浙江扇脉杓兰野生居群的表型性状变异及其与地理-土壤养分因子的相关性

为揭示扇脉杓兰(Cypripedium japonicum Thunb.)表型性状的变异规律,以浙江临安6个野生居群(老殿、宝剑石、红蛇洞、清凉峰、大明山和里横塘)为研究对象,分析了叶片、萼片、子房及唇瓣等18个表型性状的变异幅度,并讨论了表型性状变异与地理-土壤养分因子间的相关性以及居群间和居群内的表型多样性.结果显示:6个居群18个表型性状(地径、下叶长、下叶宽、下叶长/宽比、上叶长、上叶宽、上叶长/宽比、中萼片长、中萼片宽、苞片长、苞片宽、子房长、花梗直径、花梗长、唇瓣长、唇瓣宽、植株展度和株高)测量值的F值为1.240 ～ 18.666,除花梗直径和株高外,其他16个性状均有极显著差异.各性状的变异系数为5.937％ ～ 26.349％,其中,唇瓣长的平均变异系数最小(6.119％)、苞片宽的平均变异系数最大(24.124％)；居群间各性状的变异系数为8.139％～ 13.663％,平均变异系数为11.143％,其中,里横塘居群的平均变异系数最大、宝剑石居群的最小.各性状的多样性指数平均为1.977,其中地径的多样性指数最大(2.045)、苞片宽的最小(1.663).通过UPGMA聚类分析,可将6个居群划分为3组:清凉峰、大明山、老殿和宝剑石居群为1组；红蛇洞和里横塘居群分别各自成组,其中清凉峰和大明山居群的遗传距离最近.各表型性状间存在显著或极显著的相关关系；但仅地径与速效钾含量显著正相关(r=0.854),子房长、唇瓣长和宽与土壤全磷含量显著正相关(r值分别为0.916、0.854和0.914),植株展度与土壤pH显著正相关(r=0.810),其余性状与地理因子(包括经度、纬度和海拔)及土壤养分因子均无显著相关性.研究结果表明:扇脉杓兰野生居群表型性状存在丰富的变异和多样性,且与生境土壤中速效钾及全磷含量及土壤pH有关.

Variation of phenotypic traits of wild populations of Cypripedium japonicum in Zhejiang Province and its correlation with geographical-soil nutrient factors

To reveal variation regulation of phenotypic traits of Cypripedium japonicum Thunb.,taking 6 wild populations(Laodian,Baojianshi,Hongshedong,Qingliangfeng,Damingshan and Lihengtang) in Lin’an of Zhejiang Province as research objects,variation range of 18 phenotypic traits of leaf,sepal,ovary and labellum was analyzed,and its correlation with geographical-soil nutrient factors and morphological diversity among or within populations were discussed.The results show that F values of 18 phenotypic traits(including ground diameter,length and width and ratio of length to width of lower leaf,length and width and ratio of length to width of upper leaf,length and width of middle sepal,length and width of bract,ovary length,diameter and length of pedicel,length and width of labellum,plant exhibition degree and plant height) are 1.240-18.666 among six populations,there are extremely significant differences among sixteen traits except of pedicel diameter and plant height.Coefficients of variation(CV) of all traits are 5.937%-26.349%,in which,average value of CV of labellum length is the smallest(6.119%) and that of bract width is the biggest(24.124%).And CV values of all traits among populations are 8.139%-13.663% with an average CV value of 11.143%,in which,average value of CV of Lihengtang population is the biggest and that of Baojianshi population is the smallest.The average of diversity index of all traits is 1.977,in which,diversity index of ground diameter is the highest(2.045) and that of bract width is the lowest(1.663).According to UPGMA cluster analysis result,six populations can be classified into three groups,one group includes populations of Qingliangfeng,Damingshan,Laodian and Baojianshi,other two groups are Hongshedong and Lihengtang,respectively.In which,genetic distance between populations of Qingliangfeng and Damingshan is the closest.There are significant or highly significant correlations among different traits.But only ground diameter has a significant positive correlation with available potassium content in soil(r=0.854),ovary length and length and width of labellum have significant positive correlations with total phosphorus content in soil(r=0.916,0.854 and 0.914) and plant exhibition degree has a significant positive correlation with pH in soil(r=0.810),while other traits have no significant correlations with geographical factors(longitude,latitude and altitude) and soil nutrient factors.It is suggested that there are rich variation and diversity of phenotypic traits among C.japonicum populations,which relates to contents of available potassium and total phosphorus and pH in habitat soil.