生物有机肥对香蕉枯萎病及根系分泌物的影响

摘要

生物有机肥通过调节微生物群落多样性来改善土壤生态环境，而根际微生物生态环境变化取决于根系分泌物的种类和数量。研究通过盆栽试验和离位溶液培养法研究了生物有机肥对香蕉枯萎病及香蕉根系分泌物的影响。结果表明，生物有机肥对香蕉枯萎病的防病效果高于有机肥和不施肥处理，生物有机肥和有机肥防病效果分别达到55.4%和28.5%；香蕉根系分泌物中低分子量有机酸包括草酸、苹果酸和反丁烯二酸，以草酸为主，ρ(草酸)占ρ(有机酸总量)的百分比为83.6%~93.0%；生物有机肥比有机肥更显著降低香蕉根系分泌物中ρ(苹果酸)、ρ(反丁烯二酸)和ρ(有机酸总量)，不同处理处理根系分泌物的ρ(有机酸)依次为：有机肥＞生物有机肥＞不施肥；生物有机肥处理的氨基酸种类和质量浓度最大，有机肥次之，生物有机肥处理中根系分泌物的ρ(γ-氨基丁酸)、ρ(β-丙氨酸)、ρ(a-氨基丁酸)、ρ(谷氨酸)、ρ(天冬氨酸)和ρ(磷酸丝氨酸)均显著高于有机肥和不施肥处理；生物有机肥处理的主要氨基酸[各氨基酸质量浓度占ρ(氨基酸总量)的百分比大于5%]有磷酸丝氨酸、苏氨酸、γ-氨基丁酸、乙醇氨和肌肽，其中ρ(磷酸丝氨酸)和ρ(γ-氨基丁酸)显著高于不施肥和有机肥处理；香蕉枯萎病病情指数与ρ(磷酸丝氨酸)、ρ(丝氨酸)、ρ(异亮氨酸)呈显著负相关，相关系数分别为-0.99、-0.98和-0.95，与ρ(鹅肌肽)呈极显著正相关，相关系数为1.00。生物有机肥降低了根系分泌物中有机酸的质量浓度，增加了氨基酸的种类和质量浓度，且香蕉枯萎病病情指数与根系分泌物中一些氨基酸质量浓度存在显著相关性，这可能是生物有机肥在香蕉枯萎病防治中起作用的原因之一。%Bio-organic fertilizer may be improving soil ecological environment through adjusted community diversity, but the changes of rhizosphere micro-ecology environment depends on the amount and type of root exudates. The influence of bio-organic fertilizer on banana fusarium wilt and root exudates were studied by using in vitro bathing root system under the condition of pot experiment. The results showed that the control effect of banana fusarium wilt by using bio-organic fertilizer were better than organic fertilizer and control treatments,control effect of bio-organic fertilizer and organic fertilizer on banana wilt disease were 55.4%and 28.5%respectively. Oxalic acid, malic acid and fumaric acid were found in organic acid, and organic acid content was dominating of oxalic acid in banana root exudates,the content of oxalic acid was 83.6%-93.0% of organic acid content. In contrast to organic fertilizer treatments, bio-organic fertilizer would reduce malic acid, fumaric acid and organic acid amount in banana root exudates markedly. Organic acids content of different treatment in banana root exudates was:organic fertilizer>bio-organic fertilizer>no fertilizer. The kind and total of amino acid are the most in biological organic fertilizer treatments, followed by the organic fertilizer, and g-ABA, b-Ala, a-ABA, Glu, Asp and P-Ser content in root exudates of biological organic fertilizer treatments are significantly higher than organic fertilizer and no fertilization. Main amino acids (The content of various acids were more than 5%total of amino acid) of biological organic fertilizer treatments have P-Ser, Thr, g-ABA, EOHNH2 and Car, in which P-Ser and g-ABA are significantly higher than organic fertilizer and no fertilization. The index of banana wilt disease was significantly negative correlation with P-Ser, Ser and Ile, the correlation coefficients are-0.99,-0.98 and-0.95 respectively. but it significantly positive correlation with Ans,the correlation coefficients is 1.00. Organic acid amount in banana root exudates was decreased, the kind and total of amino acid were increased by using biological organic fertilizer, and the index of banana wilt disease was significant correlation with some amino acid in banana root exudates, which maybe play very important roles in controlling the banana wilt.