不同株穗形水稻超高产品种形态特征的研究

在大田和盆栽试验条件下,对不同株穗形超高产水稻品种的形态特征、上三叶对子粒贡献率及子粒灌浆动态的研究结果表明:①不同类型超高产水稻品种的冠层形成动态在不同肥力和栽培密度条件下反应不同,但所有类型参试品种的叶面积生长均呈二次曲线,符合Y=b1X+b2X2方程;在高肥水栽培条件下,半直立穗形品种冠层形成动态为最合理的“快起慢落”型,同时群体消光系数小、直射光透过系数大、全叶平均开张角度小,株形收敛,在较高的LAI条件下保持较好的田间通透性,使中下部叶片得到较多的阳光,有利于发挥中下部叶片对子粒的贡献作用,增加有效光合面积,发挥更大的增产潜力。②群体生长量与叶面积指数呈极显著正相关,前期大部时间的生长量与产量呈显著正相关。③不同株穗形水稻超高产品种抽穗后上三叶对子粒贡献率不同,半直立穗形品种倒三叶贡献率最大,且倒二叶与剑叶对子粒贡献率相似,弯曲穗品种剑叶对子粒贡献最大,倒二、倒三叶的贡献极小;直立穗形品种虽倒三叶贡献率最大,但与半直立穗形品种相比,倒三、倒二叶贡献率不如半直立穗形品种。④穗颈大维管束数与穗粒数呈显著正相关;穗下第1茎节的大维管束数与施氮量呈显著正相关。⑤以穗颈弯曲程度为指标,可将水稻划分为直立穗、半直立穗、弯曲穗3种类型,并且穗颈弯曲程度与剑叶长、剑叶长宽比、剑叶角度呈显著或极显著正相关,穗颈大维管束数与穗颈弯曲程度呈极显著负相关。

Studies on Morphological Characters of the Super Rice Varieties with Different Plant and Panicle Types

The result of studies on the morphological character, rate of the upper three leaves contribution to grains and analysis of grain filling characteristics of Super Rice varieties with different plant and panicle types indicated that: 1. The response to nitrogen supply and density of transplants varied with different plant and panicle types, but the growth curves of all varieties fitted to formula: Y=b1X b2X2. Under high fertility and high plant density,eaf area of the semi-erect type varieties increased rapidly in the early season and reduced slowly in the late season. So the LAI was high in the heading stage and the light extinction coefficient(K) of canopy was small. The average leaf angle was less than other type of varieties. The light regime in lower parts of canopy was improved,so total effective leaf area increased and yield raised. 2. The LAI was significantly positively correlated with the mass growth and the yield was positively correlated with the growth in early season. 3. The contribution rate of upper three leaves to grain varied with different plant and panicle types.In semi-erect panicle varieties, the third leaf contribution rate was the highest an the contribution rate of second leaf and flag leaf was similar. In curved panicle type varieties, the contribution rate of flag leaf was the highest,whereas that of second and third leaf was smaller, Although contribution rate of the third leaf in erect panicle varieties was the highest, the contribution of the second and third leaf is less than that in semi-erect type varieties. 4. Significant correlation was observed between the number of the large vascular bundles in neck-panicle and grain numbers per panicle. The number of the large vascular bundles in neck-panicle was positively correlated with nitrogen application. 5. The curvature of panicle neck was significantly positively correlated with length, length-width ratio and angle of flag leaf, but it negatively correlated with the number of vascular bundle.