中国山芹属的核型演化及地理分布的研究

A STUDY ON KARYOTYPES AND GEOGRAPHICAL DISTRIBUTION OF OSTERICUM (UMBELLIFERAE) IN CHINA

本文报道了山芹属Ostericum5种1变种13个居群的核型,其中4种为首次报道。其核型如下:隔山香O.citriodorum广东宝安的居群,2n=22=16m+6sm;江西鹰潭的居群,2n=22=14m+6sm+2st;华东山芹O.huadongensis本所药物园居群,2n=22=16m+6sm;安徽广德的居群,2n=22=16m+4sm+2sm(SAT);绿花山芹O.viridiflorum内蒙古额右旗的居群,2n=22=18m+4sm;黑龙江双鸭山居群,2n=22=18m+2sm+2st(SAT);山芹 O.sieboldii辽宁庄河居群,2n=22=4sm+16st+2st(SAT);吉林长白山居群,2n=22=2sm+20st;狭叶山芹O.sieboldii var.praetieritum辽宁鞍山的居群,2n=22=2sm+20st;大齿山芹O.grosseserratum辽宁庄河居群,2n=18=2sm+16st;江苏宜兴居群,2n=18=2sm+16st;安徽广德居群,2n=18=18st;浙江天目山居群,2n=18=18st。隔山香、华东山芹和绿花山芹具较原始的2A型,山芹和大齿山芹则具较为进化的4A型。此外,大齿山芹具有下行性的染色体基数n=9,这在整个前胡族中都具独特性。根据各居群在种分布区内的核型演化方向及现代地理分布格局并结合形态和孢粉学资料,提出本属的起源是从近缘的当归属起源地横断山区沿着东北和东南两个方向迁移扩散,演化发展形成两个现代次生分布中心,一个是东北向具温带性广布型的分布中心(东北地区)。

There are about 10 species of Ostericum in the world, of which seven are distributed in China. The present paper deals with the karyotypes of five species and one variety (covering 13 populations) within this genus. The karyotype formulae are as follows: O. cit-riodorum (Hance) Yuan & Shan 2n = 22= 16m+ 6sm (Baoan, Guangdong) and 2n = 22 = 14m+6sm + 2st( Yingtan, Jiangxi) ; O. huadongensis Z. H. Pan & X. H. Li 2n=22 = 16m + 6sm (Nanjing, Jiangsu, cultivated) and 2n = 22 = 16m + 4sm + 2sm (SAT) (Guangde, Anhui); O. viridiflorum (Turcz. ) Kitagawa 2n = 22 = 18m + 4sm (Ergun Youqi, Nei Mongol) and 2n = 22 = 18m + 2sm + 2st (SAT) (Shuangyashan, Heilongjiang) ; O. sieboldii (Miq.) Nakai 2n = 22 = 4sm + 16st + 2st ( SAT) (Zhuanghe, Liaoning) ; and 2n = 22 = 2sm + 20st (Changbaishan, Jilin) ; O. sieboldii var. praeteritum (Kitagawa) Huang 2n= 22 = 2sm+ 20st (Anshan, Liaoning) ; O. grosseserratum (Maxim. ) Kitagawa 2n = 18 = 2sm + 16st (Zhuanghe, Liaoning), 2n = 18 = 2sm + 16st ( Yixing, Jiangsu), 2n = 18 = 18st (Guangde, Anhui) and 2n= 18 = 18st (Tianmushan, Zhejiang) . The karyotypes of O. cit-riodorum, O. huadongensis and O. viridiflorum belong to 2A, while those of O. sieboldii and O. grosseserratum belong to 4A. Besides, O. grosseserratum has decreasing chromo- some number (n = 9), which is very unique in the tribe Peucedaneae.Based on the karyotypes and geographical distribution of the species, as well as gross morphology and pollen morphology, we considered that there might be two secondary diversity centres of Ostericum in NE and E China, which have developed and migrated from the Hengduanshan region, the origin and diversity center the of related genus——Angelica.