江淮下游地区水稻品种生产力纬向差异及其合理利用

Latitudinal Difference of Rice Varieties Productivity in the Lower Yangtze and Huai Valleys and Its Rational Utilization

以江苏种植的代表性水稻品种类型为材料,在稻麦两熟制条件下,于江苏沛县(34.7°N)、东海(34.5°N)、宿豫(34.0°N)、建湖(33.4°N)、扬州(32.4°N)、昆山(31.3°N)6地分别设置5个播期试验,系统研究了不同生育类型品种丰产性和稳产性的纬向差异,并探讨了江苏水稻品种的合理布局。结果表明,不同生育类型水稻品种产量在纬向与播期间存在极显著差异,产量(Y)与播期(t)可用Y=at2+bt+c拟合,因方程a、b取值不同,产量与播期的关系可分为3种类型,且在温光条件不同的地区或年份间转化。迟熟中粳类型品种丰产性和稳产性具有较强优势,适宜种植区域较广。随着品种熟期的进一步推迟,晚粳类型品种的丰产性指数(Pi)下降,稳定性指数(Si)上升,丰产性与稳定性均有变差趋势。杂交中籼稻两优培九产量丰产性较好,仅次于迟熟中粳类型品种,但产量稳定性仅高于早熟中粳类型品种。与早熟类型品种相比,偏晚熟类型品种在丰产性和稳产性方面均有明显优势。根据不同生育类型水稻品种丰产性和稳产性以及江苏省不同稻区常年温光气候条件,划分为适宜种植区、亚适宜种植区、可种植区和不宜种植区来确定不同生育类型水稻品种的合理布局。苏北、苏中、苏南稻区分别以中熟中粳、迟熟中粳、早熟晚粳类型品种为主体,兼作生育期相近的类型品种;杂交中籼类型品种仅适宜于江苏西部丘陵稻区。江苏淮北稻区以早播为宜,苏中、苏南稻区强调适期播种,过早或过迟播种均不利于提高产量。在确保安全生育成熟的前提下,选用偏迟熟类型品种及在籼粳同季兼作地区扩种粳稻均有利于提高水稻生产力。

Rice grain yield is affected significantly by the latitudinal environment factors. However, little is known about the latitudinal difference of prolificacy and stability of grain productivity in rice varieties with different growth durations in the downstream of Yangtze River and Huai River Valleys. In this study, under the condition of rice-wheat cropping rotation, a field experi- ment with five seeding dates using 11 rice varieties with different growth durations in Jiangsu Province was conducted to investi- gate the latitudinal difference of prolificacy and stability of grain productivity and the rational distribution of the varieties in Peixian （34.7° N）, Donghai （34.5° N）, Suyu （34.0° N）, Jianhu （33.4° N）, Yangzhou （32.4° N）, and Kunshan （31.3° N） of Jiangsu Province in 1997-2000. Results showed that there was a highly significant difference in grain yield of rice varieties with different growth durations and different seeding dates in different latitudinal sites. The equation Y = ar^2＋bt＋c was used to describe therelationship between grain yield and seeding date for all varieties, according to the change of values a and b there were three types of parabola which might be transformed between each other due to the change of sites or years. Compared with other rice varieties the prolificacy and stability of grain productivity of late-maturity medium japonica rice varieties were better, thereby their suitable planting zones were wider. But with the mature date prolonging unceasingly, the prolificacy index （Pi） decreased and the stability index （Sl） increased in late-maturity japonica rice varieties, so the yield prolificacy and stability became poor. The prolificacy of Liangyoupeijiu （hybrid mid-maturity indica rice variety） was only less than that of late-maturity medium japonica rice varieties but better than that of other rice varieties, while its yield stability was just better than that of early-maturity medium japonica rice varieties. Compared with the early-maturity rice varieties, the late-maturity rice varieties had significantly better prolificacy and stability than other varieties. Based on the prolificacy and stability of varieties with different growth durations and the conditions of annual temperature and light in Jiangsu, we rationally regionalized planting area into suitable region, sub-suitable region, pos- sible region and unsuitable region to confirm the distribution of rice varieties. Medium-maturity medium japonica rice varieties, late-maturity medium japonica rice varieties and early-maturity late japonica rice varieties were the main varieties suitable to plant in Subei, Suzhong and Sunan regions, also some varieties with closer growth duration could be planted as a supplement. However, hybrid mid-maturity indica rice varieties were only suitable to be planted in western hilly land of Jiangsu Province. In northern Huai River zone appropriately otherwise, earlier sowing was available and in Suzhong and Sunan regions the seeding date had to be suitable, otherwise, earlier or later sowing was not available to increase grain yield. On the premise of safely matur- ity accomplished, it is beneficial for increasing rice productivity to select partial late maturing varieties and plant more japonica rice varieties in the indica-japonica region.