转PEPC基因水稻花粉株系不同生育期的光合生理表现

Photosynthetic Performance of Transgenic Rice with Phosphoenolpyruvate Carboxylase Gene during Different Developmental Stages

以父本转玉米PEPC基因水稻、母本粳稻9516和杂交后代稳定的花粉株系JAAS45为材料,研究了JAAS45及其亲本的不同生育期的光合色素含量、净光合速率和水分利用效率。结果表明:分蘖期以后,杂交后代JAAS45的单位叶面积Chl含量超过母本9516,并一直维持着较高水平,与PC相近。在整个生育期,JAAS45和PC的叶绿素a/b一直高于9516。JAAS45苗期的净光合速率(Pn)与9516相近,而到了分蘖期,其Pn超过了9516,尤其到了抽穗及灌浆期,其Pn还超过了PC。从苗期到抽穗期,JAAS45的水分利用效率(WUE)与PC相接近,明显高于9516。这些结果说明,JAAS45具有较高的光合能力和水分利用效率,与父本PC相似。通过转PEPC基因水稻和杂交稻的亲本杂交,可将玉米PEPC基因转移到普通水稻品种中,培育出高光合效率和高产的水稻品系。

F1 hybrids were obtained by crossing PEPC transgenic rice germplasm as male parent with Japonica rice cultivar 9516. Processed with the cultivation of pollen lines, selection by photosynthetic characteristic and en- zyme activity, and systematic reselection and re-identification of three generations, stable JAAS45 pollen lines ofpure-bred diploid plants were achieved. The content of photosynthetic pigment, net photosynthetic rate and water use efficiency of JAAS45 and its parents were investigated in this paper. After tillering stage chlorophyll contents were higher than 9516,and retained a much higher level close to PC. From seeding to heading period the chla/b ratio ofJAAS45and PC were higher than that＇s of 9516. The net 9516 at the seeding stage, but it exceeded 9516 at tillering ing stage. From seeding to heading period, water use effi photosynthetic rate （Pn） of JAAS45 approximated that of stage, which was even higher than PC at heading and fill- ciency of for JAAS45 was evidently higher than 9516,whereas close to PC. Theses results suggested that the photosynthetic characteristics of JAAS45 exhibited higher photosynthetic capacity and water use efficiency, which was similar with that＇s of the male parent PC. By crossing PEPC transgenic rice germplasm as male parent with the hybrid male of japonica rice,the PEPC transgenic rice canbe utilized in transferring the maize PEPC gene into the common rice genome and also useful in the breeding of new rice cuhivars with high photosynthetic efficiency and high yield.