Effects Of The Vigor Of Tobacco Seed By Several Treatments

Seeds play a very importance role in tobacco production. Good tobacco variety and good quality seed with high level vigor can lead to produce good quality seeding and laying a good foundation for quality leaf production. The test was conducted to study the effect of different treatments on tobacco seed vigor to explore effective ways to improving seed vigor of tobacco and providing theoretical evidence for the industrialization of tobacco seed. The tobacco variety involved was Yunyan87 with 7 seed lots of different levels of seed vigor, the treatments employed were the physical ones (including hydration and dehydration, artificially accelerated aging) and the chemical ones (treating with H₂O₂, choline chloride and PEG respectively), the results of different seed treatments were investigated and analyzed by using physiological (such as germination viability, germination index) and biochemical indexes (conductivity). The overall results indicated:1. Seeds being treated with accelerated aging showed that the higher the level of seed vigor, the stronger the seed anti-aging ability. The hydration and dehydration treated seed, the choline chloride and H₂O₂ and PEG treated seed, all showed improvements more or less on their vigor, some indexes reflecting the seed vigor including seed germination viability, germination rate, (simplified ) germination index and (simplified) vigor index all increased obviously; the relative conductivity of the imbibed seed was significantly declined compared with the ck, therefore, these treatments are effective means to increasing the vigor of tobacco seed with lower or medium level vigor.2. Seeds with higher vigor treated with hydration and dehydration, choline chloride, H₂O₂ and PEG respectively, the seed vigor was slightly restrained. Among the hydration and dehydration treatments, the best effect treatment was moisture equilibrium - imbibition in water - drying. Among the H₂O₂ treatments, the best effect treatment was with the concentration of 0.2% and imbibed in water for 1d. Among the choline chloride treatments, the better effect went to the concentration at 200mg/L. Among the PEG treatments, the better effect obtained from the one with the molecular weight at 2000, the concentration at 20% and soaked for 1 d.3. This study probed the effects and mechanism of physical and chemical factors on improving tobacco seed vigor. Based on the factor that during the process of seed treatments, the structure of the cell membrane got improved in certain degree, thus making it possible for the function of the cell membrane renewed to some extent. In the mean time, it was confirmed that the germination viability, germination rate, (simplified) germination index had extreme positive correlation with (simplified) seed vigor of tobacco seed, while the relative conductivity of imbibed seed had extreme negative correlation with the vigor index of tobacco seed. The study results could be applied in quicker identification of tobacco seed quality and for the improvement of tobacco seed vigor.