Brassinosteroids(BRs)play critical roles in a wide range of plant developmental processes.However,it is unknown whether and how BRs mediate the effect of high temperature(HT)stress during anthesis on the pistil activi...Brassinosteroids(BRs)play critical roles in a wide range of plant developmental processes.However,it is unknown whether and how BRs mediate the effect of high temperature(HT)stress during anthesis on the pistil activity of photo-thermosensitive genetic male-sterile(PTSGMS)rice(Oryza sativa L.)lines.This study investigated the question.Three pot-grown PTSGMS rice lines were subjected to HT stress during anthesis.The contents of 24-epibrassinolide(24-EBL)and 28-homobrassinolide(28-HBL),the major forms of BR in rice plants,and levels of reactive oxygen species(ROS)or antioxidants(AOS),hydrogen peroxide(H2O2),1-aminocylopropane-1-carboxylic acid(ACC),ascorbic acid(AsA),and catalase activity in pistils,were determined.HT stress significantly reduced the contents of both 24-EBL and 28-EBL relative to those under normal temperatures,but the reduction varied by PTSGMS line.A line with higher BR contents under HT stress showed lower contents of ACC and H2O2,higher catalase activity and AsA content in pistils,and higher fertilization rate,seed-setting rate,and seed yield when the line was crossed with a restorer line,indicating that higher levels of BRs increase HT stress resistance.Applying 24-EBL,28-HBL or an inhibitor of BR biosynthesis confirmed the roles of BRs in response to HT stress.The results suggest that BRs mediate the effect of HT stress on pistil activity during anthesis and alleviate the harm of HT stress by increasing AOS and suppressing ROS generation.展开更多
Breeding of male-sterile lines has become the mainstream for the heterosis utilization in foxtail millet,but the genetic basis of most male-sterile lines used for the hybrid is still an area to be elucidated.In this s...Breeding of male-sterile lines has become the mainstream for the heterosis utilization in foxtail millet,but the genetic basis of most male-sterile lines used for the hybrid is still an area to be elucidated.In this study,a highly male-sterile line Gao146A was investigated.Genetic analysis indicated that the highly male-sterile phenotype was controlled by a single recessive gene a single recessive gene.Using F 2 population derived from cross Gao146A/K103,one gene controlling the highly male- sterility,tentatively named as ms1,which linked to SSR marker b234 with genetic distance of 16.7 cM,was mapped on the chromosome VI.These results not only laid the foundation for fine mapping of this highly male-sterile gene,but also helped to accelerate the improvement of highly male-sterile lines by using molecular marker assisted breeding method.展开更多
Cytoplasmic male sterility(cms)is determined by nuclear-cytoplasmic interactions. Up to now, most studies are focused on the comparison of cytoplasmic DNAs of male-sterile lines and male-fertile lines, and analysis of...Cytoplasmic male sterility(cms)is determined by nuclear-cytoplasmic interactions. Up to now, most studies are focused on the comparison of cytoplasmic DNAs of male-sterile lines and male-fertile lines, and analysis of nuclear DNA has not been documented yet. In order to find out the possible difference in nuclear genome of male-sterile line A1 Tx623 and corresponding male-fertile line Tx623 of sorghum, random amplified polymorphic DNA(RAPD)approach was used to analyze their cytoplasmic and nuclear genomes. Total DNAs of them were amplified at first to screen primers, which were able to generate reproducible bands specific to male-sterile line or male-fertile line. Then the selected primers were used to amplify their mitochon-drial DNA(mtDNA)and chloroplast DNA(cpDNA). The origins of all the polymorphic fragments were analyzed. After ruling out those amplified from cytoplasmic DNA, seventeen polymorphic fragments were determined to be amplified from nuclear DNA. These fragments originated from nuclear DNA indicate that differences in sequence exist between the nuclear DNA of male-sterile line and male-fertile line of sorghum, which do not agree with the traditional standpoint that they have identical nucleus.展开更多
Three male-sterile soybean (MS) groups were selected out through various methods. A number of filial generations and hybrid strains with special characters were obtained by the methods of isolated plot and backcross. ...Three male-sterile soybean (MS) groups were selected out through various methods. A number of filial generations and hybrid strains with special characters were obtained by the methods of isolated plot and backcross. Among them Jinping 1 and Jinping 2, two sister lines,with higher production,big and pretty seed,green coat and a rich perfume,are suitable to a vegetable in city. It was proved that the MS have wide utilization potential as follows; (a)the MS could solve a lot of troubles of artificial cross ;for instance,the green seed coat can be used as a gene marker; (b)the MS showed a high hybrid vigor and its potential ratio ranged from 132% to 347% ;and (c)the effects of recurrent selection of MS were obvious and the characters of yield of F5 in 18 strains were higher than that of F3.展开更多
Re-cross was conducted between five ES cytoplasm male-sterile hybrids and four high-oil hybrids, and five normal hybrids, respectively. The oil content, yield, 1000-kernel weight and kernel size were estimated. Result...Re-cross was conducted between five ES cytoplasm male-sterile hybrids and four high-oil hybrids, and five normal hybrids, respectively. The oil content, yield, 1000-kernel weight and kernel size were estimated. Results were as follows: The average kernel oil content in the male-sterile hybrid ×high-oil hybrid was 1.6% higher than that of the female parent. The xenia effect value of oil genes was 0.30. The yield and 1000-kernel weight of male-sterile hybrids were 10.1% and 5.8% higher than that of corresponding fertile hybrids respectively, which showed significant cytoplasm effect. The yield of the male-sterile hybrid × high-oil hybrid was similar to that of the female parent, but its 1000-kernel weight was 7.3% lower than that of the female parent. Compared with the high-oil male parent, grain yield, 1000-kernel weight and kernel size of the male-sterile hybrid× high-oil hybrid were higher. Seed-filling rate, the days of seed-filling and IAA content in the male-sterile hybrid × high-oil hybrid showed average heterosis tending the female parent, which may be perhaps one of the reasons resulting in the average heterosis tending to the female parent on kernel oil content, yield, 1000-kernel weight and kernel size.展开更多
A screen for Arabidopsis fertility mutants, mutagenized by low-energy argon ion beam, yielded two partial male-sterile mutants tc243-1 and tc243-2 which have similar phenotypes. tc243-2 was investigated in detail. The...A screen for Arabidopsis fertility mutants, mutagenized by low-energy argon ion beam, yielded two partial male-sterile mutants tc243-1 and tc243-2 which have similar phenotypes. tc243-2 was investigated in detail. The segregation ratio of the mutant phenotypes in the M2 pools suggested that mutation behaved as single Mendelian recessive mutations, tc243 showed a series of mutant phenotypes, among which partial male-sterile was its striking mutant characteristic. Phenotype analysis indicates that there are four factors leading to male sterility, a. Floral organs normally develop inside the closed bud, but the anther filaments do not elongate sufficiently to position the locules above the stigma at anthesis, b. The anther locules do not dehisce at the time of flower opening （although limited dehiscence occurs later）, c. Pollens of mutant plants develop into several types of pollens at the trinucleated stage. as determined by staining with DAPI （4＇,6-diamidino-2-phenylindole）. which shows a variable size. shape and number of nucleus. d. The viability of pollens is lower than that of the wild type on the germination test in vivo and vitro.展开更多
A male sterile mutant plant was found from the rice field of the local rice variety which was cultivated for a long time in the west of Hubei Province. The plant has more vigorous tillering ability. Its plant height o...A male sterile mutant plant was found from the rice field of the local rice variety which was cultivated for a long time in the west of Hubei Province. The plant has more vigorous tillering ability. Its plant height of 95 cm was a bit shorter than that of the normal ones. The plant type, the leaf shape and the color of leaf sheath and glume tip of this mutant were identieal to that of the normal plant whereas the color of arrowhead-shape anther was milky white. This mutant set no seed during self-pollination. When it was crossed with IR24. IR26, Minhui 63 or Xieqing-zaoxuian. the Ffertilities were normal. The fertility of this mutant could be restored by IR24, IR26 and Minhui 63 and maintained by Xieqing-zaoxian. Maxie A was developed in 1987 by the successive backcrossing of the mutant with Xieqing-zaoxian. The percentage of abortive pollen in Maxie A in uninucleate microspore to early binucleate microspore stage is展开更多
We studied the relationship between the head-ing sensitivity and the male-sterile sensitivityin photoperiod-sensitive genie males-sterile rice(PGMSR)and conventional rice.Materialsused in this study were 7001S,a late ...We studied the relationship between the head-ing sensitivity and the male-sterile sensitivityin photoperiod-sensitive genie males-sterile rice(PGMSR)and conventional rice.Materialsused in this study were 7001S,a late maturingPGMS japonica strain derived from Nongken58S; Akihikari and Youmang-zaojing(YMZJ),two early maturing conventional Japonica rice;and CPSLO-17,a Wide compatible convention-al indica rice.The heading date and seed-set-ting rate of Fand Fof three cross combina-tions between PGMSR and conventional riceswere examined in phytotron which was adjust-ed at 25±1℃ with day-length of 14.5 h(LD)and 12 h(SD).The segregation ratio of fertile:sterile in Funder LD was in accordance展开更多
The effect of day length and temperature on the pollen fertility of five photoperiod-sensitive genic male-sterile japonica rice lines (PGMSR) and three temperature-sensitive genic malesterile indica rice lines (TGMSR)...The effect of day length and temperature on the pollen fertility of five photoperiod-sensitive genic male-sterile japonica rice lines (PGMSR) and three temperature-sensitive genic malesterile indica rice lines (TGMSR) were investigated in phytotron. The light source used for illumination was xenon lamp, and the light intensity which plant accepted on the leaf surface was 300—350μmol photons ms. The results indicated that pollens of PGMSR 7001S and E47S aborted completely whereas a little part of 31116S pollens appeared normal under long day photoperiod (LD,25℃,15h) (Table 1). High temperature (HT, 30℃, 12h) and lower temperature (LT,展开更多
Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes ...Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes that run through his works.His novel Never Let Me Go tells a story of a group of clones growing up in the Hailsham,who are given the mission to donate organs at birth.So,there is no doubt that they will inevitably end their lives in the process of donating organs to human beings again and again.The tragic life of clones is determined by the motivation of human to create them.展开更多
With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the pr...With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the process of their identity quest as well as role identification.Through the specific analysis,it is concluded that the clones,represented by Kathy,Tommy and Ruth,have gained self-certainty and social identity by realizing the role identity as a“carer”and a“donor”,in the meantime,they have constructed their identity as social persons with souls like ordinary people.Furthermore,the findings shows that Never Let Me Go is actually a microcosm of human’s quest for identity.Ishiguro aims to express his meditation on human life in the novel:human life is a process of seeking self-identity and social roles,and then fulfilling the obligations of the roles,which confirms Ishiguro’s internationalism that he attempts to convey his contemplation on human existence through his works.展开更多
基金supported by the National Natural Science Foundation of China(31771710,31901445)the National Key Research and Development Program of China(2016YFD03002064,2018YFD0300800)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Top Talent Supporting Program of Yangzhou University(2015-01)。
文摘Brassinosteroids(BRs)play critical roles in a wide range of plant developmental processes.However,it is unknown whether and how BRs mediate the effect of high temperature(HT)stress during anthesis on the pistil activity of photo-thermosensitive genetic male-sterile(PTSGMS)rice(Oryza sativa L.)lines.This study investigated the question.Three pot-grown PTSGMS rice lines were subjected to HT stress during anthesis.The contents of 24-epibrassinolide(24-EBL)and 28-homobrassinolide(28-HBL),the major forms of BR in rice plants,and levels of reactive oxygen species(ROS)or antioxidants(AOS),hydrogen peroxide(H2O2),1-aminocylopropane-1-carboxylic acid(ACC),ascorbic acid(AsA),and catalase activity in pistils,were determined.HT stress significantly reduced the contents of both 24-EBL and 28-EBL relative to those under normal temperatures,but the reduction varied by PTSGMS line.A line with higher BR contents under HT stress showed lower contents of ACC and H2O2,higher catalase activity and AsA content in pistils,and higher fertilization rate,seed-setting rate,and seed yield when the line was crossed with a restorer line,indicating that higher levels of BRs increase HT stress resistance.Applying 24-EBL,28-HBL or an inhibitor of BR biosynthesis confirmed the roles of BRs in response to HT stress.The results suggest that BRs mediate the effect of HT stress on pistil activity during anthesis and alleviate the harm of HT stress by increasing AOS and suppressing ROS generation.
基金supported by the Postdoctoral Management Committee,China(92948)the Natural Science Foundation of Shanxi Province,China(2012011032-1)the Chinese Agricultural Research System(CARS-07)
文摘Breeding of male-sterile lines has become the mainstream for the heterosis utilization in foxtail millet,but the genetic basis of most male-sterile lines used for the hybrid is still an area to be elucidated.In this study,a highly male-sterile line Gao146A was investigated.Genetic analysis indicated that the highly male-sterile phenotype was controlled by a single recessive gene a single recessive gene.Using F 2 population derived from cross Gao146A/K103,one gene controlling the highly male- sterility,tentatively named as ms1,which linked to SSR marker b234 with genetic distance of 16.7 cM,was mapped on the chromosome VI.These results not only laid the foundation for fine mapping of this highly male-sterile gene,but also helped to accelerate the improvement of highly male-sterile lines by using molecular marker assisted breeding method.
文摘Cytoplasmic male sterility(cms)is determined by nuclear-cytoplasmic interactions. Up to now, most studies are focused on the comparison of cytoplasmic DNAs of male-sterile lines and male-fertile lines, and analysis of nuclear DNA has not been documented yet. In order to find out the possible difference in nuclear genome of male-sterile line A1 Tx623 and corresponding male-fertile line Tx623 of sorghum, random amplified polymorphic DNA(RAPD)approach was used to analyze their cytoplasmic and nuclear genomes. Total DNAs of them were amplified at first to screen primers, which were able to generate reproducible bands specific to male-sterile line or male-fertile line. Then the selected primers were used to amplify their mitochon-drial DNA(mtDNA)and chloroplast DNA(cpDNA). The origins of all the polymorphic fragments were analyzed. After ruling out those amplified from cytoplasmic DNA, seventeen polymorphic fragments were determined to be amplified from nuclear DNA. These fragments originated from nuclear DNA indicate that differences in sequence exist between the nuclear DNA of male-sterile line and male-fertile line of sorghum, which do not agree with the traditional standpoint that they have identical nucleus.
文摘Three male-sterile soybean (MS) groups were selected out through various methods. A number of filial generations and hybrid strains with special characters were obtained by the methods of isolated plot and backcross. Among them Jinping 1 and Jinping 2, two sister lines,with higher production,big and pretty seed,green coat and a rich perfume,are suitable to a vegetable in city. It was proved that the MS have wide utilization potential as follows; (a)the MS could solve a lot of troubles of artificial cross ;for instance,the green seed coat can be used as a gene marker; (b)the MS showed a high hybrid vigor and its potential ratio ranged from 132% to 347% ;and (c)the effects of recurrent selection of MS were obvious and the characters of yield of F5 in 18 strains were higher than that of F3.
文摘Re-cross was conducted between five ES cytoplasm male-sterile hybrids and four high-oil hybrids, and five normal hybrids, respectively. The oil content, yield, 1000-kernel weight and kernel size were estimated. Results were as follows: The average kernel oil content in the male-sterile hybrid ×high-oil hybrid was 1.6% higher than that of the female parent. The xenia effect value of oil genes was 0.30. The yield and 1000-kernel weight of male-sterile hybrids were 10.1% and 5.8% higher than that of corresponding fertile hybrids respectively, which showed significant cytoplasm effect. The yield of the male-sterile hybrid × high-oil hybrid was similar to that of the female parent, but its 1000-kernel weight was 7.3% lower than that of the female parent. Compared with the high-oil male parent, grain yield, 1000-kernel weight and kernel size of the male-sterile hybrid× high-oil hybrid were higher. Seed-filling rate, the days of seed-filling and IAA content in the male-sterile hybrid × high-oil hybrid showed average heterosis tending the female parent, which may be perhaps one of the reasons resulting in the average heterosis tending to the female parent on kernel oil content, yield, 1000-kernel weight and kernel size.
基金Key Innovative Project of Chinese Academy of Sciences(No.KSCX2-SW-324)Director's Foundation of the Institute of Plasma Physics(No.152900500301)
文摘A screen for Arabidopsis fertility mutants, mutagenized by low-energy argon ion beam, yielded two partial male-sterile mutants tc243-1 and tc243-2 which have similar phenotypes. tc243-2 was investigated in detail. The segregation ratio of the mutant phenotypes in the M2 pools suggested that mutation behaved as single Mendelian recessive mutations, tc243 showed a series of mutant phenotypes, among which partial male-sterile was its striking mutant characteristic. Phenotype analysis indicates that there are four factors leading to male sterility, a. Floral organs normally develop inside the closed bud, but the anther filaments do not elongate sufficiently to position the locules above the stigma at anthesis, b. The anther locules do not dehisce at the time of flower opening （although limited dehiscence occurs later）, c. Pollens of mutant plants develop into several types of pollens at the trinucleated stage. as determined by staining with DAPI （4＇,6-diamidino-2-phenylindole）. which shows a variable size. shape and number of nucleus. d. The viability of pollens is lower than that of the wild type on the germination test in vivo and vitro.
文摘A male sterile mutant plant was found from the rice field of the local rice variety which was cultivated for a long time in the west of Hubei Province. The plant has more vigorous tillering ability. Its plant height of 95 cm was a bit shorter than that of the normal ones. The plant type, the leaf shape and the color of leaf sheath and glume tip of this mutant were identieal to that of the normal plant whereas the color of arrowhead-shape anther was milky white. This mutant set no seed during self-pollination. When it was crossed with IR24. IR26, Minhui 63 or Xieqing-zaoxuian. the Ffertilities were normal. The fertility of this mutant could be restored by IR24, IR26 and Minhui 63 and maintained by Xieqing-zaoxian. Maxie A was developed in 1987 by the successive backcrossing of the mutant with Xieqing-zaoxian. The percentage of abortive pollen in Maxie A in uninucleate microspore to early binucleate microspore stage is
文摘We studied the relationship between the head-ing sensitivity and the male-sterile sensitivityin photoperiod-sensitive genie males-sterile rice(PGMSR)and conventional rice.Materialsused in this study were 7001S,a late maturingPGMS japonica strain derived from Nongken58S; Akihikari and Youmang-zaojing(YMZJ),two early maturing conventional Japonica rice;and CPSLO-17,a Wide compatible convention-al indica rice.The heading date and seed-set-ting rate of Fand Fof three cross combina-tions between PGMSR and conventional riceswere examined in phytotron which was adjust-ed at 25±1℃ with day-length of 14.5 h(LD)and 12 h(SD).The segregation ratio of fertile:sterile in Funder LD was in accordance
文摘The effect of day length and temperature on the pollen fertility of five photoperiod-sensitive genic male-sterile japonica rice lines (PGMSR) and three temperature-sensitive genic malesterile indica rice lines (TGMSR) were investigated in phytotron. The light source used for illumination was xenon lamp, and the light intensity which plant accepted on the leaf surface was 300—350μmol photons ms. The results indicated that pollens of PGMSR 7001S and E47S aborted completely whereas a little part of 31116S pollens appeared normal under long day photoperiod (LD,25℃,15h) (Table 1). High temperature (HT, 30℃, 12h) and lower temperature (LT,
文摘Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes that run through his works.His novel Never Let Me Go tells a story of a group of clones growing up in the Hailsham,who are given the mission to donate organs at birth.So,there is no doubt that they will inevitably end their lives in the process of donating organs to human beings again and again.The tragic life of clones is determined by the motivation of human to create them.
文摘With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the process of their identity quest as well as role identification.Through the specific analysis,it is concluded that the clones,represented by Kathy,Tommy and Ruth,have gained self-certainty and social identity by realizing the role identity as a“carer”and a“donor”,in the meantime,they have constructed their identity as social persons with souls like ordinary people.Furthermore,the findings shows that Never Let Me Go is actually a microcosm of human’s quest for identity.Ishiguro aims to express his meditation on human life in the novel:human life is a process of seeking self-identity and social roles,and then fulfilling the obligations of the roles,which confirms Ishiguro’s internationalism that he attempts to convey his contemplation on human existence through his works.
