黑麦草杂交F2代光合及水分利用效率研究

在晴朗无云天气下,利用C-340df便携式光合测定仪分别于分蘖期、拔节期和初花期对4个黑麦草品种(百盛Lolium perenne L.cv.Bison,邦德Lolium multiflorum L.cv.Abundant,多福L.perenne cv.Tove,卓越L.perenne cv.Eminent)及其杂交F₂代的光合蒸腾速率、生态因子(光合有效辐射、大气温度、大气湿度、叶温)和生理因子(胞间二氧化碳浓度、气孔导度)进行测定,并同期测定叶片相对含水量,旨在从F₂代中筛选出高光合、高水分利用率株系,并探讨影响黑麦草光合及水分利用效率的主要生理生态因子。结果表明:121个F₂代株系中,F₂-2(百盛×多福)的净光合速率最高、蒸腾效率最低(P<0.05),为F₂代中高光合、高水分利用率的最优株系;F₂-2(百盛×多福)相关性分析结果表明,蒸腾作用显著影响黑麦草叶片光能利用率和水分利用效率(P<0.05),气孔导度是影响黑麦草叶片光能利用率和水分利用效率的主要生理因子,可作为筛选高光合作物的生理指标。

Study on Photosynthesis and Water Use Efficiency in F2 Hybrids of Ryegrass

In order to select higher light use efficiency(LUE)and higher water use efficiency(WUE)strain from 121 F₂ hybrid plants of 4 ryegrass parents(Lolium perenne L.cv.Bison,Lolium multiflorum L.cv.,Abundant,Lolium perenne L.cv.Tove,Lolium perenne L.cv.Eminent),the factors that affect photosynthesis and water use efficiency and related ecological and physiological factors were measured using portable C-340 df photosynthesis at 3 different growth stages(tiller stage,elongation stage,and early flowering stage)in the morning on sunny days.The parameters measured were net photosynthetic rate(Pn),transpiration rate(Tr),photosynthetic active radiation(PAR),air temperature(Ta),relative atmospheric humidity(RH),leaf temperature(Tl),intercellular CO₂ concentration(Ci),stomata conductance(Gs),and leaf relative water content(LRWC).and their F₂ hybrids plants The results show that F₂-2(Bison× Tove)was the superior plant among the 121 hybrids with highest Pn,lowest Tr(P<0.05),and highest LUE and WUE.The correlation analysis of F₂-2 indicate that Tr affected LUE and WUE remarkably and Gs was the key physiological factor affecting the leaf LUE and WUE;Tr and Gs could be the key physiological indices to screen the higher LUE plants.