[Objective] Strain Biok Av-023 used as the control was employed on screening of high-avermectin yield mutants by rational screening.[Method] With Biok Av-023 as the original strain,the positive mutation strain was fir...[Objective] Strain Biok Av-023 used as the control was employed on screening of high-avermectin yield mutants by rational screening.[Method] With Biok Av-023 as the original strain,the positive mutation strain was firstly screened by routine UV mutagenesis,and then the high-yield avermectin producing strain was selected by the breeding way inferred by L-Ile induction.[Result] UV mutation and L-Ile directional screening had showed that the best L-Ile screening concentration was 0.5%,and the high-yield mutation strain AV60s-32 after re-screening reached the highest titer of 4520 IU/ml,which increased by 23.4% compared with the original strain.[Conclusion] The production of avermectin can be effectively enhanced by the combined way of UV mutation and L-Ile rational breeding.展开更多
The aim of this study was to identify tea varieties with less bitterness and astringency index that could be used as important sources for breeding and in the production of high quality tea. We studied 36 cultivars or...The aim of this study was to identify tea varieties with less bitterness and astringency index that could be used as important sources for breeding and in the production of high quality tea. We studied 36 cultivars or lines which had been preserved in Tea Germplasm Garden of Fujian. The contents of catechins in spring tea shoots, summer tea shoots and autumn tea shoots in 36 varieties and lines were analyzed by HPLC. Analysis of these tea varieties and lines revealed that the catechins contained in the tea shoots in different seasons are highly variable. The content of ester-catechins in spring and summer tea shoots was higher than that of autumn, while non-ester-catechins did not showed the same characteristic. The content of EGCG showed an extremely significant positive correlation with T1 （T1 = EGC ＋ EGCG ＋ GCG ＋ EGC）, an extremely significant negative correlation with DL-C, the content of EGC showed the same characteristic. Among them, 10 cultivars with less bitterness and astringency index （the annual average bitterness and astringency index 〈 8.0） were considered good candidates as important breeding materials tbr tea infusion quality improvement.展开更多
基金Supported by 863 Project (2009AA032904 )Scientific ResearchStarting-up Project for Young Teachers in Changshu Institute oTechnology" Hundreds of Entrepreneurs into Campus" Project inChangshu Institute of Technology~~
文摘[Objective] Strain Biok Av-023 used as the control was employed on screening of high-avermectin yield mutants by rational screening.[Method] With Biok Av-023 as the original strain,the positive mutation strain was firstly screened by routine UV mutagenesis,and then the high-yield avermectin producing strain was selected by the breeding way inferred by L-Ile induction.[Result] UV mutation and L-Ile directional screening had showed that the best L-Ile screening concentration was 0.5%,and the high-yield mutation strain AV60s-32 after re-screening reached the highest titer of 4520 IU/ml,which increased by 23.4% compared with the original strain.[Conclusion] The production of avermectin can be effectively enhanced by the combined way of UV mutation and L-Ile rational breeding.
基金This research was supported by Natural Science Foundation of Fujian （No. 2009J01063）. Determination of catechins was finished in Tea Research Institute, Chinese Academy of Agricultural Sciences and in Tea Quality Supervision and Inspection Center, Ministry of Agriculture.
文摘The aim of this study was to identify tea varieties with less bitterness and astringency index that could be used as important sources for breeding and in the production of high quality tea. We studied 36 cultivars or lines which had been preserved in Tea Germplasm Garden of Fujian. The contents of catechins in spring tea shoots, summer tea shoots and autumn tea shoots in 36 varieties and lines were analyzed by HPLC. Analysis of these tea varieties and lines revealed that the catechins contained in the tea shoots in different seasons are highly variable. The content of ester-catechins in spring and summer tea shoots was higher than that of autumn, while non-ester-catechins did not showed the same characteristic. The content of EGCG showed an extremely significant positive correlation with T1 （T1 = EGC ＋ EGCG ＋ GCG ＋ EGC）, an extremely significant negative correlation with DL-C, the content of EGC showed the same characteristic. Among them, 10 cultivars with less bitterness and astringency index （the annual average bitterness and astringency index 〈 8.0） were considered good candidates as important breeding materials tbr tea infusion quality improvement.
