高产杂交水稻剑叶全展后主要光合生理特征的研究

测定了杂交水稻两优培九和汕优63剑叶全展后的叶绿素含量、光合速率、光合系统电子传递活性、抗氧化系统等,结果显示:两优培九的光合速率在剑叶全展期一直占具优势,叶绿素含量较高,这可能是两优培九的光合速率高于汕优63的原因之一;两杂交水稻光系统的电子传递活性差异不明显,但在全展后期光系统活性均表现出不协调,这可能是杂交水稻剑叶衰老的原因之一;SOD的活性总体上呈先上升后下降的趋势。与汕优63相比较,两优培九的SOD活性较强,持续时间长;POD活性也呈先上升后下降的趋势,两优培九的POD活性较汕优63强;叶片中MDA的变化趋势与POD相似。表明除叶绿素含量较高外,两优培九光系统活性的优势并不明显;在抗逆性方面的优势可能是其光合速率较高、产量高的原因。

CHARACTERISTICS OF FLAG LEAVE OF HIGH YIELD RICE HYBRIDS AFTER THE LEAVE FULLY SPREAD

Characters of flag leave of hybrid rice,Liangyoupeijiu and Shanjiu 63,were studied after the flag leave fully spread.The results showed that the content of chlorophyll and photosynthetic rates of Liangyoupeijiu were higher than that of Shanyou 63,and electronic transport activities of thylakoid membranes(PSⅠand PSⅡ) increased first and then dropped.There was no obvious difference in activity of PSⅠ and PSⅡ amoung two hybrids,but the activity of PSⅡ dropping down earlier than PSⅠ.The disharmony between PSⅡ and PSⅠ may lead to free radical rising,which could be harmful to membranes.POD activity also increased first and then dropped;POD in Liangyoupeijiu was more active and lasted longer than that in Shanyou 63.The SOD activity in Liangyoupeijiu also lasted longer and stronger than that in Shanyou 63.There was no obvious difference in electron transport activities of thylakoid membranes between Liangyoupeijiu and Shanyou 63.That photosynthetic rates of Liangyoupeijiu were higher than that of Shanyou 63,which may be the possibly reason for that the protective enzymes in Liangyoupeijiu was more active than that in Shanyou 63.