Induced soil suppressiveness to a root-knot nematode species by a nematicide
Induced soil suppressiveness to a root-knot nematode species by a nematicide
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DOI：
10.1006/bcon.2001.0961
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发表时间：
2001-10-01
影响因子：
4.2
通讯作者：
Kloepper, JW
中科院分区：
文献类型：
--
作者：
Fernández, C;Rodríguez-Kábana, R;Kloepper, JW
研究了杀线虫剂敌百虫对南方根结线虫的土壤抑制作用。为了确定敌百虫对土壤中对线虫具有拮抗作用的微生物的影响，在高压灭菌和非灭菌土壤中加入敌百虫，在处理后10、30和60天，将装有南方根结线虫卵的海藻酸盐筛埋在土壤中70h，取出，在24℃下培养5d，测定寄生虫卵和幼虫的百分比。在30天和60天时，灭菌处理的非灭菌土壤中寄生卵和幼虫的比例高于对照，而灭菌土壤中未观察到敌百虫的影响。为了进一步研究敌百虫对土壤微生物群落的影响，在番茄植株根际和土壤中加入敌百虫后，对土壤和根际中特定微生物种群的数量进行了量化。与对照相比，敌百虫处理30天和60天后，土壤和根际土壤中的几类微生物的种群水平都有不同程度的提高。还研究了微生物生理特性的变化，这些特性提高了线虫的生存能力或拮抗线虫；然而，狄氏菌的应用与任何一种特定生理特性的频率变化没有相关性。为了研究微生物群落的功能变化，测定了灭菌或未灭菌土壤中双乙酸酯荧光素水解酶、过氧化氢酶、壳聚糖酶、蛋白酶和脲酶的活性，以及灭菌后1、10和43d的土壤pH值和电导率。与对照相比，添加敌百虫的处理最早在1日龄就检测到了更高的酶活性。我们的结果表明，在土壤中应用敌百虫能够增强根结线虫的拮抗作用，这与根际细菌群落的结构和功能的变化有关。(C)2001年学术出版社。
Investigations were conducted to determine whether the nematicide DiTera, could induce soil suppressiveness to the root-knot nematode Meloidogyne incognita. To determine the effects of DiTera on soil microorganisms with antagonistic potential to nematodes, DiTera was added to autoclaved and nonautoclaved soils, and at 10, 30, and 60 days after treatment (DAT), alginate screens with M. incognita eggs were buried in the soil for 70 h, removed, and incubated at 24 degreesC for 5 days to determine percentages of parasitized eggs and juveniles. At 30 and 60 DAT, the nonautoclaved soil treated with DiTera had higher percentages of parasitized eggs and juveniles than did the control, whereas no effects of DiTera were observed in the autoclaved soil. To further investigate the effects of DiTera on soil microbial communities, populations of specific groups of microorganisms from the soil and rhizosphere of tomato plants were quantified after DiTera addition. An increase in the population level of several groups of microorganisms from the soil and rhizosphere after DiTera treatment was observed 30 and 60 DAT compared with the control. Changes in traits of microbial physiology that confer enhanced survival or antagonism toward nematodes were also investigated; however, the application of DiTera was not correlated with a change in frequency of any one specific physiological trait. To investigate functional changes of the microbial community, activities of several soil enzymes including fluorescein diacetate hydrolysis, catalase, chitobiase, protease, and urease were measured along with pH and electrical conductivity from autoclaved or nonautoclaved soil treated with DiTera at 0, 2.5, or 5.0 g/kg soil after 1, 10, or 43 DAT. More enzymatic activity was measured as early as 1 DAT in the treatments with DiTera compared with the control. Our results demonstrate that application of DiTera to soil led to enhanced antagonism of root-knot nematodes and that this was associated with structural and functional changes of the rhizosphere bacterial community. (C) 2001 Academic Press.