低温胁迫对大豆花期叶片蔗糖代谢及产量的影响

Low Temperature Stress at Soybean Flowering Stage: Effect on Sucrose Metabolism of Leaves and Yield

为了研究低温胁迫对大豆花期产量形成的影响,以‘垦丰16’(耐冷型品种)和‘合丰50’(冷敏感型品种)为试验材料,采用盆栽试验,测定了叶片蔗糖含量以及代谢相关酶活性,成熟期测产。结果表明,大豆花期低温胁迫显著降低了大豆的株高和产量,底荚高度增加,随低温胁迫时间的延长,减产损失逐渐增加,与对照相比,‘合丰50’减产幅度为10.29%~30.88%,‘垦丰16’减产幅度为9.58%~24.22%,敏感品种的减产幅度大于耐冷品种。叶片内的淀粉和蔗糖含量随胁迫时间延长逐渐降低,果糖含量随胁迫时间延长逐渐增加,酸性转化酶、中性转化酶和蔗糖合成酶活性提高,蔗糖磷酸合成酶活性被抑制。低温恢复期间(低温处理4天后自然环境下恢复1~4天)上述指标呈现相反的变化趋势,不同品种间呈现相同的变化趋势。大豆花期遭遇低温胁迫致使蔗糖分解代谢加快,合成途径受到抑制,叶片内的蔗糖含量急剧减少,并且其危害不能在4天内恢复,这不利于大豆产量的形成,推断这是低温胁迫造成大豆减产的重要原因之一。

To study the effect of low temperature stress on the yield formation of soybean at flowering stage,‘Kenfeng 16’(chilling tolerant variety) and‘Hefeng 50’(chilling sensitive variety) were used as research materials, the sucrose content and metabolic enzyme activities were determined with pot experiment. The yield was measured at maturity stage. The results showed that plant height and yield were significantly reduced in both soybean varieties, and the height of bottom pods was increased. With the low temperature treatment prolonging, the production reduction was gradually increased. Compared with the control(H-CK and K-CK),the yield of‘Hefeng 50’was significantly decreased by 10.29%-30.88%, and that of‘Kenfeng 16’was significantly decreased by 9.58%-24.22%. The production reduction of chilling sensitive variety was higher than that of chilling tolerant variety. Starch and sucrose content declined and fructose content increased in leaves with the low temperature treatment prolonging. The activities of acid invertase, neutral invertase and sucrose synthase were improved, and the activity of sucrose phosphate synthase was inhibited by low temperature stress. The above indicators showed opposite trends in both soybean varieties during recovery period(1-4 days in natural environment after 4 days of low temperature treatment). The catabolism pathway of sucrose was accelerated, and the synthesis pathway of sucrose was inhibited, and finally sucrose content in leaves was drastically reduced when soybeans were exposed to low temperature stress during the flowering period, and the damage could not be restored within 4 days under natural environment. This is not conducive to the formation of soybean yield, and could be regarded as one of the important factors of soybean yield reduction caused by low temperature stress.