Evaluation on Female Flower Fertilization and Fruit Setting of 43 Litchi (Litchi chinensis Sonn.) Germplasm Resources

【Objective】The present study is to know the number of female flowers per panicle, fertilization and fruit setting characteristics of different litchi germplasm resources in order to provide references for utilization of Litchi germplasm resources and variety breeding.【Methods】43 litchi germplasm resources from the National Germplasm – Guangzhou Litchi Nursery were used to investigate the differences in their biological traits such as number of female flowers per panicle, fertilization rate and weekly fruit setting rate in 2018.【Results】There were differences in the same traits for different litchi germplasm. The number of female flowers per panicle varied from 449.33 in‘Feizixiao’to 69 in ‘Cuixiangli’. The highest and lowest fertilization rates were found in‘Chenzi’(60.20%) and ‘Feizixiao’(11.63%) respectively. The highest and lowest final fruit setting rates were found in ‘Zengbu Zaoheiye’ (26.06%) and ‘Ziniangxi’ (1.03%), respectively. All the materials under test were divided into three main groups through clustering analysis. There were seven germplasms in Group Ⅰ , with high fruit setting rate; There were ten germplasms in Group Ⅱ , with low fruit setting rate; and there were twenty-six germplasms in Group III, with the value of fruit setting rate was between that of Group Ⅰ and Group Ⅱ . The dynamic change on fruit setting rate of each group was consistent with the final fruit setting rate.【Conclusion】 A significant negative correlation existed between the number of female flowers per panicle and the fertilization rate.The degree of fruit abscission within one month after flowering had the greatest impact on the final fruit setting. The fertilization and fruit setting characteristics of the above varieties will provide a reliable basis for the management of litchi flowers and the parental selection in cross breeding.