【作者】 邹养军；

【导师】 李嘉瑞；

【作者基本信息】 西北农林科技大学 ， 果树学， 2006， 博士

【摘要】 我国农业生产同时存在水资源严重不足和灌溉浪费水严重的双重矛盾。根系分区灌水是一种地面灌溉新技术,每次仅部分根系灌水,根系始终处于干湿交替状态,这样干旱根系会产生土壤干旱信号物质,使气孔导度在叶片水分状况未发生明显变化时下降,降低蒸腾使植株从奢侈用水变为节约用水。本研究以根系分成相等4部分的皇家嘎拉苹果2～3年生盆栽植株为试材,研究了1/4、2/4、3/4根系体积交替和固定位灌水植株的水分状况、根系与枝叶生长、叶片生理功能、内源激素、植株抗旱性以及节水效率等变化规律;同时在盛果期红富士苹果上进行了树盘分区局部灌水的初步应用研究。主要结果如下:1.苹果1/4、2/4、3/4根系体积灌水处理较全根系灌水处理分别减少灌水量75%、50%、25%,其中2/4、3/4根系分区交替灌水处理,在整个生育期均能满足植株的水分需求,叶水势和叶片相对含水量同全根系灌水处理差异不显著,1/4根系分区交替灌水在夏秋高温季节不能满足植株对水分的需求,内膛小叶黄化;1/4、2/4、3/4根系体积从萌芽后开始持续固定位灌水时,植株水分状况正常。2.苹果1/4、2/4根系体积灌水,新梢生长速率较全根系灌水植株分别降低37.3%、28.6%,叶片的生长速率降低了63.3%、48.9%,处理3周后80%以上的新梢停长,最终影响了植株枝类组成,使长度小于30cm的枝条比例增大,长度大于60cm的枝条比例降低,来年开花株率、花序数量、坐果率均较全根系灌水增加,3/4根系体积灌水控梢成花效应不显著。3.苹果2/4、3/4根系交替灌水使根系分布更加均匀,提高了根系活力,表现出补偿生长,各类粗度的根系生物量均增加,植株根冠比增大;苹果根系分区固定位灌水时,湿区根系活力提高,干区根系随着干旱程度加重根系活力逐步降低,湿区根系补偿生长,干区直径小于2mm根系逐渐死亡,根系类型以直径大于2mm的木质化根系为主。4.苹果1/4、2/4根系体积交替灌水,在处理2天后叶片气孔阻力显著大于全根系灌水植株,而且根系干旱的体积愈大,气孔阻力也愈大,较全根系灌水植株最大可增加1.14倍、0.77倍,同时叶片净光合速率降低23.3%、11.2%,叶片蒸腾速率下降了41.8%、31.3%,蒸腾速率下降的幅度比净光合速率大,因此提高了水分利用效率,并且这种较高的水分利用效率伴随着根系的干湿交替灌水可以持续。5.苹果1/4、2/4根系体积交替灌水,叶片中玉米素、赤霉素、吲哚乙酸含量较全更多还原

【Abstract】 There are two serious problems in Chinese agriculture. The water resource is not enough for agriculture but most of water were wasted because of flood irrigation. Partial rootzone irrigation (PRI) is a novel irrigation technique which improves the water use efficiency when the production isn’t decreased. The technique requires that only partial root system is always maintained in a dry or drying state while the remainder of the root system is irrigated. The wetted and dried sides of the root system are alternated after a period of time. In experiment we used two or three years old splits–root potted apple trees (Royal Gala), where the root system was divided between four containers. There are five experiment groups of irrigations : complete irrigated part, 3/4, 2/4, 1/4 and no irrigation part. In the condition of no rainfall we had studied only 1/4, 2/4, 3/4 rootzone alternative or fixed irrigating apple trees’condition of water, growth of roots and shoots, the changes of plant’s physiological functions, endogenous hormones, drought resistance and water use efficiency and so on. We also had studied on the grown Fuji apple trees of applying partial rootzone irrigation. The main results are as follows:1. Only 1/4, 2/4, 3/4 rootzone irrigation can save water quantity 75%, 50%, 25% than whole rootzone irrigation. But the plants of only 2/4, 3/4 rootzone alternant irrigation could satisfy the needing of water in the whole growth moment, whose leaves water potential and leaf water relative content are the same with the whole rootzone irrigating plants. Only 1/4 rootzone irrigation can not apply enough water for apple plants in summer or autumn, whose small leaves was etiolated. The plants of only 1/4, 2/4, 3/4 rootzone fixed irrigation from the rudimentary could sustain the well-balanced water condition.2. The shoot growth rate of the plants of only 1/4, 2/4 rootzone irrigation decreased about 37.3%, 28.6% the whole rootzone irrigated plants.flowering trees and number of buds and the rates of fruits setting were increased than the plants of whole rootzone irrigation. But only 3/4 rootzone irrigated plants had not significant difference with the plants of whole rootzone irrigation.3. The distribution of root’s density of plants only 2/4, 3/4 rootzone alternant irrigation were more well-proportioned in the soil than the whole rootzone irrigated plants. The plants更多还原