吉林省不同年代育成水稻品种上三叶光合特性的变化

为了解不同年代育成水稻品种上三叶光合特性的变化及其与产量的关系，以吉林省1958—2005年间育成的33个水稻品种为材料，研究了植株上三叶净光合速率(P_n)、光合能力及叶源量的变化。结果表明，抽穗期剑叶的P_n、光合能力和叶源量对植株的光合能力贡献最大，占单株总光合能力的42.45%，倒二叶占28.27%，倒三叶占15.69%。剑叶P_n、光合能力和叶源量的增加最小，倒二叶次之，倒三叶最大。相关分析表明，倒三叶的P_n、光合能力和叶源量与育成年代和产量呈显著正相关，剑叶和倒二叶的P_n、光合能力和叶源量与育成年代和产量的关系并没有达到显著水平。吉林省47年来水稻品种产量的遗传改良主要导致了植株倒三叶光合能力的显著提高，剑叶光合能力的变化并不大。

Changes of Photosynthetic Characteristics in Top Three Leaves of Rice (Oryza sativa L.) Cultivars Released in Different Years in Jilin Province

In order to understand the changes of photosynthetic characteristics in top three leaves and its relationship with yield in the genetic improvement of rice, 33 typical japonica rice cultivars released from 1958 to 2005 were planted under field conditions. to determine net photosynthetic rate (Pn), photosynthetic capacity and leaf sources capacity (LSC) after heading stage. The result indicated that the Pn, photosynthetic capacity and LSC of flag-leaf at heading had the most contribution to plant photosynthe...