毛竹伐蔸根系养分含量、抗氧化能力与伐后年数的关系

Annual Variation of Nutrient Stoichiometry and Resistance Physiology of Phyllostachys edulis Stump Roots

【目的】揭示毛竹伐蔸根系养分含量和抗氧化能力的年际变化规律,为毛竹林伐蔸促腐技术研究提供理论参考。【方法】以6年生活立竹的蔸根为对照,分析比较了笋材两用毛竹林伐后2 a、4 a、6 a的伐蔸根系C、N、P、丙二醛(MDA)、可溶性蛋白质含量和根系活力、抗氧化酶活性。【结果】表明随着毛竹立竹伐后年限的增加,伐蔸根系的细胞膜脂过氧化程度提高,渗透调节能力降低,根系活力明显降低,抗氧化能力逐渐下降。但毛竹立竹伐后,甚至伐后6 a时,伐蔸根系仍有较强的生理活性和生长更新能力,具有较高的C、N、P含量,尤其是C含量明显提高,主要养分化学计量比产生适应性调节,N/P相对稳定,C/N、C/P趋于升高。【结论】毛竹伐后6 a,蔸根仍具有较强的养分吸收能力,也能通过与竹鞭的联系从活立竹转运利用有机C,这是毛竹伐蔸难以腐解的重要机制。

To approach annual variation of nutrient content and antioxidant ability of Ph.edulis stump roots and pro-vide theoretical guidance for research on accretion decay technology,concentration of carbon （C）,nitrogen （N）, phosphorus （P）,malondialdehyde （MDA）,soluble protein and activities of antioxidative enzymes,and root vigor of stump roots from bamboo stumps after cutting 2a,4a,6a and 6-years living bamboo were determined.With the increasing of cutting years,cell osmotic adjustment ability decreased,and cell membrane lipid peroxidation of stump root increased,while the root vigor and resistance physiological activity reduced gradually.Physiological activity and ability of growth and regeneration for bamboo stump root was high even after cutting 6 years,concentrations of C, N,P were also high.Furthermore,C concentrations increased greatly after bamboo cutting.Main nutrient stoichi-ometry adjusted adaptively,and N/P remained stable while C/N and C/P tended to increase.Stump root was able to adsorb nutrients from soil,and obtained C from the living bamboo parts through the rhizomes,which may be the important mechanism of slow decaying of bamboo stumps.