十五种萱草植株光合特性对低温处理的响应及耐冷性分析OA

Taking fifteen varieties of Hemerocallis plants as experimental materials,and temperature treatments at 20 ℃(control,CK),10 ℃,5 ℃,and 0 ℃ were established in an artificial climate chamber.Measurements of net photosynthetic rate(Pn),intercellular CO2 concentration(Ci),stomatal conductance(Gs),transpiration rate(Tr),maximum photochemical quantum yield of PS Ⅱ(Fv/Fm),actual photochemical quantum efficiency(ΦPS Ⅱ),photochemical quenching coefficient(qP),and non-photochemical quenching coefficient(NPQ)were taken at 0,24,48 hours,and 72 hours.Additionally,the leaf chilling injury index for each treatment was assessed at the 72th hour.Using correlation analysis and principal component analysis,the differences in cold tolerance among 15 varieties were studied,in order to provide a reference for daylily cultivation and breeding.The results indicated that compared with the control,with the decrease in treatment temperature and the extension of time,Pn,Gs,Tr,Fv/Fm,ΦPS Ⅱ,and qP across the 15 Hemerocallis varieties generally demonstrated a declining trend,whereas the leaf chilling injury index and Ci exhibited an increasing trend.NPQ showed a trend of initial increase followed by a decrease.Notably,significant correlations were identified among the physiological indicators of each Hemerocallis variety.Principal component analysis revealed that the comprehensive ranking of cold tolerance among the 15 Hemerocallis varieties was as follows:'Hemerocallis hybrida'＞'Congmingdexiaosheji'＞'Hongyun'＞'Coopers Promis'＞'Zhijiagezhihuo'＞'Jinqingranshao'＞'Naiyoujuan'＞'Ertongjie'＞'Jixing'＞'Xiguahong'＞'Yaoqianshu'＞'Xiaochongwu'＞'Dongfangbubai'＞'8 Fenduan'＞'Shuilong',which was basically consistent with the results of the leaf chilling injury index.