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10余年来对滇西和滇中的云南松天然优良林分疏伐营建母树林及遗传增益的研究结果表明 :疏伐是优良林分营建母树林的重要技术措施。改建 16年生左右的云南松天然优良林分为母树林 ,以选择 0 3 (郁闭度 )疏伐强度为好 ,母树林经 2次疏伐后即可定型 ,其疏伐间隔期不超过 4年。 1993~ 1995年 ,母树林平均单株结球果达 6 0个 ,每公顷结 10 32 9个 ,结实株率达 95 6 5 % ,分别是对照的 5 0 8倍、 1 2 6倍和 1 15倍。母树的结实性状较为稳定 ,单株结实量的频率分布呈对数正态分布 ,一般以 4年为 1个结实周期。云南松天然优良林分和母树林子代均具有干型通直、木纹理扭转度小、生长量大的特点。云南松诸性状间较多地受基因连锁或共效基因的作用 ,而受环境的影响相对较小 ,大多数性状具有较高的遗传稳定性。在云南松种子的调拨中应注意不同种源的适生区域。云南松优良林分和母树林子代林 6~ 10年生的树高、胸 (地 )径、材积和木纹理扭转度的遗传增益分别为 5 74%~ 2 0 14%、 8 6 1%~ 40 46 %、 2 7 88%~ 10 7 11%和 17 42 %~ 5 9 79%
More than 10 years of Yunnan yunnan in Yunnan and natural stands thinning construction of the parent tree and genetic gain of the results showed that: thinning is an excellent stand construction of the parent forest important technical measures. The 16-year-old natural Pinus yunnanensis reforestation was divided into the parent tree forest. The thinning intensity of 0 3 (canopy density) was good, and the parent tree forest could be shaped after 2 times of thinning. The thinning interval was no more than 4 year. From 1993 to 1995, the average number of single fruit per plant reached 60, with 10 32 9 plants per hectare and 95 6 5% of firm plants, respectively, which were respectively 508, 126 and 1 15 times. The robust traits of mother trees were more stable, and the frequency distribution of per plant weight showed a lognormal distribution, usually 4 years as a sturdy cycle. Natural Pinus yunnanensis stands and female parent tree offspring have a dry through straight, wood texture twist is small, the growth of large features. Most of the characters of Pinus yunnanensis were affected by gene linkage or gene silencing, but were less affected by the environment, and most of the traits had higher genetic stability. In the allocation of Yunnan pine seeds should pay attention to different provenances suitable area. The genetic gains of tree height, chest (ground) diameter, volume and twist of wood texture were respectively 5 74% ~ 2 0 14% and 8 6 1% ~ 6% 40 46%, 2 7 88% ~ 10 7 11% and 17 42% ~ 5 9 79%