Effects Of Different Hormone Treatments On Seedling Formation And Seedling Growth Of Bletilla Striata

In order to improve the germination rate of Bletilla striata seeds and promote the seedlings growth,this paper had studied the effects of three plant growth regulators,NAA,6-BA and SA,on the direct seed germination and seedling growth of Bletilla striata and had obtained the following results.Effects of different concentrations of NAA,6-BA and SA on seed germination of Bletilla striata.The experiment set different concentrations of NAA(0.5?1.0?1.5?2.0 mg/L),6-BA(0.5?1.0?1.5?2.0 mg / L)and SA(1.0?2.0?4.0?8.0 mg/L),to measure the seed germination rate by using seed soaking treatments.The study found that the use of hormone NAA,6-BA and SA soaking seeds of Bletilla striata can increase the germination rate,and with the increase of treatment concentration,the seed germination rate increased first and then decreased.By comparing the effects of three hormones on Seed Germination rate,it can be found that the overall effect of promoting seed germination rate is as follows,6-BA>NAA>SA.Among the three hormones,the treatment of 1.0 mg/L 6-BA got the best effect,the treatment of 0.5 mg/L NAA got the second effect,and the treatment of 4.0 mg/L SA got the third effect.The seed germination rate of CK group was 53.80%,while the seed germination rates of these three hormones were 86.17%,81.37% and 63.10% respectively,which were increased by 60.22%,51.30% and 17.29% comparing with CK treatment.So it is suggested to soak seeds of Bletilla striata with 1.0 mg/L 6-BA in production.Effects of different concentrations of NAA,6-BA and SA on the growth of Bletilla striata seedlings.Different concentrations of NAA(5.0,10,15,20 mg/L),6-BA(5,10,15,20 mg/L),SA(10,20,40,80 mg/L)were sprayed on the leaves of Bletilla striata seedlings.The plant height,root length,stem diameter,bulb fresh weight,chlorophyll content,soluble sugar content,peroxidase activity and malondialdehyde content of Bletilla striata seedlings were determined.It was found that spraying NAA,6-BA and SA at appropriate concentration on the leaves could promote the morphological growth and optimize the physiological status of the seedlings,increase the chlorophyll content and soluble sugar content of the seedlings,decrease the peroxidase activity and malondialdehyde content ofthe seedlings,and promote the growth of the seedlings and increase the resistance of seedlings.By comparing the effects of three hormones on Physiological Indexes of seedlings,the results showed that the effect of promoting the increase of chlorophyll content was NAA > SA > 6-BA,the effect of promoting the increase of soluble sugar content was SA > NAA > 6-BA,and it was found that SA had the best effect on reducing peroxidase activity and malondialdehyde content,while NAA and 6-BA had little difference.Comparing comprehensively,the optimum hormone and concentration of 40 mg/L SA were found to affect physiological indexes of seedlings.