| Popis: |
To explore the alleviation effect of spraying phytohormone on physiological characteristics and yield of sweet potato under drought stress in different periods, and to determine the best period of spraying external plant hormones, the effects on endogenous hormone content, photosynthetic fluorescence characteristics and yield of sweet potato were examined by spraying 6-benzylaminopurine (6-BA), α-naphthylacetic acid (NAA) and abscisic acid (ABA) respectively under drought stress after transplanting for 20 days (early stage), 60 days (middle stage) and 100 days (later stage) under artificial water control. The results showed that compared with spraying water, exogenous phytohormones significantly increased the yield of sweet potato under drought stress, among which 6-BA had the highest effect, followed by NAA and ABA. The effect of spraying in early stage was better than that in middle and late stages. Exogenous phytohormones significantly increased photosynthetic and chlorophyll fluorescence parameters of sweet potato leaves under drought stress at different stages, alleviated the decrease in eatin ribonucleoside (ZR) and auxin (IAA) caused by drought. Stepwise regression analysis showed that endogenous hormones and photosynthetic characteristics were key factors affecting yield of sweet potato. Results of path analysis showed that spraying exogenous plant hormone affected sweet potato yield by changing net photosynthetic rate (P为探讨不同时期干旱胁迫下喷施外源植物激素对甘薯生理特性和产量的影响,明确喷施外源植物激素的最佳时期,在人工控水条件下研究了移栽后20(前期)、60(中期)和100 d(后期)干旱胁迫下喷施6-苄氨基嘌呤(6-BA)、α-萘乙酸(NAA)和脱落酸(ABA)对甘薯内源激素含量、光合荧光特性和产量的影响。结果表明: 与喷清水相比,喷施外源植物激素均能显著提高甘薯产量,以6-BA增幅最大,其次是NAA和ABA;前期喷施效果好于中期和后期。不同时期干旱胁迫下,喷施外源植物激素可显著提高甘薯叶片的光合和叶绿素荧光参数,缓解因干旱引起的玉米素核糖核苷(ZR)和生长素(IAA)含量下降的现象。逐步回归分析表明,内源激素和光合特性是影响甘薯产量的关键指标。通径分析表明,前期干旱胁迫下喷施外源植物激素主要通过影响净光合速率( |
