水稻黄叶突变体光合特性的日变化

THE DIURNAL VARIATION OF PHOTOSYNTHESIS OF A XANTHA MUTANT IN RICE(Oryza sativa L.)

对水稻黄叶突变体黄玉B及其亲本龙特甫B孕穗期的光合速率和叶绿素荧光参数的日变化所进行的研究表明:(1)在自然日照条件下,当光强上升到1043.4μmol/m2.s时,野生型出现光饱和点并表现出光抑制现象,而突变体没有出现光饱和点;(2)在野生型出现光抑制阶段(12:00—14:00),突变体的光合速率(Pn)、PSⅡ原初光化学效率(Fv/Fm)、PSⅡ光量子效率(фPSⅡ)、非循环光合电子传递速率(ETR)和热耗散(NPQ)均高于野生型。突变体在强光条件下(PFD>1149.2μmol/m2.s)能有效利用光能并耗散过剩光能,其对强光光响应能力优于野生型亲本。

A xantha rice mutant （c. v. Huangyu B） and its wild type parent （c. v. Longtefu B） were used to study the diurnal variation of photosynthetic rate and chlorophyll fluorescence parameters at booting stage. The results showed that ： （ 1 ） under the condition of natural sun light, the wild type had the light saturation intensity, i.e. 1043.4μmol/m^2·s, above that point photoinhibition will occurr. However, the mutant did not show a light saturation point; （2）when Longtefu B was in the photoinhibition period （12：00- 14：00）, its mutant was more efficient in photosynthesis; its photosynthetic rate （Pn）, initial photochemical efficiency （FV/FM） , quantum efficiency of PS Ⅱ （φbPS Ⅱ ）, non-cyclic electron transport rate （ETR） and nonphotochemical quenching （NPQ） all of these parameters were higher than those of Longtefu B. The results indicated that the mutant was very efficient in solar energy utilization and could quench the surplus solar energy, thus surpassing its parent in response to the intense solar light（PDF 〉 1149.2μmol/m^2·s）.