铜绿假单胞菌与长枝木霉对杂交竹梢枯病的协同增效生防研究
Synergistic biocontrol mechanism of Pseudomonas aeruginosa and Trichoderma longibrachiatum on Arthrinium phaeospermum
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摘要: 铜绿假单胞菌和长枝木霉均对杂交竹梢枯病菌具有明显的拮抗作用。通过室内抗生素、紫外诱变和杀菌剂胁迫培养,获得铜绿假单胞菌和长枝木霉突变菌株,此突变体在形态特征、平板抑菌活性上与原始菌株差异不显著,且具有长期稳定的抗药性。田间喷施突变菌株菌悬液或孢子悬液可以使其成功定殖到杂交竹叶表面。铜绿假单胞菌和长枝木霉的亲和性研究显示,二者浓度低于108 cfu/mL,均无明显抑制作用,具有高度亲和性,这有利于2菌株在杂交竹梢枯病生物防治中协同作用的发挥。利用铜绿假单胞菌悬液和长枝木霉孢悬液进行梢枯病菌田间协同防治试验,结果表明:预先接种拮抗菌防效最高,其次是同时接种,后施拮抗菌防效最低,说明铜绿假单胞菌和长枝木霉均有良好的防病作用。另外,2菌株的联合使用在3种处理中防效均最优,尤其是在先接种病原菌的处理中,协同防效得到很大提高,说明二者联合使用有良好的梢枯病治理作用。Abstract: Pseudomonas aeruginosa and Trichoderma longibrachiatum can effectively antagonize Arthrinium phaeospermum. With the antibiotics and UV mutagenesis-germicide stresses cultivation, the mutation strains of P. aeruginosa and T. longibrachiatum were obtained. The differences were insignificant between mutant and the original strain in the morphological characteristics and the antibacterial activity, and mutants had long-term stable resistance. After spraying bacterial or spore suspensions in the field, the mutation strains could colonize rapidly on hybrid bamboo leaves. The affinity of P. aeruginosa and T. longibrachiatum indicated that both did not have significant inhibition but high affinity with the concentration under 108 cfu/mL, which was beneficial for two strains to generate the synergistic effects in the biological control of hybrid bamboo blight. The bacterial suspensions of P. aeruginosa and spore suspensions of T. longibrachiatum were used for the synergistic field test of biological control. The results showed that the antagonistic effects with pre-inoculation were best, then worse with simultaneous inoculation, and worst with post-inoculation, indicating that both P. aeruginosa and T. longibrachiatum had good control effects against hybrid bamboo blight. Moreover, the control effect of jointed utilization of two strains was best in three treatments; especially in the treatment of pre-inoculation, the effect had been vastly improved, which revealed that the jointed utilization of two strains had quite ideal antagonistic effect on hybrid bamboo blight.