宜昌市72份野生中华猕猴桃果实性状多样性分析与综合评价

Analysis and comprehensive evaluation of fruit trait diversity of 72 Actinidia chinensis accessions in Yichang

【目的】猕猴桃具有很高的营养价值和经济价值,随着产业的发展,开发具有区域适应性的地方品种尤为重要。通过对湖北省宜昌市野生猕猴桃果实表型性状多样性研究,为地方优良资源挖掘及新品种选育提供基础。【方法】以从湖北省宜昌市收集的72份野生中华猕猴桃果实为材料,对单果质量、果实纵径、果实横径、果形指数、可溶性固形物含量、干物质含量以及果实形状、果肉颜色等20个表型性状进行测量或记录,利用统计软件分析其遗传多样性,基于数量性状进行聚类分析和主成分分析,通过种质资源主成分得分进行综合评价,依据排名筛选出优异种质。【结果】72份野生中华猕猴桃种质果实的各个性状均具有丰富的遗传变异。14个质量性状的遗传多样性指数(H’)变幅为0.25(果心颜色)~1.36(果实形状)之间,变异系数(coefficient of variation,CV)介于11.79%(果心颜色)~71.15%(果实形状)之间;6个数量性状的遗传多样性指数变幅为1.84(单果质量)~2.02(果形指数),变异系数介于14.68%(果实横径)~42.22%(单果质量)之间。聚类分析在欧式距离为15处将供试种质划分为4个组,组内具有相似特征,组间具有显著差异。部分数量性状间具有显著的相关性,主成分分析和综合评价结果表明,前3个主成分累积贡献率为94.643%,各种质的综合得分范围为-1.72~2.17。其中,YC36、YC66、YC08、YC07、YC69、YC18、YC67和YC68共8份种质的综合得分大于1,可作为优异野生育种资源加以利用。【结论】宜昌72份野生中华猕猴桃种质资源的果实表型遗传多样性指数高,变异系数大,具有丰富的遗传多样性;筛选出8份综合性状表现优良的种质,为培育地方品种提供了理论基础和材料支撑。

【Objective】Kiwifruit has high nutritional and economic values. Actinidia has 75 species or variants, most of which are found only in China. Actinidia chinensis(including A. chinensis var. chinensis and A. chinensis var. deliciosa) is currently the most important domesticated species, with more than one hundred cultivars. These cultivars are mostly from the wild resources. China’s abundant wild Actinidia resources have greatly contributed to the development of the world kiwifruit industry. Hayward, the most widely grown cultivar in the world, comes from the wild resources in Yichang, Hubei Province,and has spawned more than 20 related varieties. In recent years, there has been a lack of information about wild kiwifruit germplasm resources in Yichang. We collected in Yichang 72 wild A. chinensis.Through the study of trait diversity, excellent varieties can be screened.【Methods】The 72 wild A. chinensis fruits collected from Yichang, Hubei province were used as the materials. A total of 14 qualitative traits including fruit shape, fruit shoulder shape, head shape, beak shape, surface hairiness, calyx ring, sepals persistence, degree of lenticel protrusion, cross section shape of fruit center, flesh color,flesh center color, fruit flavor, degree of soft rot during storage were described. Fruit weight, longitudinal and transverse diameters, fruit shape index, soluble solid content and dry matter content were determined. Statistical software was used to analyze genetic diversity and carry out cluster analysis and principal component analysis based on quantitative traits, and comprehensive evaluation was conducted based on principal component score, and the excellent accessions was screened out according to ranking.【Results】The 72 wild A. chinensis fruits had abundant genetic variation in each trait. The genetic diversity index(H’) of the 14 qualitative traits ranged from 0.25(flesh center color) to 1.36(fruit shape), and the coefficient of variation(CV) ranged from 11.79%(flesh center color) to 71.15%(fruit shape). The genetic diversity index of the six quantitative traits ranged from 1.84(fruit weight) to 2.02(fruit shape index), and the coefficient of variation ranged from 14.68%(fruit diameter) to 42.22%(fruit weight). Cluster analysis divided the accessions into 4 groups at 15 Euclidean distance. Group Ⅰconsisted of 15 accessions, and the content of soluble solid and dry matter were significantly higher than those of the other groups, while the fruit diameter was significantly smaller than that of the other groups. The soluble solid and dry matter contents in group Ⅱ, which consisted of 29 accessions, were significantly lower than those of the other groups. Group Ⅲ was composed of 11 accessions and the fruit shape index in this group was significantly higher than in the other groups, and the longitudinal diameter of fruit was the largest. Group Ⅳ included 17 accessions and their single fruit weight and fruit transverse diameter were significantly higher than those in the other groups. The results of principal component analysis and comprehensive evaluation showed that the accumulative contribution rate of the first three principal components was 94.643%;the characteristic value of the first principal component was 2.704, and the contribution rate was 45.070%, which was mainly determined by the higher characteristic vector value of single fruit weight, fruit longitudinal diameter and fruit transverse diameter. The characteristic value of the second principal component was 1.587, and the contribution rate was26.450%, which was mainly determined by the characteristic vector value of soluble solid content and dry matter content. The characteristic value of the third principal component was 1.387 and the contribution rate was 23.123%, which was mainly determined by the fruit shape index. The comprehensive scores of the accessions ranged from-1.72 to 2.17, and YC36, YC66, YC08, YC07, YC69, YC18,YC67 and YC68 had comprehensive scores greater than 1, which could be used as excellent wild breeding materials.【Conclusion】The 72 wild kiwifruit accessions in Yichang have high phenotypic diversity index, high coefficient of variation and rich genetic diversity. Eight of them with excellent comprehensive characters were screened for breeding of local varieties.