苦参的染色体核型

苦参(Sophora flavescens Ait)是豆科槐属(Sophora L.)的多年生草本植物,我国南北各省区均产,苏联、朝鲜和日本亦有分布。在细胞学方面,Kawakami^[3]、Hexob^[8]和Kodama^[4]都报道过苦参的染色体数目为2n=18,但Nagl^[8]却报道2n=28。本文作者在对苦参作染色体基数的基础上,进行了核型的描述和分析。

KARYOTYPE OF SOPHORA FLAVESCENS AIT.

A karyotype analysis for Sophora flavescens Ait. (Legumino-sae) has been carried out and the number of chromosomes has been found to be 2n=18, in accord with those reported by Kawakami^[3], Hexob^[8] and Kodama^[4], but disagreeing with the report of 2n=28 of Nagl^[6]. According to the chromosomal terminology defined by Levan and al.^[5], the karyotype for-mula is K(2n)=18=2M(SAT)+10m+4m(SAT)+2sm. In the light of Stebbins'^[7]classification of karyotypic asymmetry, the ka-ryotype belongs to "2A" type and should therefore be considered as a rather primitive one. Aneuploidy is evident in the ancient and diverse genus Sophora L. The genus has a wide range of chromosome num-bers with n=14, 11, 9 and 8, with the most frequent number n=9. It is generally admitted that x=14 is most likely thebasic number for Tribe Sophoreae as a whole, and the number has been originated from polyploid caesalpinioid stock. Sub-sequent evolution has involved descending aneuploidy probably due to framentation as proposed by Yakovlev and others^[2].The only species:Sophora japonica, S. affinis and S. chinensis (probably identical with S. japonica as suggested by P. C.Tsoong and al.^[1]) heretofore known with n=14 in the genus Sophora are all arborescent, while species with lower numbers (n=11, 9 and 8) are usually smaller trees or shrubs or even perennial herbs. It seems that the perennials S. flavescens and S. alopecuroides L. as well must be viewed cytologically as de-rived aneuploids from members having a higher basic number in the genus.