Cucumis hytivus染色体组间交换重组及其对雄配子育性的影响

Genomic Exchange and Rearrangement and Its Effect on Fertility of Male Gametophyte in Cucumis hytivus

采用染色体压片技术对双二倍体种Cucumishytivus染色体组间交换重组及其对雄配子育性的影响进行了细胞学研究。找到了该物种染色体组间交换重组的细胞学证据:包括前期的"8"字形、"十"字形结构和中期环状、链状多价体。研究还发现各种可能导致遗传物质不均衡分离的异常结构如染色体桥、染色体滞后、染色体组分离、微核等。染色体组间广泛的交换和重组导致约93%的多分体及部分异常四分体的形成,多分体中大量的畸形小孢子和四分体中遗传物质不平衡的小孢子因不能正常发育而最终形成败育的雄配子,直接影响到Cucumishytivus育性。

Genomic exchange and rearrangement of the amphidiploid species Cucumis hytivus and its effect on fertility of male gametophyte were cytologically studied through making slides.Cytolo-(gical) evidences for genomic exchange and rearrangement were found,such as'8'and'cross'configu-(rations) at prophase,chain and ring multivalents at metaphase Ⅰ,as well as various abnormal chro-(mosome) structure including chromosome bridges,lagging,genomic separation,micronuclei etc,which probably resulted in unequivalent distribution of genetic germplasm.Such an extensive geno-(mic) exchange and rearrangement led to 93% polyads and some abnormal tetrads.Abnormal micro-(spores) in polyads and microspores with unbalance germplasm could not develop into normal male gametophytes,which is responsible for the low fertility of male gametophyte in Cucumis hytivus.