湖南6种毛莨科植物的核型研究

本文对产于湖南的６种毛莨科植物的染色体进行了研究。裂叶星果草［Ａｓｔｅｒｏｐｙｒｕｍｃａｖａｌｅｒｉｅｉ（Ｌｅｖｌ．ｅｔＶａｎｔ）Ｄｒｕｍｍ．ｅｔＨｕｔｃｈ．）的染色体属于Ｒ型，核型公式为２ｎ＝１６＝１２ｍ＋２ｓｍ＋２ｔ，核型类型属于ＺＢ；打破碗花花（ＡｎｅｍｏｎｅｈｕｐｅｈｎｓｉｓＬｅｍ．）的核型公式为２ｎ＝１６＝１０ｍ＋４ｓｔ＋２ｔ（２ｓａｔ），核型类型属于２Ａ；粗齿铁线莲［Ｃｌｅｍａｔｉｓａｐｉｉｆｏｌｉａｖａｒ．ａｒｇｅｎｔｉｌｕｃｉｄａ（Ｌｅｖｌ．ｅｔＶａｎｔ）Ｗ．Ｔ．Ｗａｎｇ］的核型公式为２ｎ＝１６＝１０ｍ＋２ｓｔ＋４ｔ（２ｓａｔ）或２ｎ＝１６＝１０ｍ＋２ｓｔ＋４ｔ（４ｓａｔ）随体染色体数目在居群之间有变化，核型类型属于２Ａ；扬子铁线莲［Ｃｌｅｍａｔｉｓｇａｎｉｐｉｎｉａｎａ（Ｌｅｖｌ．ｅｔＶａｎｔ）Ｔａｍｕｒａ］的核型公式为２ｎ＝１６＝１０ｍ＋２ｓｔ＋４ｔ（４ｓａｔ），核型类型属于２Ｂ；毛莨（ＲａｎｕｎｃｕｌｕｓｃａｎｔｏｎｉｅｎｓｉｓＤＣ．）的核型公式为２ｎ＝１６＝６ｍ＋４ｓｔ＋６ｓｔ（２ｓａｔ），核型类型属于３Ａ；毛莨（ＲａｎｕｎｃｕｌｕｓｊａｐｏｎｉｃｕｓＴｈｕｎｂ．）的核型公式为２ｎ＝?

A KARYOTYPIC STUDY OF SIX SPECIES IN THE RANUNCULACEAE FROM HUNAN, C CHINA

Investigated in this work were karyotypes of nine samples of six species of four genera in the Ranunculaceae from Hunan Province, C China. The Ikaryotypes were formulated as follows: .2n=16-12m+2sm+2t for Asteropyrum covaleriei,with the chomosomes being fairly large and belonging to Ranunculus-type, andkaryotype asymmetry belonging to 2B: 2n=16=10m+4st+2t (2sat ) for Anemone hupehensis, with karyotype asymmetry belonging to 2A: 2n=16=10m+2st+4t (2sat ) inone sample and 2n=16=10m+2st+4t (4sat) in the other for Clematis apiifolia varargentilucida, with karytype asymmetry both belonging to 2A: 2n=16=10m+2st+4t(4sat ) for Clematis ganipiniana, with karyotype asymmetry belonging to 2B; 2n=16=6m+4sm+6st (2sat ) for Ronunculus cantoniensis and 2n=14=6m+4sm+4st I (2sat )for Ranunculus japonicus, with their karyotype asymmetry belonging to 3A and 3Brespectively. The chromosome numbers and karyotypes of Asteropyrum cavaleriei,Clematis apiifolia var. argentilucida and C. ganipiniana were reported here for thefirst time. In addition, pollen grains of Asteropyrum covaleriei were investigatedunder scanning electron microscope for the first time. They are pantoporate, withspinulate exine surface. As a result of this and previous studies, the systematicPosition of Asteropyrum and the phylogenetic relatiomship between its only two taxa,A. cavalerfei and A. peltatum were emphatically discussed. We consider that Asteropyrmu, with Rauunculus-type chromosomes, should be a member of the subfam.Helleboroideae, and that A. cavaleriei, with karyotype of 2B type and pantoporatepollen grains, might be phylogenetically more advanced than A. peltatum, which haskaryotype of 2A type and pantocolpate pollen grains. We also point out the factthat intermediate individuals between the two taxa are found to occur in the SWSichuan abed NE Yunnan, where the two taxa overlap in distribution, might suggestthat they be better treated as two subspecies rather than two separate species, butmore studies are needed to justify this point.