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

Abstract:

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.

Key words:Hevea brasiliensis;Cultivated germplasm;C value;Variation