干旱胁迫下枯草芽孢杆菌对玉米种子抗旱性及生理指标的影响

Effects of Bacillus subtilis on Drought Resistance and Physiological Indexes of Maize Seeds under Drought Stress

为了寻找有助于增强玉米种子萌发期抗旱性的菌种,研究了干旱胁迫下枯草芽孢杆菌菌种对玉米种子萌发的生理调控作用。以4种来自贵州省不同地点且不同植物根际的枯草芽孢杆菌菌种(R29-1、R9-1、R59、R60)为材料,运用隶属函数和标准差系数赋予权重法分析干旱胁迫下玉米种子发芽指标以及生理生化指标。结果表明,接种4种枯草芽孢杆菌均增强了玉米萌发过程中的抗旱性,抗旱性评价为R60>R9-1>R59>R29-1>CK2(15%PEG),尤其接种枯草芽孢杆菌R60与R9-1能够更好地提升玉米抗旱性。接种枯草芽孢杆菌能同时提升玉米萌发过程抗逆性与叶片游离脯氨酸含量,降低叶片超氧化物歧化酶、过氧化氢酶和过氧化物酶的活性,从而减轻细胞膜受到的伤害,因此接种枯草芽孢杆菌R60能有效促进玉米的萌发及萌发期的生长。

In order to find strains increasing the drought resistance of maize during germination period under drought condition, we explored the physiological regulation of Bacillus subtilis strains on maize seed germination under drought stress. The experiment used four Bacillus subtilis species(R29-1, R9-1, R59, R60) from different locations and different plant rhizospheres in Guizhou province as materials. Maize seed germination indexes and physiological and biochemical indexes were analyzed by the weighting method of membership function and standard deviation coefficient under drought stress. The results showed that the inoculation of Bacillus subtilis R29-1, R9-1, R59, and R60 all enhanced the drought resistance of maize during germination period. The drought resistance was evaluated as R60 > R9-1 > R59 > R29-1 > CK2(15% PEG), especially the inoculation of Bacillus subtilis R60 and R9-1 could better improve the drought resistance of maize. Inoculation of Bacillus subtilis could increase the stress resistance and free proline content of leaves during the germination process, and reduce the activities of superoxide dismutase, catalase and peroxidase of leaves so as to effectively reduce the damage of cell membrane. In conclusion, inoculation with Bacillus subtilis R60 could effectively enhance the germination and growth during the germination period.