Objective   The segregation and genetic variations on the traits of branches and leaves of F1 litchi hybrid population were examined for parent selection in cross breeding. Methods Ten branch and leaf characteristics, such as length of compound leaf and areas of petiole and leaves, of 258 F1 hybrids of Litchi chinensis Sonn. between Sanyuehong (♀) and Ziniangxi (♂) were examined. The amplitude, distribution frequency, coefficient of variation, and general heritability of the traits were determined and classified.

  Results   The coefficients of variation on the 10 quantified phenotypic characteristics ranged from 9.23% to 15.67% with an average of 12.37%. Among the traits, leaf area had the highest coefficient at 15.67% followed by length of compound leaf at 13.93%, and the lowest, leaf length at 9.23%. All measured indices were normally distributed. The average spindle length, leaf length, leaf width, fresh weight, dry weight, leaf area, and specific leaf weight of compound leaves were higher than those of the parents, while the average petiole length, leaf shape index, and branch bark rate lower than those of the parents. It indicated that the gene recombination could, to some degree, give a non-additive effect leading to the emergence of F1 hybrids with traits surpassed those of the parents. The averaged general heritability on all traits was 0.45, with petiole length being the greatest at 0.87 and leaf shape index at 0.75. The greatest extremely high parentage rate at 99.22% was observed on leaf width, while the lowest of low parentage rate on petiole length that accounted for 86.82% of the F1 population.

  Conclusion   The branch and leaf traits of litchi F1 hybrids varied widely. Some of the characteristics were easily affected by the environment.