稀土对甘蔗增产增糖机理的探讨

以盆栽试验为主,结合大田生产试验来研究稀土微肥对甘蔗增产增糖的机理。研究结果表明,稀土能提高甘蔗叶片叶绿素含量,改善叶片的超微结构,增加叶肉细胞和维管束鞘细胞的叶绿体数,增加叶肉细胞叶绿体中的基粒数和基粒片层数,增大叶片光合膜面积,能促进根系生长,提高根系活力,促进根系对N、P、K等营养元素的吸收;能提高甘蔗体内K、Ca、Zn、Cu等元素的水平,而相对降低Mn、Na等元素的水平;能提高甘蔗伸长期叶片酸性转化酶活性,降低成熟期叶片酸性转化酶活性,提高伸长期及成熟期叶片中性转化酶活性,协调甘蔗的生长和蔗糖分的积累,能调节细胞的渗透压,维持细胞膜结构和功能的稳定性和完整性,增强细胞壁的伸缩性,提高甘蔗的抗旱性;能改善质膜的透性,提高其选择吸收能力,减轻高浓度Na~+的毒害,提高甘蔗的耐盐能力。

STUDY ON THE MECHANISM OF INCREASED YIELD AND INCREASED SUCROSE CONTENT OF SUGARCANE SPRAYED WITH RARE EARTH SOLUTIONS

The mechanism of increased yield and sucrose content of sugarcane sprayed with rare earth (RE) solution was studied by means of pot experiments and field production experiments. The results showed that RE could increase the chlorophyll content and improve the ultrastructure of leaves and increase the number of grana and grana lamellae in the chloroplasts. So. it could increase the area of the photosynthetic membranes and the photosynthesis rate of the sugarcane. It could increase the activity of roots and promote the absorption of more N. P and K. and enhance nutrition metabolism. Sugarcane sprayed with RE solution had high levels of K. Ca. Zn. Cu and relatively low levels of Mn and Na. RE might regulate cane growth by regulating the balance of nutrient elements in the sugarcane.Tbe activity of acid and neutral invertases was raised in the stem elongation stage. But in the maturity stage, the activity of acid invertase was lowered while the activity of neutral invertase still remained very high. The sugarcane sprayed with RE solution grew quickly in the elongation stage and slowed down in the mature period to accumulate sucrose. RE could raise the drought resistance of sugarcane by maintaining the structure and function of the plasmolemma. controlling the osmotic pressure of cells and raising the plasticity of cell walls. It could also raise the salt tolerance of sugarcane by improving the permeability and the selective absorption of the plasmolemma. thus decreasing the harm due to high Na + content.