Influence of growth on reproductive traits and its effect on fertility and gene diversity in a clonal seed orchard of Scots pine, Pinus Sylvestris L.

This study was carried out in a clonal seed orchard of scots pine (Pinus sylvestris L.), to determine the difference and interaction for reproductive and growth characters among clones and its impact on fertility variation and gene diversity. Numbers of female and male strobili, and height and diameter at breast height were studied on six grafts chosen randomly in each of the 27 clones for the purpose. One-way analysis of variance revealed large differences in both reproductive and growth characters among clones. The differences were higher in growth characters than in reproductive traits. There was significant phenotypic correlation among growth and reproductive characters. So, growth characters had a greater effect on male and female fertility. Estimates of total fertility variation (Sibling coefticient= 1.012), status number (26.8) and relative gene diversity (0.981) were computed. Fertility variation among clones was low, which caused a high relative population size (99% of census number). The positive phenotypic correlation between growth and reproductive characters showed that enhanced growth rate could be effective in improving fertility and gene diversity of seed orchard crop. The results of the study have implications in breeding and selection of plus tree and populations, establishment and thinning of seed orchards of the species.