苦瓜种质资源遗传多样性分析及抗枯萎病种质筛选

【目的】分析江西地方苦瓜种质农艺性状的遗传多样性，为苦瓜抗枯萎病品种选育及遗传改良提供参考。【方法】 2018—2020年分别在江西不同地点开展苦瓜表型性状和枯萎病抗性鉴定，分析其遗传多样性，并对其进行聚类分析和相关分析，筛选出商品性佳且抗枯萎病种质。【结果】多年多地表型性状和病害的综合鉴定表明，55份苦瓜种质表型性状具有丰富的变异，遗传多样性指数（H'）的变幅为0.091~2.122，其中第一雌花节位的H'最高，商品瓜横径和商品瓜纵径的H'次之。聚类分析将供试种质资源分成四大类群，第I类群种质早熟且综合农艺性状优异，可用于苦瓜品种早熟、高产改良；第II类群多为江西地方古老种质；第III类群瓜形美观，符合江西省消费习惯，可用作改良苦瓜商品性的亲本材料；第Ⅳ类群多为野生型苦瓜，果实较小，可用作观赏和提取功能性物质。在16个表型性状中，除瓜面光泽外，其他性状间均存在显著（P<0.05）或极显著（P<0.01，下同）相关，其中单瓜重与瓜横径和瓜纵径均呈极显著强相关，说明提高苦瓜产量可从改良瓜横径等性状着手。主成分分析结果表明，5个主成分因子对表型变异累积方差贡献率达77.544%。枯萎病抗性试验鉴定出高抗材料4份，抗病材料18份，中抗材料5份，感病材料10份，以及高感材料18份。【结论】江西地方苦瓜种质资源具有丰富的遗传多样性，育种潜力巨大，可将单瓜重、瓜纵横径、肉厚和瓜瘤大小等性状作为产量性状进行改良，以第一雌花节位和雌花数作为早熟性状进行筛选。

Genetic diversity analysis and Fusarium wilt resistance screening of bitter gourd germplasm resources

【Objective】To analyze genetic diversity of agronomic characters of bitter gourd germplasm in Jiangxi Province,so as to provide reference for the breeding and genetic improvement of bitter gourd varieties resistant to Fusarium wilt.【Method】From 2018 to 2020,identification of bitter gourd phenotypic traits and Fusarium wilt resistance was carried out in different places of Jiangxi province to analyze genetic diversity,conduct cluster and relationship analysis,so as to screen quality bitter gourd germplasm resources resisted to Fusarium wilt.【Result】 According to the results of comprehensive identification of phenotypic traits and diseases,the phenotypic traits of 55 bitter gourd germplasms had rich variations,with the genetic diversity index of 0.091-2.122 under different environmental conditions,and the diversity index of first female flower node was the highest,followed by that of fruit diameter and length. Germplasm resources were divided into four groups in the cluster analysis:group I,with great agronomic properties,early maturity,could be applied to improve varieties of early maturity and higher production;group II originated in Jiangxi province;group III,a good shape,was widely accepted by local customers,which could be used as parent material for improvement;and group Ⅳ were wild bitter gourd with small fruits which could be used for sight seeing and extracting functional substances. The correlation analysis showed that besides fruit gloss,significant correlation(P<0.05)or extremely significant correlation(P<0.01,the same below)existed among the 16 agronomic traits,among which weight per melon was significantly positively correlated to fruit diameter,fruit length,indicating that the yield could be improved by increasing the fruit diameter. The principal component analysis showed that the cumulative contribution rate of the five principal component factors was 77.544%. Four high resistance(HR),18 resistance(R),5 middle resistance(MR), 10 susceptibility(S)and 18 high sensitivity(HS)varieties were identified through Fusarium wilt resistance test.【Conclusion】The local ancient varieties of balsam pear in Jiangxi Province have rich genetic diversity and great breeding potential. Single melon weight, melon vertical and horizontal diameter, flesh thickness and melon tumor size can be improved as yield traits, and the node position of the first female flower and the number of female flowers can be screened as early maturing traits.