低温胁迫对大花三色堇和角堇光合作用与叶绿素荧光的影响

Effect of Low Temperature Stress on Photosynthesis and Chlorophyll Fluorescence of Viola×wittrockiana and Viola cornuta

旨在探讨低温对大花三色堇和角堇光合作用的影响,为大花三色堇和角堇的抗寒栽培及育种提供参考,以1个大花三色堇资源HAR和3个角堇资源JB、E01、08H为试材,采用人工模拟低温条件(-5℃8h,-5℃16h,-5℃24h,-10℃7h,-10℃14h)对其进行低温处理,测定其光合及叶绿素荧光参数变化。结果表明,低温胁迫导致大花三色堇和角堇叶片的净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、PSⅡ的最大光化学效率(F_v/F_m)、光化学淬灭系数(q_P)和实际光化学效率(Φ_(PSⅡ))下降,且随低温胁迫程度增加呈下降趋势,而胞间CO_2浓度(C_i)和初始荧光(F_0)、非光化学淬灭系数(q_N)则呈上升趋势,且变化幅度因基因型不同而存在差异。依据低温胁迫下各试材的光合和叶绿素荧光指标变化情况,角堇E01和JB耐寒性较强,其次为角堇08H,大花三色堇HAR耐寒性较差。

In order to understand effects of low temperature on photosynthesis of Viola×wittrockiana and Viola cornuta,and provide reference for cultivation and breeding under environment of low temperature ,an experiment was conducted with a Viola×wittrockiana germplasm,named HAR,and three Viola cornuta germplasm,named JB,E01 and 08H.The photosynthetic and chlorophyll fluorescence parameters of 4 pansies were measured after the plants treated under five low temperature conditions,namely,-5 ℃ for 8 h,16 h and 24 h,-10 ℃ for 7 h and 14 h.The results showed that under low temperature stress,the net photosynthetic rate（Pn）,stomatal conductance（Gs）,transpiration rate（Tr）,Fv/Fm,photochemical quenching coefficient（qP） and actual photochemistry（ΦPSⅡ） of pansies decreased with the increace of low temperature stress,while the intercellular CO2 concentration（Ci）,initial fluorescence（F0） and non photochemical quenching coefficient（qn） increased.The degree of change was different among four genotypes.According to changes of photosynthetic and chlorophyll fluorescence parameters of the tested materials,we found that E01 and JB had stronger cold tolerance,the next one was 08H,while the cold tolerance of HAR was poor relatively.