水稻亚种间杂种F1 光合特性研究

用绵恢725、蜀恢527和蜀恢881三个籼型恢复系、1个美国稻Lemont和1个爪哇稻香大粒作母本, 与1个日本特早熟粳稻Kitaake杂交, 研究了5个杂种F1及其亲本的光合生理表现。结果表明, 在高光通量密度(Photosynthetic flux density, PFD)条件下, 5个杂种F1净光合速率(Pn)明显高于双亲或双亲之一, 推测亲本与杂种F1之间不同的Pn同叶片中Rubsico活性有关。杂种F1的比较中, 在表观量子效率(j)、羧化效率(CE)、CO2补偿点(G)等方面, 籼粳亚种间杂种F1(绵恢725/Kitaake、蜀恢527/Kitaake、蜀恢881/Kitaake)对2个亚种内杂种F1香大粒/Kitaake(粳爪交)、Lemont/Kitaake(不同生态型的粳粳交, 美国稻属于特殊粳稻)具有明显的优势, 而蜀恢881含有粳型血缘, 蜀恢881/Kitaake也比典型籼粳亚种间杂种F1 绵恢725/Kitaake、蜀恢527/Kitaake优势稍逊一筹。5个杂种F1因为具有不同的遗传差异而表现出不同的光合优势, 在这方面, 典型籼粳亚种间杂交蜀恢527/Kitaake、绵恢725/Kitaake要优于其他杂交种, 说明亲本间遗传差异越大, 其杂种F1的光合优势越强。

Studies on the Photosynthetic Characteristics of Intersubspecific Hybrid F1 in Rice

Three indica rice restorer lines, Mianhui725, Shuhui527, Shuhui881, an American rice　variety Lemont and a javanica rice Xiangdali were crossed with Japanese japonica Kitaake.Studies of photosynthetic characteristics indicated that under strong photosynthetic flux density　(PFD), the net photosynthetic rate (Pn) that 5 F1 hybrids reached was significantly higher than that of their own parents or one of them. According to the findings about stomatal conductance (Gs) and intercellular CO2 concentration (Ci), differences in Rubsico activity in leaves might exist among parents and hybrids. During the investigation of photosynthetic indexes such as Quantum efficiency (j), Carboxylation efficiency （CE） and CO2 compensation point (G), the intersubspecific hybrids F1 Mianhui725/Kitaake, Shuhui527/Kitaake, and Shuhui881/Kitaake had significant photosynthetic heterosis as compared with the intersub-subspecific hybrids Xiangdali/Kitaake (javanica/japonica)、Lemont/Kitaake (japonica/japonica). Moreover, Shuhui881 had some japonica consanguinity, which made Shuhui 881/Kitaake with less photosynthetic heterosis than Mianhui725/Kitaake or Shuhui527/Kitaake. Therefore, the photosynthetic heterosis of 5 F1 hybrids existed in their genetic differences, and the typical intersubspecific hybrids Mianhui725/ Kitaake and Shuhui527/Kitaake were better than others.