不同水稻品种产量形成过程的能量积累与热值特征

通过测定晚季稻汕优63 (三系杂交稻)、两优2186（两系杂交稻）和IR64（常规稻）生长过程中的干物质和热值，研究了不同水稻品种生长过程中的热值动态和能量固定特征.结果表明，完熟期汕优63、两优2186和IR64 3种水稻的干物质积累量分别为1926.38、1933.80和1842.30 g·m^-2，能量积累量分别为31137.05、31060.63和30454.89 kJ·m^-2，不同水稻品种的干物质及能量积累量间无显著差异.在灌浆过程中，汕优63、两优2186和IR64总的能量表观转化率分别为38.95%、 28.38%和32.66%，汕优63和IR64的能量流动比两优2186顺畅，两优2186茎器官能量输出受阻.完熟期3种水稻分配到籽粒中的能量依次占53.03%、46.43%和50.11%，三系杂交稻汕优63具有能量分配优势.热值分析表明，3种水稻各生育期间的热值平均值间无显著差异；不同器官热值大小依次为：叶＞籽粒＞鞘＞茎＞根，热值范围为：叶16.81～17.25 kJ·g^-1，籽粒15.89～16.54 kJ·g^-1，鞘14.33～15.49 kJ·g^-1，茎14.23～15.15 kJ·g^-1，根11.51～13.25 kJ·g^-1，叶片的热值显著高于其它器官，而根的热值显著低于其它器官.水稻叶片热值与其碳含量、叶绿素a含量、氮含量存在显著正相关，确定系数R²分别为0.609、0.471和0.485.

Energy accumulation and caloric value in yield-forming process of different rice cultivars

Based on the determination of dry matter and caloric value, this paper studied the characteristics of energy accumulation and the dynamics of caloric value in the yield-forming process of rice cultivars Shanyou 63 ( three-line hybrid rice) , Liangyou 2186 (two-line hybrid rice) , and IR64 (conventional rice). The results showed that at fully grain-maturing stage, the amount of dry matter in Shanyou 63, Liangyou 2186 and IR64 was 1926. 38 g x m(2), 1933.80 g x m(-2) and 1842.30 g x m(-2), and that of accumulated energy was 31,137.05 kJ x m(-2) 31 060.63 kJ x m(-2) and 30 454.89 kJ x m(-2) , respectively, showing no significant difference among the cultivars. In the process of grain filling, the apparent transformation ratio of energy in Shanyou 63, Liangyou 2186 and IR64 was about 38. 95% , 28. 38% and 32. 66% , respectively, implying that the energy flow in Shanyou 63 and IR 64 was smoother than that in Liangyou 2186, and the output of energy from stem to the sink of grain was blocked in Liangyou 2186. The ratio of energy partitioning to the sink of grain was 53. 03% , 46. 43% and 50. 11% for Shanyou 63, Liangyou 2186 and IR64, respectively, showing the energy partitioning heterosis in three-line hybrid rice Shanyou 63. As for the caloric value, it had no significant difference among the three cultivars, but decreased in the order of leaf> grain > sheath > stem > root, ranging from 16.81-17.25 kJ x g(-1) , 15.89-16.54 kJ x g (-1) 14.33-15.49 kJ x g(-1) , 14.23-15.15 kJ x g , and 11.51-13.25 kJ x g(-1), respectively. It was also shown that there was a significant positive correlation of caloric value with carbon content, chlorophyll a content, and nitrogen content in rice plant, with the determination coefficient R(2) being 0.609, 0.471 and 0.485, respectively.