赖草联会消失突变体的细胞遗传学研究

A Study on Cytogenetics of Desynaptic Mutant in Aneurolepidium Dasystachys

对赖草（Ａｎｅｕｒｏｌｅｐｉｄｉｕｍｄａｓｙｓｔａｃｈｙｓ）自发联会消失突变体的研究结果表明：突变体在偶线期、终变期尚能正常配对．但从终变期开始，大部分“×”、“Ｖ”、“‖”状二价体提早解离成单价体，从而导致以后各时期持续紊乱。和正常株不同，突变体出现了一定频率的“中—后”期分裂相。这是联会消失突变体的减数分裂特征。突变体的减数分裂过程中出现更多的染色体结构变异，这说明联会消失突变和结构变异有相关的遗传背景。由于减数分裂行为十分紊乱而导致突变体的配子育性和结实率大大下降。

Meiotic studies on the mutant plant of Aneurolepidium dasystachys showed that pairing of homologous is regular in the zygotene and pachytene , but a number of“×”,“‖”and“‖”shaped bivalents occurredspotaneously to desynapsis in the mutant.“Metaphase-Anaphase” pattern is major characteristic of mutantin the meiosis,Variations in chromosome structure occurred in the meiosis of mutant were more than that ofnormal plant. This showed that genetic background of desynapsis is related to that of variations inchromosome structure. Because of irregular meiosis , fertility of the gamete in the mutant is lower than thatof normal plant.