Path-Physiology Research Of Jujube Fruit Shrink Disease

The fruit of Ziziphus jujuba Mill. (belongs to Ziziphus genus, Rhamnaceae family) is rich in nutritional and medicinal value. Jujube tree is an unique and important tree in our country, but because of all kinds of diseases and harm graveness, economic losses to our country are tremendous. The fruit shrink disease is mainly harmful to Jujuba fruit that getting smaller after being infected by pathogen, then pericarp shrinkage and pulp necrosis, fruit carducous at last. Due to fruit shrink disease infection, disease fruit rate reach to 30%-80%, most serious area exceed to 90% or even no crop in the main jujube producing county, such as Taihang mountain jujube area of Hebei, Xinzheng jujube area of Henan and Jinzhong jujube area of Shanxi. The-Fruit shrink disease caused serious damage to the jujube production.The aim of this study is analyzing the changing regularity of physical signs and probing physical mechanism of generating the fruit shrink disease by determining the mineral element and moisture content of soil and fruits, the content of Vc,soluble sugar and phenolic compounds and the ability of antioxidant enzyme in fruits during Fruit Shrink Disease, thus providing scientific proof for better prevention and cruing Fruit Shrink Disease. The major study result as follows:(1) The potassium content of the soil in fruit shrink disease area is significantly lower than normal area; The calcium content of the soil in fruit shrink disease area is significantly higher than normal area; The content of nitrogen, iron,manganese,copper,zinc and magnesium are slightly below normal area, and the difference is not significant.(2) The potassium content of the fruit in fruit shrink disease area is lower than normal area. The calcium content of the soil in fruit shrink disease area is significantly higher than normal area.(3) The Vc content of the fruit of different period in fruit shrink disease area is generally lower than normal area; The content of soluble sugar is no significant difference; The content of reducing sugar at full riening stage is significantly higher than normal area.(4) During the fruit shrink disease process, the variation trend in the ability of SOD and POD, production rate of O2·- and phenolic compounds of fruit between fruit shrink disease area and normal area keep the same.(5) During the fruit shrink disease process, the variation trend in the ability of SOD and POD, production rate of O2·- and phenolic compounds of fruit between fruit shrink disease area and normal area keep a positive correlation, whis is good for early screening of Resistant germplasmic.(6) To apply potassium fertilizer in soil can reduce the incidence of fruit shrink disease incidence and increase output of fruit.