Physiological Mechanism Of High-voltage Electrostatic Field To Alleviate Damage Caused By Rapid Dehydration Of Maize Seeds

Maize is one of the three major food crops in China,and its sown area and output rank is the head of food crops.Maize stand out in the national food security strategy and in ensuring China’s future food supply and demand plays an important role.The quality of Maize seeds directly affects the yield of Maize cultivation.At present,Maize seed production has basically achieved standardized production.After harvesting,most Maize seeds are dehydrated and dried by high temperature(45°C)and fast drying(24-48h)at a factory.When the seeds are subjected to high temperature and rapid dehydration,Because the maturity and size of seeds are difficult to be uniform,the water content of seeds is also inconsistent.When the water content of the seeds is relatively high,high-temperature rapid dehydration treatment of the seeds will inevitably cause harm to the seeds.How to apply scientific seed treatment technology to pre-treat the seeds before rapid dehydration treatment to alleviate the damage caused by high-temperature rapid dehydration and drying to seeds is worth further research.In this study,the female parent PH6 WC,male parent PH4 CV,and hybrid seeds of the maize Xianyu335 variety that were widely promoted for production were used as research materials.Before the seeds were subjected to high-temperature rapid dehydration and drying,the seeds were pretreated with a hightemperature electrostatic field.Screen the best seed treatment conditions for high-voltage electrostatic field pretreatment to mitigate the damage caused by high temperature and rapid dehydration,and use the best electric field treatment conditions to pretreat the seeds to determine the physiological and biochemical indicators of seeds and seedlings during seed germination and early seedling growth.The effects of electric field pretreatment on the physiological and biochemical indexes of seeds and seedlings were analyzed,and the physiological and biochemical mechanisms of high-voltage electrostatic field pretreatment to alleviate the damage caused by high temperature and rapid dehydration to seeds were investigated.The main results are as follows:1.Adopt secondary universal rotating combination design,the electric field strength is 1.2-6.8kV/cm,the processing time is within the range of 18-112 min,the best treatment condition for male seed is electric field strength 4.0 k V / cm,the time is 60 min.Under this condition pretreatment,the relative conductivity of the seed was reduced by 2.07%(24h)than its direct high-temperature rapid dehydration treatment;the germination potential,germination rate,germination index and vitality index were higher 94.74% and13.29% than their direct high-temperature rapid dehydration treatment,respectively,18.16% and 34.67%;the best pretreatment conditions for female seeds are also electric field strength 4.0 k V / cm,the time is 60 min.Under this condition pretreatment,the relative conductivity of seeds is reduced by 32.24%(24h)compared with its direct high-temperature rapid dehydration treatment;germination potential,germination rate,germination index,vigor index are respectively 43.75% and 13.68% higher than their direct high-temperature rapid dehydration treatment,20.28% and 42.96%;the best pretreatment conditions for hybrids are electric field strength 6.0 k V / cm and treatment time 60 min.Under this condition pretreatment,the relative conductivity of the hybrid was reduced by 21.44%(24h)than its direct high-temperature rapid dehydration treatment;Electric field pretreatment,the germination potential,germination rate,germination index and vitality index of the hybrid were faster than the other higher is 130.00%,3.62%,15.52% and21.91%.2.The male parent and female parent seeds were pretreated with 4.0 k V / cm,60 min,and the hybrids with 6.0 k V/cm,60 min high voltage electrostatic field pretreatment,which improved the seed germination and seedling SOD,POD,CAT the activity and content of soluble protein and soluble sugar reduced the content of MDA and superoxide anion(O2.-)in the process of early seedling growth Seedling.3.Examining the three indexes of seed germination rate,germination index and vitality index,it is found that the effects of different types of seeds on alleviating high temperature rapid dehydration damage under the optimal electric field treatment conditions were also different.Relatively speaking,the effect of electric field treatment to improve the vigor of male and female parents is better than that of hybrids.4.The mechanism of high voltage electrostatic field pretreatment to alleviate the damage of high temperature rapid dehydration and drying to seeds is:(1)High voltage electrostatic field pretreatment reduces the damage of high temperature rapid dehydration to the embryonic cell membrane.(2)Pretreatment with high voltage electrostatic field enhances seed tolerance by inducing enhanced seed protection enzyme activity and accumulation of soluble protein and soluble sugar.High-voltage electrostatic field treatment can be used as Maize seed processing technology in Maize seed production and processing practices.