铝胁迫下栝楼根系分泌物对根际土壤微生态的影响

Effect of root exudates on rhizosphere soil micro ecological changes of Trichosanthes kirilowii Maxim. under aluminum stress

为阐明栝楼自身缓解铝胁迫的过程,探寻其避免化感自毒现象的方法,以安国栝楼(耐铝型)和浦江栝楼(铝敏感型)为材料,以7,14和21 d为周期,用不同浓度的铝和外源根系分泌物进行实验处理,共分9组,对栝楼根际土壤的速效养分、酶活性及微生物进行了分析.实验结果表明:低、中浓度的栝楼根系分泌物增加了2个品种栝楼根际土壤中速效钾、碱解氮和速效磷的含量,增强了根际土壤中磷酸酶、蔗糖酶和过氧化氢酶的活性,增加了土壤中细菌、放线菌和真菌的数量;高浓度的栝楼根系分泌物会抑制土壤微生态的发展;中等浓度根系分泌物对栝楼根际土壤微生态的处理效果最佳.

In order to clarify the process of aluminum stress relief, seek methods to avoid allelopathic autotox-icity, it was taken the Trichosanthes kirilowii of Anguo （A 1 resistance genotype） and Pujiang （A1 sensitive genotype） as experimental materialB, 7, 14 and 21 days as different cycle, and divided into 9 groups, experi-mented with different A1 concentration and root exudates concentration, analysis of Trichosanthes kirilowii soil nutrients, soil enzyme activity and soil microorganism were made. Experimental results showed that： low con-centrations of root exudates （30 and 20 mL） increased the content of soil available K, alkaline hydrolysis ni-trogen ,available phosphorus, enhanced the activity of soil catalase, invertase, phosphatase, raised the num- ber of bacteria, actinomycetes and fungi of 2 varieties of Trichosanthes kirilowii, and high concentration of root exudates （10 mL） inhibited the soil micro ecological development, the optimal concentration of root exudates to alleviate Trichosanthes kirilowii was 20 mL.