摘要
【目的】获得生产生物能源的优质原料.【方法】在田间采用LI-6400便携式光合作用测定仪对‘热研4号’王草Pennisetum purpureum×P.americanum cv.Reyan No.4和五节芒Miscanthus floridulus的光合特性日变化进行研究,并分析了其净光合速率(Pn)与主要影响因子的相关性.【结果和结论】‘热研4号’王草和五节芒的净光合速率日变化均呈"单峰型",无光合"午休"现象,且‘热研4号’王草日均Pn(25.45μmol·m-2·s-1)略高于五节芒(25.08μmol·m-2·s-1).2种草的蒸腾速率(Tr)、水分利用效率(WUE)、光能利用率(LUE)和气孔导度(Gs)与Pn一样,最大值均出现在13:00时左右,且‘热研4号’王草的Tr、LUE和Gs也都略高于五节芒,只有WUE略低于五节芒.气孔限制值(Ls)日变化呈正钟型,在11:00时左右达最高值(均为0.86μmol·m-2·s-1),早晚最低,而胞间CO2摩尔分数(xi)日变化趋势与之相反.此外,‘热研4号’王草和五节芒的Pn均与大气CO2摩尔分数(xa)呈显著负相关(P<0.05),且分别与空气相对湿度(RH)和Gs呈显著正相关(P<0.05).以上结果说明‘热研4号’王草的光合能力比五节芒强.
【Objective】The purpose of this study was to obtain high quality raw materials for producing biofuels. 【Method 】 Diurnal variation of photosynthetic characteristics of Pennisetum purpureum × P.americanum cv. Reyan No. 4 and Miscanthus floridulus was studied and the correlation between net photosynthetic rate and major impact factors was analyzed using the LI-6400 portable photosynthesis analyzer in the field. 【Result and conclusion】The results showed that diurnal variation of the net photosynthetic rate（ Pn） of ‘Reyan No. 4＇and M. floridulus showed a ＂single peak＂,with no ＂midday depression＂phenomenon. Pn of ‘Reyan No. 4＇（ 25. 45 μmol·m^-2·s^-1） was slightly higher than that of M. floridulus（ 25. 08 μmol · m^-2·s^-1）. Transpiration rate（ Tr）,water use efficiency（ WUE）,light use efficiency（ LUE） and stomatal conductance（ Gs） were similar to Pn and reached the maximum at about13： 00. Tr,LUE and Gs of ‘Reyan No. 4＇were slightly higher than those of M. floridulus. Diurnal variation of stomatal limitation value（ Ls） for both grasses was bell-shaped,reaching the highest value（ 0. 86μmol·m^-2·s^-1） at about 11： 00 and the lowest in the early morning and late afternoon,but diurnal variation of intercellular CO2 mole fraction（ xi） was the opposite. Pn of two grasses was negatively corre-lated with atmospheric CO2 mole fraction（ xa）（ P〈0. 05）,and positively correlated with relative air humidity（ RH） and Gs（ P〈0. 05）,respectively. These results indicate ‘Reyan No. 4 ＇has a stronger photosynthetic capacity than M. floridulus.
出处
《华南农业大学学报》
CAS
CSCD
北大核心
2015年第2期55-60,共6页
Journal of South China Agricultural University
基金
"十二五"国家科技支撑计划(2011BAD17B02-05)
关键词
'热研4号’王草
五节芒
光合特性
能源植物
Pennisetum purpureum × P.americanum cv.Reyan No.4
Miscanthus floridulus
photosynthetic characteristic
energy plant
