磷胁迫下不同基因型大豆的症状表现及耐性极限研究

Symptoms and Tolerant Limit of Different Genotype Soybeans under Phosphorus Stress

通过水培试验,研究8个不同基因型大豆品种在5种不同浓度磷营养处理下的生长发育情况、症状表现以及不同生育期耐低磷和耐高磷极限。结果表明,多数大豆品种水培的适宜磷营养浓度在1.5mmolL-1左右;水培大豆苗期和鼓粒期对磷的需求相对较少,开花期和结荚期需磷较多;大豆缺磷表现出嫩叶淡绿色、叶片褐斑、褐脉、叶皱缩扭曲、主根变褐、植株丛化、叶缘焦枯、生长点干枯坏死、花少和荚少等10种症状;磷过量表现出嫩叶淡绿色、叶片褐斑、褐脉、生长点干枯坏死等4种症状;缺磷和磷过量症状均存在轻、中、重的差异;不同基因型大豆不同生育时期对磷的耐性极限存在较大差异。

Eight soybean genotypes were used to study the effect of phosphorus stress （excessive or lacking）on the growth and development and tolerant limit of the solution cultured plants. The results showed that 1.5 mmol L^-1 of phosphorus was suitable for most of the soybean genotypes. Hydroponic soybean plants required less phosphorus in flowering and pod setting stages but more at seedling and pod filling stages. Lacking of phosphorus resulted in pea- green young leaves, speckle or erimple leaves, brown veins, brown taproot, clumped plants, withered leaf edge, dry rot growth point,less flowers and pods. In the excessive phosphorus treatment, the soybean plants expressed pea-green leaves, speckle leaves, brown veins and dry rot growth point. All symptoms showed light, moderate and severe levels. The result also indicated that the tolerant limit to P stress was significantly different among soybean genotypes.