Mating system and progeny genetic diversity of Camellia oleifera ‘Ruan Zhi’

Abstract

Camellia oleifera Abel. is an important economic tree species of southern China. In this study, we evaluated the mating system and genetic diversity of a series of cultivars of C. oleifera ‘Ruan Zhi’. A total of 159 individuals from the progenies of four cultivars were tested by simple sequence repeat molecular markers. Results reveal that 11 pairs of primers showed polymorphism and their polymorphism information content value was greater than 0.73, suggesting that these primers could be used to identify the genetic diversity of open-pollinated populations. The average number of effective alleles (Ne = 4.88) was significantly different from the average number of alleles (Na = 12.18), and their distribution in the sample population was not uniform. The average observed heterozygosity (Ho = 0.96) was greater than the average expected heterozygosity (He = 0.79), and the population heterozygote was excessive. Shannon index was 1.84 and populations showed high genetic diversity. As regards to the mating system, the multilocus outcrossing rate was 0.996, and the single locus 0.866. These results indicate a high degree of outcrossing by C. oleifera ‘Ruan Zhi’. We recommend selecting individuals for high genetic gain from the progenies of cultivars because of outcrossing characteristics and genetic diversity for application to germplasm conservation and promotion.