Mitigative Effect Of Exogenous Chemical Substance On Salt Stress Of Muskmelon Seedlings In Sand Cultur

Muskmelon is salinity tolerant. It is the one of the economical crops about salt irrigation and development of soil salinization. Muskmelon was used as materials. the experiment simulates salinity of soil salinization,try to study the effect of use different consistence exogenous chemical substance in the different period growth and development,production as well as the metabolism of muskmelon. Try to supply the theory evidence of agritechnology for the salicylic acid the alleviation salt resistance,Now it concludes:1,Effect of exogenous chemical substance on muskmelon seedling harmed by salt stress: ALA,SA and CaCl₂ alleviated the inhibition of muskmelon seedlings'growth under salt stress(150mmol/L NaCl). However, ALA was the best one, secondly is SA and CaCl₂.Dry and fresh leaf weight were 1.31 and 1.17 times over that of CK, they were all very significantly higher than contrast,root activity was 2.16 times over that of CK,leaf areas was much improved by 2.4%;stem diameter and aera of leaf were much improved by 5.8% and 15.5% than CK, the difference is clear, It could induce salt resistance, salt tolerance and decrease alleviate damage degree of salt of muskmelon seedlings. 100-200mmol/L of SA and 5mmol/L of CaCl₂ showed better effect than other concentration treatments of the same chemical substance.2,Mitigative effect of exogenous ALA on salt stress of muskmelon seedlings: exogenous ALA obviously alleviated the inhibition of muskmelon seedlings' growth under salt stress(220mmol/L);The results from physiological and biochemical indexes showed that the optimal concentration was 9g/100m² on tendril elongation. 12g/100m² on inflorescence-fruit stage, But its mechanism needs some deep research.3,Mitigative effect of exogenous CaCl₂ on salt stress of muskmelon seedlings: Root activity increased on tendril elongation , Area of leaf ,chlorophyll content increased on inflorescence-fruit stage after 5m mol/L CaCl₂ treatments; dry/fresh weight and root activity were increased on tendril elongation,protein content of leaf of muskmelon increased; MDA content and cell membrane decreased on inflorescence-fruit stage, after 10m mol/L CaCl₂ treatments and received satisfying effect.fruit yield reductions were significant (p<0.01) about all treatment under 220mmol/L brackish water, but it changed fruit quality. Sugar content and soluble protein content increased on growth stage after 5-10m mol/L CaCl₂ treatments, meantime Vc content was significant(p<0.01) about CK although its content reduced on tendril elongateon stage and growth stage.