同源B组染色体进行了比较。携带有黑麦B组染色体的四倍体小麦在A组染色体减数分裂过程中产生严重的畸形。它们通过减少环状二价染色体和增加棒状二价、单价染色体的频率而使细胞中交叉染色体的频率显著降低。在细胞分裂中期Ⅰ,单价染色体频率的提高还导致细胞分裂后期Ⅰ和二分体与四分体微核形成的滞后现象。携带有单一B染色体的植株的授粉和结实性明显降低,对籽粒性状也有显著的负效应。B组染色体对植株营养体发育的大多数形态性状具有强烈的正效应。B组染色体在四倍体小麦中较在六倍体小麦中表现出更为明显的细胞遗传特性,可能与前者缺乏D组染色体有关。
In this paper, the cytogenetic effects of Triticum durum Desf carrying chromosome B of rye were studied and compared with the same number of homologous Group B chromosomes of T.aestivum. Tetraploid wheat carrying chromosome group B rye produces severe deformities during meiosis of group A chromosomes. They significantly reduce the frequency of cross-chromosomal events in cells by reducing the number of circular bivalent chromosomes and increasing the frequency of rod-shaped bivalent, monovalent chromosomes. In the metaphase I, the increase in the monovalent chromosome frequency also leads to the lag in the formation of I and II and the tetrad micronuclei during late metaphase. Plants carrying a single B chromosome significantly decreased pollination and seed set, and also had a significant negative effect on grain traits. Chromosome B has a strong positive effect on most morphological traits of plant vegetative development. Group B chromosomes showed more obvious cytogenetic characteristics in tetraploid wheat than in hexaploid wheat, which may be related to the lack of chromosome D in the former.