巴西橡胶树栽培种质基因组C值测定和变异分析

为了解巴西橡胶树(Hevea brasiliensis)栽培种质的变异情况,以53份在云南植胶区综合性状表现较好的巴西橡胶树栽培种质为材料,采用流式细胞术测定了基因组C值,并进行了变异分析。结果表明,浅绿色嫩叶是巴西橡胶树流式细胞术测定的最适样品。53份巴西橡胶树栽培种质的细胞核DNA含量和基因组C值存在一定差异,基因组的平均C值是1.531 696×109 bp,最小的是CRTG-272种质(1.465 908×10~9 bp),最大的是CRTG-83种质(1.600 381×10~9 bp),变异系数较小(CV=0.035 5)。53份巴西橡胶树栽培种质中有47份为二倍体,6份为三倍体。在已测定基因组大小的40种大戟科(Euphorbiaceae)植物中,基因组大小变异较大(CV=1.248 6),与"C值悖论"观点相一致。因此,应用流式细胞术能快速、准确地测定巴西橡胶树细胞核DNA含量、基因组C值和染色体倍性。

Genome C Value and Variation Analysis of Cultivated Rubber Tree (Hevea brasiliensis) Germplasms by Flow Cytometry

In order to understand the variation of cultivated germplasm of Hevea brasiliensis, the genomic C value of 53 cultivated germplasms with high quality characters in Yunnan rubber planting areas were measured by flow cytometry, and their variations were analyzed. The results showed that light green young leaves of H. brasiliensis were suitable samples for flow cytometry. There were differences in nuclear DNA content and genomic C value among 53 cultivated germplasms. The average genomic C value was 1.531 696×10⁹bp, the smallest was CRTG-272 (1.465 908×10⁹bp), the largest was CRTG-83 (1.600 381×10⁹bp), and the variation coefficient (CV) was small (0.035 5). Among 53 cultivated germplasms of H. brasiliensis, forty-seven were diploid and 6 were triploid. The genome sizes had big CV up to 1.248 6 among 40 species of Euphorbiaceae, which is consistent with the view of the C value paradox. Therefore, flow cytometry can achieve rapid and accurate determination of the nuclear DNA content, genomic C value, and chromosome ploidy of H. brasiliensis.