Studies On The Regeneration System And Characteristics Of Physiology And Biochemistry From Mature Embroys Of Different Rice Cultivars

High frequency regeneration system is the basis of rice genetic transformation. By using the mature embryos of different rice of production type as explants on the basis of Wuyujing3, the manifestations of tissue culture ability were studied comparatively, including callus induction frequency of mature embryo, differentiation rate and regeneration rate of10kind of Japonica,9kind of indica and11kind of hybrid rice combination in different medium, in order to establish a high frequency regeneration system of extensive adaptability of different rice varieties. Meanwhile, the physiological and biochemical and ultrastructure of different rice varieties with different inductivity of callus were studied comparatively to provide theoretical basis about differentiation mechanism of rice callus. The main results were showed as follows:(1) By using the mature embryos of Wuyujing3as explants, the optimum medium (M8) and the optimum concentration of sucrose (30g/L) and2,4-D (2mg/L) were determined, meanwhile, the effect of the inductivity of callus of different proportion of exogenous hormones are studied. The result showed, rational coordination of the hormones of2mg/L2,4-D,0.5mg/L6-BA and0.5mg/L KT can obtain the highest inductivity of callus (87.5%).(2) When using M8as basic medium, and adding30g/L sucrose、8g/L agar and2mg/L2,4-D, single addition of cytokinin of lower concentration (0.3mg/L6-BA) in induction medium obtained higher callus induction frequency to Japonica between13.0%and89.2%; based upon adding two cytokinins (2mg/L6-BA and0.5mg/L KT), further adding1mg/L NAA, the callus induction frequency of indica was improved obviously, between9.1%and100%; and the callus induction frequency of11kind of hybrid rice were higher between40.0%and86.3%when adding1mg/L6-BA and1mg/L KT, and there requirements for cytokinins between Japonica and indica. On this basis adding0.5mg/L2,4-D and1mg/L6-BA (Japonica), or0.2mg/L2,4-D and0.5mg/L6-BA (indica and hybrid rice) in the MS differentiation medium, regeneration rates of plants that were4.5%-59.5%(Japonica)、 3.6%-87.5%(indica) and17.2%-43.2%(hybrid rice) were obtained respectively.(3) The Japonica (Yangfujing7, Wuyujing3and Suhuxiangjing) and Indica (Yangfuxian6, Hui76and Huanghuazhan) rice with significantly different inductivity of callus were selected, and they were inoculated on the optimal different induced medium respectively. Different inoculation time and different materials were used to study changes of the soluble protein contents, MDA, SOD, POD and CAT during the callus inducement. The results showed, these had correlation with callus inductivity, callus browning rate, callus differentiation rate, regeneration rate and so on. The CAT activity had a inverse proportion with the different rice materials of different callus inductivities, and the CAT may be as a marker enzyme of different rice callus inductivities.(4) The Japonica (Yangfujing7, Wuyujing3and Suhuxiangjing) and Indica (Yangfuxian6, Hui76and Huanghuazhan) rice with significantly different inductivity of callus were selected, and they were inoculated on the optimal different induced medium respectively. The different materials of different inoculation periods were used to observe by transmission electron microscopic. The results showed that the different rice materials with different callus inductivities developed differently at the same induction time. It suggested that the callus inductivities of Japonica and indica rice have close relation with cell development rate, physiological function and senescence as well.