不同育苗方式及种粒大小对擎天树苗木生长的影响

[目的]研究不同育苗方式及种粒大小对擎天树苗木生长的影响,为选择优质擎天树苗木、加强育苗技术管理、提高苗木产量、质量和大面积造林提供参考依据.[方法]采用营养袋和苗床直播两种方式对不同粒级的种子进行育苗对比试验,测定和比较苗木的生长量及生物量指标,根据苗高与地径生长因子对苗木进行分级.[结果]营养袋苗的平均苗高、地径及叶片数分别比田间苗床的直播苗提高12.0%、22.0%和11.5%,各项根形态指标均大于田间苗床的直播苗;营养袋苗的平均侧根数量达25.5条,比田间苗床的直播苗增加了63.5%;平均侧根数、地下部分干重及根冠比指标在两种育苗方式间的差异均达到显著水平,营养袋苗的地下部分干重及根冠比显著大于苗床直播苗;大粒、中粒种子苗木的苗高、地径和叶片数的生长与小粒种子苗木相比均达到极显著差异,而大粒与中粒种子苗木的各项生长指标之间则差异不显著.[结论]营养袋育苗的擎天树生长量和苗木质量明显高于田间苗床的直播育苗,有利于苗木的高径生长和根系生长;生产上应选用大、中粒种子进行育苗,以提高苗木的产量和质量.

Effects of different seedling-raising methods and seed sizes on the nursery stock growth of Parashorea chinensis

【Objective】This paper aimed to explore the effects of different seedling-raising methods and seed sizes on the nursery stock growth of Parashorea chinensis to provide references for selecting high quality seedlings， strength seedling-raising management， increase yield and quality， and provide large scale afforestation of Parashorea chinensis. 【Method】Two types of seeding with different seed sizes， the nutritive bag seeding and field sowings seedling， were used to raise the seedlings and to compare the seedlings growth and biomass of Parashorea chinensis. The seedlings were graded based on the main growth of height and basal diameter factors. 【Result】There were significant differences between the two different seedling-raising methods. The average seedling height，basal diameter，and numbers of leaves per plant under the nutritive bags seeding treatment increased by 12.0， 22.0， and 11.5% respectively in comparison with the results from the field sowing seedlings treatment. The root morphological indexes of nutritive bag seedlings were greater than that of the field sowing seedlings. The average numbers of lateral roots in nutritive bag seedlings reached up to 22.5 per plant and increased by 63.5% in comparison with those measured in the field sowing seedlings. The average number of lateral roots， the dry weight of underground growth part， and the ratio of root-to-shoot were significantly different between the seedling-raising methods. There were significant differences between large seed vs. small seed and between middle seed vs. small seed in the seedling height， basal diameter， and the number of leaves， but there were no significant differences detected between large seed and middle seed in all the growth indexes. 【Conclusion】The nutritive bag seedling method was better than the field sowing seedling method； therefore， the nutritive bag seedling method improved the seedling height， diameter growth， and root system development. Raising seedlings with the nutritive bag would be the more appropriate measure for cultivating high quality seedlings and should be promoted in relevant production industries. Large seeds and middle seeds of Parashorea chinensis should be used for seedling production to improve seedling yield and quality.