The year 2008 will mark the 80 th anniversary of mutation induction in plants. The application of mutation techniques has generated a vast amount of genetic variability and has led to the off icial release of at leas...The year 2008 will mark the 80 th anniversary of mutation induction in plants. The application of mutation techniques has generated a vast amount of genetic variability and has led to the off icial release of at least more than展开更多
Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction...Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc.展开更多
<div style="text-align:justify;"> <i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> species affect the potenti...<div style="text-align:justify;"> <i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> species affect the potential productivity of cereals in sub-Saharian Africa due to the lack of durable </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;">-resistance in host crops. This study aimed at inducing the new source of resistance in sorghum using gamma irradiation. Dry seeds of three Sorghum varieties;Grinkan, ICV1049 and Sariaso14 were gamma-irradiated with 200 Gy, 300 Gy, 400 Gy and 500 Gy. Screening strategies involved a 2-year field and greenhouse experiments, where mutant Sorghum families, their parents and resistant control were artificially infected with </span><i><span style="font-family:Verdana;">Striga hermonthica</span></i><span style="font-family:Verdana;"> seeds. Field screenings revealed induced genetic variability among them, forty families significantly reduced the number of emerged </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> plants or showed good Sorghum grain yield performance despite the infection by S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> ecotype from Burkina Faso. The induced putative resistant mutants were identified across the four applied gamma-irradiation doses. Greenhouse experiment confirmed </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> resistance in seven mutant Sorghum families leading to no emergence of Burkina’s S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> ecotype along with high resistance index (RI) and low </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> damage score. Among them, two mutants SA38M5 and IC47M5 withstood S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> ecotype from Sudan. The induced mutants will be evaluated for the release to farmers for commercial production. Further studies are ongoing on confirmed mutants to highlight their </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> resistance mechanisms and explore the potential of pyramiding different mechanisms to produce durable resistance to S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> in sorghum.</span> </div>展开更多
[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After n...[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.展开更多
[Objectives]This study was conducted to breed high-yielding wheat varieties. [Methods] A new breeding technology of "Artificial mutagenesis to increase genetic differences between parents and to enhance heterosis...[Objectives]This study was conducted to breed high-yielding wheat varieties. [Methods] A new breeding technology of "Artificial mutagenesis to increase genetic differences between parents and to enhance heterosis" was put forward. Longnan 71 a and Longnan 71 a mutants bred by this technology were crossed with other mutants and normal materials. [Results] In the Wudu experimental field of Longnan City, the traits of super-large grain appeared in the obverse and inverse cross with Longnan 71 a as parents. The trait of super-large grain was dominantly inherited. The traits of various combinations in the Fgeneration were segregated. In the Fgeneration, one super-large-grain low-stalk line and other lines with specific traits were selected. In the Fgeneration, two super-large-grain low-stalk large-ear lines were selected. These three super-large-grain low-stalk wheat lines had reduced plant height and good lodging resistance, and possessed two high-yielding characters among the three factors of yield, so they were expected to be further bred into high-yielding wheat varieties. One line with the largest grain length of 10.3 mm was selected in the Fgeneration. After two years of breeding, in 2022, the largest grain length was measured to be 10.6 mm, and the average 1 000-grain weight and the largest 1 000-grain weight were 75.8 and 100 g, respectively. [Conclusions] This study is about the major progress in artificial cultivation of super-large-grain wheat and has considerable practical value.展开更多
文摘The year 2008 will mark the 80 th anniversary of mutation induction in plants. The application of mutation techniques has generated a vast amount of genetic variability and has led to the off icial release of at least more than
文摘Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc.
文摘<div style="text-align:justify;"> <i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> species affect the potential productivity of cereals in sub-Saharian Africa due to the lack of durable </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;">-resistance in host crops. This study aimed at inducing the new source of resistance in sorghum using gamma irradiation. Dry seeds of three Sorghum varieties;Grinkan, ICV1049 and Sariaso14 were gamma-irradiated with 200 Gy, 300 Gy, 400 Gy and 500 Gy. Screening strategies involved a 2-year field and greenhouse experiments, where mutant Sorghum families, their parents and resistant control were artificially infected with </span><i><span style="font-family:Verdana;">Striga hermonthica</span></i><span style="font-family:Verdana;"> seeds. Field screenings revealed induced genetic variability among them, forty families significantly reduced the number of emerged </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> plants or showed good Sorghum grain yield performance despite the infection by S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> ecotype from Burkina Faso. The induced putative resistant mutants were identified across the four applied gamma-irradiation doses. Greenhouse experiment confirmed </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> resistance in seven mutant Sorghum families leading to no emergence of Burkina’s S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> ecotype along with high resistance index (RI) and low </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> damage score. Among them, two mutants SA38M5 and IC47M5 withstood S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> ecotype from Sudan. The induced mutants will be evaluated for the release to farmers for commercial production. Further studies are ongoing on confirmed mutants to highlight their </span><i><span style="font-family:Verdana;">Striga</span></i><span style="font-family:Verdana;"> resistance mechanisms and explore the potential of pyramiding different mechanisms to produce durable resistance to S. </span><i><span style="font-family:Verdana;">hermonthica</span></i><span style="font-family:Verdana;"> in sorghum.</span> </div>
基金Supported by Basic Research Fund for Central Nonprofit Institutes(Agro-environmental Protection Institute of Ministry of Agriculture)~~
文摘[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.
基金Supported by 2021 Financial Linkage Fund for Promoting Rural Revitalization in Wudu District,Longnan City (WNLF (2021)3)。
文摘[Objectives]This study was conducted to breed high-yielding wheat varieties. [Methods] A new breeding technology of "Artificial mutagenesis to increase genetic differences between parents and to enhance heterosis" was put forward. Longnan 71 a and Longnan 71 a mutants bred by this technology were crossed with other mutants and normal materials. [Results] In the Wudu experimental field of Longnan City, the traits of super-large grain appeared in the obverse and inverse cross with Longnan 71 a as parents. The trait of super-large grain was dominantly inherited. The traits of various combinations in the Fgeneration were segregated. In the Fgeneration, one super-large-grain low-stalk line and other lines with specific traits were selected. In the Fgeneration, two super-large-grain low-stalk large-ear lines were selected. These three super-large-grain low-stalk wheat lines had reduced plant height and good lodging resistance, and possessed two high-yielding characters among the three factors of yield, so they were expected to be further bred into high-yielding wheat varieties. One line with the largest grain length of 10.3 mm was selected in the Fgeneration. After two years of breeding, in 2022, the largest grain length was measured to be 10.6 mm, and the average 1 000-grain weight and the largest 1 000-grain weight were 75.8 and 100 g, respectively. [Conclusions] This study is about the major progress in artificial cultivation of super-large-grain wheat and has considerable practical value.