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研究了野生种Cucum is hystrix(2n=2x=24)与栽培黄瓜C.sativusL.(2n=2x=14)种间杂种F1(2n=2x=19)及其双二倍体(2n=4x=38)自交S1~S4代的细胞遗传学特征及花粉育性。结果表明:减数分裂中期Ⅰ,杂种F1代花粉母细胞(pollen mother cell,PMC)染色体主要以单价体存在,染色体构型为:16.75Ⅰ+0.5Ⅱ+0.25Ⅲ+0.13Ⅳ;双二倍体染色体构型以二价体为主,伴随着自交,平均每个PMC所含二价体比例逐渐增加,非二价体配对比例减少。四分体时期,F1代不能形成正常的四分孢子,主要以多分孢子形态存在;双二倍体以四分孢子为主,并随着自交世代的增加,其比例增高。花粉育性观察发现,随着自交世代的增加,双二倍体花粉育性呈增高趋势。以上结果暗示,双二倍体在遗传上逐渐趋于稳定;双二倍体PMCs在后期Ⅰ和Ⅱ普遍含有落后染色体、染色体桥及染色体不均等异常现象,可能是导致其花粉育性较低的原因。
The interspecific hybrid F1 (2n = 2x = 19) and its diploid diploid (2n = 2x = 14) of wild Cucum is hystrix (2n = 2x = 24) and cultivated cucumber C. sativus L. (2n = 38) Cytogenetic Characteristics and Pollen Fertility of Selfing S1 ~ S4 Genes. The results showed that the chromosomes of pollen mother cell (PMC) of hybrid F1 were mainly monovalent in metaphase Ⅰ, the chromosome configuration was: 16.75Ⅰ +0.5Ⅱ + 0.25Ⅲ + 0.13Ⅳ; Chromosome configuration dominated by bivalents, accompanied by selfing, the average proportion of each containing PMC gradually increased, reducing the proportion of non-bivalents decreased. During the tetrad period, the F1 generation could not form normal tetradospores, and mainly existed in the form of multiple spores. The diploid was dominated by tetradospores and its proportion increased with the selfing generation. Pollen fertility observation showed that with the increase of selfing generations, double diploid pollen fertility showed an increasing trend. The above results suggest that the diploid ploidy tends to be genetically stable. Diploid diploid PMCs generally contain lagging chromosomes, chromosome bridges and chromosomal anomalies in late stage I and II, which may result in lower pollen fertility the reason.