Of Gaseous No The Growth And Development Of Garlic On The Garlic

Nitric oxide(NO) is a bioactive molecule;accumulating evidence indicates that it is one of the widely distributing signal molecules in plants.Nitric oxide was used as an important regulatory factor in plant growth and development,can generate response of all biological and abiotic stress. Nitric oxide in plant growth and development and the environment co-ordination process of interaction plays a central role.However,NO on the bulb of the plant growth and development study a little at present.In the present study,The Gailiang garlic were fumigated with different concentrations of NO gas(0.1,0.5 and 1.0μmol·L^-1) under anaerobic conditions.We investigated the effects of NO on the growth of garlic seedlings in dormancy and after removal of dormancy.To understand the mechanisms of NO-promoted seedling growth,the effects of exogenous NO on the membrane lipid peroxidation and photosynthesis of garlic sprouts were also been investigated,and to expect to increase yield of garlic sprouts.The main results were presented as follows:1.Garlic in dormancy and after removal of dormancy was fumigated with different concentrations of NO gas could increase sprouting rate and promote the seed germination.The results showed that sprouting rate,the fresh and dry weight of the over-ground part and roots,plant height, max leaf length,pseudo-stem length,pseudo-stem width and soluble protein of garlic seedlings fumigated with 0.1 or 0.5μmol·L^-1 NO were higher than those without fumigation of NO.But the growth of seedlings was inhibited by 1.0μmol·L^-1 NO gas.The bulb treated with NO gas also promoted seedling growth.The optimum concentration of NO gas was 0.5μmol·L^-1.2.The activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT), ascorbate peroxidase(APX),glutathione(GSH) and ascorbic acid(ASC) of garlic in dormancy fumigated with 0.1 or 0.5μmol·L^-1 NO were increased.But the malondialdehyde(MDA) content, relative membrane permeability,the superoxide(O₂^-.) anion and content of H₂O₂ were decreased. The optimum concentration of NO gas was 0.5μmol·L^-1.The bulb treated with exogenous NO can decrease membrane lipid peroxidation of garlic seedlings.3.Compared to control treatment,0.5μmol·L^-1 NO resulted in increases in the contents of photosynthetic pigments,net photosynthetic rate(Pn),stomatal conductance(Gs) and transpiraton rate(Tr) of garlic seedlings in dormancy,which were accompanied by decreases in intercellular CO₂ concentration(Ci) and stomatal limitation values(Ls) in garlic sprouts.The results showed that the main reason of photosynthetic rate in garlic sprouts treated with 0.5μmol·L^-1 NO was higher than control treatment was caused by non stomatai factor.Furthermore,0.5μmol·L^-1 NO enhanced Rubisco content,These results indicated that exogenous NO can improved efficiency of carbon assimilation of and stomatal limitation values in garlic sprouts.Compared to control treatment,1.0μmol·L^-1 NO caused the reduction of Pn,Gs,Ci,Tr and Rubisco content,the enhancement of Ls in garlic sprouts.These results showed that the inhibitive effect of 1.0μmol·L^-1 NO treatment on photosynthetic of garlic sprouts caused by stomatal factor and non stomatal factor together.However, all parameters of 0.1μmol·L^-1 NO treatment had no difference.Garlic in dormancy fumigated with NO,maximal photochemical efficiency of PSⅡ(Fv/Fm), actual photochemical efficiency of PSⅡ(yield),the potential activity of PSⅡ(Fv/Fo) and the photochemical quenching(qP) of garlic seedlings fumigated with 0.1 or 0.5μmol·L^-1 NO were higher than those without fumigation of NO.But initial fluorescence(Fo) and the non-photochemical quenching(qN) were below control and 1.0μmol·L^-1 NO gas.The results indicated that the garlic treated with NO gas declined of chlorophyll fluorescence parameter Fv/Fm, Yield,Fv/Fo and qP of garlic sprouts.