EFFECTIVE NUMBER AND SEED PRODUCTION IN A CLONAL SEED ORCHARD OF PINUS KORAIENSIS

摘要

Theory on the tradeoff between effective number and seed production was applied to a clonal seed orchard of Pinus koraiensis in Korea. By controlling maternal fertility, a balancing between equalizing maternal contribution and obtaining an acceptableamount of seed was achieved. Constrains on seed production was made on the maternal proportion as both lower and upper bounds. For maternal gametes in the seed orchard of P. koraiensis (180 clones), the effective number of parent (N_p) was estimated to 132.1 clones (73% of census number, N) based on the average observation of 9 years, For the level of clone, N_p was estimated to 66.8 clones (37 % of census number) if all seeds were collected and used. Higher effective number of parents could be obtainedby balancing the number of seeds collected per clone, but such increase of the effective number would result in substantial loss of seed production. If it was decided to truncate the seed production from 90% of census number and to collect the equal amount of seed from the best 10% clones, this increased the effective number from 132.1 to 143.7 and the loss of seed production would be 5.5%.