Influenza virus strain A/PR/8/34(H1N1)acquired a high-yielding property after serial passages in fertilized eggsSix internal RNA segments of the high-yielding strain were sequenced from their cloned cDNAs and co...Influenza virus strain A/PR/8/34(H1N1)acquired a high-yielding property after serial passages in fertilized eggsSix internal RNA segments of the high-yielding strain were sequenced from their cloned cDNAs and compared with the corresponding original sequences in the prime A/PR/8/34(H1N1)strainNinety-three point mutations were found accumulated in six genes(PB2,PB1,PA,NP,M,and NS),which lead to 27 amino acid changesA significant low mutation frequency without amino acid change was observed in PA geneThe mutation frequency at the amino acid level was the highest(about 3%)in M2 proteinOur data suggest that the unequal distribution of mutations among different viral proteins may correlate with individual role of each protein in viral展开更多
[ Objective] In order to study the effects of 2,4-D and 6-BA on callus cultivation from mature embryos of hsien rice. [ Method] 2,4-D and 6-BA were set at different concentrations in callus induction and differentiati...[ Objective] In order to study the effects of 2,4-D and 6-BA on callus cultivation from mature embryos of hsien rice. [ Method] 2,4-D and 6-BA were set at different concentrations in callus induction and differentiation mediums to study their effects on callus induction, seedling formation and regenerated seedlings rooting. [ Result] In the callus induction medium treated with 0.5 mg/L 2,4-D, the callus induction effects on the varieties like Jiayu 948, Yanghui 559, Yangxian 6547, Zhong＇erruanzhan, Minghui 86, Guanghui 998 and Zunxian 3 were the best; If 0.2 mg/L 6-BA was added into the callus induction medium containing the optimum level of 2,4-D, there was no obvious effect on induction rate of callus, but the differentiation and seedling of callus were inhibited; If the concentration of 6-BA was reduced appropriately in the differentiation medium, the seedling rate of callus would be not only no decreased but increased, meanwhile the quality of regenerated plants would be improved. [ Conclusion] The study results provided some references for the reasonable uses of 2,4-D and 6-BA in callus culture of hsien rice.展开更多
文摘Influenza virus strain A/PR/8/34(H1N1)acquired a high-yielding property after serial passages in fertilized eggsSix internal RNA segments of the high-yielding strain were sequenced from their cloned cDNAs and compared with the corresponding original sequences in the prime A/PR/8/34(H1N1)strainNinety-three point mutations were found accumulated in six genes(PB2,PB1,PA,NP,M,and NS),which lead to 27 amino acid changesA significant low mutation frequency without amino acid change was observed in PA geneThe mutation frequency at the amino acid level was the highest(about 3%)in M2 proteinOur data suggest that the unequal distribution of mutations among different viral proteins may correlate with individual role of each protein in viral
基金Supported by the National Natural Science Foundation (30571049)~~
文摘[ Objective] In order to study the effects of 2,4-D and 6-BA on callus cultivation from mature embryos of hsien rice. [ Method] 2,4-D and 6-BA were set at different concentrations in callus induction and differentiation mediums to study their effects on callus induction, seedling formation and regenerated seedlings rooting. [ Result] In the callus induction medium treated with 0.5 mg/L 2,4-D, the callus induction effects on the varieties like Jiayu 948, Yanghui 559, Yangxian 6547, Zhong＇erruanzhan, Minghui 86, Guanghui 998 and Zunxian 3 were the best; If 0.2 mg/L 6-BA was added into the callus induction medium containing the optimum level of 2,4-D, there was no obvious effect on induction rate of callus, but the differentiation and seedling of callus were inhibited; If the concentration of 6-BA was reduced appropriately in the differentiation medium, the seedling rate of callus would be not only no decreased but increased, meanwhile the quality of regenerated plants would be improved. [ Conclusion] The study results provided some references for the reasonable uses of 2,4-D and 6-BA in callus culture of hsien rice.
