日本落叶松种子园种子产量及结实规律研究

STUDY ON SEED PRODUCTION AND FRUITING LAW OF SEED ORCHARD IN \%LARIX KAEMPFERI\% (LAMB.) CARR

根据辽宁省大孤家林场日本落叶松种子园种子产量和不同无性系结实习性等有关资料 ,对种子园不同年龄阶段生产率、结实规律等进行了系统分析。结果表明 ,用嫁接苗建立的日本落叶松初级种子园 ,1 6年前种子产量十分有限 ,年最高产种量仅 2 1 0kg/hm2 。园龄 2 2～ 2 6年生时大年种子产量虽可增加到 2 5 0 0kg/hm2 ,但这个年龄阶段的生产率仍然较低 ,仅 5 81kg/hm2 ·a。园龄 2 7～ 31年生时生产率才进一步提高到1 6 4 3kg/hm2 ·a。日本落叶松种子园大小年间种子产量变幅大 ,周期性明显 ,大年每隔 5～ 6年到来一次。种子产量与园龄、结实母株数量呈显著到极显著正相关 ,种子品质 (空粒率 )与园龄、结实母树数和种子产量呈显著的负相关。树高与球果产量的相关关系不显著 ,但大年球果产量与冠幅、胸径呈显著正相关。无性系间球果产量差异极为明显 ,结实前 3年和前 8年球果累计产量与各平年、大年和总产量间呈显著到极显著的正相关。丰产无性系早期选择可根据前 3年和前 8年球果产量分 2次进行。大小年产量相差悬殊。

Seed production, interval yielding and bearing habits of different clones were analysed systematically based on the data from 1973～1995 in the seed orchard of \%L. Kaempferi\% on Dagujia Forest Farm, Liaoning Province. The Primary seed orchard with 158 clones was established in 1965 coving an area of 14.7 hectares. The mother trees are taller due to failure to keep the height under well control. Seed collection started in 1973 though a few of trees flowered and beared in 1971. Up to the year of 1995, 1935. 58kg seed was harvested in total. Seed production was quiet low within 16 years since the orchard had been established, and the maximum yield was no more than 2.1?kg/hm\+2\5a. Seed yield increased to 25.0?kg/hm\+2 when the orchard was 25 years old, yet productivity still remained in low level (5.81kg/hm\+2\5a) during the orchard was 22～26\|year\|old. Interval yielding was obviously in the seed orchard of \%L. Kaempferi\% and aboundant year occured 5～6 year interval. There were significant to extremly significant positive correlation between seed yield and age of orchard, number of producing trees, but significant negative corretion was found between seed qulity(Percentage of empty seeds) and age of orchard, number of producing tree, seed production. Significant to extremely significant positive correlations were also found between crown diameter of mother trees and cone production in aboundant year, total cones produced in recently three years, but there was not any obvious correlation between the height of mother trees and cone yielded. Cone production differed obviously for different clones. Rank correlation analysis indicated that there was significant correlation between cone yield at the early and final stage. It is possible that the early selection of high\|yield clones of \%L.Kaempferi\% can be conducted according to the cone yield in the first three years, and five years later, final selection could be made according to cone yield in the first eight years. The main factors to lead low productivity of the Jepanese Larch Orchard are extremely difference of seed production on\|year and off year, a long interval period between on\|years, and less high\|yield clones.