论文标题:氮、磷营养供应对落叶松幼苗内源激素的影响
Effect of Nitrogen and Phosphorus Supply on Endogenous Phytohormones of Larch Seedlings
论文作者 白冰
论文导师 阎秀峰,论文学位 硕士,论文专业 生态学
论文单位 东北林业大学,点击次数 107,论文页数 54页File Size2177k
2005-05-01论文网 http://www.lw23.com/lunwen_413803637/ 落叶松;生长素;赤霉素;细胞分裂素;脱落酸
Larch; auxin; gibberellin; cytokinin; abscisic acid
落叶松(Larix gmelinii)是我国东北地区的重要造林树种。但由于东北地区冬季时间长、气温低,凋落物的分解及有机物的矿化过程较为缓慢,林地氮、磷营养常常成为落叶松生长的限制因子。同时植物也能通过调节自身的生理过程,以减少营养变化对自身的影响。本研究设置低氮(0 mmol/L)、正常供氮(8 mmol/L)、高氮(16 mmol/L)三个供氮浓度梯度,和低磷(0 mmol/L)、正常供磷(1 mmol/L)、高磷(2 mmol/L)三个供磷浓度梯度,观察不同氮、磷营养水平处理第40天和第80天时落叶松幼苗内源激素(IAA、ABA、GA_3、ZR)的浓度,结果表明: 1、低氮和高氮处理均使落叶松幼苗根的IAA浓度暂时高于正常供氮植株,第80天时又均低于正常供氮植株;低氮和高氮处理的落叶松幼苗根的GA_3浓度比正常供氮水平的低;低氮和高氮处理对根的ZR浓度的调控表现在不同时期,但基本上与供氮水平呈负相关;低氮和高氮处理落叶松幼苗根的ABA浓度比正常供氮植株的高。 低氮处理对落叶松幼苗针叶的IAA、GA_3浓度的影响不明显;高氮处理第40天时,植株针叶的IAA、GA_3浓度比正常供氮植株的高,到处理第80天时又恢复到与正常供氮的一致。低氮和高氮处理针叶的ZR浓度都比正常供氮的低;除高氮处理第80天植株针叶ABA浓度显著升高外,低氮和高氮处理均使植株ABA浓度降低。 2、低磷和高磷处理第40天时根的IAA浓度比正常供磷的高,处理第80天时根的IAA浓度与供磷水平呈负相关;低磷和高磷处理的落叶松幼苗根的GA_3和ZR浓度都比正常供磷的低;在磷素营养处理过程中,根的ABA浓度始终与磷素供应水平呈负相关。 低磷、高磷处理落叶松幼苗针叶的IAA、GA_3浓度与正常供磷的差异不大。磷素营养处理第40天时针叶的ZR浓度与磷素供应水平呈明显的正相关,而到处理第80天时,针叶的ZR浓度与磷素供应水平又呈明显的负相关。低磷和高磷处理均使针叶ABA浓度降低。 并简要探讨了内源激素在氮、磷营养影响落叶松幼苗生长过程中所起的调节作用,以及在落叶松幼苗对氮、磷营养变化作出适应性反应的过程中内源激素所起的作用。
Larch {Larix gmelinii) is an important sylvicultural species in northeast China. However, the growth of Larch is often limited by nitrogen and phosphorus shortage for slow decomposition rate of litter resulting from low temperature and long winter in northeast area. Plant can also adjust physiological process to lessen influence of external nutritional conditions. In the present research, the nitrogen nutritional gradients were nitrogen deficiency (0 mmol/L), control (8 mmol/L) and high nitrogen (16 mmol/L). The phosphorus nutritional gradients were phosphorus deficiency (0 mmol/L), control (1 mmol/L) and high phosphorus (2 mmol/L). Endogenous phytohormones (IAA、ABA、GA_3、 ZR) of seedlings under different nutritional conditions were measured on the 40th and the 80th day after treatment. The results showed as follows:1. IAA level in seedling root under nitrogen deficiency and high nitrogen supply was both higher than the control on the 40th day, and lower than the control on the 80th day. Treatments with both nitrogen deficiency and high nitrogen supply decreased GA3 concentration in root. There is a positive correlation between ZR level in root and external nitrogen supply. ZR level in the root under nitrogen deficiency and high nitrogen conditions was higher than the control.Treatment with nintrogen deficiency, IAA and GA3 concentrations in needles had no difference from the control. After 40 days of treatment with high nitrogen, IAA and GA3 concentrations in needles were higher than the control, but on the 80th day they are both went back to the control level. Both treatments with nitrogen deficiency and high nitrogen decreased ZR level in needles. Except on the 80th day of high nitrogen treatment, ABA concentrations were all lower than the control.2. IAA level in root of Seedlings under phosphorus deficiency and high phosphorus supply were both higher than the control on the 40th day, however it was negatively regulated by external phosphorus nutrition conditions. Treatments with both phosphorus deficiency and high phosphorus decreased GA3 and ZR concentritions in root. ABA level in root is always negatively related to external phosphorus nutrition.IAA and GA3 concentrations in needles were steady in different phosphorus levels. Positive relationship between ZR level in needles and phosphorus nutrition condition was found on the 40th day after treatment, and negative relationship was done on the 80th day. Treatments with both phosphorus deficiency and high phosphorus level decreased ABA concentrition in needles.We have also briefly discussed the regulational role of endogenous phytohormones on the growth of Larch seedlings under different nitrogen and phosphorus nutritional conditions, and the possible functions of endogenous phytohormones in the course of Larch seedlings adapting to the change of nitrogen and phosphorus nutritional conditions.
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