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经过严格的表面消毒后发现,棉花的种子、幼苗和胚中均含有大量的内生细菌。幼苗的根含量高达10~5个/每克鲜重,幼苗的叶含量次之,为10~4个/每克鲜重,种子和幼胚中含量较少,约10~3个/每克鲜重。从分离到的大量内生细菌中筛选出2株假单胞菌(Pesudomonas spp.)B_2和L_(29)。在平板条件下,它们对棉花炭疽病菌(Colletotrichum gossypii)和立枯病菌(Rhizoctonia solani)表现出很强的颉颃作用。完全抑制生长时间(生长抑制率为100％时的时间):L_(29)为96和40小时,B_2为96和32小时。在无菌土的接种试验中,B_2和L_(29)均能显著降低由棉花炭疽病菌引起的死苗率。B_2处理的死苗率比对照降低31.3％,L_(29)降低27.4％。在自然病土的接种试验中,B_2和L_(29)的拌土和拌种处理均对苗病有抑制作用,B_2拌种处理的死苗率为对照的59.5％,L_(29)拌土处理为对照的30.1％。
After a rigorous surface disinfection and found that cotton seeds, seedlings and embryos contain a large number of endophytic bacteria. The root content of seedlings is as high as 10 to 5 per gram of fresh weight, followed by the leaf content of seedlings of 10 to 4 per gram fresh weight, less in seeds and immature embryos, about 10 to 3 per gram Fresh weight. Two isolates of Pseudomonas (Pesudomonas spp.) B_2 and L_ (29) were screened from a large number of isolated endophytic bacteria. Under plate conditions, they show a strong antagonistic effect against Colletotrichum gossypii and Rhizoctonia solani. Complete inhibition of growth time (growth inhibition rate of 100% of the time): L_ (29) for 96 and 40 hours, B_2 for 96 and 32 hours. In the inoculation test of sterile soil, B_2 and L_ (29) could significantly reduce the rate of dead seedlings caused by the pathogen of cotton anthracnose. The dead seedling rate of B_2 treatment decreased by 31.3% and that of L_ (29) decreased by 27.4%. In the inoculation experiment of natural soil, B 2 and L 29 mixed seedling and seed dressing treatments all inhibited seedling disease, the seedling emergence rate of B 2 seed dressing treatment was 59.5% of the control, L 29 mixed soil The treatment was 30.1% of the control.