甘蓝型油菜和诸葛菜属间杂种高世代材料形态学和细胞学分析

目的]进一步揭示甘蓝型油菜和诸葛菜属间远缘杂种高世代(F8～F10)材料的遗传变异规律。方法]以甘蓝型油菜和诸葛菜属间杂种高世代群体为材料,对甘蓝型油菜和诸葛菜远缘杂交后代表型偏白菜型油菜变异群体进行形态、细胞学方面的研究。结果]形态学分析表明,杂种后代叶型、叶色、株型、早花性状偏向白菜型油菜,而二级分枝数、角果长度和千粒重与甘蓝型油菜Oro更为接近;细胞学研究表明,这些杂种高世代材料细胞中已不含诸葛菜染色体,多数植株都为少于38条染色体的亚倍体;与白菜型油菜杂种的减数分裂配对结果显示,这些亚倍体后代细胞中丢失的可能是来自C基因组的染色体,随着世代的增加,体细胞染色体数目都有向甘蓝型油菜2n=38升高和回归的趋势。结论]该研究为揭示杂种后代亚倍体中丢失染色体的来源及形态学改变的原因奠定基础。

Morphologic and Cytogenetic Study on the Highly Inbred Progenies of Generic Hybrids between Brassica napus and Orychophragmus violaceus

Objective] This study aimed to reveal the genetic change of advanced generation hybrids between Brassica napus and Orychophragmus violaceus.Method] The morphological characteristics such as plant shape,branching sites,leaf shape,leaf color,primary branches and secondary branches,as well as cytological characteristics of the highly generation hybrids(F8-F10) between B.napus and O.violaceus were observed.Result] The morphology analysis revealed that the hybrid progeny was more like B.rapa in leaf shape,leaf color,plant shape and early flowering phenotype,whereas more like B.napus in number of secondary branches,silique length and 1 000-seed weight.Cytogenetics study showed that these highly inbred progenies were hypoploids with less than 38 chromosomes;moreover,all chromosomes of O.violaceus had been lost.Chromosome pairings at meiotic diakinesis of hybrids between the highly inbred progenies and B.rapa revealed that chromosomes lost in hypoploids plants possibly belonged to C genome of B.oleracea.With generations developing,chromosomes number of plants from two populations gradually increased and developed into the number of B.napus(2n=38).Conclusion] This study will provide reference to reveal the source of chromosome lost in hypoploids and the mophorlogical change of hybrids.