扬麦16“灌浆快”与颖果显微结构和内源生长素的关系

扬麦16是长江中下游麦区种植面积最大的品种,具有灌浆速度快、粒重高等特点。为探明扬麦16"灌浆快"与颖果结构和内源生长素的关系,以宁麦13为对照,显微观察了扬麦16颖果维管束、胚乳细胞和传递细胞发育的变化特征,测定了千粒重和生长素含量。结果表明,扬麦16胚乳中淀粉体和蛋白体发育好,胚乳充实饱满,最终粒重高;灌浆过程中扬麦16颖果内源生长素水平高,促进了同化物向籽粒的调运和胚乳细胞的分裂;扬麦16颖果维管束发达,筛管面积大,韧皮部卸载能力强;扬麦16颖果传递细胞分化早,细胞壁内突结构发达,养分转运能力强。

Relationship between Caryopsis Microstructure and Endogenous Auxin Level and the Fast Grain Filling of Yangmai 16

Yangmai 16,with the largest planting area in the middle and lower Yangtze river,has features such as high speed of grain filling and high grain weight. In order to elucidate the relationship between rapid grain filling and the microstructure of caryopsis and the endogenous auxin,with Ningmai 13 as control,the systematic development and microstructural changes of the vascular cells,endosperm cells and transfer cells of Yangmai 16 caryopsis were observed. The thousand kernel weight and endogenous auxin(IAA) contents were studied. The main results indicated that,the starch granule and protein body were better developed in Yangmai 16,thus the endosperm enriched well and the final grain weight was higher. The endogenous auxin level in caryopsis of Yangmai 16 was higher during grain filling,which promoted the allocation and transportation of assimilates to caryopsis and the division of the endosperm cells. In Yangmai 16,the vascular bundles,especially the sieve tube,were significantly developed,and thus the phloem unloading ability of assimilate was stronger. The differentiation of transfer cells in Yangmai 16 was earlier,and the abundant cell wall ingrowth were conducive to give full play to transport function.