Effects Of Priming On Seed Vigor And Seedling Quality Of Seedless Watermelon

This study has proposed to find an optimal priming condition of temperature, humidity and time by test the germination rate, germination energy and germination index of seedless watermelon (Mihong) seeds which treated with vermiculite priming and drum priming. We also try to find the effects of priming on physiological characteristic. In addition, we also have study the germination rate and seeding growth of seedless watermelon seeds with different priming treatments. Here are the main results as below:1.The optimal priming conditionWhen treating with drum priming,the optimal priming condition was proved to be 21 degrees Centigrade,70 percent humidity and 2 days,under which conditions the germination rate increased by 48.7 percent,germination energy 43.7 percent and germination index 11.0. It has remarkable effects on enhancing germination characteristics when soaking seed before vermiculite priming, of which the most suitable conditions turned out to be 25 degrees Centigrade,60 percent humidity and 24 hours. After priming and drying treatment, the seeds could keep a high germination rate and activity in short period of time. However, the germination rate declined a litter during the following 4 months. Although being much higher than the contrast which was only 5.3 percent, it declined much after artificial aging, from 66.7 percent to 25.3 percent.2. Effects of priming on physiological and biochemical changes of seedless watermelon seeds.The study turned out that priming can significantly improve the activity of the enzymes in watermelon seeds, including CAT, POD, SOD, G-6-PDH and 6-P-GDH, and decreased MDA content, all those responding to higher seed vigor. Besides, the best treatments approved to be the ones that soaking seed before vermiculite priming. The activity of G-6-PDH and 6-P-GDH changed following with the progress of the germination, which indicates that they may make a big difference during germination.3. Effects of priming on seed germination and seedling growth of seedless watermelon seeds.Different priming treatments could increase germination rate and seedling emergence rate of seedless watermelon seed. At the same time, it play an effective role in enhancing the seeding growth. Soaking seed before vermiculite priming could achieve a better result. Their germination rates have improved 57.0% and 53.9% when soaking seed with H2O2 or GA3 before priming, while the emergence rates improved 56.0% and 52.6% and their seedings' root length, root weight, stem diameter and plant height are significantly better compared to the other treatments.