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The mutagenic effect of major economic characters and favourable variation in M_(2)F_3 , and variated characteristics and selective effect in M_(3)F_4 were studied with early indica rice F_1seeds irradiated by~(137)Cs-γ rays for 4 single and 2 multiple cross combinations. Conventional cross breeding procedures were conducted as being the control with same cross combinations. The result indicated that the mutation frequencies increased in M_(2)F_3 , and average mutation frequency of major economic characters... The mutagenic effect of major economic characters and favourable variation in M_(2)F_3 , and variated characteristics and selective effect in M_(3)F_4 were studied with early indica rice F_1seeds irradiated by~(137)Cs-γ rays for 4 single and 2 multiple cross combinations. Conventional cross breeding procedures were conducted as being the control with same cross combinations. The result indicated that the mutation frequencies increased in M_(2)F_3 , and average mutation frequency of major economic characters in M_(2)F_3 generation of 6 combinations was 6.24% higher than that in F_ 3 generation. The mutation frequencies of multiple cross seeds treated by radiation were higher than that of single cross. The variation range of plant height, number of grain per panicle and 1000-grain weight and favourable character variation rate in M_(2)F_3 were found to be higher than that in F_3. The range of character in M_(3)F_4 was more narrow than that in F_4 for single cross and greater than that in F_4 for multiple cross. It shows that the segregation and stability of characters in the progenies of F_1 seeds treated by radiation were related to cross manner and heterozygosity of hybrids. 用~(137)Cs-γ射线辐照籼稻4个单交和2个复交组合的F_1代种子,以常规杂交处理作对照.结合育种实践,研究了M_2F_3代主要经济性状突变频率,有利性状变异率以及M_3F_4代的变异特点和选择效果。结果表明,辐照水稻杂种一代可提高变异率,6个组合M_2F_3主要经济性状突变频率平均比F_3提高6.24%;辐照复交杂种的突变频率大于辐照单交杂种。M_2F_3株高、每穗粒数和千粒重的变幅以及有利性状变异率大于F_3。单交组合M_3F_4性状变异小于F_4,复交组合M_3F_4性状变异大于F_4。表明辐照杂种F_1代性状的分离和稳定与配组方式和杂种的杂合程度有关。M_3F_4优良单株中选率比F_4平均提高0.55%。 This paper summarizes the advances of research technique in seedless grape breeding, covering the conventional cross-breeding of seedless grape, embryo culture and ovule culture, seed processing technologies for seedless grape, multiploid breeding, trans-genetic technologies for seedless grape and etc. The problems for future research in this field were discussed. 总结了国内外无核葡萄育种技术的研究进展,内容包括无核葡萄的常规杂交育种,胚、胚珠培养,无核葡萄的有籽处理技术,多倍体无核葡萄育种,转基因技术等,并对今后研究提出展望。 The IRBB near isogenic lines were identified for their resistance to bacterial leaf blight (BLB) using the mixed strains of the epidemic races in Zhejiang Province. The results showed that the polymerization of different BLB resistant genes was favourable to strengthen the resistance. IRBB52, IRBB54 and IRBB60 which have the polymeric BLB resistant genes were used as the donors of BLB resistant genes and crossed with the blast resistant restorer lines CDR448, Minghui 63. New restorer lines with resistance... The IRBB near isogenic lines were identified for their resistance to bacterial leaf blight (BLB) using the mixed strains of the epidemic races in Zhejiang Province. The results showed that the polymerization of different BLB resistant genes was favourable to strengthen the resistance. IRBB52, IRBB54 and IRBB60 which have the polymeric BLB resistant genes were used as the donors of BLB resistant genes and crossed with the blast resistant restorer lines CDR448, Minghui 63. New restorer lines with resistance to both BLB and blast could be developed by anther culture or conventional cross breeding methods. 利用浙江省流行小种混合菌系对IRBB近等基因系进行抗白叶枯病鉴定 ,结果表明 ,多个白叶枯病抗性基因的聚合有利于抗性的提高。育种上可利用聚合有多个白叶枯病抗性基因的IRBB5 2、IRBB5 4、IRBB6 0等作为抗源供体 ,与抗稻瘟病恢复系CDR44 8、明恢 6 3等杂交 ,利用花培、常规遗传选育等方法 ,选育双抗恢复系
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