Study On High Intensity Pulsed Electric Field To The Biological Effects Of Vegetable Seeds

Seed was the elements of agricultural production and seed vigor would influence plant all the life time. Degradation of seed vigor was an inviolable natural rule. When the germination percentage declined to a certain extend, we must breed and rebirth it. So it had important practical significance that study on seed degradation to open out the mechanism and find out method to solve seed degrading. In recent years, study of physical factor especially for outer electric field is regarded important. Cell membrane of Vigorous seed has voltage and outer electric field on seeds could enhance membrane voltage to accelerate compound of ATP. ATP could offer energy to activate many kinds of enzyme. High intensity pulsed electric field (PEF) is an integrated physical field, and it has many advantages. It is an easy and effective method to treat with aged seeds and increased seed vigor.This study used PEF technology on old vegetable seed germination and plant growth. The effects of field strength and time and seed water contents on germination of old seeds were researched. The effects of PEF technology of resistance of chilling and resistance of drought were studied. We studied the mechanism of it too. The results were as followed:1. By means of quadratic general rotational combination design, the effect of field strength and time on germination of old pepper seed were researched. A quadric regression model was obtained:Pepper:Y=54.5896+3.0008x₁+1.2209x₂-2.7476x₁²-1.2941x₂² +0.9217x₁x₂ Eggplant:Y=127.4040+6.1367 x₁+4.4452 x₂-9.7288 x₁² -3.2138 x₂²+2.5975 x₁x₂ Tomato:Y=148.8244+5.4232x₁+4.6233x₂-10.6941 x₁²-4.0218x₂² +5.2482x₁x₂ The dosage of PEF treatment was different with different vegetable. The optimum dosage was as followed: pepper is 7.90kv/cm of field strength and 270 seconds of time; eggplant is 7.64kv/cm of field strength and 266 seconds of time; tomato is 7.66kv/cm of field strength and 277 seconds of time.2. PEF treatment could accelerate metabolize of old seeds sugar and protein.The soluble sugar contents reached maximum was brought forward one day compared with ck. The protein contents reached maximum was brought forward two day compared with ck; PEF treatment could accelerate activities of seed SOD and POD, and played down seed relative conductivity and contents of MDA and .O2-.3. PEF treatment could stimulate growth of vegetable seedling and enhance vegetable seedling photosynthesis. PEF treatment could enhance vegetable yield. The yield of pepper seedling enhanced 69.05%; the yield of eggplant seedling enhanced 71.02%; the yield of eggplant of tomato seedling enhanced 59.00%. PEF treatment had little effects on vegetable quality.4. Some inherent laws between seed germination, such as field strengthx1,timex2 and seed water contentsx3 with mathematic model were found out by the study after two times orthogonal rotational repressible tests with multi-levers. A quadric regression model was as followed:Y=106.88676+1.91933x1+0.27849x2+8.72715x3-0.027524x12-0.00067161x22 -0.57804x32-0.00089981x1x2+0.056785x1x3+0.0040095x2x3The result showed that the three factors had significant influence on seed germination. The influence sequence from significant to common is seed water contents,field strength and time. The optimum dosage for cucumber of PEF technology was field strength is 7.84kv/cm,time is 210s and seed water contents is 50%.5. PEF treatment could enhance resistance of chilling of pepper seedling. The seedling fresh weight enhanced 50.96%; plant height enhanced 34.38%; stem thick enhanced 33.33%. The life full percentage of pepper seedling enhanced 47.29%.6. PEF treatment could enhance resistance of chilling is relevant to change of cell inter circumstance and safeguard of membrane. Proline contents enhanced 80.00% and 43.75% after chilling and restore growth. Relative conductivity enhanced 48.94% and 53.57% after chilling and restored growth. Contents of SOD,CAT,POD and Vc were increased after chilling and restore growth. MDA contents were decreased after chilling and restore growth.7. PEF treatment could enhance resistance of drought of pepper seedling. The seedling fresh weight and dried weight enhanced39.35% and 59.47% compared with ck2 after drought. Plant height and stem thick 40.72% and 50.94% compared with ck2 after drought. The life full percentage of pepper seedling enhanced 40.16%.8. PEF treatment could enhance resistance of drought is relevant to change of cell inter circumstance and safeguard of membrane. Relative conductivity of PEF treatment played down 34.39% compared with ck2. MDA contents of PEF treatment played down 36.89% compared with ck2. ACP activities of PEF treatment played down 16.93% compared with ck2. SOD,CAT,POD activities of pepper seed and seedling were decreased. Vc content of pepper seed and seedling were decreased.