枯草芽孢杆菌对花生镉积累及生理性状的影响.docVIP

枯草芽孢杆菌对花生镉积累及生理性状的影响 　　摘要：盆栽条件下，研究了轻度镉胁迫下施用不同浓度枯草芽孢杆菌对花育31号花生生理性状、植株性状和籽粒镉积累量的影响。结果表明，施用枯草芽孢杆菌能提高花生苗期、花针期和成熟期的叶片叶绿素含量和根系活力，降低叶片相对电导率；施用量为2 g/kg和4 g/kg时均能显著提高不同生育期叶片的SOD活性和POD活性，显著降低叶片MDA含量；1 g/kg和2 g/kg枯草芽孢杆菌均能较大幅度提高花生主茎高、侧枝长、植株鲜重、单株果重和饱果率，均能显著减少籽粒镉的积累量。综上，施用2 g/kg枯草芽孢杆菌对缓解花生轻度镉胁迫的效果最好，能显著提高叶绿素含量和根系活力，降低镉胁迫对细胞膜的损坏程度，显著增加单株果重和饱果率，籽粒镉积累量降低25.37%。 　　关键词：花生；枯草芽孢杆菌；镉胁迫；生理特性；产量 　　中图分类号：S565.201 文献标识号：A 文章编号：1001-4942（2014）03-0017-05 　　AbstractThe pot experiment was carried out to study the effects of applying different concentrations of Bacillus subtilis on the physiological and plant characters， and cadmium content in seeds under mild cadmium stress. The results showed that applying Bacillus subtilis could improve the leaf chlorophyll content and root activity， reduce relative conductivity in leaves of peanut at seedling stage， flowering stage and mature stage.Applying 2 g/kg and 4 g/kg Bacillus subtilis could both significantly increase the SOD and POD activities，significantly reduce the MDA content in leaves at different growth periods. Applying 1 g/kg and 2 g/kg Bacillus subtilis could obviously improve stem height， lateral branch length， plant fresh weight， fruit weight per plant and plump rate， significantly reduce the cadmium accumulation in seeds. This study showed that applying 2 g/kg Bacillus subtilis had the best effects of relieving mild cadmium stress on peanut. The chlorophyll content and root activity were significantly increased， the damage of cadmium stress on cytomembrane was decreased， the fruit weight per plant and plump rate were significantly increased， and the cadmium accumulation in seeds was decreased by 25.37%. 　　Key wordsPeanut； Bacillus subtilis； Cd stress； Physiological characters； Yield 　　花生是一种对重金属镉吸收能力较强的食油兼用作物，我国是世界上重要的花生生产和出口国。近年来，籽粒镉含量偏高已成为制约我国花生出口的重要因素[1]。镉被作物大量吸收后会出现重金属毒害症状，不同作物对Cd的反应不一致，一般会导致叶片失绿、生长迟缓、植株矮化、生物量降低等[2]。花生开花期根和叶的细胞膜透性是对Cd胁迫响应最敏感的生理参数[3]。另外，Cd胁迫还会导致花生株高降低，根长和侧根数减少，超氧化物歧化酶（SOD）和过氧化物酶（POD）活性降低等[4]。 　　枯草芽孢杆菌（Bacillu