作 者 ：何 斐1,张忠良2,刘列平3,崔 鸣4,5,薛泉宏6*
期 刊 ：西北植物学报 2015年 2期 页码：364~372
Keywords:Amorphophallus konjac, soil microecology, microflora, acacia forest,
摘 要 ：通过对刺槐林和农田魔芋健株根区、根表及根外土壤微生物区系及养分含量比较,探索刺槐林魔芋健康高产的土壤微生态机制。结果表明:(1)刺槐林魔芋根外和根表土壤细菌数量分别较农田增加11.8%和588.9%,根区土壤真菌数量较农田显著减少74.4%。(2)刺槐林魔芋根区、根表及根外土壤中的有益优势微生物数量及其比例远高于农田魔芋,有害微生物数量远低于农田魔芋;在刺槐林魔芋根区、根表及根外土壤中,3种优势细菌为放射型根瘤菌(Rhizobium radiobacter)、苏云金芽孢杆菌(Bacillus thuringiensis)及摩氏假单胞菌(Pseudomonas mosselii),其中,根表土壤中放射型根瘤菌及苏云金芽孢杆菌数量分别为农田的25.7倍及13.0倍;2种优势真菌为黒附球菌(Epicoccum nigrum)和疣孢青霉(Penicillium verruculosum),1种优势放线菌为绿淀粉酶链霉菌(Streptomyces viridodiastaticus),其中刺槐林魔芋根表和根外土壤中黒附球菌数量分别较农田高159.2%和120.3%;大量存在于刺槐林下魔芋根外土壤中的疣孢青霉、以及根区、根表、根外土壤中的绿淀粉酶链霉菌在农田魔芋相应部位均未检出。(3)刺槐林下魔芋根外、根区土壤有机质含量分别较农田显著增加167.6%、39.6%,但速效P、K含量较农田分别显著降低85.6%～91.3%、12.4%～13.0%。研究认为,刺槐林魔芋健康高产与其根区、根表及根外土壤中特有的有益优势微生物数量多、有害微生物数量少以及土壤有机质含量高密切相关。
Abstract:The aim of this research is to explore the microecological mechanism of healthy growth and higher yield of Amorphophallus konjac under acacia forest.The content of soil nutrition was measured by normal method.Dilution method was used to measure the number of bacteria(B),fungi(F) and actinomycetes(A) in the bulk,rhizosphere and rhizoplane soils of A.konjac under acacia forest and in the farmland.Dominant microorganisms were identified by molecular techniques.The results indicated that:(1)The number of bacteria in the bulk and rhizoplane soils of A.konjac under acacia forest markedly increased by 11.8% and 588.9%,while the quantity of fungi in the rhizosphere soil significantly decreased by 74.4% compared with A.konjac in the farmland(P<0.05).(2)The quantity and percent of beneficial microorganisms in the bulk,rhizosphere and rhizoplane soils of A.konjac under acacia forest were much higher than that of plants in the farmland,while the quantity and percent of harmful microorganisms were far lower than that of A.konjac in the farmland.In the bulk,rhizosphere and rhizoplane soils of A.konjac under acacia forest,three strains were dominant species,which included Rhizobium radiobacter,Bacillus thuringiensis and Pseudomonas mosselii.In the rhizoplane soil,the quantity of Rhizobium radiobacter and Bacillus thuringiensis were 25.7 and 13.0 times as many as the number of plants in the farmland.In addition,two fungi(Epicoccum nigrum and Penicillium verruculosum) and one actinomycete Streptomyces viridodiastaticus also were dominant microorganisms.And the quantity of dominant fungi Epicoccum nigrum in the rhizoplane and bulk soils of A.konjac under acacia forest were increased by 159.2% and 120.3% compared with the control group,respectively;while dominant species Penicillium verruculosum and Streptomyces viridodiastaticus were not detected in the corresponding soils of A.konjac in the farmland.Among which,Penicillium verruculosum was occurring widely in the bulk soil,and S.viridodiastaticus was abound in the bulk,rhizosphere and rhizoplane soils of A.konjac under acacia forest.(3)Significant difference was observed in the nutrition content of soils under acacia forest and the control group.The content of organic matter in the bulk and rhizosphere soils of A.konjac under acacia forest markedly increased by 167.6% and 39.6%,while available P and K significantly decreased by 85.6% to 91.3% and 12.4% to 13.0%.It was suggested that healthy growth and higher yield of A.konjac under acacia forest was closely related to more certain beneficial dominant microorganisms and less harmful microbes in the bulk,rhizosphere and rhizoplane soils of A.konjac under acacia forest,as well as higher organic matter content.