江西南方红豆杉球果表型性状多样性分析

Phenotypic Diversity of Taxus wallichiana var. mairei Cones in Jiangxi,China

【目的】通过对南方红豆杉球果的表型多样性分析和综合评价,为其食用和观赏品种的选育提供理论基础。【方法】以采自江西的37份南方红豆杉为材料,对其球果和种子的长度、宽度和长宽比以及假种皮颜色等9个数量性状和5个描述性状进行观测,计算Shannon-Weaver指数,进行相关性、主成分和聚类分析,并进行综合评价。【结果】江西南方红豆杉球果的表型性状存在着丰富的变异,5个描述性状的多样性指数在0.494~1.876,其中球果形状的多样性指数最大,为1.876;8个数量性状的变异系数范围在7.49%~26.55%,变异程度由大到小依次为球果百粒质量(26.55%)、假种皮厚度(22.90%)、种子千粒质量(16.51%)、球果长(13.02%)、球果长宽比(12.56%)、种子长宽比(10.57%)、球果宽(10.39%)、种子宽(8.12%)、种子长(7.49%),其中种子长的变异系数最低,球果百粒质量的变异系数最高。相关性分析显示:球果长、球果宽、球果百粒质量、球果长宽比之间都存在极显著的正相关性(P<0.01),种子长和种子宽之间相关性不显著(P>0.05)。主成分分析显示:前4个主成分累计贡献率97.494%,能较好地反映出南方红豆杉球果的大部分性状。其中主成分1反映的是球果的大小,主成分2反映的是种子的宽度,主成分3反映的则是种子的质量。聚类分析结果显示:在欧式距离为10处,37份南方红豆杉球果被聚成4类。A类,包含11个单株,种子的表现较好;B类,包含13个单株,各表型表现均为中等;C类,包含6个单株,假种皮较厚,可食率较高;D类,包含7个单株,球果性状优良。【结论】江西南方红豆杉球果表型多样性丰富,具有较高的园林景观价值和极具开发潜力的食用价值。其中,JA-SC-O3单株综合评分最高,GZ-LN-02单株评分最低。

[Objective]Phenotypic diversity analysis and comprehensive evaluation of Taxus wallichiana var. mairei cones were carried out to provide a theoretical basis for the breeding of edible and ornamental varieties.[Method]By collecting cones of Taxus wallichiana var.mairei from Jiangxi,China,9 quantitative traits,such as the length,width and their ratios to the cone,the length,width and their ratio of the seed,aril color and thickness,and 5 descriptive characters,were observed and analyzed with the calculation of the Shannon-Weaver index.The correlation analysis and principal component analysis were also performed.[Results]The cone diversity of Taxus wallichiana var. mairei was rich with the diversity index between 0.494 and 1.876 and the coefficient of variation between 7.49% and 26.55%,the diversity index of cone shape was the largest,which was1.876.The order of the divers degrees of the characters was 100-seed weight of cones(26.55%),aril thickness(22.90%),1000-grain weight of seeds(16.51%),cone length(13.02%),cone aspect ratio(12.56%),seed aspect ratio(10.57%),cone width(10.39%),seed width(8.12%),and seed length(7.49%). The CV of seed length was the lowest,and the CV of 100-seed weight of cones was the highest.Moreover,the correlation among cone length,cone width,weight per 100 cones,and cone length-to-width ratio,was significantly positive(P<0.01),while the correlation between seed length and seed width was not notable(P>0.05).The principal component analysis showed that the cumulative contribution rate of the four principal components was 97.794%,which could reflect most characteristics of Taxus wallichiana var.mairei cones.And principal component 1 reflected the size of the cone,principal component 2 reflected the width of the seed,and principal component 3 reflected the weight of the seed.The cluster analysis showed that 37 samples of Taxus wallichiana var. mairei cones were clustered into four clusters based on the Euclidean distance of 10.Category A,contained 11 individual plants,and the seed performance was better;category B contained 13 individual plants,each with a moderate phenotypic performance;category C,contained 6 individual plants,which had thicker arils and a higher edible rate;category D contained 7 individual plants with excellent cone traits.[Conclusion]The phenotypic diversity of cones of Taxus wallichiana var.mairei in Jiangxi is rich and has high garden landscape value and edible value with great development potential.JA-SC-O3 has the highest score,and GZ-LN-02 has the lowest score.