Establishment Of Regeneration System Of Pea And Study On Physiological Mechanisms Of NO Improve Salt Tolerance To Pea Seedlings

Pea （Pisum sativum L.） is a leguminous herbs of a year or more, is also an importantfood, vegetables, fodder, green manure and soil improving crop. In recent years, traditionalplanting and breeding methods has been unable to meet the production demand.Establishment of regeneration system by plant tissue and study on sress resistance willprovide a good scientific base and technical preparation for gene transform, asexualreproduction and planted in saline soil in the future.The experiment includes two main contents: by comparing different explants, mediums,hormones, culture conditions and other factors, established a full regeneration system wasachieved; At the same time, germination and seedlings growth of pea and NO on alleviatingstress tolerance under salt stress was studied.The results are followed:Establishment of regeneration system of pea.1.The best explants is pea stem; The best medium for callus induction is MS+1.0mg.L^-12,4-D+0.2mg.L^-16-BA; The best inoculation is horizontally; Callus induction in differentlight conditions, blue light promoted and yellow light inhibited significantly; The explantswere cultured on MS with TDZ to induce, no callus formation and browning eventually, noadventitious bud formation also. Adding2,4-D into MS with TDZ, the callus induction rate isvery low, but not conducive to later differentiation.2. The best callus proliferation medium is MS+1.0mg.L^-1NAA+1.0mg.L^-16-BA;Stems differentiation rate is the highest, reached26.21%in MSB5+0.2mg.L^-1NAA+2.0mg.L^-16-BA; Cotyledons differentiation rate is the highest, reached14.80%in MS+0.5mg.L^-1NAA+2.0mg.L^-16-BA; the best medium for rooting is1/2MS+0.5mg.L^-1NAA, onwhich66%plants rooted.3. The best medium for direct adventitious bud differentiation of pea aseptic seedlings isMS+0.2mg.L^-1NAA+1.0mg.L^-16-BA, the average number of adventitious bud differentiationreached3.20; The best rooting medium is1/2MS+0.2mg.L^-1NAA, the rooting rate reached85%, and with the seed of physiological age increased and decreased.Study on resistance of two, pea1．In this thesis, two pea varieties,"long wan1, S4008" have used as the experimentmaterials, under different concentrations of NaCl stress, response of germination and seedlinggrowth of Pea seeds were investigated. The results show that:10mmol·L^-1NaCl couldpromote seed germination,2varieties of pea germination rate, germination, plumule and radicle length, seedling fresh weight and dry weight, relative water content, chlorophyllcontent were significantly higher than controls （p<0.05）;25mmol·L^-1NaCl treatment wasslightly higher than the control, but the difference was not significant; germination indexdecreased with increasing salt concentration,10,25mmol·L^-1treatment and the control werenot significant; High concentration of NaCl (50,100,200mmol·L^-1) significantly inhibitedthe germination rate, germination, plumule and radicle length, seedling fresh weight and dryweight, relative water content and chlorophyll content （p<0.05）, and the radicle down trendthan germ; Extremely high concentration NaCl (300mmol·L^-1) stress could not germinatedpractically. The cell membrane permeability and malondialdehyde increased with the saltconcentration increased significantly （p<0.05）; The proline content is increased firstly andthen decreased （p<0.05）,25mmol·L^-1reaches the minimum value. Comprehensiveevaluation: the radicle is more sensitive parts of under salt stress, Two pea varieties of saltresistant ability: S4008>longwan1.2．A pea variety "longwan1" was employed to study the effect of exogenous NO donorsodium nitropprusside （SNP）, NO scavenger c-PTIO and sodium nitroprusside analoguessodium ferrocyanide on the growth and oxidative damage in pea seedlings under NaCl stress.The results showed that: the pea seedlings of plumule and radicle length, seedling dry weight,root and shoot ratio and chlorophyll content were increased significantly （p<0.05）, the contentof soluble protein and sugars were increased, the activities of SOD, POD and CAT and thecontent of proline were increased （p<0.05）, meanwhile, exogenous NO alleviated theaccumulation of MDA and decreased membrane relative permeability in leaves of peaseedling under salt stress. However, NO donor sodium nitroprusside analogues sodiumferrocyanide had no obvious effects on pea seedlings growth and oxidative damage, NOscavenger c-PTIO inhibited the pea seedling growth and oxidative damage under salt stress,but the inhibition effect could be mitigated by supplementing SNP. It was suggested thatexogenous NO and endogenous NO were involved in the physiological and biochemicalresponses under salt stress.