【摘要】 通过对江淮稻区种植的主要粳稻品种的品质和二十多年来育成的中粳品种(系)农艺性状演变趋势进行了分析,结果表明,外观品质性状中的垩白率偏高和垩白度大是引起该稻区稻米品质不良的主要原因,随着产量水平的提高,在主要农艺性状中,有着单位面积穗数下降、总颖花数和每穗实粒数上升、着粒密度增加、株高变高、穗长变短、结实率和千粒重提高、生育期变长的趋势。产量水平的提高主要是由穗粒数增加引起的。近些年来,选育出的直立穗型粳稻品种数量明显增加,弯曲穗型粳稻品种数量急剧下降。更多还原

【Abstract】 The quality of planting japonica varieties and agronomical changes of middle mid-ripe japonica varieties (pedigrees) bred in recent 20 years were analysed, the results showed that high chalkiness rate and large chalkiness degree were main factors of low rice grain quality in Jianghuai region.With the yield increasing, there were the trends that ear numbers per unit decreased, total grain and filled grain numbers per ear increased, grain density got high, plant height increased, ear got short, filled grain rate and 1000-grain weight increased, and growth period became long. The main reason that caused the high yield was that filled grain numbers increased. The number of erect-panicle japonica varieties increased, but that of cured-panicle varieties obviously decreased in recent years.更多还原