金怡猕猴桃实生后代雄株花性状变异分析

Variation analysis of flower traits in male lines of Jinyi kiwifruit seedling progeny

[目的]分析金怡猕猴桃实生后代雄株花性状变异程度,为有效利用金怡猕猴桃雄株资源提供理论指导。[方法]金怡猕猴桃是湖北省农业科学院果树茶叶研究所选育的中华猕猴桃(Actinidia chinensis Planch.var.chinensis)品种。以金怡猕猴桃实生后代120份雄株资源为试验材料,统计雄花花药数、单花药花粉量、花粉萌发率,并分析其变异特点。[结果]雄株花药数、单花药花粉量和花粉萌发率分布区间分别为31.50~99.40个、6.08万~19.17万粒·花药-1、1.00%~86.24%,变异系数分别为18.21%、22.63%、64.17%;3个性状均符合正态分布规律;经主成分分析,第一主成分中萌发率特征向量值最大,贡献率为43.16%。雄花性状综合表现较好的为JY-402、JY-275、JY-212、JY-403、JY-260。[结论]金怡猕猴桃实生后代雄株花性状变异丰富,为猕猴桃雄株选育提供了丰富的资源。JY-402、JY-275、JY-212、JY-403、JY-260可以作为中华猕猴桃优良授粉雄株的候选资源,其中JY-402综合性状最佳,可重点关注。

【Objective】Kiwifruit is a dioecious and self-sterile plant,requiring an appropriate number of male plants or artificial pollination for effective fertilization.Insufficient pollination will result in re-duced seed numbers,low endogenous hormone levels,and ultimately,smaller or deformed fruit.Identi-fying superior male plants with high pollen yield and viability can enhance pollination efficiency,lower production costs,and improve fruit quality.However,there has been limited reports on the varieties of male kiwifruit plants.This study aimed to screen male plants with desirable traits from 120 progeny of Jinyi kiwifruit seedlings in order to provide valuable resources for breeding new male variety.【Meth-ods】The experiment was conducted in April 2022 at the kiwifruit breeding orchard of Shen Shan Xing Nong Science and Technology Co.,Ltd.,Chibi City,Hubei Province.The experimental materials con-sisted of 120 four-year-old male seedlings of Jinyi.Traits such as the number of anthers per male flow-er,pollen quantity per anther,and pollen germination rate were measured.In addition,analyses of varia-tion patterns,outliers,distribution characteristics,and principal components were performed.【Results】The analysis revealed that the average number of anthers per flower,pollen quantity(10000 grains)per anther,and pollen germination rate(%)were 45.60±8.30,10.30±2.33,and 34.66±22.24,respectively.The median values were 44.10,10.04,and 33.72,and the modes were 44.60,10.17,and 70.53,with dis-tribution ranges of 31.50-99.40,6.08×10000 grains-19.17×10000 grains,and 1.00%-86.24%,respec-tively.The coefficients of variation for these traits exceeded 18%,with the highest variation observed in the pollen germination rate(64.17%),indicating substantial variation within the sample population.The maximum-to-minimum ratios for these traits were greatest for pollen germination rate(86.24 times),fol-lowed by the number of anthers(3.16 times)and pollen quantity(3.15 times).The outlier analysis iden-tified JY-334 and JY-250 as mild high outliers in anther number,JY-402 and JY-130 as mild high outli-ers in pollen quantity,and JY-329 as an extreme outlier in anther number.No outliers were observed in the pollen germination rate.After excluding outliers,the distribution analysis showed that the median anther number was 43.80,predominantly ranging from 36.00 to 54.00(82.50%of samples).The medi-an pollen quantity was 99800 grains,mainly between 70000 and 130000 grains(80.83%of samples).The median pollen germination rate was 33.72%,with the majority of samples(65.83%)distributed be-tween 10.00%and 60.00%.The skewness(Sk)and kurtosis(Su)values for anther number,pollen quanti-ty,and pollen germination rate were 0.514,0.406,and 0.417(Sk),and 0.085,-0.28,and-0.74(Su),re-spectively.Frequency distribution plots indicated a continuous distribution of these traits,with a larger number of intermediate plants,fitting a normal distribution pattern.The principal component analysis indicated that the eigenvector value of the pollen germination rate was the largest,and the contribution rate was 43.16%.Based on the comprehensive evaluations,the male plants JY-402,JY-275,JY-212,JY-403,and JY-260 had superior male flower traits.【Conclusion】Significant variation was observed in the male flower traits from seedlings of Jinyin.JY-402,JY-275,JY-212,JY-403,and JY-260 were identified as potential candidates for use in breeding programs,and JY-402 showed the best overall performance.