Effects Induced By Exogenous Chemical Matter On Resistance Of Seeding Of Tomato To Chilling Injurg

Tomato (Lycopersicon esculentum Mill.) origins from tropic and subtropical, it is sensitive to temperature. Low temperature can delay its growth and development. It is a new technology toincrease tolerance of plants treated by exogenous chemical matter. Our study focused on mechanism of responsing to cold, especially on its components and their functions. We can provide a solid basis for application of exogenous chemical matter to enhance plants tolerance to stress."dongnong710"and "dongnong704"were selected for materials. At the same time we choosed 10 kinds of chemical matter used for exogenous inducter. 5 leaves old tomatoes were induced by 10 kinds of chemical matter, treated by low temperature after 6 days, collected to assay physiological changes. Several leaves old tomatoes were induced by the various concentration of ABA for different time and were assayed the activity of POD, CAT, EC. We used Abscisic acid, Ethylene, Salicylic acid to treat tomatoes to survey the changes of the activity of POD, CAT and so on. We drew a conclusion that 10 kinds of exogenous matter can obviously enhance tomatoes' tolerance to cold, only on the appropriate concentration of Abscisic acid, Ethylene, Salicylic Acid, CCC, CC, L-Cysteion, Vc and Allantoin. Relative electrical conductance of "dongnong710"and "dongnong704"treated by exogenous matter were decreased and increase the activity of POD .the concentration of Chlorophyll was up regulated. ABA(200mg/L), ETH(300mg/L), GA3(30mg/L),(SA30mg/L) ,CCC (200mg/L) , CC (800mg/L) , L-Cysteion (600mg/L) , Vc (1000mg/L) , Allantoin (300mg/L), CaCl2 (1400mg/L) can effectively affect tomatoes' response to cold.among them ,tomatoes' tolerance treated by ABA and SA can be obviously increased to cold stress, ETH and CaCl2 were also effective to plants on resist cold stress.Exogenous ABA can harm tomatoes without treated by other chemical matter, and tomatoes got heavier damage with the concentration of ABA increasing. We used different concentration of ABA to induce tomato, we found that the relative electrical conductance were deceased in the former and increased in the latter. The activity of POD and the content of Chlorophyll also showed the same strends. When the tomatoes were treated by exogenous ABA for 6 days, all the parameters of induced materials were better than control. We treated different leaves old tomatoes with ABA (200mg/L) we found that Only 5~6 leaves old tomatoes treated by ABA had obviously effect on tolerance of cold.Tomatoes treated by ABA, SA, ETH show the more resist to cold than those treated by thecold in the earlier stage and those untreated. At the same time we concluded that tomatoes suffered cold stress in the earlier stress showed more tolerant of cold than control only sprayed with water. The tomato treated by exogenous matter and those treated by cold in the earlier stage show the same activity of POD and the contents of chlorophyll at last. All the parameters of "dongnong710"and "dongnong704" treated by exogenous matter or cold in the earlier stage were better than corresponding controls. In a word we elucidate that materials treated by ABA and SA had most obviously effect on increasing tomatoes' tolerance of cold, ETH was in the next place.