Salt Tolerance Evaluation Of Kenaf Germplasm Resources At Germination And Seeding Stage

Soil stalinization has become a global problem, which greatly limits the development of agriculture. Improving the utilization of saline-alkali land has become essential in today’s growing population and declining arable land. Kenaf (Hibiscus cannabinus L.) is an annual bast fiber crops, has an important position in the textile and paper. It has strong resistance, wide adaptability, and able-salt, alkali, suitable for planting in saline soil. While, there is a big difference in salt tolerance between the different kenaf materials, so identified the salt tolerance of kenaf and screened the kenaf varieties with strong salt tolerance, is of great significance to enhance the development and utilization of saline-alkali soil. At the same time it provides genetic resources for physiology researching and breeding of salt-tolerant kenaf varieties.In this study,25kenaf germplasm resources were used to study seed germination rate, germination index, vigor index, bud length, and other indicators of Kenaf seeds, under250mmol/L NaCl,150mmol/L Na2SO4and150mmol/LNa2CO3treatments. Plant height, stem diameter, fresh weight, water content, soluble sugar, praline and other indicators of differences Kenaf Seedlings were tested in the250mmol/L NaCl treatment. The main results were as follows:1. The salt-tolerance comparison among tested materials(1) K03A/992had the most salt-tolerant in three salt stresses during all tested materials at germinating stage, whose complex membership function value reached0.79. Followed by R3and R7, whose complex membership function values were0.68and0.67.The complex membership function value of P3A was0.08, whose salt-tolerant was the worst.(2) The salt-tolerant of N10-30was the best during all tested materials at seeding stage, its complex membership function value reached1.00, followed by N10-37and P3B, whose complex membership function values were0.94and0.84, respectively. The salt-tolerant of917B was the worst.(3) The salt-tolerant of N10-30was the best during all tested materials at seeding and germinating stage. Its complex membership function value reached0.74.The next was N10-68and K03A/992, whose complex membership function values were0.94and0.84.The salt-tolerant of N10-79was the worst, its complex membership function value was only0.17.2. The effect of salt stress on the seed activity of kenaf during all tested materials(1) In the250mmol/L NaCl stress, the salt evaluation of N10-75was0.95, whose salt-tolerance was the strongest, followed by N10-50and R12. The comprehensive evaluation of Rl was0.02, which had the worst salt-tolerance.(2) In the150mmol/L Na2SO4stress, K03A/992had the strongest salt-tolerance, the sum of salt evaluation of K03A/992was up to1.0; followed by N10-36and R3; The comprehensive evaluation of P3A was0.01, whose salt tolerance was the worst.(3) In the150mmol/L Na2CO3stress, the comprehensive evaluation of R3was0.95, whose salt tolerance was the strongest, followed by R7and K03A/992; the salt tolerance of R1was the worst.(4) Under the same concentration of Na2SO4, Na2CO3stress, kenaf seeds was more sensitive to Na2CO3stress, its seed activity was reduced significantly higher than Na2SO4stress. Under150mmol/L Na2SO4salt stress, the inhibition of kenaf seeds was stronger than under250mmol/L NaCl salt stress.(5) Comprehensive considering three salt stress, R3had stronger salt tolerance than other materials. Under Na2SO4and NaCl salt stress, R6had stronger salt tolerance; Under Na2SO4and Na2CO3salt stress, K03A/992and R7had stronger salt tolerance;3. Correlation analysis of tested Kenaf materials under salt stress between germination and seedling stageCorrelation analysis between complex membership function value at germination stage and relatively dry weight at seedling stage, the correlation coefficient was0.27, it was not significant. The reason for the result was need to be further investigated.4.Correlation analysis between salt tolerance indices and the salt-tolerance of tested materials(1) Among those salt-tolerance related indicators at germinating stage, relative vigor index had the best correlation with salt-tolerant, the average correlation coefficient was up to0.96, the indicator could be used as evaluation the salt-tolerance of kenaf. Followed by relative germination index and relative germination rate, whose average correlation coefficient reached0.95and0.93. Relative bud length was the lowest, the average correlation coefficient was0.81。(2) Among the salt tolerance related indicators at seedling stage, SOD content and relatively dry weight had the strongest correlation with salt tolerance, the average correlation coefficient reached0.93, next was soluble sugar content and relative conductivity, whose average correlation coefficient were0.91and0.90, those indicators could be used as evaluation the salt-tolerance of kenaf. Relative water content was the lowest correlation with salt tolerance, it was only0.50.