The growth laws of leaves of flue-cured tobacco in different positions in various periods were summarized. The results showed that the growth speed of new leaves of flue-cured tobacco increased constantly until their ...The growth laws of leaves of flue-cured tobacco in different positions in various periods were summarized. The results showed that the growth speed of new leaves of flue-cured tobacco increased constantly until their growth was the fastest, and then it reduced irreversibly. The length and width of leaves in each position increased fastest when they grew depending on photosynthates instead of or- ganic compounds from functional leaves. Therefore, it is concluded that the increases of leaf length, width and area, and dry matter, and the peak of photosynthetic rate appear successively during the process of leaves of flue-cured tobacco, and the leaf area correction coefficient of leaves of flue-cured tobacco is related to the shape of leaves, which are affected by leaf position and the variety of flue-cured tobacco. The study can provide scientific reference for further research on the growth laws of leaves of flue-cured tobacco.展开更多
选用美棉33B和泗棉3号两个叶色深浅差异明显的品种,设置氮素水平(0、120、240、360和480 kg hm-2纯氮)试验,研究棉花主茎叶SPAD值的叶位分布,对棉花进行氮素营养诊断。结果表明,棉花主茎顶部4张定型叶片的SPAD值对施氮水平反应的敏感程...选用美棉33B和泗棉3号两个叶色深浅差异明显的品种,设置氮素水平(0、120、240、360和480 kg hm-2纯氮)试验,研究棉花主茎叶SPAD值的叶位分布,对棉花进行氮素营养诊断。结果表明,棉花主茎顶部4张定型叶片的SPAD值对施氮水平反应的敏感程度存在显著差异,随施氮量增加,棉花主茎顶1、2、3、4定型叶SPAD值的大小位次发生明显变化,其中以顶1定型叶对施氮量增加的响应最为敏感,顶4定型叶最为迟钝。利用顶1定型叶与顶4定型叶SPAD值的相对差值,可较精确地诊断棉花的氮素营养水平,并能克服品种和生育时期不同的影响,是一种具有普适性的棉花氮素营养诊断指标。展开更多
为探索地域及部位对烤烟成熟鲜烟叶化学成分的影响,采用红花大金元品种在昆明烟区海拔1920和1650 m 2个试点对3个部位成熟鲜烟叶的10种化学成分进行同步研究。结果表明,①总糖、还原糖含量在叶片中自下而上的增减趋势与海拔关系密切,高...为探索地域及部位对烤烟成熟鲜烟叶化学成分的影响,采用红花大金元品种在昆明烟区海拔1920和1650 m 2个试点对3个部位成熟鲜烟叶的10种化学成分进行同步研究。结果表明,①总糖、还原糖含量在叶片中自下而上的增减趋势与海拔关系密切,高海拔点呈递减趋势,低海拔点呈递增趋势,而其他8种成分的变化趋势2个点基本一致,主要受叶片生长部位控制。②成熟鲜烟叶蛋白质、总多酚和总氮含量在叶片中自下而上呈递增趋势,淀粉含量呈"抛物线"变化,下部叶和中部叶两地含量差异较小,仅上部叶含量差异较大。③成熟鲜烟叶石油醚提取物、烟碱、挥发碱和挥发酸含量均随部位的升高而递增,两地间的含量差异是上部叶最大,中部叶次之,下部叶最小。展开更多
文摘The growth laws of leaves of flue-cured tobacco in different positions in various periods were summarized. The results showed that the growth speed of new leaves of flue-cured tobacco increased constantly until their growth was the fastest, and then it reduced irreversibly. The length and width of leaves in each position increased fastest when they grew depending on photosynthates instead of or- ganic compounds from functional leaves. Therefore, it is concluded that the increases of leaf length, width and area, and dry matter, and the peak of photosynthetic rate appear successively during the process of leaves of flue-cured tobacco, and the leaf area correction coefficient of leaves of flue-cured tobacco is related to the shape of leaves, which are affected by leaf position and the variety of flue-cured tobacco. The study can provide scientific reference for further research on the growth laws of leaves of flue-cured tobacco.
文摘选用美棉33B和泗棉3号两个叶色深浅差异明显的品种,设置氮素水平(0、120、240、360和480 kg hm-2纯氮)试验,研究棉花主茎叶SPAD值的叶位分布,对棉花进行氮素营养诊断。结果表明,棉花主茎顶部4张定型叶片的SPAD值对施氮水平反应的敏感程度存在显著差异,随施氮量增加,棉花主茎顶1、2、3、4定型叶SPAD值的大小位次发生明显变化,其中以顶1定型叶对施氮量增加的响应最为敏感,顶4定型叶最为迟钝。利用顶1定型叶与顶4定型叶SPAD值的相对差值,可较精确地诊断棉花的氮素营养水平,并能克服品种和生育时期不同的影响,是一种具有普适性的棉花氮素营养诊断指标。
文摘为探索地域及部位对烤烟成熟鲜烟叶化学成分的影响,采用红花大金元品种在昆明烟区海拔1920和1650 m 2个试点对3个部位成熟鲜烟叶的10种化学成分进行同步研究。结果表明,①总糖、还原糖含量在叶片中自下而上的增减趋势与海拔关系密切,高海拔点呈递减趋势,低海拔点呈递增趋势,而其他8种成分的变化趋势2个点基本一致,主要受叶片生长部位控制。②成熟鲜烟叶蛋白质、总多酚和总氮含量在叶片中自下而上呈递增趋势,淀粉含量呈"抛物线"变化,下部叶和中部叶两地含量差异较小,仅上部叶含量差异较大。③成熟鲜烟叶石油醚提取物、烟碱、挥发碱和挥发酸含量均随部位的升高而递增,两地间的含量差异是上部叶最大,中部叶次之,下部叶最小。
