【作者】 张绍阳；

【导师】 杨军；

【作者基本信息】 安徽农业大学 ， 果树学， 2008， 硕士

【摘要】 生产优质果品是当前果品发展的一种重要趋势。然而,目前所生产的油桃果实大多都存在着许多品质问题。光合作用所合成的碳水化合物是果实品质形成的物质基础,与果实品质关系极其密切。钾营养是果树生长发育过程中一种十分重要的大量元素,对于增进果树的光合性能和促进光合同化产物运转都具有非常的积极作用,其对果实品质发展也具有很大的作用。然而目前有关此方面的研究报道很少。所以,本试验通过研究四种不同钾营养水平（NPK₀即CK、NPK₁、NPK₂和NPK₃）对四年生艳光油桃光合特性和果实质量的影响,初步探讨钾营养提高果实品质的机理,以期为油桃生产钾肥合理施用提高果实品质提供理论指导和实践参考。主要研究结论如下。1.钾营养能够增加油桃叶片的内含物质。施用钾肥可以提高艳光油桃叶片的钾营养含量、叶绿素a含量、总叶绿素含量、叶绿素a与叶绿素b比值以及比叶重,进而促进光能的吸收与传递和光合产物的同化和积累。2.钾营养能够改善油桃叶片的叶绿素荧光特性。合理施用钾肥可以降低艳光油桃叶片的Fo和qN以减少光能的无效损耗,提高Fm、Fv、Fv/Fo、Fv/Fm、Yield以及qP来增强光系统Ⅱ（PSⅡ）的潜在活性和原初光能转化效率,进而提高光量子产额和原初光能转化能力,从而改善艳光油桃的原初反应特性。3.钾营养可以改善油桃叶片的光合特性。钾营养可以通过提高油桃叶片的气孔导度,促进叶片蒸腾作用来调节叶表温度和提高水分利用效率,同时促进CO₂在叶片细胞内的吸收和固定,从而提高了油桃叶片的光合速率和光合利用能力,进而加强了叶片内光合物质的同化和积累过程。4.钾营养对油桃叶片利用光照具有调节作用。合理增施钾肥能够增加艳光油桃叶片的光合利用效率和光合作用最大潜力,提高其在通常光强下的净光合速率;同时,还能够增强艳光油桃叶片对弱光的利用能力,但是,其对强光的利用能力则相对减弱,对光强的适应范围也相对缩小一些。5.钾营养能够显著提高油桃的果实品质。施用钾肥不仅可以显著地提高果实中可溶性固形物、可溶性糖、糖酸比、维生素C以及钾的含量,提高了果实的内在品质;也可以提高果实的单果重、着色指数以及果顶和果胴的L、a、b值,改善了果实的外观品质;还能够明显地减少果实裂果,增大果实硬度,延长果实常温（25℃）贮藏期和低温（5℃）贮藏期,进而改善果实的抗裂果特性和贮运特性。6.钾营养提高油桃果实质量的初步机制。钾营养可以显著地提高艳光油桃的光合特性,促进叶片光合产物的转化和积累,为果实生长发育提供物质基础。而且,还可能由于钾营养又能够促进光合产物向果实中运输和果实内营养物质的转化,从而使施钾处理油桃的果实品质都比对照好,进而改善了果实品质。其中,NPK₂处理的钾肥施用水平是本试验艳光油桃适宜钾肥施用量。更多还原

【Abstract】 It’s an important tendency of present fruits’ development to yield high quality fruits. However,there are lots of quality problems in almost of the nectarine[Prunus persica var. nectarina（Air） Maxim.]fruits produced at present.Photosynthetic reaction is very close related to fruit quality,for the carbohydrates synthesized in it are the material basis of fruit quality’s formation.And potassium,a macro-element,is very important for the growth and development of fruit,which takes a very active part not only in enhancing fruiter’s photosynthetic properties and the transfer of its photosynthetic outputs,but also in developing fruit qualities.However,at present,the research reports on the aspect are very few.Therefore,the experiments primarily explored the system of potassium raising fruit qualities,with studying the effects of four different potassium nutrition levels（NPK₀ or CK、NPK₁、NPK₂ and NPK₃） on the photosynthetic characteristics and fruit quality of four-year old ’Yanguang’ nectarine,to provide theory direction and the reference of potassium fertilization applying mete.And the following are the research conclusions.1.Potassium nutrition could prompt the formation of nectarine leaves’ inner materials. Applying potassium fertilizer could increase the contents of potassium,chlorophyll a, total chlorophyll and the ratio of chlorophyll a to chlorophyll b in the leaves of ’Yanguang’ nectarine and its ratio of dry leaf weight to the correspondence leaves area, and prompted light’s absorption and passing and photosynthetic outputs’ synthesizing and accumulation.2.Potassium nutrition could improve the chlorophyll fluorescence specialty of nectarine leaves.Applying potassium fertilizer with reason could decrease the original fluorescence（Fo） and quenching of non-photoreaction（qN） to reduce the wastage of light,and raise maximal fluorescence（Fm）,variable fluorescence（Fv）,the ratios of Fv to Fo and of Fv to Fm,Yield and quench of photoreaction（qP） to enhance the potential activity and primary light transformation efficiency of photosystemⅡ（PSⅡ）,and then raised the yield of light photons and the ability of primary light transformation,and improved the primary reaction characteristics of ’Yanguang ’ nectarine. 3.Potassium nutrition could enhance the photosynthetic characteristics of nectarine leaves.With elevating the stomata conductance（Gs） of nectarine leaves,potassium nutrition could prompt their transpiration to adjust temperature of leaf（T1） and heighten water use efficiency（WUE）,and simultaneously prompted the absorption and fixation of carbon dioxide（CO₂） in the cells of leaves,and then raised net photosynthetic rate（Pn） and photosynthesis use capacity,and enhanced the assimilation and accumulation of photosynthetic matter in leaves.4.To some extent,potassium nutrition took a part in the light utility of nectarine leaves. Raising the applying quality of potassium fertilizer in reason could increase the photosynthetic use efficiency（PUE） and maximum photosynthetic potential（Pm） of ’Yanguang’ and raised the net photosynthetic rate under usual light.Simultaneously,it could enhance the weak light utility of ’Yanguang’ nectarine leaves,but slacked strong light utility of them and dwindled the proper scope of light.5.Potassium nutrition could raise nectarine fruit quality significantly.Potassium fertilization could not only improve the fruit inner quality significantly due to raising the contents of soluble solid content,soluble sugar,ratio of sugar to acid,vitamin C and mineral K,but also beautify the fruit appearance through heightening single fruit weight and pigmentation index and the value of L,a and b of fruit tip and fruit body. Additionally,it could decrease fruit cracking rate,increase fruit firmness and lengthen fruit preservation periods under normal temperature（25℃） and low temperature（5℃） separately,so as to elevate the characteristics of resistance to fruit cracking and preservation.6.The primary system of potassium raising the fruit quality of nectarine.Potassium nutrition could elevate the photosynthetic characteristics of ’Yanguang’ nectarine and prompt the transformation and accumulation of its leaves’ photosynthetic output so as to provide material basis to the growth and development of fruit.Besides that,it was also likely to accelerate the transportation of photosynthetic yield to fruit and the transformation of nutrition materials in fruit.So the fruit quality of ’Yanguang’ nectarine was improved.And the potassium fertilizer applying level of NPK₂ was the proper potassium fertilizer applying quality of ’Yanguang’ nectarine in the experiments.更多还原