Abstract:

Photosynthetic and agronomic characteristics of regeneration plants derived from somatic cell fusion between a japonica rice variety 8411(Oryza sativa L.,C3 plant) and Pennisetum squamulatum Fresen(C4 plant) were studied during 2005 and 2006.Compared with the japonica rice 8411,the regeneration plants showed a longer growth duration,shorter plant height,smaller panicle,lower seed setting rate and higher grain weight.The photosynthetic rate,stomatal conductance,transpiration rate,intercellular CO2 concentration and water use efficiency of the regeneration plants were between those of rice 8411 and P.squamulatum,and the leaf photosynthetic rate was significantly higher than that of rice 8411.Compared with rice 8411,the regeneration plants showed higher photosynthetic rates under lower light intensity and higher light saturation point.Chlorophyll fluorescence data(Fm,Fv/Fo,Fv/Fm) and chlorophyll contents of the regeneration plants showed higher heterosis than their parents.All those indicated that there may be C4 photosystem functioned in the regeneration plants.

Key words: Pennisetum squamulatum, Oryza sativa, somatic cell fusion, photosynthetic character, agronomic trait

摘要： 以粳稻8411（C3植物）与非洲狼尾草（C4植物）经体细胞杂交后获得的融合体再生植株为材料，测定体细胞融合再生植株的光合特性及农艺性状。 与栽培稻8411相比，再生植株的生育期延长、植株矮化、穗形变小、千粒重增加、结实率下降。 再生植株的光合速率、气孔导度、叶片蒸腾速率、胞间CO2浓度及水分利用效率等光合参数为栽培稻8411与非洲狼尾草的中间值，其中叶片光合速率显著高于栽培稻8411。 体细胞融合再生植株在弱光下表现出比栽培稻8411更高的光合速率，并具有较高光饱和点。 再生植株的最大荧光值Fm、能量捕捉效率Fv/Fo、光化学效率Fv/Fm、叶绿素含量等指标表现出显著的超亲优势。这些结果初步表明，体细胞融合再生植株具有C4循环固定CO2的光合系统的特征。

关键词: 非洲狼尾草, 水稻, 体细胞融合, 光合特性, 农艺性状