共查询到20条相似文献，搜索用时 109 毫秒
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以湖南省洪江市马尾松二代种子园设计方案为例。对种子园园址选择，种子园区划，无性系配置，建园步骤以及种子园管理等全过程进行了阐述，为建立马尾松二代种子园提供了具体方法，具有操作性。 相似文献
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利用同工酶标记对广西覃塘林场马尾松无性系种子园及其附近一人工林的亲子代群体遗传结构进行研究。研究结果表明，不论是种子园还是附近人工林均表现为：亲代群体处于遗传平衡状态，杂合体相对过量，但子代已偏离遗传平衡，杂合体相对不足，亲子代的基因频率变化不大。种子园亲代群体的遗传多样性略高于子代，而附近人工林的亲代群体遗传多样性略低于子代。本文研究的种子园具有较宽的遗传基础，该种子园附近人工林的遗传多样性与种子园接近，但不论是人工林本身还是它的子代其多样性平均水平都较种子园的亲代和子代略低。 相似文献
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杉木种子园施肥效果研究 总被引：2，自引：1，他引：1
本文根据四年来成年杉木种子园施肥，评价了种子园的施肥效果，并筛选出肥料配比，施肥量，施肥次数及时间，对提高成年杉木种子园产量具有指导意义。 相似文献
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樟子松种子园花期观察研究初报李树春，盛佩卿，高峰（吉林省永吉县林木种子园１３２２００）吉林省永吉县林木种子园，樟子松１９９０年开始有少量植株开花结实，到１９９３年结实株数达９５％。为了解和研究樟子松无性系种子园花期规律，对搜集区的部分无性系进行了３年... 相似文献
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浙江长乐杉木种子园，始建于1976年，目前已建成初级种子园514亩，一代种子园136亩，本文对该种子园的建园技术路线，主要经营技术和改良效果作了较系统深入的研究，资料分析表明，杉木资源较少的浙江地区，大量收集杉木中心产区的优树材料建立种子园，其后代增益十分明显，7．5年生子代林平均材积比当地对照增长30％以上，研究还表明，气象因子特别是2－3月份的降水量和日照时数，以及亲本来源，土壤状况和坡向等是影响种子园种子产量和质量的重要原因。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):377-381
Genetic gain and diversity were estimated based on three simulated thinning scenarios at various thinning intensities in a breeding seed orchard of Quercus acutissima. The seed orchard was composed of 32 families with 744 individual trees with volume at age 15. The three thinning scenarios were individual thinning (IT) which thinning was based on the individual performance, family thinning (FT) with the removal of inferior families regardless of individual performance, and family + within family thinning (FWF) with family first and then individual from inferior families. The genetic gain was estimated based on stem volume. Expected genetic gain (volume at age 15) under IT was higher than FT and FWF at all thinning intensities. The FWF provided higher genetic gain than FT but lower than IT. The FT gave the lowest genetic gain compared to the other thinning scenarios at all thinning intensities. The loss of gene diversity (GD), estimated by coancestry and family size, was higher under FWF and lower under FT at moderate thinning intensities. The study showed that genetic gain estimation and GD loss were inversely coupled. The IT gave highest genetic gain but lowest GD at the highest thinning intensity. 相似文献
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为探索思茅松种子园保留密度对生长量和球果产量的特性,对7年生相同家系的思茅松种子园开展5种不同疏伐强度(疏伐强度25%、疏伐强度30%、疏伐强度45%、疏伐强度50%和不疏伐)的疏伐试验,观测试验前、2年后的生长量(树高、胸径、冠幅)和球果数,计算出相应的增长量,对增长量进行方差分析。结果表明:5种不同疏伐强度2年后树高、胸径、冠幅和球果数增长量最大的处理均是疏伐强度为50%的处理,树高增长量次之的处理是疏伐强度为25%的处理,胸径、冠幅和球果数增长量次之的均是疏伐强度为42%的处理。树高、胸径、冠幅和球果数增长量小的处理均是对照CK。5种不同疏伐强度的树高增长量差异不显著,胸径、冠幅和球果数增长量差异均显著。该差异可作为思茅松种子园郁闭期保留密度依据之一。 相似文献
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福建柏初级种子园营建及管理技术研究 总被引：4，自引：1，他引：3
总结了福建省尤溪国有林场福建柏初级种子园的营建和管理技术措施,并对福建柏初级种子园营建效果进行了分析,结果表明种子园产种量平均为10.93 kg.a-1.hm-2,效果比较明显,最后根据福建柏树种的特性,提出了福建柏初级种子园营建和管理的要点。 相似文献
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采用约束变换区组设计，借助计算机对种子园进行高产模式配置设计，营建生产性嫁接种子园，模拟预测结果表明：接株３年生进入结实期后，高产配置比一般配置，每年每公顷可增产种子６５．０５％，球果败育率降低２．５７％，子代高生长增加３．３５％；生产性种子园应考虑配置系统疏伐模式，第一次疏伐在接株５年生时进行，第二次疏伐在７年生时进行。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1-4):513-520
The proportion of background pollen grains in the seed crops of two Pinus sylvestris seed orchards in Central Finland was estimated with the aid of multilocus allozyme markers. The orchards studied were more than 30 years old and in full pollen production. For the bulked seed crops of the seed orchard with southern clones the estimated average of background pollination over four years was 26%. There were statistically significant differences between years. No significant heterogeneity in the degree of background pollination between clones was found. Among single ramets there was significant heterogeneity in the estimated contamination rates, but the variation was not related to position in the orchard. For the seed orchard with northern clones the bulked seed crop was studied only for one year and the level of background pollination was found to be 33 %. These estimates are fairly high, but lower than for many other orchards. Background pollination at this level will cause losses in expected genetic gains. Part of the seeds from northern orchards will not be adapted to the intended area of use. 相似文献