大穗型水稻BL006和R-农白籽粒灌浆过程中源-流-库特性分析

以大穗型水稻品种BL006和R-农白为试验材料，中穗型品种黄华占为对照，在大田栽培条件下，比较不同穗型水稻品种的灌浆动态、群体干物质积累、茎鞘非结构性碳水化合物（NSC）含量、输导组织特征及产量性状，探讨大穗型水稻品种的灌浆结实特性及源-流-库特性。结果表明：（1）大穗型水稻品种BL006和R-农白灌浆起步早、前期灌浆速率快，最终粒重高，不同部位籽粒的灌浆动态基本一致，部位间互为同步灌浆。（2）与中穗型水稻品种相比，大穗型水稻品种BL006和R-农白的穗粒数和千粒重分别升高16.83%、33.75%和13.19%、10.07%，谷粒充实率无显著差异，每穴有效穗数及R-农白的受精率分别降低39.48%、31.24%和10.78%；大穗型水稻品种BL006（全生育期）和R-农白（齐穗期后）的群体干物质积累量升高36.06%和6.59%；灌浆期间茎鞘NSC含量升高99.03%和70.32%；穗颈维管束数量、面积和枝梗维管束的面积显著增加。总之，大穗型水稻品种BL006和R-农白的灌浆速率高、灌浆耗时短、粒重高，其中，BL006的受精率更高，籽粒灌浆更优。灌浆期间，两个大穗型水稻品种“源”足、“流”畅，通过适当减少有效穗数，实现了籽粒的优异灌浆充实，这为探明大穗型水稻品种的灌浆特性及调控机理奠定了基础。

Source-flow-sink Characteristics of Heavy Panicle Rice BL006 and R-nongbai

Field experiment was conducted with two heavy panicle rice cultivars (BL006, R-nongbai) and one medium panicle rice cultivar (Huanghuazhan). Grain filling characteristics, dry matter accumulation, non-structural carbohydrate (NSC) content in stem-sheath, vascular bundle characters and yield traits were investigated to elucidate characteristics of grain filling and source-flow-sink for heavy panicle rice cultivars. Results showed that: (1) heavy panicle rice cultivars showed earlier grain growth, higher grain filling rate at early grain filling stage, heavier grain weight, and synchronous filling dynamic among spikelets on the different positions. (2) Compared with Huanghuazhan, spikelets per panicle and 1000-grain weights of BL006 and R-nongbai were increased by 16.83%, 33.75% and 13.19%, 10.07%, but filled-grain percentages were not significantly influenced, and effective panicles per hill of the two cultivars and spikelet fertility of R-nongbai were significantly decreased by 39.48%, 31.24% and 10.78%, respectively. Dry matter accumulation was increased by 36.06% in BL006 during the growth stage and 6.59% in R-nongbai after full heading, and NSC contents in stem-sheath were increased by 99.03% and 70.32%, and better vascular bundle characters of panicle neck and branches were observed as well. In a conclusion, heavy panicle rice cultivars BL006 and R-nongbai showed higher grain filling rate, shorter grain filling duration and heavier grain weight, and BL006 showed higher spikelet fertility and superior grain filling than R-nongbai. During grain filling, the two heavy panicle rice cultivars had sufficient source and unobstructed flow, and good grain filling was achieved by reducing appropriately effective panicle per hill. It laid the foundation for exploring the characteristics of grain filling and regulation mechanism of heavy panicle rice cultivars.