贵州野生白及属药用植物种质资源分布规律及核型研究

Study on the Distribution Regularities and Karyotype of the Wild Medicinal Germplasm Resources in Bletilla Rchb.f.from Guizhou

对贵州野生白及属药用植物种质资源的分布规律进行研究,并以根尖为原材料,采用常规压片法分析染色体核型,研究不同居群核型特征,为野生白及属种质资源保护和人工选育提供依据。结果表明,贵州野生白及属药用植物种质资源全省广布,其中,黄花白及海拔分布范围在398~1300 m之间,生长环境以草丛为主,小白及海拔分布范围在620~1899 m之间,生长环境以草丛、岩壁或石壁为主。核型分析结果表明,8个居群染色体均为二倍体,染色体基数x=16,染色体数目2n=2x=32,着丝点位置有m、sm、st三种,以m类型染色体为主,核型类型有2B、2C两种,以2B型为主,其中,黄花白及的核不对称系数介于59.18%~62.18%之间,小白及的核不对称系数介于57.44%~60.34%之间。黄花白及与小白及在分布区域上存在差异性,前者以中低海拔为主,后者以中高海拔为主;贵州野生白及属药用植物种质资源核型多样,种内和种间均存在一定差异。

The distribution of germplasm resources of wild Bletilla Rchb.f.medicinal plants in Guizhou Province was studied,and the chromosome karyotypes of different populations were analyzed by means of conventional tablet method using root tips as raw materials,so as to provide the basis for wild Bletilla Rchb.f.germplasm conservation and artificial breeding.The results showed that the wild Bletilla Rchb.f.germplasm resources were widely distributed in Guizhou Province.Among them,the altitude distribution of Bletilla ochracea Schltr.ranged from 398 m to 1300 m,and the growth environment was mainly grass,while the altitude distribution of Bletilla formosana(Hayata)Schltr.ranged from 620 m to 1899 m,of which growth environment was mainly grass,rock wall or stone wall.Karyotype analysis showed that all 8 populations were diploid,with chromosome base x=16 and chromosome number 2n=2x=32.There were three centromere locations,m,sm and st.There were two types of karyotype,2B and 2C,mainly 2B,among which the nuclear asymmetry coefficient of Bletilla ochracea Schltr.and Bletilla formosana(Hayata)Schltr.ranged from 59.18%to 62.18%,and the nuclear asymmetry coefficient of Bletilla formosana(Hayata)Schltr.was from 57.44%to 60.34%.The distribution of Bletilla ochracea Schltr.and Bletilla formosana(Hayata)Schltr.was different.The former was mainly at middle and low altitude,while the latter was mainly at middle and high altitude.Germplasm resources of wild Bletilla Rchb.f.medicinal plants in Guizhou were diverse in karyotype,and there were some differences between species and within species.