摘花和打顶措施对毛竹林下多花黄精块茎生物量积累特征的影响

【目的】摘花可减少毛竹林下多花黄精养分在生殖生长上的消耗,打顶能去除顶端生长优势。研究摘花和打顶措施对多花黄精地下块茎生长促进的影响,可为毛竹林下多花黄精高效复合经营提供参考。【方法】以毛竹林下种植3年的多花黄精为对象,研究了打顶、摘花及摘花打顶处理的多花黄精1年生、多年生块茎及根系生物量积累与分配特征,并分析其异速生长关系。【结果】与对照相比,打顶、摘花及摘花打顶处理的多花黄精1年生块茎生物量及其分配比例显著提高,而多年生块茎生物量分配比例显著下降。其中,摘花处理1年生块茎生物量及其分配比例略高于打顶,均显著低于摘花打顶处理。打顶、摘花及摘花打顶处理的多花黄精多年生块茎-总生物量异速生长指数虽仅略有升高,但1年生块茎-总生物量异速生长指数则显著增加,且均以摘花打顶处理的异速生长指数最大。【结论】摘花和打顶措施通过调控多花黄精的源-库关系,实现光合碳同化物与养分的定向输运与分配,能显著提高多花黄精1年生块茎生物量、增长速率与分配比例,其中以摘花打顶措施增产效果最好,可以在生产中应用。

Responses of tuber biomass accumulation and its allometry to topping and flower plucking measures of Polygonatum cyrtonema grown under Phyllostachys edulis forests

【Objective】 The compound management of bamboo forests is regarded as an efficient, intensive and ecological land management pattern of bamboo forest management. Polygonatum cyrtonema grown under Phyllostachys edulis(moso bamboo) forest is one of the typical patterns of the compound management of bamboo forests. Topping and flower plucking can reduce nutrient demands for the reproductive growth or weaken apical dominance of Polygonatum cyrtonema, and can also promote transportation and allocation of nutrients and carbon assimilation to tubers. The study of the effects of topping and flower plucking on the growth of tubers will provide a theoretical guidance for the compound management of forests with Phylpstachys edulis and Polygonatum cyrtonema. 【Method】 Biomass of annual and perennial tubers and root from 3-year-old Polygonatum cyrtonema grown under Phyllostachys edulis were determined. The biomass accumulation, allocation and allometric growth of annual and perennial tubers and root biomass were also analyzed. 【Result】 Compared to the control(CK), biomass of annual tubers and its allocation in plants treated with topping, flower plucking, and combination of flower plucking and topping increased significantly;however, biomass allocation to perennial tubers decreased considerably. Furthermore, biomass of annual tubers and its allocation in plants treated with flower plucking were slightly higher than those treated with topping;however, those treated with the combination of both treatments were evidently higher than those treated with flower plucking or topping. The allometric growth index for perennial tubers-total tubers biomass of plants treated with topping, flower plucking, and combination of flower plucking and topping increased slightly, but those for the annual tubers-total tubers biomass of topping, flower plucking, and combination of topping and flower plucking increased significantly. The allometric growth index for tubers-total tuber biomass of flower plucking and topping was the highest among all the four treatments. 【Conclusion】 Topping and flower plucking regulated the growth polarity and source-sink relationship and induced the directional transportation and allocation of carbon assimilation and nutrients. The biomass of annual tubers, its allocation and the allometric growth rate of flower plucking and topping treatment increased significantly, which is thus a suitable approach to promote the tuber growth for the compound management of forests with Phyllostachys edulis and Polygonatum cyrtonema.