横断山区伞形科4种7个居群植物的核型研究

Karyotypes of Seven Populations Belonging to Four Species of Umbelliferae in Hengduan Mountains

对横断山区伞形科棱子芹属2种植物(松潘棱子芹Pleurospermum franchetianumHemsl.和西藏棱子芹Pleurospermum hookeriC.B.Clarke var.thomsoniiC.B.Clarke)和茴芹属2种植物(异叶茴芹Pimpinella diversi-foliaDC.和锐叶茴芹Pimpinella argutaDiels)共7个居群进行体细胞染色体数目观察和核型比较分析,结果表明,棱子芹属和茴芹属植物属内种间染色体基数存在差异,其中松潘棱子芹为2n=2x=18=16sm+2st,西藏棱子芹为2n=2x=22=16m+6sm;茴芹属光果组中锐叶茴芹为2n=2x=22=22m,毛果组中异叶茴芹为2n=18=18st或2n=18=2sm+16st.松潘棱子芹、西藏棱子芹、锐叶茴芹的染色体数目和核型均为首次报道,从而为棱子芹属和茴芹属的分类和演化研究提供细胞学依据.

Chromosome numbers and karyotypes of seven populations, which were located in Hengduan Mountains belonging to two species of Pleurospermum Hoffm. , P. franchetianurn Hemsl. and P, hookeri C. B. Clarke var. thomsonii C. B. Clarke and two species of Pirnpinella L. , P. diversifolia DC. and P. arguta Diels in Umbelliferae were observed and comparatively examined. It was shown that there existed difference between the basic numbers of chromosomes of Pleurospermum and Pirnpinella, the karyotype formula of P. franchetianum is 2n=2x=18=16sm＋2st,and P. hookeri var. thomsonii is 2n=2x=22=16m＋6sm; the karyotype formula of P. arguta belonging to Sect. Tragoselinum of genus Pimpinella is 2n=2x=22= 22m,and P. diversifolia belonging to Sect. Tragium of genus Pirnpinella is 2n= 18= 18st or 2n= 18=2sm ＋ 16st. The chromosome numbers and karyotypes of P. franchetianum, P. hookeri C. B. Clark var. thomsonii C. B. Clark and Pimpinella arguta Diels were reported for the first time and this provided cytological basis for studying the classification and evolution of Pleurospermum and Pimpinella.