禺毛茛多倍体复合体及其近缘种核型研究

STUDIES OF KARYOTYPES OF RANUNCULUS CANTONIENSIS POLYPLOID COMPLEX AND ITS ALLIED SPECIES

本文报道了禺毛茛Ranunculus cantoniensis DC.多倍体复合体及近缘种中6种植物的核型。棱喙毛茛Ranunculus trigonus Hand-Mazz.有两种核型(首次报道):矮株型2n=2x=16=4m+6sm+6st(2SAT);高株型2n=2x=16=4m+2sm+10st(2SAT)。茴茴蒜Ranunculus chinensis Bunge.2n=2x=16=6m+2sm+8st。卷喙毛茛Ranunculus silerifolius Levl.2n=2x=16=6m+2sm+6st+2t。禺毛茛2n=4x=32=4m(a)+2m(b)+2sm(b)+4t(SAT)(c)+4st(d)+2m(e)+2sm(e)+2sm(f)+2st(f)+4st(g)+2st(h)+2m(h)。褐鞘毛茛Ranunculus vaginatus Hand.-Mazz.2n=5x=40=3m(a)+2sm(a)+2st(b)+3sm(b)+2t(c)+3t(SAT)(c)+5st(d)+5m(e)+5sm(f)+5st(g)+5m(h),(首次报道)。扬子毛茛Ranunculus sieboldii Miq.2n=6x=48=6m(a)+2st(b)+4sm(b)+2st(SAT)(c)+4t(SAT)(c)+6st(d)+6m(e)+6sm(f)+6st(g)+6m(h)。禺毛茛(4x)由2个类似本文中的卷喙毛茛或茴茴蒜的染色体组和两个“短m-型”染色体组组成。褐鞘毛茛(5x)和扬子毛茛(6x,8x)则由不同的“短m-型”染色体组组成。复合体成员及近缘种可能是通过“短m-型”染色体组产生关系,构成一个柱架式多倍体复合体。根据染色体及形态特征,建议恢复卷喙毛茛的种级地位。

Ranunculus cantoniensis DC. polyploid complex was proposed by Okada. In order to clarify the structure of the ployploid complex, it is necessary to carry out a karyotype study on the complex and its allied species from China, where is the main distribution region of the complex. The karyotype analysis followed Li et al. The ployploid chromosomes in the complex were arranged according to the length of chromosomes and the position of centromere. The experimental materials are listed and the vouchers are deposited in JJT and PE. The experimental results and essential points are as follow: Ranunculus trigonus Hand. -Mazz. was found to have two cytotypes, which are correlated with the plant height. The short plant population has the karyotype 2n = 2x= 16 = 4m + 6sm + 6st (2SAT) , while the high plant one has the karyotype 2n=2x = 16 = 4m + 2sm + 10st (2SAT). The two kary-otypes are first reported. Ranunculus silerifolius Levl. was reduced to a synonym of Ranunculus cantoniensis DC. by L. Liou in 《F1. Reip. Pop. Sin》 Vol. 28. According to the characteristic of their chromosomes and morphology of experimental materials in the study, we suggest that the Ranunculus silerifolus Levl. be treated as an independent species. The karyotype (2n = 2x = 16 = 6m+2sm+8st) of Ranunculus chinensis Bunge, from Beijing, are almost entirely similar to that from Japan except that satellites are not found. The karyotype of Ranunculus silerifolius Levl. (2n = 2x = 16 = 6m + 2sm+6st + 2t) in Guizhou Province of China is similar to the Mastuyama-type or Mugi-type of Ranunculus silerifolius in Japan. The karyotype (2n = 4x=32 = 4m(a) + 2m(b) + 2sm(b) + 4t(SAT) (c) + 4st(d) + 2m(e) + 2sm(e) + 2sm(f) + 2st(f) + 4st(g) + 2st(h) + 2m(h)) of Ranunculus cantoniensis DC. from Jiangxi Province of China is similar to the Kushikino-type in Japan. It consists of two different genomes. One of them is similar to the that of Ranunculus silerifolius (2x) or Ranunculus chinensis (2x) reported in the paper. The other is the genome named 'short m-type', which must have a pair of satellite chromosomes, No. 11 or No. 12, and a pair of 'short m-type' chromosomes, No. 16. The karyotype (2n = 5x = 40 = 3m(a) + 2sm(a) + 2st(b) + 3sm(b)+2t(c) + 3t(SAT)Cc)+5st(d) + 5m(e) + 5sm(f)+5st(g) + 5m(h)), of Ranunculus vaginatus Hand. -mazz. which is first reported, is basically similar to that of Ranunculus siebodii Miq. (2n = 6x = 48 = 6m(a) + 2st(b)+4sm(b) + 4t(SAT) (c) + 2st(SAT) (c) + 6st(d) + 6m(e) + 6sm(f) + 6st(g) + 6m(h)) except ploid level and the morphology of two taxa is also similar to each other. They consist of two or three different 'short m-type' chromosome sets respectively. We think that Ranunculus vaginatus has probably originated from the hybridization between R. sieboldii (6x) and an unknown allied tetraploid. It is probable that the members in the complex and its allied species became related through the genome called 'short m-type' (Plate 2) and thus a polyploid pillar complex formed.