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【目的】从生菜根际土中筛选出2株具有多种生物学特性、促生和生防效果的芽孢杆菌。【方法】土样经过80°C高温处理,得到2株细菌。通过形态学、生理生化、16S rRNA和gyr B基因鉴定菌株。对其溶磷、合成IAA和嗜铁素能力及对植物病原真菌的拮抗作用进行测定。用2株细菌处理生菜种子,评价其促生效果。用菌株WXD 3-2处理小麦,评价其生防效果。【结果】经过鉴定,确定菌株WXD 3-1为巨大芽孢杆菌(Bacillus megaterium),WXD 3-2为枯草芽孢杆菌(Bacillus subtilis)。2株菌均有溶磷、合成嗜铁素、IAA能力和促生能力,菌株WXD 3-2能够对多种病原菌产生拮抗作用,抑制其生长。经过WXD 3-1和WXD 3-2处理,生菜植株高、叶片宽、植株鲜重及植株干重与对照相比分别增加21.51%和8.88%、31.93%和14.51%、41.30%和13.58%、42.76%和26.35%。菌株WXD 3-2能够减轻小麦根腐病病症,小麦根部病斑减少。【结论】分离出的2株芽孢杆菌均具有溶磷、合成IAA和嗜铁素能力,能够促进生菜的生长,且菌株WXD 3-2还具有生防效果。
【OBJECTIVE】 Two strains of Bacillus with multiple biological characteristics, growth-promoting and biocontrol effects were screened from lettuce rhizosphere soil. 【Method】 The soil samples were treated at high temperature of 80 ° C to get 2 strains of bacteria. Strains were identified by morphological, physiological and biochemical, 16S rRNA and gyr B genes. The effects of dissolving phosphorus, synthesizing IAA and anthraquinon and their antagonism on plant pathogenic fungi were tested. Lettuce seeds were treated with 2 strains of bacteria to evaluate their promoting effect. Wheat WXD 3-2 was used to evaluate its biocontrol effect. 【Result】 After identification, strain WXD 3-1 was identified as Bacillus megaterium and WXD 3-2 was Bacillus subtilis. The two strains of bacteria have the functions of dissolving phosphorus, synthesizing siderophore, IAA and promoting ability. The strain WXD 3-2 can antagonize various pathogenic bacteria and inhibit their growth. After WXD 3-1 and WXD 3-2 treatment, the plant height, leaf width, plant fresh weight and plant dry weight increased by 21.51% and 8.88%, 31.93% and 14.51%, 41.30% and 13.58% respectively compared with the control, 42.76% and 26.35%. Strain WXD 3-2 reduced wheat root rot disease and reduced wheat root lesion. 【Conclusion】 The results showed that all of the two Bacillus isolated had ability of dissolving phosphorus, synthesizing IAA and anthraquinone, which could promote the growth of lettuce. The strain WXD 3-2 also had biocontrol effect.