【作者】 孙协平；

【导师】 马锋旺；

【作者基本信息】 西北农林科技大学 ， 果树学， 2013， 博士

【摘要】 我国西北干旱半干旱地区水资源短缺是苹果产业发展的主要限制因素，提高水分利用效率对苹果生产效益的提高和可持续具有重要意义，而筛选合适的砧穗组合是提高水分利用效率（WUE）的一种重要手段。本试验对6个品种4个砧木的组合进行了WUE的评价，并研究了双接穗和双砧木法对苹果WUE的影响。为旱区果园选择适宜的砧穗组合以及矮化砧木的发展提供一定的指导。主要研究结果如下：1.24个苹果砧穗组合苗期的WUE存在一定的差异。中度干旱胁迫两个月，品种‘秦冠’和‘粉红女士’的WUEL较高，‘长富2号’嫁接在任何一个砧木上长期水分利用效率（WUEL）均低于在正常供水的。以平邑甜茶（MH）为砧木在中度干旱需水量最多。接穗特性决定了地上部相对干物质积累量（RDMG），而砧木对水分的需求量起决定作用，砧穗之间的交互作用对RDMG和灌溉量同样也起显著性作用。不同砧穗组合的WUEL与叶片的氮（N）磷（P）和钾（K）线性关系弱，因此在选择砧木高WUE也不能忽视营养利用效率。2.双接穗法分析‘秦冠’和‘粉红女士’在中度干旱胁迫下的WUE以及部分生理指标，结果表明双接穗处理下‘粉红女士’的光合速率（P_N）、胞间二氧化碳浓度（Ci）、气孔导度（gs）和蒸腾速率（E）均低于‘秦冠’，但是‘粉红女士’的叶片水平上的WUE（P_N/gs）高于‘秦冠’。‘秦冠’的RDMG和WUEL大于‘粉红女士’。叶片‘秦冠’的K和N的含量高于‘粉红女士’，P的含量两者相似。以上结果与两个品种单接穗处理结果一致。3.富平楸子（MP）和T337砧木靠接后嫁接品种‘红盖露’，在中度干旱胁迫下，株高变化趋势和WUEL一致为MP>双砧木>T337，光合参数动态变化中，总体上P_N、gs、E的变化趋势同样也为MP>双砧木>T337。不同砧木处理对根系的影响最大，在干旱胁迫下，单砧木处理T337侧根根系干物质显著低于MP，双砧木处理时，两种砧木侧根差异不显著。在茎流方面，双砧木干旱处理的夜间出现小波动茎流量，这也是缓解干旱胁迫的一种方式。干旱胁迫对酚类物质中的芦丁和异槲皮苷的影响较大。双砧木处理能够改善T337根系的生长，且提高了WUEL。4.‘粉红女士’进行60d的中度干旱胁迫后进行交替灌溉，品种的株高、接穗和砧木的直径、总叶面积和干物质积累量升高，但是仍然显著低于正常供水。交替灌溉的茎流量高于干旱胁迫的但是显著低于正常供水。叶片平均P_N总灌溉量以及干物质积累量与WUEL呈显著线性相关。而P_N/gs与WUEL呈显著负相关。利用称重法测量的水分耗散与茎流法测量的差异较大，主要因为试验条件控制不严。5.以4个品种嫁接在八棱海棠（MB）和平邑甜茶的水分耗散和水通道表达分析表明，在中度干旱胁迫下，嫁接在MH上的气孔导度（gs）、蒸腾速率（E）、以及灌溉量均高于嫁接在MB上的，除了‘红盖露’/MH总灌溉低于嫁接在MB的。以MB为砧木时干旱胁迫下叶片水平上的水分利用效率（P_N/E和P_N/gs）和整株水平上的水分利用效率（WUEL）高于MH上的。中度干旱胁迫水控蛋白AtPIP1;1、AtPIP2;1、OsTIP1;1和OsTIP2;1在转录水平上的表达总体趋势是上调的。总之砧木调控地上部的水分耗散和叶片水平上的WUE，同时也影响整株水平上的灌溉量和WUEL。更多还原

【Abstract】 Water shortage in northwest and semi-arid areas of China is a major factor to limit appleindustry development, and indirectly influence plant responses to nutrients. Improving plantwater use efficiency (WUE) is a critical way to adapt to water deficiency. In our study, fourChinese rootstocks and six cultivars of different scion-rootstock combinations were used toresearch the growth parameters, nutrition contents and WUE, under well-watered andmoderate drought conditions. Moreover, double scion-one rootstock and one scion-tworootstock combinations were used to evaluate water transport and WUE under droughtcondition. This experiment aims at providing some guidance for arid regions orchard to selectappropriate scion combinations and dwarfing rootstock. The main contents are as follows:1. Cultivar ‘Qinguan’(QG) and ‘Pink Lady’(PL) owned the higher long-term water useefficiency (WUEL) under moderate drought condition, while ‘Fuji Nagafu No.2’(FN) hadlower WUELunder drought condition than under well-watered condition, regardless ofrootstocks. Scion genotype plays an important role in relative dry mass gain (RDMG), androotstock genotype determines total water irrigation (TWI). Meanwhile, the scion-rootstockinteraction also significantly affects RDMG and TWI. There is a weak linearity betweenWUELand nutrition contents, hence, the selection of scion-rootstock combination that ownshigher WUEL, nutritional status of plants should also be taken into consideration.2. Two cultivars in one-scion one rootstock combination performed under droughtcondition as follows: PL had higher instantaneous water use efficiency (WUEI) and SPADvalue, but had lower shoot height, dry mass of root, stem and leaf than QG. The QG leafcontents of K and N were higher than PL. P content of QG was similar to PL. All in all, QGperformed better than PL. In double-scion grafting system, double scion Qinguan (D QG) alsoperformed better than double scion Pink Lady (D PL). This study shows that larger canopycan increase plant WUEL; double-scion grafting system can truly expose that different scionsperform on gas exchange, growth parameters, SPAD value, and the nitrogen (N), phosphorus(P), potassium (K) contents as compared to one scion-one rootstock combination.3. The material was three kinds of grafting system, as one scion-two root grafting system as cultivar ‘Gale Gala’(GG) grafted on MP (Malus prunifolia (Willd) Borkh) and T337, GGgrafted on MP, and GG grafted on T337. Under moderate drought condition, the range ofplant height and WUELwere the same as MP>Double-root>T337, after2months treatment.Meanwhile, the trend of photosynthesis parameters (P_N, gs, E) was MP>Double-root>T337,too. The significant effect by the three rootstocks under drought condition was branch root drymass, which GG/T337was obviously lower than GG/MP. In two-root grafting system, branchroot dry mass of T337was slightly lower than MP. In terms of sap flow, daily plant sap flowchanged as MP>Double-root>T337. In addition, there was a small sap flow of double-root innight, which is a way to alleviate drought stress. Under moderate drought, different rootstocksare mainly affected by the rutin and isoquercitin. In a word, double rootstock can improveroot’s development and WUELcompared with one rootstock T337.4. PL applyed alternate deficit irrigation after60days drought treatment (ADI),compared with the drought-stressed plants, those treated via ADI showed better height growth,larger scion diameters, and greater totalleaf area, as well as significantly increased gains indry biomass and rootstock diameters. However, their performance was still much lower thanthose cultivated by continuously well-watered. Sap flow was greater under ADI than underdrought, but less than under control conditions. The average rate of net photosynthesis, totalamount of irrigation water applied, and dry biomass gain had highly and positively linearcorrelations with WUEL. The same was applied to average stomatal conductance and WUEL.By contrast, instantaneous water-use efficiency (WUEI) was very negatively correlated withWUEL. In addition, values for WUELwere much higher from well-watered plantswhencompared with either drought-stressed trees or those treated per ADI. Therefore, the way ofADI following a period of long-term drought can be used to improve growth and WUELbythis cultivar.5. Water transpiration and aquaporin protein expression of four cultivars grafted on MBand MH performed as follow: under moderated drought condition, the gs, E, and total waterirrigation (TWI) of4cultivars grafted on MH higher than those grafted on MB, except forTWI of GG/MH; On the leaf level WUE (P_N/E and P_N/gs), and on the whole plant level WUE(WUEL)4cultivars grafted on MB higher than grafted on MH. Under the drought condtion,the trends of aquaporins of AtPIP1;1, AtPIP2;1, OsTIP1;1, and OsTIP2;1were upward on thelevel of transcriptional. In summary, rootstock controls water transpiration aboveground andleaf WUE, as well as impacts on the whole plant irrigation and WUEL.更多还原