超级稻根系形态生理特征及其与产量形成的关系

2011年与2012年于水培池种植超级稻品种两优培九(两系杂交籼稻)和扬粳4038 (粳稻)及常规高产品种扬稻6号(籼稻)和扬辐粳8号(粳稻)，观察各生育期根系形态生理特征及其与产量形成的关系。结果表明，与常规高产品种相比，超级稻品种具有强大的产量潜力，其高产潜力主要得益于较多的每穗颖花数与较大的总库容量(单位地面积颖花量)。超级稻品种在整个生育期较大的根量、生育早中期较高的单株根系氧化力、根系总吸收表面积与活跃吸收表面积及根系中较高的玉米素与玉米素核苷含量是其产量库容大和产量高的重要原因。超级稻存在着结实率较低的问题，这可能与其在灌浆期根系活性下降较快有关。提高超级稻灌浆期根系活性，是提高其结实率、促进其产量进一步提高的重要途径。

Morphology and Physiology of Roots and Their Relationships with Yield Formation in Super Rice

Two super rice cultivars, Liangyoupeijiu (indica-inclined two-line hybrid) and Yangjing 4038 (japonica), and two high-yielding rice cultivars, Yangdao 6 (indica) and Yangfujing 8 (japonica), were grown in nutrient solution in 2011 and 2012. Changes in morphological and physiological traits of roots at different growth stages and their relationships with growth and development were investigated. The results showed that both super rice varieties had greater yield potential and higher grain yield than the two elite check varieties，which was mainly due to the larger sink from the larger panicle in the super rice varieties. Root and shoot dry weight was significantly greater in super rice varieties than in check ones throughout the growth season. Root oxidation activity (ROA), total root absorbing surface area, active absorbing surface area and root zeatin (Z) plus zeatin riboside (ZR) content, on a single plant basis, were significantly greater in super rice than in check varieties at the early stage. The low percentage of filled grains was closely associated with a quickly decreased root activity during grain filling. These results suggest that the yield of super rice varieties could be further increased by increasing seed setting rate through enhancing root activity during the grain filling period.