Effects Of Snp And Peg On The Related Physiological Indices Of Potato Seedlings In Vitro Under Low Tempetature

Potato is an important crop in China. The yield and quality is directly related to people's livelihood.Low temperature and drought appear from time to time in early spring or late spring in recent years, which seriously affect the production of potato. Using the exogenous nitric oxide donor SNP, expect to improve the cold resistance and drought tolerance to potato in Northwest of China.Study the effects on superoxide dismutase (SOD), peroxidase(POD) and catalase (CAT) activity as well as on the contents of malondidehyde(MDA), soluble protein, proline and chlorophyll of LongshuIII and LongshuVI seedlings in vitro treated with 5%-25%of polyethylene glycol(PEG-6000) or 0.05-2mmol/L of sodium nitroprussede (SNP) or treated all together with 5% of polyethylene glycol(PEG-6000) and 0.10mmol/L of sodium nitroprussede (SNP) under 4℃low temperature. The study shows:(1) Only under the 4℃low temperature, LongshuⅢand Longshu VI potato seedlings in vitro treated with low temperature, MDA, proline content increased. Soluble protein,chlorophyll content decreased. SOD, POD, CAT activity levels are on the rise. To resist and adapt to low temperature stress environment.(2) Under the 4℃low temperature, Mix 5%-25% of the PEG-6000 in the LongshuⅢand Longshu VI potato seedlings in vitro,leading their enzymatic activity and the contents of MDA,soluble protein, proline and to an increase, the changes of contents of chlorophyll in LongshuⅢand LongshuVI is not obvious. The study reveals that Longshu III and LongshuⅥsensitivity to drought stress is lower than cold stress.(3) Under the 4℃low temperature,Mix 0.05-2mmol/L of the SNP in the Longshu III and Longshu VI potato seedlings in vitro, the two varieties died in SNP concentration greater than or equal 0.50 mmol/L, indicating higher than 0.50 mmol/L SNP potato plantlets will produce toxic effects.0.05 mmol/L and mmol/L SNP treatment significantly enhanced activities of antioxidant enzymes, MDA content increased and then decreased, proline content was lower than the control, protein and chlorophyll content increased. The study reveals that in particular the low concentration 0.10 mmol/L SNP to delay the stress caused by cold temperatures promote the growth of potato plantlets,(4) Simultaneous treated with 5% of polyethylene glycol(PEG-6000) and 0.10mmol/L of sodium nitroprussede (SNP) under 4℃low temperature, SNP significantly alleviated the PEG-6000 caused by drought stress. The results shows that the effects of SNP to mitigation the drought stress was stronger than the effects of mitigation low temperature stress.(5) Experiments further confirmed whether LongshuIII and LongshuⅥ, their own cold and drought resistance are strong or not, the drought tolerance of LongshuVI is higher than that of LongshuⅢ.