木兰科3个杂交组合及其亲本的核型研究

Karyotypic Studies on Three Hybrids and Their Parents in Magnoliaceae

摘要:

研究了木兰科(Magnoliaceae) 3个杂交组合的亲本和杂交后代的核型。结果表明，云南含笑(Michelia yunnanensis)﹑灰岩含笑(Michelia calcicola)及其杂交组合A的核型分别为2n=2x=38=36m+2sm、2n=2x=38=34m+4sm和2n=2x=38=26m+12sm；紫花含笑(Michelia crassipes)及其与云南含笑杂交组合C的核型分别为2n=2x=38=32m+6sm和2n=2x=38=24m+12sm+2st；山玉兰(Magnolia delavayi)﹑广玉兰(Magnolia grandiflora)及其杂交组合U的核型分别为2n=2x=38=28m+10sm、2n=6x=114=88m+10sm+16st和2n=4x=76=57m+15sm+4st。杂交组合的核型与理论核型存在明显的差异，可能是在杂交组合的形成过程中，来自亲本的染色体发生了结构变异。

Abstract:

The karyotypes of three hybrids and their parents in Magnoliaceae were studied. Their karyotype formulae are as follows: 2n=2x=38=36m+2sm for Michelia yunnanensis, 2n=2x=38=34m+4sm for Michelia calcicola and 2n=2x=38=26m+12sm for their hybrid A; 2n=2x=38=32m+6sm for Michelia crassipes and 2n=2x=38=24m+12sm+2st for hybrid C from Michelia crassipes and Michelia yunnanensis; 2n=2x=38=28m+10sm for Magnolia delavayi, 2n=6x=114=88m+10sm+16st for Magnolia grandiflora and 2n=4x=76=57m+15sm+4st for their hybrid U. The results showed that the karyotypes of these hybrids were markedly different from the expected ones according to the parental karyotypes, which might result from the structural variation of the parental chromosome during the hybridization. Therefore, it is difficult to identify these hybrids by the karyomorphological characters.