Studies On Optimum Prescription And Concentration Of Nutrient Solution On Virus-free Minituber Production By Aeroponic Cultivation

Virus-free minituber of potato is the basis of seed potato production . One of the key points in potato production is to increase propagation coefficient of minituber, decrease production cost and enhance economic profit. The technique of minituber production, the optimum prescription and concentration of nutrient solution and the development of minituber were studied by aeroponic cultivation which could exert the potential ability of virus-free minituber production. The main results were as follows:1.Plants grown in nutrient solution prescription in treatment 2 were better than plants grown in other treatments, content of photosynthetic pigment were higher,expanding speed was faster and minipotato number of per plant and yield were higher than other treatments. Plants grown in this nutrient solution description could show the advantage of virus-free minituber.2.It was easy to observe the development of stolon and tuber in aeroponic cultivation, and it was most appropriate for potato which took tuber as product. Minituber grown in aeroponic cultivation could be harvested in one time or several times. There were more advantages in being harvested in several times than in one time. Minituber could be picked when they developmented to suitable size, this could not only promote the formation and expanding of tuber in later growth period, but also increase the yield of minituber and the efficiency of nutrient solution, reduce product post at the same time.3.The formation of tuber was controlled by several kinds of inner hormones. The prescription of nutrient solution could influence the content of inner hormones, but the changing trend of the hormone were same. The content of GA in leaves descent continuously through the growth period, which provided precondition for the formation of tuber. Content of ZR was highest when stolon took place, ZR played promotive role in the course of tuber formation. Changing trend of ABA content was the same as ZR, ABA could counteract the activity of GA and benefited for the formation of tuber, The changing trend of IAA content was identical as ZR and ABA.4. Both too high and] too low nutrient solution concentration(EC) could effect the growth and development of potato by aeroponic cultivation.For example,when nutrient solution concentration was 1500μs/cm or 3000μs/cm,content of photosynthetic pigments in leaves was reduced, the number of stolon were increased.Plants grown in 2000-2500μs/cm were in well condition,the yield was also high.5.Nutrient solution concentration could influence absorption of mineral nutrition in potato plants.With the improvement of concentration,Content of N,P,K were all increased.However,content of P and N in stem were increased as before,content of K, N in roots and leaves were reduced when EC was 3000μs/cm.