Effects Of High Temperature On The Formation Of Starch And Yield Of Potato

In order to investigate the effection on starch and yield of potato under high temperature in Ningxia,Qingshu No.9 was studied under the high temperature in the southern part of Ningxia.The effection on the starch content and activity of key enzymes and root,photosynthetic characteristics,protective enzymes and the yield formation under high temperature were studied.The results showed:1.Under the high temperature(35±2?),amylose,amylopectin and total starch content in potato tubers showed different degrees of decrease.The contents of total starch,amylose,amylopectin and the key enzymes ADPG-PPase,UDPG-PPase,GBSS,SSS and SBE were significantly lower than those of T2(25±2?),which were lower than T2:21.4%,21.74%,39.37%,17.72%,17.79%,25.09%,20.19%and 60.00%respectively.The results showed that high temperature stress inhibited the activity of key enzymes in starch synthesis in potato tubers,which caused the starch synthesis of potato tubers to be blocked,which was not conducive to the synthesis of starch in potato tubers.2.The growth and development of potatoes were inhibited under a brief high temperature after the tuber formation period.The height of plant,crown width,LAI and the activity of root potato were significantly lower than those of T2 and T3(29±2?)under the condition of T1,while the appropriate temperature could significantly increase the chlorophyll content and SPAD of potato.The Pn,Fv/Fm,Fv/Fo and PI were increased at different level,Potato tuber enlargement period,The Pn,Fv/Fm,Fv/Fo,PI about T2 treatment increased by 62.28%,7.77%,22.68%,67.83%,which compared with T1.It was beneficial to the photosynthesis of potato functional leave that reducing significantly the Fo/Fm and ABS/RC.3.The cell membrane permeability,MDA,proline and soluble sugar content of functional leaves were significantly increased,and it showed T1>T3>T2.After high temperature,the activity of SOD and POD increased rapidly,and significantly higher than that of T2 and T3,then decreased rapidly,and it was significantly lower than that of T2 and T3.CAT activity raised firstly,then decreased rapidly at starch accumulation period.The results showed that the activity of antioxidant enzymes increased rapidly in the leaves of potato,and then decreased rapidly,the degree of lipid peroxidation of potato leaves were aggravated,which was not conducive to the normal growth of potato.4.Under the high temperature,the accumulation of dry matter,the distribution and yield of photosynthetic products of potato were different,and the results showed:T2>T3>T1,It was adverse for the total dry matter of potato,the accumulation of matter and the weight per pot,the number of large potatoes under high temperature.The yield of T2 was 29.42%,51.15%higher than that of T3 and T1.