Screening Of Cucumber Breeds For Different Nitrogen Use And Differengce On Its Root Bioloogy Characteristic

In rencent years, a great deal use of nitrogenous fertilizer has made higher content of nitrate than health standard, as soon as made the descend of nitrogen use, has became the one of the main bottleneck facilities development. Cucumber (Cucumis sativus L.) is one of the major vegetables in the protected horticulture, Cucumber were taken as experimental material in this study, study their response by comparing their fruit yield, over ground biomass and total uptake nitrogen and fruit total accumulate nitrogen under normal nitrogen and low nitrogen stress. on the grond of the experiment of screening for nitrogen efficiency on eighteen breeds,analyse their difference of root morphology and physiological characteristics. Provid a theory for ascertaining difference of root biology in cucumber breeds with different N use efficiency and improving nitrogen use efficiency and reducing content of nitrate and screen cucumber breeds. The main results obtained were as follows.1. It is analyse that yield and over ground biomass and total uptake nitrogen and fruit total accumulate nitrogen in18different cucumber breeds.The tested cucumber breeds could be classified into four different types:(1)Number2、4、6、10、13belonged to HH-LH type;(2) Number7、8、12belonged to HH-LL type;(3) Number5belonged to HL-LH type;(4) Number1、3、9、14、15、16、17、18belonged to HL-LL type.Jinyou2、Jinyou31、Jinlv30、Meihao is choose as materials for difference of root biology.2. On the hand of root morphology, under low nitrogen stress, the root length, root surface area, root volume of HH-LH type was highly significantly HH-LL type in cucumber growth early days,the number of root tips was highly significantly HH-LL type in cucumber whole growth. Root morphology characteristics of different breeds of nitrogen efficiency is ruleless under normal nitrogen.3. On the hand of root physiological, under low nitrogen stress,root SOD and POD vitality of HH-LH type was highly significantly HH-LL type in cucumber growth metakinesis,the root bleeding rate was highly significantly HH-LL type in cucumber whole growth. Root morphology characteristics of different breeds of nitrogen efficiency is ruleless under normal nitrogen.The total uptake nitrogen of HH-LL type was highly significantly HH-LL type in cucumber whole growth..4. Characteristic of root morphologic and tphysiology and biochemistry were obviously diversity in different N use efficiency at twenty days after plaining.lt is show that root volume, the number of root tips root, root vitality, POD vitality, bleeding rate of HH-LH type was highly significantly HH-LL and HL-LL type,correlation analysis showed that twenty days after plaining have the biggest contribution for total uptake nitrogen. Therefore, this period was auxiliary sceen period. 5. On the hand of root ultrastructure, low nitrogen stress largen cell nucleus of cucumber.But types of different N use efficiency is ruleless.Form the above, the cucumbers of HH-LH type has strongly ability for Tolerance To Low Nitrogen Stress.It is show that their number of root tips and root bleeding rate was highly significantly HH-LL type in cucumber whole growth.It is explain that lateral root well-developed and good root vigor in favour of uptake nitrogen effectively. Characteristic of good root morphologic and physiological of HH-LH type in cucumber growth early days Provid a theory for absorbing nitrogen effectively.