硅肥对甘蔗叶片一些光合特性的影响

Effects of Silicate on Some Photosynthetic Characteristics of Sugarcane Leaves

探讨了硅肥对甘蔗叶片光合特性的影响,尤其对上部叶和下部叶进行比较,测定了叶绿素含量、硝酸还原酶活性、叶面积指数、叶片的夜间光合产物输出量。结果表明:施硅能增加甘蔗的叶绿素含量,尤其是下部叶的叶绿素含量;能提高下部叶的硝酸还原酶活性;能延长叶片的功能期,增加群体叶面积系数;增加了中下部叶片的夜间光合产物输出量。传统上对于甘蔗生理生化性状的研究一般都是取+1叶进行测定,本研究发现硅肥对于甘蔗上下部叶作用的差异性,有必要对甘蔗下部叶作更多的研究;在甘蔗生产中有剥除老叶习惯的地方,施用硅肥之后,可以多留1片叶。

Effects of silicate on some photosynthetic characteristics of sugarcane leaves were studied. The upper and lower leaves were compared,including leaf water content, water potential, leaf erectness, chlorophyll content,activity of nitrate reductase, leaf area index and photosynthate amount exported out of leaves in the night. Results indicated that silicate increased water content, water potential, chlorophyll content of sugarcane leaf, especially that of the lower leaves. Silicate increased activity of nitrate reductase （NR） of lower （old） leaves, prolonged the functional period of leaf and increased the leaf area index of the population. Silicate increased photosynthate transported amount out of middle and lower leaves in the night, implying an increased contribution of photosynthates contributed by the middle and lower leaves to the plant. Traditionally, ＋1 leaves were sampled in studies of physiological and biochemical characteristics of sugarcane. Results revealed that significant differences existed between upper leaves and lower leaves in physiological characteristics. In sugarcane cultivation regions where lower old leaves were cleared off, one more lower leaf could be left on the cane plant if silicate is applied.