内生菌73a在不同抗性品种棉花体内的定殖和消长动态研究

STUDIES ON THE POPULATION FLUCTUATION OF ENTOPHYTIC BACTERIA 73a IN COTTON PLANT

通过标记天然不具有 Rif抗性的内生菌 73a,获得抗 Rif 10 0μg/ ml突变体菌株 ,其表观和对大丽轮枝菌的抑菌作用没有变化 ,可以进行消长动态研究。经回收试验证明 ,内生菌 73a可以在棉花体内定殖。针刺接种后 ,内生菌 73a的数量都表现一个共同的“由增到减”趋势 ,即在 1～ 5 d内是一个持续增长的过程 ,在第 5 d达到最高水平 ;灌根处理表明 :上段内的菌株数逐渐增加 ,中段内的菌株数在1～ 5 d内逐渐上升 ,随后慢慢下降 ,下段内的菌株数逐渐减少 ;浸种处理后 ,73a在棉苗体内定殖的数量均有一个下降的过程 ,其中常抗棉第 3d体内的内生菌数量是第 15 d的 11.5 0倍。

73a mutant of resistant Rif 100 μg/ml was acquired by continuously screening on series concentration of antibiotic substance Rif mediums. Compared with original strains, whose inhibition to verticillium dahliae and formation weren't changed. The recycling experiment showed that the entophytic bacteria 73a could live in the cotton plant and the population fluctuation of 73a was studied. After needle penetrating inoculation treatment, the population of the 73a had the same development trend in the different cultivars 'First increasing then decreasing', which was a increasing progress from the first day to the fifth day, after five day it decreases. With watering root treatment, the population of 73a slowly increased in the up part, first increased from the first day to the fifth day then decreased in the middle part, decreased in the button part. After dipping seed treatment, the population of 73a living in the cotton seedlings had a decreasing progress. The population of 73a in the third day was 1150% than that in the fifteenth day.