长江中下游地区常规中熟粳稻产量、品质及氮素吸收性状的相互关系分析

Relationships among grain yield,rice quality and nitrogen uptake of inbred middle-ripe japonica rice in the middle and lower reaches of Yangtze River

于2017—2018年分别收集长江中下游地区90份和105份常规中熟粳稻品种(系)为材料,研究各供试品种(系)的产量、稻米品质以及氮素吸收量,对产量、品质、氮素吸收之间的相互关系进行系统分析,以期探索长江中下游地区常规中熟粳稻产量、品质和氮素吸收协同提升途径。结果表明,产量与千粒重、穗粒数呈极显著正相关,与结实率呈负相关,与有效穗数相关性不显著。穗粒数对产量的直接促进作用最大,而有效穗数通过其他产量构成因素对产量形成的限制作用最大,千粒重通过其他产量构成因素对产量形成的限制作用最小。总吸氮量与茎、叶、穗的干重均呈极显著正相关,与茎、叶、穗含氮率相关性较弱,增加茎、叶、穗的干重是增加氮素吸收量的有效途径。直链淀粉、蛋白质与稻米加工品质、外观品质以及稻米食味均存在显著的相关性,降低直链淀粉和蛋白质含量,有利于提升稻米食味品质,但不利于加工品质和外观品质的改善。影响产量的关键指标千粒重、穗粒数与影响氮素吸收的关键指标茎干重、叶干重、穗干重均呈极显著正相关。直链淀粉与茎干重、叶干重、穗干重、千粒重以及穗粒数无显著相关性,而蛋白质与茎干重、叶干重、穗干重、千粒重、穗粒数总体呈负相关。综上所述,在直链淀粉淀粉含量相对较低的品种中,选择生物量较大,且穗粒数较多、千粒重较高的品种,能够实现长江中下游地区常规中熟粳稻产量、氮素吸收以及食味品质的协同提升,但这可能不利于加工以及外观品质的改善,有待于进一步研究其中的平衡关系。

In 2017 and 2018,90 and 105 inbred middle-ripe japonica rice varieties(lines)in the middle and lower reaches of Yangtze River were collected and planted in a unified way,and grain yield,rice quality and nitrogen uptake of each variety were measured at mature stage.The relationships among grain yield,rice quality and nitrogen uptake were analyzed,so as to clarify the coordinated improvement path of grain yield,rice quality and nitrogen uptake of inbred middle-ripe japonica rice in the middle and lower reaches of Yangtze River.The results indicated that grain yield was significantly positive correlated with spikelet per panicle and 1000-grain weight,and negatively correlated with percentage of filled grains.There was no significant correlation between grain yield and the number of effective panicles.Spikelet per panicle had the greatest direct path coefficient to grain yield,the number of effective panicles had the greatest limiting effect on yield formation through other yield components,and 1000-grain weight had the least limiting effect on yield formation through other yield components.The total nitrogen uptake was significantly positive correlated with the dry matter weight of stem,leaf and panicle.Path analysis showed that increasing biomass had a positive effect on increasing nitrogen uptake.Amylose and protein were significantly correlated with rice milling quality,appearance quality and taste value.Reducing amylose and protein content was beneficial to improve eating quality,but not conducive to the improvement of milling and appearance quality.The results of correlation analysis showed that there was a significant positive correlation between 1000-grain weight,spikelet per panicle,dry weight of stem,leaf and panicle.There was no significant correlation between dry weight of stem,leaf and panicle,1000-grain weight,spikelet per panicle and amylose content,but they were significantly negatively correlated with protein content.To sum up,the selection of varieties with low amylose content among those with large biomass,suitable population spikelet and higher 1000-grain weight would be an effective way to realize the coordinated improvement of grain yield,nitrogen uptake and eating quality of inbred middle-ripe japonica rice in the middle and lower reaches of Yangtze River.However,this may not be conducive to the improvement of milling and appearance quality and it needs to be further studied.