Screening Of Germplasm Tolerant To Mixture Saline-Alkali Stress And Establishment Of Regenation System In Sweet Sorghum

Sweet sorghum is one of the most advantageous biomass energy crops. It is very important for the development and utilization of saline-alkaline land and the development of ethanol fuel industry to screen salt tolerant varieties of sweet sorghum. The rapid and efficient in vitro regeneration technology of sweet sorghum is the basis of rapid improvement of agronomic traits of sweet sorghum using transgenic technology.In this study, four kinds of mixed salt-alkali soils were mixed with different proportions of neutral salt and alkaline salt to simulate the natural conditions, and 9 sweet sorghum varieties were treated at the bud stage and seedling stage, Based on 12 different stress tolerance The salt tolerance of nine sweet sorghum varieties was determined by the membership function method and the gray relational analysis method, and the reliability of the 12 indicators in the determination of salt-alkali resistance of sweet sorghum was analyzed. Then, the callus regeneration system was optimized by selecting mature seeds of sweet sorghum varieties with high salt and alkali tolerance as explants. The results are as follows:1. According to the weighted salt-resistance index and the amount of salt-resistant D,9 samples were sorted by salt-alkali resistance. The results showed that the comprehensive salt-resistance of nine cultivars was from strong to weak. Siza 25> Yajin 4340> Yajin 4184> Yajin 106> Yajin 2> Yajin 4589> Yajin 4590> Yajin 10> Longzha 9. Siza 25 and Ya Jin 4340 two materials, the weighted salt-resistance index and the amount of salt-resistant D are the first and second, are strong anti-saline materials. The weighted average salt-resistance index and the amount of salt-resistant D of Longza 9 and YajinlO were the smallest, suggesting that the salt tolerance of this material was poor, which belonged to saline-alkali sensitive material.2. The correlations of 12 traits (seed germination rate, fresh weight of stem and leaf, root length, fibrous root number, leaf relativity electrical conductivity, leaf SOD activity, leaf proline content and five chlorophyll fluorescence parameters) to comprehensive salt tolerance index analysis. The results showed that the fresh weight, leaf relative electrical conductivity, root length and Fv/Fo ratio were all higher than 0.9, which was the best index to evaluate the salt tolerance of sweet sorghum, followed by Fv/Fm and germination rate, Fm, Fv and Fo were the least, and should be used with caution.3. The factors affecting callus regeneration of mature seeds of sweet sorghum were studied. The results showed that:1) Seeds were treated with 0.1% mercuric chloride for 10 minutes, and with 2 drops of Tween20, seeds had lower pollution rate and higher germination rate.2) MSB5 basic medium with the concentration of 3.0mg/L auxin,2,4-D and 0.3mg/L of 6-BA, mature seeds with the highest recovery rate.3) Yajin 106, Yajin 4184, Yajin 4340 and Siza 25 had the highest rate of callus recovery, which was 81.7%.4) The germination rate of mature seed callus in Yajin 4184 was 93.3% on B5 medium supplemented with 0.2 mg/L NAA and 1.6 mg/L KT.5) The callus induction of buds from Yajin 4184 was cultured on 1×MS medium with 2.0mg/L IBA, and the maximum rooting rate was 96.7%.