黄土高原降雨梯度对刺槐不同器官内源激素分布格局及生长的影响
陈克利1, 孟 敏2, 张 鹏2, 魏芙蓉2, 王国梁2,3, 马艳萍1

(1.西北农林科技大学 林学院, 陕西 杨凌 712100; 2.西北农林科技大学 水土保持研究所, 陕西 杨凌 712100; 3.中国科学院 水利部 水土保持研究所, 陕西 杨凌 712100)

内源激素; 异速生长; 降雨梯度; 刺槐

Effects of Rainfall Gradients on the Distribution Pattern and Growth of Endogenous Hormones in Different Organs of Robinia pseudoacacia on the Loess Plateau
CHEN Keli1, MENG Min2, ZHANG Peng2, WEI Furong2, WANG Guoliang2,3, MA Yanping1

(1.College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China; 2.Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China; 3.Institute of Soil and Water Conservation, Chinese Academy of Sciences and ministry of Water Resources, Yangling, Shaanxi 712100, China)

endogenous hormone; allometric growth; rainfall gradient; Robinia pseudoacacia

备注

环境梯度如何影响树木不同器官内源激素分布格局,以及该内源激素格局变化如何影响树木不同器官的异速生长,目前尚不是十分清楚。选择黄土高原地区不同降雨量梯度神木(440.8 mm/a)、绥德(475.4 mm/a)、安塞(505.3 mm/a)和淳化(606.1 mm/a)地区的刺槐林为材料,比较其叶、枝和不同径级根(最细根(0～1 mm)、细根(1～2 mm)、粗根(2～5 mm))内源激素含量及其对器官生长的影响。结果 表明:(1)随着降雨量增加,3种器官中玉米素核苷(ZR)、赤霉素(GA3)含量增加,脱落酸(ABA)含量整体下降; 不同径级根系中w(ZR+GA3+IAA)/w(ABA),w(GA3)/w(ABA),w(ZR)/w(ABA),w(IAA)/w(ABA)比值增加,但不同器官增幅不一致。淳化地区刺槐叶,枝,最细根,细根和粗根中GA3含量比神木地区分别高55%,21%,274%,376%和279%。(2)降雨量相对较高的安塞和淳化地区刺槐各器官年均累积量均显著高于降雨量相对较低的绥德和神木地区(p3和IAA)含量主要受降雨量和土壤全氮(TN)影响。(4)根系生物量与ZR和w(ZR)/w(ABA)呈显著正相关,w(GA3)/w(ABA)和w(ZR)/w(ABA)比值与枝生物量显著负相关。沿着降雨梯度,降雨量和土壤TN通过增加不同径级根系中ZR,GA3和IAA含量从而促进刺槐根系的异速生长。

How environmental gradients affect the distribution pattern of endogenous hormones in different organs of trees, and how the changes in endogenous hormone patterns affect the allometric growth of different organs of trees are still not very clear. This study selected different rainfall gradients of Shenmu(440.8 mm/a), Suide(475.4 mm/a), Ansai(505.1 mm/a)and Chunhua(606.1 mm/a)in the Loess Plateau. Robinia pseudoacacia's leaves, branches and roots of different diameters(the finest root(0～1 mm), fine root(1～2 mm), coarse root(2～5 mm))content and their effect on organ growth were compared. The results showed that:(1)with the increase of rainfall, the contents of zeatin nucleoside(ZR)and gibberellic acid(GA3)increased, and the content of abscisic acid(ABA)decreased in all organs; the ratio of different diameter roots w(ZR+ GA3+IAA)/w(ABA), w(GA3)/w(ABA), w(ZR)/w(ABA), w(IAA)/w(ABA)increased, but the growth of different organs was inconsistent; in Chunhua area, the GA3 contents in the leaves, branches, finest roots, fine roots and coarse roots of the locusts were 55%, 21%, 274%, 376% and 279% higher than those in Shenmu area;(2)the average annual accumulation of the organs of Robinia pseudoacacia in Ansai and Chunhua areas with relatively high rainfall was significantly higher than that in Suide and Shenmu areas with relatively low rainfall (p3 and IAA)are mainly affected by rainfall and soil total nitrogen(TN);(4)there is the significant positive correlation between root biomass and ZR and w(ZR)/w(ABA)content, and w(GA3)/w(ABA)and w(ZR)/w(ABA)ratios are significantly negatively correlated with shoot biomass. Along the rainfall gradient, rainfall and soil TN promote the allometric growth of the roots of Robinia pseudoacacia by promoting the contents of ZR, GA3 and IAA in roots of different diameter classes.