【摘要】 【目的】本研究旨在探究植物根际促生菌蜡状芽孢杆菌F06菌株对不同干旱胁迫下水稻汕优63生理特性的影响。【方法】在盆栽试验条件下,以水稻汕优63为种植材料,研究了轻度(LD)、中度(MD)、重度(SD)3个干旱强度下接种蜡样芽孢杆菌(Bacillus cereus)F06对水稻生理特征的影响。【结果】与正常水分管理相比,干旱胁迫(DS)下水稻叶片光合速率(P_n)和气孔导度(g_s)逐渐降低;而干旱胁迫下接种F06可显著减缓P_n和g_s下降,与不接种(NP)处理相比,P_n和g_s分别增加7.67%、12.97%、18.14%和11.51%、16.63%、17.07%,且呈现出随着干旱胁迫程度的提高,增幅增大的趋势。干旱胁迫下水稻叶片初始荧光(F_o)、非荧光淬灭系数(NPQ)显著上升,最大光化学效率(F_v/F_m)、光化学猝灭系数(q_P)显著下降;而干旱胁迫下接种F06可显著抑制F_o、NPQ升高和F_v/F_m、q_P降低,明显改善水稻叶片光能转换效率。干旱胁迫下接种F06虽然不能改变叶片水势、相对含水量和相对电导率的变化趋势,但可以有效降低其变幅。正常水分处理下接种F06虽然没有增加光合色素含量,但干旱环境下显著抑制了光合色素的分解或降低。干旱显著降低了水稻叶片和根系细胞分裂素(CTK)含量,增加了叶片中脱落酸(ABA)的含量;在干旱胁迫下,接种F06可显著提高叶片和根系中CTK的含量。【结论】由此可见,干旱生境下接种F06,可调节植物体内的激素含量,减少干旱胁迫下光合色素的分解或流失,提高光合速率,增强水稻在干旱环境中的适应能力。更多还原

【Abstract】 【Objective】This study aims to reveal the effects of plant growth-promoting rhizobacteria Bacillus cereus F06on physiological characteristics of the rice Shanyou 63 under different drought stress treatments(light,moderate,severe and a control).【Method】The combined effects of F06 inoculation and various levels of drought stress on the photosynthetic characteristics,chlorophyll fluorescence parameters,cytokinin and abscisic acid(ABA)concentrations,relative water content,and relative electrolyte leakage were studied in a pot experiment.【Result】The results showed that P_n and g_s decreased with increasing drought stress.However,F06 inoculation significantly slowed down the decrease of P_n and g_s under drought stress compared with non-inoculation(NP)treatment,P_n and g_s increased by 7.67%,12.97%,18.14%and 11.51%,16.63%and 17.07%,respectively.With the intensifying drougnt stress,it followed an increasing trend.F06 inoculation inhibited the decrease of F_v/F_m and q_P and the increase of F_o,NPQ and improved the light conversion efficiency of rice leaves significantly under drought stress.Under the drought stress,B.cereus F06 inoculation could reduce the change amplitude of leaf water potential,relative water content and relative conductivity.However,F06inoculation could not reverse the decrease trend of leaf water potential,relative water content and relative conductivity.F06 inoculation also significantly depressed the pigment decomposition or reduction.Although no significant increase was observed under well-watered conditions,drought significantly reduced the cytokinin(CTK)content in leaves and roots of rice,and increased ABA content in leaves,but F06 inoculation significantly increased the cytokinin content of drought-stressed leaves and roots Shanyou 63.【Conclusion】In conclusion,inoculation of PGPR could reduce the decomposition or loss of photosynthetic pigments and improve the photosynthetic rate,showing real potential for practical use in arid environments as a drought stress inhibitor.更多还原