'两优培九'及其亲本苗期对氮素的生理响应

摘要

通过水培试验研究了"两优培九"及其亲本在不同氮素水平下的生物学特性及生理指标.结果表明,"两优培九"及其亲本各生物学性状在不同氮素水平下存在显著差异,且均受氮素水平,品种及品种和氮素水平互作的影响,表现为品种因素>氮素水平因素>两因素互作;各生物学性状中除最长根长外,均随着氮素水平的上升而增加;地上部和根系的干重、氮素积累量、叶绿素含量、光合速率均随氮素水平的上升而增加;在各氮素处理中,"两优培九"的株高,根系体积、干重、氮素积累量、叶绿素含量和光合速率均处于最高水平,表现出明显的超亲优势;随着氮素水平的提高,水稻植株吸氮量相应增加,但植株体内的氮素利用率呈现下降趋势;"两优培九"及其亲本的各项生理指标对氮素的响应趋势基本一致,但地上部和地下部对氮素的响应在品种间呈现较大差异.%The biological characteristics and physiological indices of “Liangyoupeijiu” (“LYP9”) and its parents were studied in hydroponic experiments under different nitrogen levels.The results showed significant differences in biological characteristics of both “LYP9” and its parents under different levels of nitrogen supply.Biological response of “LYP9” and its parents affected by variety, nitrogen level and their interaction with the effects order of variety factor ＞ nitrogen level factor ＞ interaction of the two factors.With the exception of the maximum root length, the biological characteristics and physiological indices such as aboveground (shoot) and belowground (root) dry weight, nitrogen accumulation, chlorophyll content and photosynthetic rate increased with increasing nitrogen level.In the study, “LYP9” showed the highest level and significant transgressive heterosis in plant height, root volume, dry matter weight, nitrogen accumulation, chlorophyll content and photosynthetic rate.Whereas total nitrogen uptake increased, nitrogen use efficiency decreased with increasing nitrogen level.Physiological response to nitrogen nutrient of “LYP9” and the parents at seedling stage was similar.Intervarietal differences existed in the response of aboveground (shoot) and belowground (root) systems to nitrogen.