13个铁线莲品种的核型比较分析

铁线莲属Clematis为观赏价值极高的藤本植物。铁线莲品种数量繁多，形态变异丰富，遗传背景也相对复杂，品种间存在杂交不亲和性的障碍，对杂交亲本的染色体核型分析等细胞学特征的研究显得十分重要。采用酶解法-去壁低渗火焰干燥法与Giemsa-C分带染色技术，以13个铁线莲品种自然生长的幼嫩根尖为试材，进行染色体参数和核型分析。结果表明:13个品种的染色体均为2n=2x=16，均为二倍体；染色体核型分为2种类型:2n=2x=16=10m+4st+2t，2n=2x=16=10m+6st；随体均在第6条，第7条或第8条染色体上，且位置均在短臂上；13个品种的核型类型均为“2A”，具有很大的相似性，说明杂交不亲和现象由其他因素导致。图3表3参18

Karyotypes in 13 Clematis cultivars

Clematis has extremely high ornamental value, complicated genetic background and cross-incompatibility phenomena. Studies on chromosome karyotype analysis of hybrid parent is very important. Chromosome types and karyotypes with natural growth of tender root tip materials in 13 Clematis cultivars were studied by the method of cell wall degradation and hypotonic treatment for chromosome preparations. Results indicated that all chromosomes for the 13 provenances were diploids and the chromosome number was 2n=2x=16. There were 2 types of chromosome karyotypes classified from the morphological observation:2n=2x=16=10m+4st+2t and 2n=2x=16=10m+6st. Satellites were found in chromosomes of each cultivar for numbers 6, 7, and 8. Both karyotypes were "2A". Thus, both chromosome karyotypes had a great deal of similarity. So cross incompatibility phenomena may caused by other factors.[Ch, 3 fig. 3 tab. 18 ref.]