横断山及邻近地区八种菊科植物的染色体数目及核型

Karyotypes and Chromosome Numbers of Eight Species from the Family Asteraceae in the Hengduan Mountains and the Adjacent Regions

对横断山及邻近地区风毛菊属(Saussurea)、帚菊属(Pertya)和针苞菊属(Tricholepis)的8种菊科植物进行细胞学研究,其中异叶帚菊(Pertya berberidoides)(2n=2x=32=28m+4sm)、针苞菊(Tricholepis furcata)(2n=2x=32=16m+16sm)、中甸风毛菊(Saussurea dschungdienensis)(2n=2x=30=30m+Bs)、丽江风毛菊(S.likiangensis)(2n=2x=32=26m+6sm)、倒齿风毛菊(S.retroserrata)(2n=2x=32=14m+18sm)和显梗风毛菊(S.peduncularis)(2n=2x=36=26m+10sm)为首次报道染色体数目和核型,长毛风毛菊(S.hieracioides)和三角叶风毛菊(S.deltoidea)的核型公式分别为:2n=4x=64=30m+34sm和2n=2x=34=22m+12sm,与前人报道的一致。8种植物中,除中甸风毛菊和异叶帚菊的核型不对称性为1B型外,其余6种的核型不对称性均属于2B型;在中甸风毛菊中首次发现B染色体。结合现有的细胞学资料分析表明,风毛菊属和帚菊木族的染色体数目存在变异,并且存在明显的非整倍性;此外,分布于横断山区的风毛菊属植物仅有两种倍性(二倍体和四倍体),而且多倍化并不占主导地位。

Chromosome numbers and karyotypes of 8 species of Saussurea, Pertya and Tricholepis from Hengduan Mountains with neighborhood were studied. The chromosome numbers and karyotype were reported firstly for Pertya berberidoides （ 2n = 2x = 32 = 28m＋4sm） , Tricholepis furcate （ 2n = 2x = 32 = 16m＋ 16sm）, Saussurea dschungdienen- s/s （2n=2x=30 = 30m＋Bs）, S. likiangensis （2n = 2x = 32 = 26m＋6sm）, S. retroserrata （2n = 2x = 32 = 14m＋ 18sm）, and S. peduncularis （2n = 2x = 36 = 26m ＋ 10sin ）. The chromosome numbers and ploidy of S. hieracioides with 2n = 4x = 64 = 30m＋34sm and S. dehoidea with 2n = 2x = 34 = 22m＋ 12sm are consistent with previously report. All species have type 2B karyotype asymmetry, except for Saussurea dschungdienensis and Pertya berberidoides hav- ing type 1B. B chromosome was first discovered in Saussurea dschungdienensis. The results showed that the genus Saussurea and the tribe Mutisieae have a wide range of chromosome numbers and obvious aneuploidy. In addition,only diploid and tetraploid were found in Saussurea from Hengduan Mountains, and polyploidization might have played a minor role in the chromosomal evolution of the Saussurea in the Hengduan Mountains.