探究聚-γ-谷氨酸(γ-PGA)对水稻产量、品质和养分吸收的影响,为高产优质、养分高效利用的水稻栽培技术提供理论依据和技术参考。于2022年和2023年在湖北省武穴市花桥镇开展田间试验,采用随机完全区组设计,包括黑籼稻(B)、冈特优8024(R)和黄华占(H)3个水稻品种,和不施加γ-PGA发酵液(P0)和施加25 kg hm^(-2)γ-PGA发酵液(P1)2种γ-PGA处理方式,分析了水稻干物质量、植株氮磷素积累量、产量、稻米外观品质、籽粒蛋白质含量和直链淀粉含量。结果表明,2022年施加γ-PGA对水稻产量影响显著,P1处理较P0水稻产量增加3.2%~10.8%;2023年施加γ-PGA对水稻产量无显著影响。施加γ-PGA的品种B和R的干物质量显著高于不施γ-PGA处理,BP1处理较BP0齐穗期干物质量显著增加7.5%~8.5%,成熟期干物质量显著增加5.9%~7.2%;RP1处理较RP0齐穗期干物质量显著增加8.5%~8.8%,成熟期干物质量显著增加3.3%~3.5%。施加γ-PGA对品种H的干物质量无显著影响。施加γ-PGA能显著提高水稻的氮素和磷素积累量,P1处理较P0齐穗期氮素积累量显著增加12.5%~19.0%,磷素积累量显著增加13.4%~20.3%;成熟期氮素积累量显著增加7.2%~16.5%,磷素积累量显著增加9.2%~29.0%。施用γ-PGA能显著提高稻米直链淀粉和蛋白质含量,降低胶稠度、垩白度,但对粒长、粒宽、碱消值无显著影响。因此,施用γ-PGA显著提高水稻植株干物质量和氮、磷素积累量,改善稻米品质。
为挖掘对烟草镰刀菌根腐病具有较强拮抗作用的生防菌株,绿色防治烟草镰刀菌根腐病,本研究利用平板对峙法分离筛选出一株对尖孢镰刀菌具有高效拮抗活性的菌株TH0008,抑菌率为86.3%,通过形态学、生理生化特征以及16S rRNA序列分析鉴定该菌株为高地芽胞杆菌(Bacillus altitudinis)。该菌株发酵上清液中含有几丁质酶和纤维素酶,可溶解病原菌的细胞壁;同时烟苗中PPO、POD和PAL防御酶活性升高,说明菌株TH0008能诱导烟草产生抗性。盆栽试验也发现菌株TH0008对镰刀菌根腐病的防控优于商品化的农药甲霜·锰锌可湿性粉剂,相对防效达到84.9%,表明高地芽胞杆菌TH0008在绿色防治烟草根腐病中具有较大的应用潜力。To identify biocontrol strains with strong antagonistic effects against Fusarium root rot disease in tobacco and promote environmentally friendly management of this disease, a bacterial strain TH0008 was isolated using the dual-culture method and exhibited high antagonistic activity against Fusarium oxysporum with an inhibition rate of 86.3%. The strain was identified as Bacillus altitudinis based on morphological, physiological, biochemical characteristics, and 16S rRNA gene sequence analysis. The fermentation supernatant of TH0008 contained chitinase and cellulase, which can degrade the cell walls of pathogens, and it significantly induced the activity of defense enzymes PPO, POD, and PAL in tobacco seedlings. Pot experiments further demonstrated that strain TH0008 provided superior control of Fusarium root rot disease compared to the commercial fungicide Metalaxyl-Mancozeb wettable powder, achieving a relative control efficacy of 84.9%. These findings suggest that Bacillus altitudinis TH0008 has significant potential for sustainable biological control of tobacco root rot disease.
暂无评论