| 308 bacteria strains were isolated from different tissues of Hami melon collected from Xinjiang regions. Results indicated that population of endophytic bacteria ranged from3.15×103 to 2.01×105CFU per gram of fresh weight although it might vary depending on variety ,tissue and region of the plant. Population of the endophytic bacteria were biggest in seed; secondly in root;thirdly in leaf and smallest in stem ,petiole and fruit.Of the strains isolated, 28.17% expressed antagonism against growth of Pseuodomonas syringae pv. lachrymans; 7.14% expressed antagonism against growth of Acidovoras avenae subsp.23.41% and 25.79% expressed antagonism against growth of Fusarium oxysporum f. sp. Vasinfectum and Phytophthora capsici. Of them,P38 strain and B167 strain are stronger inhibitory strains in test. Isolated strains were preliminarily classified as Bacillus spp., Xanthomonas spp., Pseudomonas spp.,Erwinia spp.,Staphylococcus spp.and Sphingomonas,Flavimonas,Paenibacillus. Among these eight genera, isolates of Bacillus were the dominant endophytic bacteria in Hami melon plants. Testing of signature sequences of 16SrDNA,P38 strain may be belonging to the Paenibacillus polymyxa. Colonizing dynamics of the two strains,P38 and B167,in Hami melon were analyzed with the label of drug resistant. The result showed that the two strains could be colonized in Hami melon by dipping seeds. It is confirmed that the both strains were endophytes in Hami melon. P38 could transfer in it and promote growth to Hami melon apparently. With the time developing, the bacterium decreased in roots gradually,but increased in stems and leaves,and then decreased. Differently, B167 only colonized in roots and restrained growth. Biocontrol funtion of P38 to Acidovoras avenae subsp. was tested by water-cultured Hami melon seedling. The result showed that relative prevention effect is 37.5%. The heat stability of metabolic substances from P38,B167 and B35 are well. |
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