【作者】 储昭胜；

【导师】 吴震； 刘明池；

【作者基本信息】 南京农业大学 ， 蔬菜学， 2011， 硕士

【摘要】 黄瓜(Cucumis sativus L.)是世界各地广为栽培的重要蔬菜作物之一。嫁接是增强瓜果类蔬菜抗逆性、克服连作障碍的有效技术措施,目前已广泛用于黄瓜生产,但传统的嫁接方式都是以单砧木嫁接为基础的,由于砧木资源的限制,许多砧木仅具有专一性或独特性的作用,如黄瓜常用砧木黑籽南瓜虽能增强抗逆性提高产量,但商品性和品质下降。针对此现象,本试验以能提高抗逆性和产量的云南‘黑籽南瓜’与具有改善品质作用的‘京欣砧5号’南瓜为砧木对黄瓜进行单砧木和双砧木嫁接,探讨双砧木嫁接及其在不同氮素水平和模拟干旱胁迫下黄瓜生理特性和产量品质的变化。主要研究结果如下：1.双砧木嫁接综合了两单砧木各自的优良特性。单砧木和双砧木嫁接均显著增强根系对水分和养分的吸收,提高水肥利用率,促进植株生长；双砧木嫁接黄瓜果实产量、瓜数和单果重均高于京欣单砧和自根对照；双砧嫁接显著提高果实可溶性糖的含量,且果实维生素C(Vc)的含量和糖酸比高于黑籽单砧和自根对照,克服了单砧嫁接导致果柄变长的缺点。2.双砧木嫁接在不同氮素水平上表现为优于京欣砧和黑籽砧两单砧处理或偏向好的一种。随着氮素水平的提高,不同处理下植株水分、Ca和P的利用率,果实产量、果数和干物质含量均表现为先升高后降低,叶绿素、硝酸还原酶、可滴定酸、蛋白质和硝酸盐含量逐渐升高,氮素利用率和可溶性糖含量逐渐减低,而对K和Vc含量没有显著影响；在低氮水平上,肥水利用率、果实产量和果数以双砧和京欣砧处理较好,在高氮上则双砧和黑籽砧处理较优,不同氮素水平上植株生长、营养品质分别以双砧和黑籽砧处理、双砧和京欣砧处理较好,且双砧比单砧处理有更低的硝酸盐含量。3.双砧木嫁接在模拟干旱条件下表现为更强的抗旱性。双砧嫁接显著促进了植株的生长；双砧比单砧处理有更低的自由水/束缚水值,含水量先降低后恢复原状,自根对照却持续下降；嫁接处理的光合色素下降幅度小于自根对照；双砧嫁接在胁迫后诱导产生的可溶性糖和脯氨酸含量小于单砧和自根对照；嫁接处理对MDA变化的影响不显著,而自根对照在胁迫后14d比胁迫前增加了108.95%。更多还原

【Abstract】 Cucumber (Cucumis sativus L.) is one of the most important vegetable in the world. Grafting, an effective measure to improve resistantance and overcome continuous cropping obstacles of melon and fruit vegetables, has been widely applied in cucumber production recently. But the traditional grafting is set up on the base of the Single-grafting.Because of the resource limitation of rootstock, the roles of many rootstocks have specificity or uniqueness. For example, the fig leaf gourd as rootstock can enhance the resistantance and improve the yield of the scion, but the marketability and quality of which are decreased. So in this experiment, double-stock grafting was adopted with cucumber as scion, figleaf gourd(Cucurbita ficifolia), a rootstock that can enhance stress resistance and’Jingxin No.5’, a rootstock that can improve quality as rootstocks, and we compared the double-stock grafting with single-stock grafting and scion-root seedling to study the effects of double-stock grafting on the physiological characteristics, yield, and quality of cucumber under the different nitrogen levels and simulating drought stress conditions. The results were as follows:1. The double-stock grafting possessed the excellent characteristics of Jingxin and Heizi. Both single and double grafting improved the absorption of water and fertilizer, increased water and fertilizer use efficiency, and promoted plant growth. The yield and fruit numbers per plant of double-stock were distinctly higher than that of the single-grafting of Jingxin and scion-root treatments. The double-stock grafting could distinctly increase the content of solution sugar, which the content of Vc and sugar-acid ratio were distinctly higher than Heizi and scion-root treatments. Double-stock grafting also could shorten the ruit stalk length cased by single-stock grafting.2. The double-stock grafting was better than Single-stock or leaned to the better one. The change trend of water, Ca and P use efficiency, yield, fruit numbers, and dry matter content of different treatments rised in the first, and declined in the follow with the increase of the nitrogen levels. The chlorophyll, nitrate reductase activity, Mg, titratable acid, protein, and nitrate rised gradually, but N use efficiency and soluble sugar were decreased gradually. There is no significant effects on K and Vc use efficiency. The water and fertilizer use efficiency, yield, and fruit number of double-stock and Jingxin treatments were better at low nitrogen level, but the double-stock and Heizi treatments were better at high nitrogen level. The plant growth of double-stock and Heizi treatments were better, and the nutritional quality of double-stock and Jingxin treatments were better at the different nitrogen levels.In addition, the nitrate content of double-stock treatment was lower than that of the single-stock.3. The drought-resistance of double-stock was higher than single-stock under simulating drought stress. The double-stock could promote plant growth. Compared with the single-stock treatment, the double-stock treatment has lower the free water/bound water ratio, and it is water content declined in the first, fllowed by an increased, while the water content of scion-root shoeed sustained decreased. The descent range of photosynthetic pigment was smaller than the that of the scion-root group. The soluble sugar and Pro content of double-stock were smaller than Single-stock and own-root after stress. Grafting treatments had no significant effect on MDA content, while the scion-root treatment increased by 108.95% at 14 days after stress.更多还原