Study On Radiation Effects On Tress Mutation Induction And Micro-propagation System Of Mei Flower In Vitro

The biologic effect of ⁶⁰Co-γradiation on the tress of Prunus mume cv.'Fenpi Gongfen' and Prunus mume cv.'Midan Lv' were studied.It was supported by the results of livability of graft lines,the status of leaves and the content of chlorophyll which were tested after the radiation.5 mutants of morphology were selected from the radiated population,and the UV-120 spectrophotometer was conducted to analyze the content of chlorophyll.Molecular markers,such as ISSR,SRAP,were used to detect DNA identification.The micro-propagation system and regeneration system of Prunus mume were primarily studied for the future research of the mutants in vitro. The results were concluded as following:1.The effect of the ⁶⁰Co-γradiation on livability of graft linesIt showed that the livability of graft lines decreased by increasing dosage of the radiation relatively.Half-life of Prunus mume cv.'Fenpi Gongfen' which suited dosage 10～40Gy is 40Gy.Half-life of Prunus mume cv.'Midan Lv' which suited dosage 10～50Gy is between 50Gy and 70Gy.2.The effect of the ⁶⁰Co-γradiation on growth status of graft linesThe indexes of two cultivars which were height of grafts,length of internodes, length,width and ratio of length/width of leaves were investigated.The height of grafts did not increase by the increase of dosage of radiation.The length of internodes presented shortened in the first investigation which increased a little in the second investigation.This indicated that the radiation did affect the internodes growth negatively,however this effect disappeared gradually after amount of time.Length, width and ratio of length/width of leaves showed no linear relativity to the dosage of radiation except the length/width of 'Midan Lv' which increased by the increasing dosage of radiation.Dosage of radiation were decided as 20Gy and 30Gy that were good for gaining mutants from Prunus mume cv.'Fenpi Gongfen',which were 20Gy and 40Gy for Prunus mume cv.'Midan Lv'.3.Selection of mutants in the fieldFour mutants of Prunus mume cv.'Fenpi Gongfen' which blossom earlier than wild line were found in the field after grafting.There was no obvious morphologic difference between mutants and wild line except less petals on mutants than on wild line.There was a mutant of Prunus mume cv.'Midan Lv' which sprouted 25 days later than the control. 4.Chlorophyll contentFour mutants of Prunus mume cv.'Fenpi Gongfen' and one mutant of Prunus mume cv.'Midan Lv' were used as material for testing chlorophyll content.The results showed that radiation had restrained the synthesis of chlorophyll.5.Molecular markers ISSR and SRAP were used to identify the mutants gained.DNA of Prunus mume cv.'Fenpi Gongfen' was used as DNA model which was used for selecting 13 ISSR primers from 38 ones.106 sites were gained in which 45 sites presented polymorphysm.DNA of'Midan Lv' was used as DNA model which was used for selecting 15 ISSR primers from 38 ones.93 sites were gained in which 20 sites presented polymorphysm.Mutant ratio of Prunus mume cv.'Fenpi Gongfen' is higher than that of Prunus mume cv.'Midan Lv' which meant Prunus mume cv.'Fenpi Gongfen' was liable to mutate.6.Tissue culture for Prunus mume using stems with axillary budsStems with axillary buds ofPrunus mume cv.'Fenpi Gongfen',Prunus mume cv.'Moshan Zhusha' and Prunus mume cv.'Midan Lv' were used as explants to optimize the tissue culture protocols.The results were as follows:KT1.0mg/L+IBA0.1mg/L was the best match for Prunus mume cv.'Fenpi Gongfen',BA0.5mg/L+NAA0.1mg/L was the best match for Prunus mume cv.'Moshan Zhusha' and BA2.0mg/L+NAA0.2mg/L was the best match for Prunus mume cv.'Midan Lv'. three kinds of disinfection methods were tested.The best protocol was that the explants were warmed up in 37℃for 2h,then using 0.1%HgCl₂ in disinfection maintained 37℃.WPM basal medium was shown to be the best for Prunus mume cv.'Midan Lv'.Tress in the middle was the best explants for Prunus mume cv.'Moshan Zhusha'.