Effects Of Different Depilling Methods On Cotton Seed Vigor And Seedling Characters Under Drought Stress

In order to study the significant advantages of laser depilation over traditional processes such as sulfuric acid depilation,the differences of cotton seed vigor at different fruit branch boll positions were discussed,and the seeds with higher vigor were obtained.Using Polyethylene glycol(PEG8000)to simulate drought stress.The response to drought stress of cotton seedlings was evaluated with different depilation methods.Using methods of sulfuric acid depilation(T1),laser depilation(T2)and laser depilation(T3),and PEG of0%(CK),5%(P5),15%(P15)and 25%(P25)for drought treatment,respectively.Then immersing seeds in different concentrations of calcium cyclophosphate,including 0 mg · L-1(CK),50 mg· L-1(P1),100mg·L-1(P2)and 150 mg · L-1(P3),respectively.The physiological characteristics of cotton seedling and germination stage,and the effects of calcium cyclamate on cotton seed vigor and seedling characters under drought stress were studied.The main results are as follows:Significant differences were found in germination rate and germination vigor among cotton seeds delinted with different methods.The germination rate,germination potential of cotton seeds delinted with sulfuric acid and laser were significantly higher than the laser delinting the long lint method.The germination index decreased with the increase of drought stress.Compared with the control,our study using5%,15%,25% PEG.By using Sulfuric acid delinting method,the rate of germination increased by 1.0%,-25.8%,and-62.4%,respectively.The germination rate decreased by 4.4%,22.0%,and 61.5%,respectively by using short lint laser delinting method.And the rate of germination by using long lint delinting decreased by 16.4%,35.6%,63.0%,respectively.Different delint methods had a certain effect on the fresh weight during cotton seedling stage.The fresh weight of cotton seeds with laser delinting is greater than that of sulfuric acid.The contents of soluble sugar,malondialdehyde,proline and peroxidase are significantly different in cotton leaves by using different delint methods.At the same time,drought stress significantly increases the contents of malondialdehyde and proline.However,significantly reduced were observed in the contents of soluble sugar and peroxidase.The vigor of cotton seeds with different delinting methods can be effectively improved by treating with calcium cyclamate.With the increase of calcium cyclamate concentration,the germination index,seedling length and root system were enhanced.The germination rate increased by 3%,14.3% and 7.8%,respectively with three treatments at P1 concentration.The activity index of each treatment increased the most between P1 concentration and P2 concentration,T1,T2,and T3 increased by 13.6%,23% and 17.16%,respectively.