播期和地点对不同生态类型粳稻稻米品质性状的影响

 以不同生态类型的5个粳稻品种为材料，在江苏省选择5个不同纬度地点，通过分期播种试验研究稻米品质性状的差异，探讨不同地点和不同播期对稻米加工、外观、蒸煮食味和营养品质的影响。结果表明，13个品质性状在地点、播期及品种间的差异均达到了极显著水平，多数性状品种间变异最大，地点次之，播期影响最小。不同品质性状在不同纬度的变化趋势不同，稻米加工品质随纬度的升高呈改善趋势，粒长、粒宽和长宽比在不同纬度间的变化较小，直链淀粉含量、糊化温度、胶稠度和食味值呈北高南低的趋势，垩白率、垩白度和蛋白质含量则呈现南高北低的趋势，食味品质随纬度的升高有提高趋势。随播期的推迟，加工品质、直链淀粉含量、糊化温度、蛋白质含量均有提高的趋势，粒长和长宽比增加，粒宽减小，胶稠度降低，垩白率和垩白度在不同播期之间存在显著差异，但变幅不大，过早或过迟播种食味值均有降低趋势。不同性状对地点和播期的反应不同，糙米率、粒宽、粒长、长宽比和精米率受影响较小，而垩白率和垩白度受影响较大，整精米率、糊化温度、蛋白质含量、直链淀粉含量、胶稠度和食味值居两者之间。不同品种不同品质性状在地点和播期间的稳定性不同，南粳46的品质性状综合表现最好，但受地点和播期的影响较大。

Effects of Sowing Date and Site on Grain Quality of Rice Cultivars Planted in Different Ecological Types

In order to elucidate the basically variable rule of rice grain quality traits in Jiangsu Province, the effect of site and sowing date on grain milling quality, appearance quality, eating quality and nutrient quality was studied in five rice planting regions with five different dominantly cultivated japonica cultivars as material under seven sowing date treatments. The main results showed that the effects of site, sowing date and cultivars on the grain qualities were highly significant, the order of effect on most rice grain qualities was as follows: cultivar> site> sowing date. The change tendency of quality traits varied with site. Grain length, grain width and ratio of grain length and width changed slightly at different latitudes. Amylose content, gel consistency, gelatinization temperature and taste value were higher in the north than in the south while chalkiness rate, chalkiness degree and protein content were higher in the south than in the north. Eating quality showed an increasing trend with increasing latitude. Along with the delayed sowing date, milling quality, amylose content, gelatinization temperature and protein content showed an increasing trend. Grain length and ratio of grain length increased whereas grain width and gel consistency decreased with delaying sowing date. Chalkiness rate and chalkiness degree were significantly different among different sowing dates with little change. And earlier or delayed sowing would result in the degradation of taste value. The response of different traits to the site and sowing date was different. Brown rice rate, grain length, grain width, ratio of grain length and width and milled rice rate were rather stable, but chalkiness rate and chalkiness degree were relatively sensitive to environmental factors. Head milled rice rate, gel consistency, protein content, amylose content, gelatinization temperature and taste value were intermediate between the above two types. The stability of various quatity traits for different cultivars varied with the site and seeding time. Nanjing 46 with the best composited quality characters, was more sensitive to the site and sowing date.