干旱胁迫下不同燕麦品种光合荧光特性及其抗旱性评价

Photosynthetic Fluorescence Characteristics and Drought ResistanceEvaluation of Different Oat Varieties under Drought Stress

为研究水分胁迫下不同燕麦品种的抗旱性差异,明确不同燕麦品种在水分胁迫下的光合、荧光生理响应机制及其与燕麦抗旱性的相关性,设置干旱胁迫和充分灌水两种处理,分别在抽穗和开花两个时期对6个燕麦品种的光合、荧光等生理指标进行测定,在成熟期对6个燕麦品种的经济性状和产量性状进行测定,并对不同生理指标和抗旱性间的相关性进行分析。结果表明,在抽穗期和开花期,干旱胁迫导致胞间CO_( 2)浓度、蒸腾速率、气孔导度、光合速率下降,且开花期受影响较为严重。水分胁迫导致Fo增加,Fm、Fv、Fv/Fm、Fv/Fo下降;隶属函数综合分析结果表明,0905-12-14为强抗旱型品种,张莜14号为抗旱型品种,张燕1号、张燕4号为中抗型品种,张燕3号、张莜7号为弱抗型品种;抽穗和开花期干旱胁迫下,产量性状和光合参数间的相关性较强,且光合速率和品种抗旱性间的相关性较强。充分灌溉条件下,产量性状和品种抗旱性与叶绿素荧光参数间有较强的相关性。综合分析表明,抗旱性强的品种对干旱胁迫的适应调节能力强,0905-12-14抗旱性最强,张燕3号、张莜7号抗旱性最弱,利用光合指标、抗旱系数、抗旱指数、敏感指数可作为燕麦抗旱性初步鉴定的指标。

In order to study the difference of drought resistance of different oat varieties under water stress and to elucidate physiological response mechanism of photosynthesis and fluorescence under water stress and their correlation with drought resistance of oat,two treatments including drought stress and adequate irrigation in this study were used to measure the physiological indexes of photosynthesis and fluorescence of six oat cultivars at heading and flowering stages respectively.Meanwhile,the economic and yield characters of 6 oat varieties were measured at maturity stage,and the correlation between different physiological indexes and drought resistance was also analyzed.The results showed that drought stress caused the decrease of intercellular CO_( 2) concentration,transpiration rate,stomatal conductance and photosynthetic rate at heading stage and flowering stage,and the effect was more serious at flowering stage.Simultaneously,Fo increased and Fm,Fv,Fv/Fm,Fv/Fo decreased under water stress.The comprehensive results from the membership function analysis(MFA)showed that the oat varieties 0905-12-14 and Zhangyou 14 were a strong drought-resistant and a drought resistance varieties respectively,while the varieties Zhangyan 1 and Zhangyan 4 both were medium resistant varieties.And,Zhangyan 3 and Zhangyan 7 were of weak resistance varieties.Under drought stress at heading and flowering stage,there was stronger correlation between yield and photosynthetic parameters while there was stronger correlation between photosynthetic rate and drought resistance of varieties.Under the condition of adequate irrigation,the yield and drought resistance of varieties were strongly correlated with chlorophyll fluorescence parameters.Comprehensive analysis showed that varieties with strong drought resistance had strong adaptability to drought stress,with the strongest drought resistance from 0905-12-14 and the weakest drought resistance from Zhangyan 3 and Zhangyou 7.Photosynthetic index,drought resistance coefficient,drought resistance index and sensitivity index could be used as the primary indexes for the identification of oat drought resistance.