四个橡胶树主要栽培品种的核型分析

Karyotype Analysis of Four Main Rubber Tree(Hevea brasiliensis) Cultivars

巴西橡胶树是重要的热带经济作物。巴西橡胶树GT1、93-114、天任31-45和RRIM623都是中国大规模推广种植的优良品种。本研究采用压片法,以橡胶树古铜期幼叶为材料,对该4个主要栽培品种的染色体数目与核型分析。结果表明:巴西橡胶树4个品种的染色体数目均为2n=36,其中,GT1的核型公式为2n=36=28m(2sat)+8sm、93-114的核型公式为2n=36=28m(2sat)+8sm、天任31-45的核型公式为2n=6=32m(4sat)+4sm、RRIM623的核型公式为2n=36=32m+4sm。其核型不对称系数依次为59.25、60.42、59.04、59.54。4个品种的核型类型均为2B型,对称程度较高。本研究可为橡胶树种质资源鉴定和育种以及细胞遗传图谱的构建提供细胞学基础。

Rubber tree （Hevea brasiliensis） is an important tropical cash crop. GT1 （Hevea brasiliensis, GT1）, 93-114 （Hevea brasiliensis, 93-114）, Tianren31-45 （Hevea brasiliensis, Tianren31-45） and RRIM623 （Hevea brasiliensis, RRIM623） are all fine varieties that have been promoted to cultivate in large scale in China. In this research, we took the young leaves in the bronze period of rubber tree as materials to analyze the chromosome numbers and karyotypes of the four main cultivars by using conventional pressing method. The results showed that the chromosome numbers of four cultivars were all 2n=36, among which the karyotype formula of GT1, 93-114, Tianren31-45 and RRIM623 was 2n=36=28 m （2sat）＋8 sm, 2n=36=28m （2sat）＋8sm, 2n=36=32m （4sat）＋4sm, and 2n=36=32m＋4sm, respectively. Their karyotype asymmetry coefficients were 59.25, 60.42, 59.04 and 59.54 in turn. The karyotypes of the four cultivars all belonged to Stebbins ＂2B＂ and their chromosomes were of high symmetry. This study could provide cytological basis for the identification and breeding of germplasm resource of rubber tree and the construction of cellular genetic map.