中文摘要：

以早熟晚粳扬粳4227为材料,研究播期对其产量结构、品质和RVA特征值的影响。结果表明,随着播栽期推迟,产量呈先上升后下降趋势,成穗数呈上升趋势,每穗总粒数和千粒重随播期推迟而减少。不同播期处理下,扬粳4227的整精米率、垩白度、直链淀粉、胶稠度和RVA的各项指标差异显著。其中,播期4月25日稻米的整精米率最高,且垩白率和垩白度最小,播期6月5日的胶稠度最小。随着播期的后移,稻米峰值黏度、崩解值和消减值呈先上升后下降的趋势。扬粳4227在江苏里下河地区理想播期可安排于5月15～25日播种,产量最高且品质较好。

英文摘要：

With the early-ripe Japonica （Oryza sativa L） variety Yangjing 4227 as material, effects of sowing and planting periods on yield and yield component, rice quality and RVA profile were studied. The results showed that.. With the delay of sowing date, yields of Yangjing 4227 firstly increased then decreased gradually, ripened panicles increased, 1000-kernel weight and kernel numbers per ear decreased. Under different sowing date treatments, head rice rate,chalki- ness percent, amylose content, setback of RVA were significantly different. Among all sowing date treatments,head rice rate was the highest and chalkiness percent/rate was the lowerest under sowing date of 25th April. Gel consistency was the smallest under sowing date of 5th June. With sowing date postponing, Peak Viscosity, Breakdown Viscosity and Setback Viscosity firstly rised then declined. To achieve high yield and good rice quality, the optimum seeding time of Yangjing 4227 is from 5th May to 25th May.