| This work aimed at the study of culturing three varieties of mustard (Yuandatoucai, Yongshengdaercai, Rongyuxiangjiecai), Starting with in vitro culture of cotyledons and hypocotyls of mustard established on the plant regeneration system. In the process of the organogenesis, this work mainly focused on the research of biochemical indicators, soluble proteins and peroxidase isoenzyme, and further research on the morphogenetic callus has been done at the cytohistology level. The main results are as follows:1 The establishment of in vitro culture system in mustardThe result showed that different varieties, hormone concentration played important roles in mustard organogenesis. The optimal way of seed sterilization was 5% NaClO +tween-20 2 drops for 15min. The optimal culture medium for sterilitas plants was 1/2MS+8.0g/L Carrageenan (pH5.8~ 6.0); the appropriate medium for explants differentiation was MS+30g/L sucrose+8.0g/L Carrageenan+3.0mg/L 6-BA+0.1mg/L NAA, when the explants were cotyledons, the highest differentiation rate of three varieties (Yuandatoucai, Yongshengdaercai, Rongyuxiangjiecai)were 72%, 84%, 76%; and when the explants were hypocotyls, the highest differentiation rate were 70%, 72%, 70%. The best medium for rooting was MS+30g/L sucrose+8.0g/L Carrageenan+0.1mg/L NAA, with good root status and 100% rootage rate.2 The studies on components and contents of the soluble proteinsThe average content of soluble proteins in morphogenetic callus was 20.88 mg/g·FW, it was higher than the content in non-morphogenetic callus, which was 12.08 mg/g-FW. Therefore, the lower-level of the proteins might be one of the important reason that let morphogenetic callus lost the capacity of redifferentiation and turned into non-morphogenetic callus.The results of SDS-PAGE electrophoresis showed that different specific proteins found separately in different stages. There were four kinds of proteins (65KDa, 29KDa, 24KDa, 16KDa) expressed during callus differentiation. And the protein weight 16KDa didn't express after callus differentiated. These four kinds of proteins might be related with the morphochoresis of organs. The proteins weight 50KDa and 30KDa were detected in non-morphogenetic callus and not in morphogenetic callus.So, these two kinds of proteins can be used as markers for non-morphogenetic callus during mustard in vitro culture.3 The studies on peroxidase isozymeThe peroxidase isozyme analyse was as follows: the thickness of isozyme bands of the morphogenetic callus was little stronger than those of the non-morphogenetic callus. The morphogenetic callus had C and G bands that the non-morphogenetic callus didn't have. C band appeared after callus differentiation, so it could be used as a biochemical marker for callus differentiation. D band appeared during callus induction, this might be a sign for the begining of explants dedifferentiation.4 Studies on physiological and biochemical indexesThe physiological and biochemical indexes in two kinds of callus are obviously different during the culture process. The physiological and biochemical indexes of the morphogenetic callus had wider change range than those of the non-morphogenetic callus. When the callus had been cultivated for 8 days, the contents of nucleic acid (DNA, RNA), the antioxides enzyme (POD, SOD, CAT) activities of morphogenetic callus were higher than that of non-morphogenetic callus, and trends of those indexes were on the rise. At the same time, the contents of soluble sugars and starch were declined. While the changes of physiological and biochemical indexes of non-morphogenetic callus changed mildly.5 Histocytological analysisBy the observation of paraffin wax slice, the morphogenetic cells of exterior and interior gradually formed two kinds of meristematic centres, which were the embryonic meristematic packed cells and the meristematic tubercles.The former would develop into primordial buds, and the latter would develop into primordial roots.
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