八倍体小黑麦与普通小麦杂种F_1细胞遗传学及性状的研究

STUDY ON CYTOGENETICS AND CHARACTERS OF F_1 HYBRIDS BY CROSSING OCTOPLOID TRITICALE AND WHEAT

本文用八倍体小黑麦与普通小麦进行正反交。用ＧｉｅｍｓａＣ－带技术对亲本及杂种Ｆ＿１的体细胞染色体进行了分析，并研究了它们的性状。结果表明体细胞染色体组成与植株性状有密切的关系；并发现八倍体小黑麦的染色体数目不稳定，有自然减小的趋势。同时，用ＧｉｅｍｓａＣ－带技术研究了八倍体小黑麦及Ｆ＿１杂种花粉母细胞的减数分裂行为。表明：减数分裂不规则是八倍体小黑麦结实率低、籽粒皱缩的重要原因之一；Ｆ＿１杂种后代的中期染色体基本构型为２１Ⅱ＋７Ⅰ，减数分裂更加的不规则，但通过分离和重组，可产生各种类型的配子，从后代中可选出稳定、高产的重组品系，对改进八倍体小黑麦的不良性状有重要的意义。

In this paper,the reciprocal cross was made between octoploid triticale and common wheat.The characters of parents and F_1 plant are studied,and the somatiC chromosome of them are analysed by Giemsa C-banding.The result shows that somatic chromosome form has a direct bearing on the plant characters;Octoploid triticale chromosome number is unstable and there's on inclinnation of natural reduction.At the same time,the behaviour of meiosis in pollen mother cells of octoploid and F_1 plant is studied.One of chief reasons of why the seed setting is low and grain shrivel's is that the meiosis is irregular;Chromosome configuration in Metaphase Ⅰ is 21 Ⅱ+7 Ⅰin F_1 hybrids,the meiosis is fairly irregular.But all kinds of gametes can be produced through separation and recombination and from offspring we can select stable and high yields ofrecombination lines.The study on cytogenetics and characters of octoploid triticale and F_1 hybridsexert great influence on improving the harmful characters of octoploid triticale.