收获期对北方杂交粳稻和常规粳稻品质的影响

研究不同收获时期对北方杂交粳稻和常规粳稻米质性状的影响,为今后从栽培措施上改良杂交粳稻和常规粳稻的米质提供理论依据。以2个杂交粳稻和3个常规粳稻为试验材料,从齐穗后30d开始,每7d取样收获1次,共取样收获7次,风干后统一测定米质性状。结果表明,不同收获时期对杂交粳稻和常规粳稻的糙米率、精米率、整精米率影响显著,随着收获时期的延后,糙米率、精米率先逐渐增加,在齐穗后65d达到最大值后显著降低,整精米率在齐穗后65d之前波动较大,无明显规律性,齐穗后65d之后显著下降;杂交粳稻的垩白粒率、垩白度整体呈上升趋势,常规粳稻的垩白粒率、垩白度整体差异不显著,5个品种的白度值整体均呈上升趋势。不同收获时期对蛋白质和直链淀粉含量的影响大多未达显著水平。食味值除丰锦品种在不同收获时期间差异不显著外,其他4个品种随收获时期的推迟整体呈下降趋势,在0.05显著水平上有差异,在0.01显著水平上差异大多不显著。同一收获时期间比较,常规粳稻的加工品质（包括糙米率、精米率和整精米率）显著优于杂交粳稻,杂交粳稻的白度值显著优于常规粳稻。在垩白粒率和垩白度性状的表现上,杂交粳稻和常规粳稻间的差异未达显著水平。杂交粳稻和常规粳稻在直链淀粉含量、蛋白质含量和食味值间并无显著的差异,在最佳收获期上也无显著差异。若要改善加工品质,需适当延后收获,一般在齐穗后58d收获较好;若要改善外观品质,提高食味值,则需适当提前收获,在齐穗后30~37d收获较好。

Effects of Harvest Time on Quality Traits of Hybrid Japonica Rice and Inbred Japonica Rice in Northern China

The effects of different harvest time on the rice quality of japonica hybrid rice and inbred japonica rice in Northern China were studied to provide the theoretical basis for improving the quality of hybrid japonica rice and inbred japonica rice through adjusting cultivation measures. Two hybrid japonica rice varieties and three inbred japonica rice varieties were used as test materials. Sampled every 7 days after 30 days from the full heading, quality traits were measured after air drying. The results showed that the effects of different harvest time on the brown rice rate, the milled rice rate and head rice rate of hybrid japonica rice and inbred japonica rice were significant. With the delay of harvest time, the brown rice rate and milled rice rate increased gradually and reached a maximum at 65 days after heading stage, and then decreased sharply. The head rice rate fluctuated significantly with no obvious regularity before 65 days after heading, but decreased significantly after 65 days after heading; The chalkiness rate and chalkiness degree of hybrid japonica rice showed an increasing trend. There was no significant difference on chalkiness rate and chalkiness degree in the inbred japonica rice varieties. An increasing trend was found on the whiteness value of the five cultivars. Most of the effects of different harvest time on the protein and amylose content did not reach a significant level. Except for Fengjin was no significant difference in taste value among different harvest time treatments, the other four varieties decreased with the postponement of harvest time and there was a significant difference at the level of 0.05 but no distinctive difference at the level of 0.01.During the same harvesting time, the processing quality (including brown rice rate, milled rice rate and head rice rate) of inbred japonica rice was significantly better than that of hybrid japonica rice, and the whiteness of hybrid japonica rice was significantly better than that of inbred japonica rice. The difference between inbred japonica rice and japonica hybrid rice on chalky grain rate and chalkiness degree was not significant, the same on amylose content, protein content and taste value. There were no significant differences on the best harvest time. The suitable delay of harvest could promote the improvement of processing quality, usually on 58 days after full heading. The suitable advance of harvest could promote the improvement of appearance quality and taste value, preferably from 30 to 37 days after full heading.