In the recent decade,plant regeneration fromprotoplast has been obtained through embryo-genic cell suspension cultures of rice.Howev-er,not only the establishment of embryogeniccell suspension cultures of rice was dif...In the recent decade,plant regeneration fromprotoplast has been obtained through embryo-genic cell suspension cultures of rice.Howev-er,not only the establishment of embryogeniccell suspension cultures of rice was difficult,but also the protoplasts became less and lessregenerable and the genetic change was gradu-ally accumulated during the prolonged culture.Since 1976(Deka.),extensive efforts have展开更多
The majority of off-type plants in in-dica hybrid rice were CMS and itsmaintainer lines.Discrimination ofmaintainer and CMS could only beconducted at heading stage.If main-tainer and CMS line could be distin-guished e...The majority of off-type plants in in-dica hybrid rice were CMS and itsmaintainer lines.Discrimination ofmaintainer and CMS could only beconducted at heading stage.If main-tainer and CMS line could be distin-guished earlier,it would be useful toavoid yield losses caused by usingcontaminated seeds.In this study,three pairs of A and B,Minghui 63,and Fand Fplants of Zhenshan97A/Minghui 63 were used to find展开更多
Analysis of genetic main effects and genotype x environment (GE) interaction effects for brown rice weight (BRW) at four different filling stages in indica lice (Oryza sativa L.) was conducted for two-year experimenta...Analysis of genetic main effects and genotype x environment (GE) interaction effects for brown rice weight (BRW) at four different filling stages in indica lice (Oryza sativa L.) was conducted for two-year experimental data by using developmental genetic models and corresponding statistical approaches for quantitative traits of seeds in cereal crops. It was indicated that the genetic main effects and their GE interaction effects of triploid endosperm, cytoplasmic and diploid maternal plant genes were important for BRW at different filling stages of rice, especially for endosperm or maternal additive main effects and their additive interaction effects. Because of the higher additive effects and additive interaction effects for BRW at different filling stages, the better improving effects for this trait could be expected by selection in rice breeding. The results of conditional genetic variance components showed that the new expression of quantitative genes in endosperm and maternal plant for BRW was mostly found at all different filling stages of rice. The gene expression, however, was most active at the early filling stages especially for the first (1-7 d) and the second filling stages (8-14 d after flowering). The phenomena that some genes were spasmodically expressible among filling stages of rice were detected for some genetic effects especially for net cytoplasmic main effects or its interaction effects and net dominance main effects. Predicted genetic effects at different filling stages of rice showed that some parents such as V20 and Zuo 5 were better than others for improving the BRW.展开更多
A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines （A） and 5 restorer lines （R） along with their F1 （A × R） and F2 populations. The unconditional and conditio...A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines （A） and 5 restorer lines （R） along with their F1 （A × R） and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content （PC） and the appearance quality traits of indica rice （Oryza sativa L.）. The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness （BRT）. Only the genetic covariance between PC and the brown rice width （BRW） was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice （WBR） or the amylose content （AC） could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length （BRL）, BRW, or BRT through the geuotype x environmental （GE） interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width （RLW） or the ratio of brown rice length to thickness （RLT）. The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW.展开更多
It is one of the key problems for application ofanther culture in hybrid breeding, geneticanalysis, and molecular mapping whether thedoubled haploid (DH) population derived fromanther culture of rice crosses represent...It is one of the key problems for application ofanther culture in hybrid breeding, geneticanalysis, and molecular mapping whether thedoubled haploid (DH) population derived fromanther culture of rice crosses represents a ran-dom array of the microspore population, i.e.whether gametic selection occurs in androgene-sis. A DH population including 132 lines de-展开更多
Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of co...Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.展开更多
Spermidine（Spd） is known to be involved in the regulation of plant responses to chilling stress and counteract the adverse effect of stress conditions.Antioxidant activities,endogenous hormones and ultrastructure ch...Spermidine（Spd） is known to be involved in the regulation of plant responses to chilling stress and counteract the adverse effect of stress conditions.Antioxidant activities,endogenous hormones and ultrastructure change under chilling stress were investigated in indica-japonica hybrid rice seedlings.12-d-old seedlings were subjected to exogenous Spd（1 mmol L^（-1）） and then a chilling stress（6℃,4 d） was induced,followed by a subsequent recovery（25℃,4 d）.Results showed that malondialdehyde（MDA） and proline content were enhanced significantly,whereas shoot fresh and dry weights decreased during chilling stress and after recovery;chlorophyll content of chilling-stressed seedlings increased slightly but declined after recovery;additionally,total soluble sugar,sucrose,fructose and starch contents increased significantly during chilling stress,and only soluble sugar and fructose contents were observed in increase after recovery;chilling stress-induced increases in superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activities,but declined after recovery,and the level of ascorbate peroxidase was lower during chilling stress and after recovery;however,endogenous indole-3-acetic acid（IAA）,zeatin riboside（ZR）,gibberellic acid（GA_3）,and abscisic acid（ABA） levels were induced decreased compared with Spd pretreatment.The microscopic analysis revealed that chilling stress-induced destruction of the chloroplast envelope during chilling stress and increased the number of plastoglobuli along with aberrations in thylakoid membranes after recovery.In contrast,exogenous Spd protected rice seedlings from chilling-induced injuries in terms of lower malondialdehyde,proline and carbohydrates accumulation coupled with increased endogenous hormones metabolism.After recovery,Spd pretreatment chilling-exposed seedlings showed higher activities of antioxidant enzymes and normal physiological function of chloroplasts.These results suggest that Spd could promote effectively chilling tolerance which might be largely attributable to the integrity of cell structure and normal metabolism of endogenous hormones in indica-japonica hybrid rice seedlings.展开更多
On the bases of archaeological discoveries, the earliest domestication of rice has been confirmed in the middle and lower Changjiang River basin, while in the region wild rice populations are found in shallow swamps u...On the bases of archaeological discoveries, the earliest domestication of rice has been confirmed in the middle and lower Changjiang River basin, while in the region wild rice populations are found in shallow swamps under a climate with freezing winter cold. These findings lead us to-examine the past ideas about domestication and differentiation of rice. Historically, in 1930s two sub-species, indica and japonica, were proposed on the basis of sterility in F1 hybrids between them. Soon after that, the two types were classified by the associations of a number of genetically independent traits. The characteristic associations of traits have been explained by the hybrid sterility or reproductive barriers which were assumed to comprise a set of duplicate recessive lethal genes and to be an inner genetic mechanism to lead to the varietal differentiations In 1980s, the hybrid sterility between Indica and Japonica types was analyzed, and Indica, Japonica, and wide-compatibility type which gives fertile hybrids when cross to Indica and Japonica types, are proved to contain an allele, S5＇, S5＇ and S5^n, respectively at a locus on chromosome 6. And those gametes having Sj allele are found to be partially aborted in the hybrid genotypes of S5＇/S5＇ while no gamete abortion occurs in S5＇/S5^n and S5＇/S5^n genotypes. Since then, the gene S5^n has been used in hybrid rice breeding to obtain fertile and vigorous hybrids between subspecies, and the long-disputed problem of hybrid sterility has been solved. Also in such studies the characteristic association of traits found in each of vadetal groups is better explained by founder effects. On the other hand, a large number of native cultivars of rice were surveyed with enzyme polymorphism in 1980s and later with molecular markers. As a result, profound genetic diversity is found in cultivated rice as well as in wild rice. These findings seem to lead us to the idea of multiple independent domestications of rice. However, before reaching such a conclusion, at least two factors, i.e., long-distance-dissemination of some genotypes and the possibilities of introgression by local wild rice to primitive cultivars need to be examined. Taking the two factors as well as the historical events into consideration, it is considered here that the perennial japonica cultivars which are close to wild rice in the Changjiang River basin were disseminated to East India through Assam or along the Bengal Bay, where they were transformed under the introgressions of local wild rice and formed a secondary center, from which some genotypes seem to be disseminated to colonies in Southeast Asia under the influence of Hinduism. Later some of the genotypes were introduced into China and constituted so called Indica type. This may be a reasonable picture for the varietal differentiation.展开更多
As early as the 1960s, Boe et al., Pittman et al. and Murr et al. have reported that the magnetic field can accelerate the maturity and growth of plants. However, the advance of this investigation about the biomagneti...As early as the 1960s, Boe et al., Pittman et al. and Murr et al. have reported that the magnetic field can accelerate the maturity and growth of plants. However, the advance of this investigation about the biomagnetic effects on展开更多
We discovered 528 putative cytochrome P450s (P450s) in Oryza sativa L. ssp. indica using Arabidopsis thaliana P450s as database. Those putative rice P450s are thought to belong to 40 families classified in Arabidopsis...We discovered 528 putative cytochrome P450s (P450s) in Oryza sativa L. ssp. indica using Arabidopsis thaliana P450s as database. Those putative rice P450s are thought to belong to 40 families classified in Arabidopsis thaliana. We compared distributions of Arabidopsis thaliana and Oryza sativa P450s and found the two species have similar distribution patterns. However, family distributions of two species also have some differences. For example, in rice, the gene number in families of CYP71, CYP72, CYP76, CYP89, CYP94 and CYP709 is more than twice that in Arabidopsis thaliana; and there are 33 CYP705 members in Arabidopsis thaliana but none in rice. We also found gene members in CYP71 and CYP81 are organized as tandem arrays repeated in the rice genome; maybe they are duplications in the evolutionary event. Furthermore, we accumulated expression sequence tag (EST) evidence for 263 putative rice P450s, which are expressed at transcriptional level and more likely to be true P450s.展开更多
Black rice Oryza sativa is primarily grown in East and North East of India. This variety could not become popular due to low yield and being expensive. It is rich in three kinds of Anthocyanin contents which exhibit g...Black rice Oryza sativa is primarily grown in East and North East of India. This variety could not become popular due to low yield and being expensive. It is rich in three kinds of Anthocyanin contents which exhibit great impact on human health. Four different kinds of ZnO nanomaterial were prepared at variable temperature ranging from 250°C to 500°C. The Interaction of black rice grain with nanozinc material leads to the observation that seeds germinated early. Rooting development was higher. Better effects were observed while those interacted with nanomaterial prepared at 350°C. In the present study the aim was to enhance the yield and value addition. To best of our knowledge this is the first scientific attempt [see also patent filed Varma et al. 2019]. The mechanism involved needs further elaborate elucidation. We hope that the goal can also be achieved by interaction of seeds with mycosymbiont—Piriformospora indica (Serendipita indica) a potent cultivable mycorrhiza. The precise objective of this communication is to illustrate the interaction of black rice seed with several synthesized nano zinc material which varied in shape, size and diameter.展开更多
WRKYgenee encode transcription factors that are Involved In the regulation of various biological processes. These zinc-finger proteins, especially those members mediating stress responses, are uniquely expanded In pla...WRKYgenee encode transcription factors that are Involved In the regulation of various biological processes. These zinc-finger proteins, especially those members mediating stress responses, are uniquely expanded In plants. To facilitate the study of the evolutionary history and functions of this eupergene family, we performed an exhaustive search for WRKY genes using HMMER and a Hidden Markov Model that was specifically trained for rice. This work resulted In a comprehensive list of WRKYgene models In Oryza sativa L. eep. indica and L. eep. Japonica. Mapping of these genes to Individual chromosomes facilitated elimination of the redundant, leading to the Identification of 98 WRKYgenee In Japonica and 102 In indica rice. These genes were further categorized according to the number and structure of their zinc-finger domains. Based on a phylogenetlc tree of the conserved WRKY domains and the graphic display of WRKY loci on corresponding indica and Japonica chromosomes, we Identified possible WRKY gene duplications within, and losses between the two closely related rice subspecies. Also reviewed are the roles of WRKY genes In disease resistance and responses to salicylic acid and Jaemonlc acid, seed development and germination mediated by glbberelllns, other developmental processes Including senescence, and responses to ablotlc stresses and abeclelc acid In rice and other plants. The signaling pathways mediating WRKY gene expreeelon are also discussed.展开更多
We reported the isolation and identification of 10828 putative full-length cDNAs (FL-cDNA) from an indica rice cultivar, Minghui 63, with the long-term goal to isolate all full-length cDNAs from indica genome. Compari...We reported the isolation and identification of 10828 putative full-length cDNAs (FL-cDNA) from an indica rice cultivar, Minghui 63, with the long-term goal to isolate all full-length cDNAs from indica genome. Comparison with the databases showed that 780 of them are new rice cDNAs with no match in japonica cDNA database. Totally, 9078 of the FL-cDNAs contained predicted ORFs matching with japonica FL-cDNAs and 6543 could find homologous proteins with complete ORFs. 53% of the matched FL-cDNAs isolated in this study had longer 5′UTR than japonica FL-cDNAs. In silico mapping showed that 9776 (90.28%) of the FL-cDNAs had matched genomic sequences in the japonica genome and 10046 (92.78%) had matched genomic se-quences in the indica genome. The average nucleotide sequence identity between the two sub-species is 99.2%. A majority of FL-cDNAs (90%) could be classified with GO (gene ontology) terms based on homology proteins. More than 60% of the new cDNAs isolated in this study had no homology to the known proteins. This set of FL-cDNAs should be useful for functional ge-nomics and proteomics studies.展开更多
Research on hybrid rice in Jiangsu Province, China began in 1970. Great progress has been made since then, which can be divided into three stages according to the development of hybrid rice breeding and production in ...Research on hybrid rice in Jiangsu Province, China began in 1970. Great progress has been made since then, which can be divided into three stages according to the development of hybrid rice breeding and production in Jiangsu Province. The first stage was beginning stage from 1970 to 1980, when progress was mainly made in cytoplasmic male sterile line breeding. The second stage could be described as developing stage, from 1980 to 1995, when indica hybrid rice was rapidly popularized, and japonica hybrid rice became popular later. From 1996, hybrid rice breeding in Jiangsu Province entered the third stage, when both indica and japonica hybrid rice breeding in the three-line system or intersubspecific hybrid rice breeding in the two-line system made a great breakthrough with the successful breeding of the hybrids Feyou 559, 9 You 138 and Liangyoupeijiu. The developing trend of hybrid rice breeding in Jiangsu Province is also discussed.展开更多
文摘In the recent decade,plant regeneration fromprotoplast has been obtained through embryo-genic cell suspension cultures of rice.Howev-er,not only the establishment of embryogeniccell suspension cultures of rice was difficult,but also the protoplasts became less and lessregenerable and the genetic change was gradu-ally accumulated during the prolonged culture.Since 1976(Deka.),extensive efforts have
文摘The majority of off-type plants in in-dica hybrid rice were CMS and itsmaintainer lines.Discrimination ofmaintainer and CMS could only beconducted at heading stage.If main-tainer and CMS line could be distin-guished earlier,it would be useful toavoid yield losses caused by usingcontaminated seeds.In this study,three pairs of A and B,Minghui 63,and Fand Fplants of Zhenshan97A/Minghui 63 were used to find
文摘Analysis of genetic main effects and genotype x environment (GE) interaction effects for brown rice weight (BRW) at four different filling stages in indica lice (Oryza sativa L.) was conducted for two-year experimental data by using developmental genetic models and corresponding statistical approaches for quantitative traits of seeds in cereal crops. It was indicated that the genetic main effects and their GE interaction effects of triploid endosperm, cytoplasmic and diploid maternal plant genes were important for BRW at different filling stages of rice, especially for endosperm or maternal additive main effects and their additive interaction effects. Because of the higher additive effects and additive interaction effects for BRW at different filling stages, the better improving effects for this trait could be expected by selection in rice breeding. The results of conditional genetic variance components showed that the new expression of quantitative genes in endosperm and maternal plant for BRW was mostly found at all different filling stages of rice. The gene expression, however, was most active at the early filling stages especially for the first (1-7 d) and the second filling stages (8-14 d after flowering). The phenomena that some genes were spasmodically expressible among filling stages of rice were detected for some genetic effects especially for net cytoplasmic main effects or its interaction effects and net dominance main effects. Predicted genetic effects at different filling stages of rice showed that some parents such as V20 and Zuo 5 were better than others for improving the BRW.
基金This work was supported by National Natural Science Foundation of China (No. 30571198) and the Science and Technology Office of Zhejiang Province (No. 2004C2020-2 and No. 011102471).
文摘A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines （A） and 5 restorer lines （R） along with their F1 （A × R） and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content （PC） and the appearance quality traits of indica rice （Oryza sativa L.）. The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness （BRT）. Only the genetic covariance between PC and the brown rice width （BRW） was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice （WBR） or the amylose content （AC） could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length （BRL）, BRW, or BRT through the geuotype x environmental （GE） interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width （RLW） or the ratio of brown rice length to thickness （RLT）. The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW.
文摘It is one of the key problems for application ofanther culture in hybrid breeding, geneticanalysis, and molecular mapping whether thedoubled haploid (DH) population derived fromanther culture of rice crosses represents a ran-dom array of the microspore population, i.e.whether gametic selection occurs in androgene-sis. A DH population including 132 lines de-
基金supported by the National 863 Program of China (2011AA10A101)the Chinese High-Yielding Transgenic Program (2011ZX08001-004)a project of the State Key Laboratory of Rice Biology,China(ZZKT201101)
文摘Quantitative trait loci（QTL） for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.
基金supported by grants from the the Earmarked Fund for Modern Agro-industry Technology Research System of China(CARS-01-09B)the Natural Science Foundation of Zhejiang Province,China(Y13C130013)the Special Fund for Basic Scientific Research Business of Central Public Research Institutes,Chinese Academy of Agricultural Sciences(2012RG004-2)
文摘Spermidine（Spd） is known to be involved in the regulation of plant responses to chilling stress and counteract the adverse effect of stress conditions.Antioxidant activities,endogenous hormones and ultrastructure change under chilling stress were investigated in indica-japonica hybrid rice seedlings.12-d-old seedlings were subjected to exogenous Spd（1 mmol L^（-1）） and then a chilling stress（6℃,4 d） was induced,followed by a subsequent recovery（25℃,4 d）.Results showed that malondialdehyde（MDA） and proline content were enhanced significantly,whereas shoot fresh and dry weights decreased during chilling stress and after recovery;chlorophyll content of chilling-stressed seedlings increased slightly but declined after recovery;additionally,total soluble sugar,sucrose,fructose and starch contents increased significantly during chilling stress,and only soluble sugar and fructose contents were observed in increase after recovery;chilling stress-induced increases in superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activities,but declined after recovery,and the level of ascorbate peroxidase was lower during chilling stress and after recovery;however,endogenous indole-3-acetic acid（IAA）,zeatin riboside（ZR）,gibberellic acid（GA_3）,and abscisic acid（ABA） levels were induced decreased compared with Spd pretreatment.The microscopic analysis revealed that chilling stress-induced destruction of the chloroplast envelope during chilling stress and increased the number of plastoglobuli along with aberrations in thylakoid membranes after recovery.In contrast,exogenous Spd protected rice seedlings from chilling-induced injuries in terms of lower malondialdehyde,proline and carbohydrates accumulation coupled with increased endogenous hormones metabolism.After recovery,Spd pretreatment chilling-exposed seedlings showed higher activities of antioxidant enzymes and normal physiological function of chloroplasts.These results suggest that Spd could promote effectively chilling tolerance which might be largely attributable to the integrity of cell structure and normal metabolism of endogenous hormones in indica-japonica hybrid rice seedlings.
文摘On the bases of archaeological discoveries, the earliest domestication of rice has been confirmed in the middle and lower Changjiang River basin, while in the region wild rice populations are found in shallow swamps under a climate with freezing winter cold. These findings lead us to-examine the past ideas about domestication and differentiation of rice. Historically, in 1930s two sub-species, indica and japonica, were proposed on the basis of sterility in F1 hybrids between them. Soon after that, the two types were classified by the associations of a number of genetically independent traits. The characteristic associations of traits have been explained by the hybrid sterility or reproductive barriers which were assumed to comprise a set of duplicate recessive lethal genes and to be an inner genetic mechanism to lead to the varietal differentiations In 1980s, the hybrid sterility between Indica and Japonica types was analyzed, and Indica, Japonica, and wide-compatibility type which gives fertile hybrids when cross to Indica and Japonica types, are proved to contain an allele, S5＇, S5＇ and S5^n, respectively at a locus on chromosome 6. And those gametes having Sj allele are found to be partially aborted in the hybrid genotypes of S5＇/S5＇ while no gamete abortion occurs in S5＇/S5^n and S5＇/S5^n genotypes. Since then, the gene S5^n has been used in hybrid rice breeding to obtain fertile and vigorous hybrids between subspecies, and the long-disputed problem of hybrid sterility has been solved. Also in such studies the characteristic association of traits found in each of vadetal groups is better explained by founder effects. On the other hand, a large number of native cultivars of rice were surveyed with enzyme polymorphism in 1980s and later with molecular markers. As a result, profound genetic diversity is found in cultivated rice as well as in wild rice. These findings seem to lead us to the idea of multiple independent domestications of rice. However, before reaching such a conclusion, at least two factors, i.e., long-distance-dissemination of some genotypes and the possibilities of introgression by local wild rice to primitive cultivars need to be examined. Taking the two factors as well as the historical events into consideration, it is considered here that the perennial japonica cultivars which are close to wild rice in the Changjiang River basin were disseminated to East India through Assam or along the Bengal Bay, where they were transformed under the introgressions of local wild rice and formed a secondary center, from which some genotypes seem to be disseminated to colonies in Southeast Asia under the influence of Hinduism. Later some of the genotypes were introduced into China and constituted so called Indica type. This may be a reasonable picture for the varietal differentiation.
文摘As early as the 1960s, Boe et al., Pittman et al. and Murr et al. have reported that the magnetic field can accelerate the maturity and growth of plants. However, the advance of this investigation about the biomagnetic effects on
文摘We discovered 528 putative cytochrome P450s (P450s) in Oryza sativa L. ssp. indica using Arabidopsis thaliana P450s as database. Those putative rice P450s are thought to belong to 40 families classified in Arabidopsis thaliana. We compared distributions of Arabidopsis thaliana and Oryza sativa P450s and found the two species have similar distribution patterns. However, family distributions of two species also have some differences. For example, in rice, the gene number in families of CYP71, CYP72, CYP76, CYP89, CYP94 and CYP709 is more than twice that in Arabidopsis thaliana; and there are 33 CYP705 members in Arabidopsis thaliana but none in rice. We also found gene members in CYP71 and CYP81 are organized as tandem arrays repeated in the rice genome; maybe they are duplications in the evolutionary event. Furthermore, we accumulated expression sequence tag (EST) evidence for 263 putative rice P450s, which are expressed at transcriptional level and more likely to be true P450s.
文摘Black rice Oryza sativa is primarily grown in East and North East of India. This variety could not become popular due to low yield and being expensive. It is rich in three kinds of Anthocyanin contents which exhibit great impact on human health. Four different kinds of ZnO nanomaterial were prepared at variable temperature ranging from 250°C to 500°C. The Interaction of black rice grain with nanozinc material leads to the observation that seeds germinated early. Rooting development was higher. Better effects were observed while those interacted with nanomaterial prepared at 350°C. In the present study the aim was to enhance the yield and value addition. To best of our knowledge this is the first scientific attempt [see also patent filed Varma et al. 2019]. The mechanism involved needs further elaborate elucidation. We hope that the goal can also be achieved by interaction of seeds with mycosymbiont—Piriformospora indica (Serendipita indica) a potent cultivable mycorrhiza. The precise objective of this communication is to illustrate the interaction of black rice seed with several synthesized nano zinc material which varied in shape, size and diameter.
基金Supported by the National Center for Research Resources （NCRR） （P20 RR 016464）, a component of the National Institutes of Health （NIH）, Its contents are solely the responsibility of the authors and do not necessarily represent the official views of NCRR or NIH. Publication of this paper is supported by the National Natural Science Foundation of China （30624808）. Acknowledgements The authors thank two former members of our laboratory namely Drs Zhonglin Zhang and Zhen Xie, for stimulating discussions and their contributions in preparing Figure 4 and compiling information for the biological functions of WRKYgenes. Dr Zhang is currently a postdoctoral fellow in Duke and Dr Xie is a postdoctoral fellow in Harvard.
文摘WRKYgenee encode transcription factors that are Involved In the regulation of various biological processes. These zinc-finger proteins, especially those members mediating stress responses, are uniquely expanded In plants. To facilitate the study of the evolutionary history and functions of this eupergene family, we performed an exhaustive search for WRKY genes using HMMER and a Hidden Markov Model that was specifically trained for rice. This work resulted In a comprehensive list of WRKYgene models In Oryza sativa L. eep. indica and L. eep. Japonica. Mapping of these genes to Individual chromosomes facilitated elimination of the redundant, leading to the Identification of 98 WRKYgenee In Japonica and 102 In indica rice. These genes were further categorized according to the number and structure of their zinc-finger domains. Based on a phylogenetlc tree of the conserved WRKY domains and the graphic display of WRKY loci on corresponding indica and Japonica chromosomes, we Identified possible WRKY gene duplications within, and losses between the two closely related rice subspecies. Also reviewed are the roles of WRKY genes In disease resistance and responses to salicylic acid and Jaemonlc acid, seed development and germination mediated by glbberelllns, other developmental processes Including senescence, and responses to ablotlc stresses and abeclelc acid In rice and other plants. The signaling pathways mediating WRKY gene expreeelon are also discussed.
基金This work was supported by National Science and Technology Special Key Project―Funct ional Genomics and Biological ChipNational Natural Science Foundat ion of China(Grant No.30321005).
文摘We reported the isolation and identification of 10828 putative full-length cDNAs (FL-cDNA) from an indica rice cultivar, Minghui 63, with the long-term goal to isolate all full-length cDNAs from indica genome. Comparison with the databases showed that 780 of them are new rice cDNAs with no match in japonica cDNA database. Totally, 9078 of the FL-cDNAs contained predicted ORFs matching with japonica FL-cDNAs and 6543 could find homologous proteins with complete ORFs. 53% of the matched FL-cDNAs isolated in this study had longer 5′UTR than japonica FL-cDNAs. In silico mapping showed that 9776 (90.28%) of the FL-cDNAs had matched genomic sequences in the japonica genome and 10046 (92.78%) had matched genomic se-quences in the indica genome. The average nucleotide sequence identity between the two sub-species is 99.2%. A majority of FL-cDNAs (90%) could be classified with GO (gene ontology) terms based on homology proteins. More than 60% of the new cDNAs isolated in this study had no homology to the known proteins. This set of FL-cDNAs should be useful for functional ge-nomics and proteomics studies.
文摘Research on hybrid rice in Jiangsu Province, China began in 1970. Great progress has been made since then, which can be divided into three stages according to the development of hybrid rice breeding and production in Jiangsu Province. The first stage was beginning stage from 1970 to 1980, when progress was mainly made in cytoplasmic male sterile line breeding. The second stage could be described as developing stage, from 1980 to 1995, when indica hybrid rice was rapidly popularized, and japonica hybrid rice became popular later. From 1996, hybrid rice breeding in Jiangsu Province entered the third stage, when both indica and japonica hybrid rice breeding in the three-line system or intersubspecific hybrid rice breeding in the two-line system made a great breakthrough with the successful breeding of the hybrids Feyou 559, 9 You 138 and Liangyoupeijiu. The developing trend of hybrid rice breeding in Jiangsu Province is also discussed.
