Screening siderophore producing bacteria as potential biological control agent for fungal rice pathogens in Thailand
Screening siderophore producing bacteria as potential biological control agent for fungal rice pathogens in Thailand
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DOI：
10.1007/s11274-009-0090-7
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发表时间：
2009-11-01
影响因子：
4.1
通讯作者：
Lumyong, Saisamorn
中科院分区：
文献类型：
--
作者：
Chaiharn, Mathurot;Chunhaleuchanon, Somporn;Lumyong, Saisamorn
水稻（Oryza sativa）是泰国的主食，此外，还养活了世界上大约一半的人口。因此，水稻的病害特别值得关注。稻瘟病和根腐病是水稻上的两种主要病原菌，尖孢镰刀菌和稻瘟病菌分别是水稻根腐病和稻瘟病的病原菌。这些病原体导致泰国和其他东南亚国家的粮食产量低。从泰国北方的稻田中采集土壤样品，并使用土壤稀释平板法在营养琼脂上分离细菌。分离得到216个细菌分离物，随后测试它们的铁载体产生和抑制水稻病原真菌（链格孢属，Alternaria sp.，尖孢镰刀菌（Fusarium oxysporum）、梨孢霉（Pyricularia pyramidum）和小核菌（Sclerotium sp.），水稻叶斑病、根腐病、稻瘟病和茎腐病的病原。结果表明，在固体平板培养基和液体培养基上，有23%的细菌产生铁载体。在双重培养技术中，产生铁载体的根际细菌对供试的链格孢菌（35.4%）、尖孢镰刀菌（37.5%）、梨孢霉（31.2%）和小核菌（10.4%）表现出较强的拮抗作用。其中链霉菌A130和假单胞菌MW2.6对链格孢菌表现出较强的拮抗作用，而人苍白杆菌D5.2对链格孢菌表现出较强的拮抗作用。尖孢菌属坚硬芽孢杆菌D 4.1对小核菌有抑制作用，嗜根库克菌4（2.1.1）对小核菌有较强的抑制作用。金色小核菌AR 1是最好的铁载体产生菌，分泌异羟肟酸型铁载体。该菌株表现出对链格孢属的体外拮抗作用，F. oxysporum和P.该分离物中铁载体的产量在15天后最大，最适温度为30 ℃，产生99.96 +/- 0.46 μ g ml（-1）铁载体。通过生化试验和分子生物学技术鉴定，最有效的菌株为芽孢杆菌属、假单胞菌属和库克菌属的成员，包括B。坚硬革兰氏菌D 4.1、金色假单胞菌AR 1和嗜根库克菌4（2.1.1）。该研究证明了对所讨论的目标病原体的拮抗活性，因此是泰国和其他国家的水稻土传病害生物防治的潜在药剂。
Rice (Oryza sativa) is a staple food in Thailand and, in addition, feeds around one half of the world's population. Therefore, diseases of rice are of special concern. Rice is destroyed by 2 main pathogens, Fusarium oxysporum and Pyricularia oryzae the causative agents of root rot and blast in rice respectively. These pathogens result in low grain yield in Thailand and other Southeast Asian countries. Soil samples were taken from paddy fields in Northern Thailand and bacteria were isolated using the soil dilution plate method on Nutrient agar. Isolation yielded 216 bacterial isolates which were subsequently tested for their siderophore production and effectiveness in inhibiting mycelial growth in vitro of the rice pathogenic fungi; Alternaria sp., Fusarium oxysporum, Pyricularia oryzae and Sclerotium sp., the causal agent of leaf spot, root rot, blast and stem rot in rice. It was found that 23% of the bacteria isolated produced siderophore on solid plating medium and liquid medium, In dual culture technique, the siderophore producing rhizobacteria showed a strong antagonistic effect against the Alternaria (35.4%), Fusarium oxysporum (37.5%), Pyricularia oryzae (31.2%) and Sclerotium sp. (10.4%) strains tested. Streptomyces sp. strain A 130 and Pseudomonas sp. strain MW 2.6 in particular showed a significant higher antagonistic effect against Alternaria sp. while Ochrobactrum anthropi D 5.2 exhibited a good antagonistic effect against F. oxysporum. Bacillus firmus D 4.1 inhibited P. oryzae and Kocuria rhizophila 4(2.1.1) strongly inhibited Sclerotium sp. P. aureofaciens AR 1 was the best siderophore producer overall and secreted hydroxamate type siderophore. This strain exhibits an in vitro antagonistic effect against Alternaria sp., F. oxysporum and P. oryzae. Siderophore production in this isolate was maximal after 15 days and at an optimal temperature of 30 degrees C, yielding 99.96 +/- 0.46 mu g ml(-1) of siderophore. The most effective isolates were identified by biochemical tests and molecular techniques as members of the Genus Bacillus, Pseudomonas and Kocuria including B. firmus D 4.1, P. aureofaciens AR1 and Kocuria rhizophila 4(2.1.1). The study demonstrated antagonistic activity towards the target pathogens discussed and are thus potential agents for biocontrol of soil borne diseases of rice in Thailand and other countries.