|
In this study, the effects of salinity on germination, growth and development, and yield of hybrids and conventional sweet sorghum varieties were investigated. We studied the germination vigor, germination rate, germination index, vigor index, growth and development, biomass, grain yield of different sweet sorghum varieties under salt stress, and the main factors affecting the yield. The main results are as follows:1. Effects of salinity on germination of different sweet sorghum varietiesGermination of hybrid and conventional sweet sorghum varieties were inhibited under 0.5%, 1.0%, 1.5%, 2.0%, 2.5% NaCl stress. The germination vigor, germination rate, germination index, vigor index, shoot length, root length, shoot weight and root weight were significantly decreased with the increasement of NaCl concentration. But the decline of hybrid varieties was significantly lower than conventional varieties at the same NaCl concentration, and this indicated that the salt tolerance of the hybrid varieties was higher than conventional varieties.2. Effects of salinity on growth and development of different sweet sorghum varietiesThe growth and development of hybrid and conventional sweet sorghum varieties were significantly affected under 0.3%, 0.6%, 0.8% salt stress. With the increasement of salt concentration, the germination rate of sweet sorghum decreased; the seedling stage, heading stageand maturity stage were delayed, and the growth period were prolonged; plant height, panicle length, panicle diameter, stem diameter decreased; the weight of leaf, sheath, ear, stem and grain decreased, whereas the sugar brix in stem increased. The changing trend of hybrid and conventional sweet sorghum varieties were same. The difference in seedling emergence time, 1000-grain weight and brix in stem between hybrid and conventional sweet sorghum varieties were not significant, while the difference in grain yield per spike was significant, and the difference in the rest indexes were very significant.3. Effects of salinity on biomass and grain yield of sweet sorghumThe difference in biomass and grain yield between hybrid and conventional sweet sorghum varieties were significant under salt stress. The biomas and grain yield decreased with the increasement of salt concentration. However, the decline in biomass and grain yield of hybrids varieties were lower than conventional varieties, indicated that the hybrids varieties had the stronger salt tolerance. The difference in grain yield between hybrids and conventional varieties was significant, and the difference in biomass was very significant. The main factors that affected the grain yield were spike grain weight, panicle weight, 1000-grain weight, panicle length, grain number per spike and panicle diameter; The main factors that affected biomass were plant fresh weight, stem weight, leaf weight, sheath weight, stem diameter and plant height.
|