The Effects Of Seed Priming And Storage On Seed Germination,seedling Growth And Cold Tolerance Of Tomato Rootstocks

Tomato is one of the main vegetable crops in China's facilities for horticulture,and the problem of continuous cropping caused by continuous planting of tomatoes has seriously restricted the development of tomato.At present,grafting seedlings are a method to effectively overcome the obstacles of continuous cropping,but tomato grafting seedlings often have the problem of low germination rate of rootstock seeds.Studies have shown that seed priming as a seed treatment method can effectively improve the vigor of seeds,promote seed germination,and improve the stress resistance of seedlings.According to the experiment,tomato rootstock variety seeds(JZM-1)were used as materials.The effects of different temperature priming and post-priming storage on the germination of tomato rootstocks and the cold tolerance of seedlings were studied by setting different priming temperatures.The main results are as follows:1.The results of different temperature vermiculite priming studies show that under the same water content,different temperature meteorites can increase the vigor of tomato rootstock seeds to different extents.Including T3(15?)temperature trigger and T6(5/20 ?)temperature two processing as T3,T6 effect is best,the germination potential,germination index and germination rate were significantly higher than the control,the germination rate was 71.3%,69.3%,respectively.Compared with the control,the increase was 27.3%and 25.3%,which significantly increased the vigor of tomato rootstock seeds.2.Different temperature vermiculite priming treatment in the cold stress experiment,the two treatments of T3 and T6 performed better.The fresh weight and strong seedling index of the shoots treated by T3 and T6 were significantly higher than the control and other treatments.Both of the above treatments can increase the content of chlorophyll,soluble sugar,soluble protein and several antioxidant enzymes in tomato rootstock seedlings to some extent,and reduce the relative electrical conductivity and MDA and O' content of the leaves to some extent.The enzyme activity,soluble sugar and soluble protein content of T3 and T6 were significantly higher than that of the control,and the performance of chilling injury index was better than that of the control.It is concluded that the low temperature priming can improve the cold resistance of the seedlings after sowing to some extent.3.The tomato rootstock seeds are primed and then dried,and then stored under different temperature conditions(5?,25?).The results showed that the germination potential and germination rate of rootstocks stored at 25? were significantly higher than those of tomato rootstocks stored at 5?.The germination rate and germination index of T3,T5 and T6 stored at 25? were significantly higher than the control,which were 14.5%,13.5%and 19.5%higher than the control,respectively.Each priming treatment at 5? was close to or lower than the control and showed signs of attenuated seed viability as a whole.It is preliminarily believed that the use of tomato rootstock seeds after 25? storage in a short period of time can maintain the seed-priming effect in the long term.4.The plant height,stem diameter,fresh weight of shoots,fresh weight and strong seedling index of tomato seedlings treated under cold stress at 25? were slightly better than 50C storage,and stored at 25?.T6 was significantly higher than the control,and there was no significant difference between the other treatments and the control.In terms of low temperature tolerance of seedlings,soluble sugar,soluble protein content and antioxidant enzyme activities of tomato rootstock seedlings stored at 25? after cold stress were significantly higher than those stored at 5?,and some antioxidant enzyme activities were stored at 5?.Each treatment was stored above 25?.The relative conductivity and MDA content of the leaves treated at 5? were close to or slightly lower than 25? for storage.These results indicate that storage at room temperature can protect seed activity and slow down seed senescence,and low temperature storage will reduce seed activity,but to some extent improve the stress resistance of seedlings under low temperature stress.