为了为落叶松叶枯病的防治提供一条高度可行的研究途径,从中国8个省的13个采样点收集了健康的落叶松枝叶。利用筛选得到的拮抗内生细菌对盆栽幼苗进行病害防治试验。对拮抗细菌进行安全性评价试验。随后,通过形态学和分子方法鉴定出预防效果好、安全性高的菌株。从健康落叶松枝叶中分离出内生细菌391株。通过初筛获得了78株具有拮抗作用的落叶松内生细菌。通过二次筛分进一步获得10株具有明显拮抗作用的内生细菌,抑制率均超过57%。其中,菌株YN2,JL6,NMG23和JL54的抑制率最高,为63.16%-65.08%,这与其他治疗方法明显不同。盆栽试验结果表明,接种病原菌14天后,菌株YN2和JL54对落叶松叶枯病的控制更有效,预防效果达到57.7%和50.0%,分别。菌株JL6和JL54在安全性评价试验中具有生物学安全性。因此,选择菌株JL54进行鉴定。通过形态学观察鉴定为解淀粉芽孢杆菌,16SrDNA序列,gyrB基因序列和16SrDNA-gyrB串联特征序列分析。
目的:落叶松叶枯病是一种分布广泛、破坏性,林木真菌病迅速蔓延,对落叶松人工林构成严重威胁。内生细菌对寄主植物具有抗病虫害的生物学效应,它们对植物有促进生长的作用。在本文中,通过筛选具有拮抗枯萎真菌功能的内生细菌,首次研究了内生细菌对落叶松枯萎病的生防效果。解淀粉芽孢杆菌JL54对落叶松枝枯病的生物防治具有较好的前景,这为该细菌的未来应用奠定了基础。
In order to provide a highly feasible research pathway for the control of larch shoot blight, healthy larch branches and leaves were collected from 13 sampling sites in 8 provinces in China. The antagonistic endophytic bacteria obtained from the screening were used to carry out disease control experiments in potted seedlings. The safety evaluation test was conducted on the antagonistic bacteria. Subsequently, the strains with better preventive effect and high safety were identified by morphological and molecular methods. A total of 391 strains of endophytic bacteria were isolated from healthy larch branches and leaves. Seventy-eight strains of larch endophytic bacteria with antagonistic effect were obtained by primary sieving. Ten strains of endophytic bacteria with obvious
antagonism were further obtained by secondary sieving, and all of them had an inhibition rate of more than 57%. Among them, strains YN 2, JL 6, NMG 23, and JL 54 showed the highest inhibition rate of 63.16%-65.08%, which was significantly different from the other treatments. The results of the pot test showed that 14 days after inoculation with the pathogen, strains YN 2 and JL 54 were more effective in the control of larch shoot blight, with the preventive effects reaching 57.7% and 50.0%, respectively. Strains JL 6 and JL 54 were biologically safe in the safety evaluation test. Therefore, strain JL 54 was selected for identification. It was identified as Bacillus amyloliquefaciens through morphological observation, 16S rDNA sequence, gyrB gene sequence and 16S rDNA-gyrB tandem feature sequence analysis.
OBJECTIVE: Larch shoot blight is a widely distributed, damaging, and rapidly spreading fungal disease of forest trees that poses a serious threat to larch plantations. Endophytic bacteria have biological effects on host plants against pests and diseases, and they have a growth-promoting effect on plants. In this paper, we investigated for the first time the biocontrol effect of endophytic bacteria on larch shoot blight by screening endophytic bacteria with the function of antagonizing dieback fungi. Bacillus amyloliquefaciens JL 54 has a better prospect of biocontrol against larch shoot blight, which lays the foundation for the application of this bacterium in the future.