辣椒苗期耐紫外性综合评价及预测

Comprehensive evaluation and prediction of ultraviolet radiation resistance of pepper at seedling stage

  • 摘要: 【目的】对青海地区主栽的9个辣椒(Capsicum annuum L.)品种苗期耐紫外性进行综合评价,并建立预测辣椒品种耐紫外性数学模型。【方法】测定9个辣椒品种在UV-B辐射剂量为28.56 kJ/(m2·d)和自然条件下(对照)幼苗的形态指标、叶片抗氧化酶活性及光合特性等17个指标,计算耐紫外系数,并进行主成分分析,联合隶属函数法和聚类分析综合比较9个品种的耐紫外性;由综合隶属值(D)与耐紫外系数建立预测辣椒品种耐紫外性数学模型。【结果】经UV-B辐射后,叶片表型上,华美105损伤最严重,乐都长辣椒变化很小;过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性在乐都长辣椒、YTS2013-13叶片中经UV-B辐射后表现为上升趋势,而华美105的酶活性均表现为下降趋势,且下降幅度是9个品种中最大的。9个品种的光合作用在UV-B辐射下均受到抑制,其中对华美105光合特性的影响最大,而乐都长辣椒受影响程度最小。主成分分析得出,最大荧光(Fm)、SOD、气孔导度(Gs)、原初光能转化效率(Fv/Fm)、净光合速率(Pn)和类胡萝卜素(Car)等指标对辣椒苗期的耐紫外性强弱影响较大。经隶属函数法及聚类分析筛选出耐紫外性强的品种2个,中等耐紫外性品种3个,紫外敏感型品种4个,通过逐步回归分析建立耐紫外性最优数学模型D=0.037SOD+1.123Pn-0.228(R2=0.913,P=0.01),耐紫外性评价的数学模型的预测平均精度为92.642%。【结论】 SOD和Pn可用于耐紫外型辣椒品种的育种筛选;乐都长辣椒幼苗的耐紫外性远强于其他品种,可考虑将其作为高原地区主栽辣椒品种,保障辣椒的优质生产。

     

    Abstract: 【Objective】 The ultraviolet radiation(UV)resistance of 9 pepper varieties(Capsicum annuum L.)at seedling stage was evaluated comprehensively,and the mathematical model for predicting UV resistance of pepper varieties was established.【Method】 The morphological indexes,antioxidant enzyme activity and photosynthetic characteristics of 9 varieties of pepper seedlings were measured under UV-B radiation dose of 28.56 kJ/(m2·d)and natural conditions(control) to calculate the UV resistance coefficient. Principal components were analyzed,and the UV resistance of 9 pepper varieties according to α combined membership function and cluster analysis were compared.Then,the mathematical model of predicting UV resistance of pepper varieties was established by integrating comprehensive membership function value (D)and UV resistance coefficient.【Result】 After exposure to UV-B radiation,9 pepper varieties showed different degree of leaf appearance damage at the end of treatment,among which Huamai 105 had the most serious damage,Ledu long pepper had a little change. Peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)activities of the leaves of Ledu long pepper and YTS2013-13 showed an increasing trend under UV-B radiation,while those of Huamei 105 showed a decreasing trend,and the decreasing range was the largest among the 9 varieties. The photosynthesis of 9 varieties was inhibited under UV-B radiation,among which Huamei 105 was the most seriously affected on photosynthetic characteristics,while Ledu long pepper was the least affected. According to principal component analysis,the indicators of maximum fluorescence (Fm),SOD,stomatal conductance (Gs),primary light energy conversion efficiency (Fv/Fm),net photosynthetic rate (Pn)and carotenoid (Car)have great influence on the UV resistance of pepper at seedling stage. Two varieties with strong UV resistance,three varieties with medium UV resistance and four varieties with UV sensitivity were screened out by combined membership function and cluster analysis. The optimal mathematical model of UV resistance was established by stepwise regression analysis:D=0.037SOD+1.123Pn-0.228(R2=0.913, P=0.01). the prediction accuracy of the mathematical model of UV resistance evaluation was 92.642%.【Conclusion】SOD and Pn can be used for breeding and screening of UV resistance varieties of pepper. In addition,the UV resistance of Ledu long pepper seedlings is much stronger than other varieties,so it can be considered as the main pepper variety in plateau area to ensure the high quality production of pepper.

     

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