Heterosis is an important biological phenomenon and widely applied in agriculture.Although many studies have been performed by using vegetative organs of F_(1) hybrid plants,how heterosis (or hybrid vigor) is initiate...Heterosis is an important biological phenomenon and widely applied in agriculture.Although many studies have been performed by using vegetative organs of F_(1) hybrid plants,how heterosis (or hybrid vigor) is initiated and formed,particularly the underlying molecular mechanism,remain elusive.Hybrid contemporary seeds of rice indica varieties 9311 and PA64 were innovatively used and analysis of DNA methylome of embryo and endosperm at early developing stages revealed the globally decreased DNA methylation.Genes,especially those relate to hormones function and transcriptional regulation present non-additive methylation.Previously identified heterosis-related superior genes are non-additively methylated in early developing hybrid contemporary seeds,suggesting that key genes/loci responsible for heterosis are epigenetically modified even in early developing hybrid seeds and hypomethylation of hybrid seeds after cross-pollination finally result in the long-term transcriptional change of F_(1) hybrid vegetative tissues after germination,demonstrating that altered DNA methylation in hybrid seeds is essential for initiation regulation and maintenance of heterosis exhibiting in F_(1) hybrid plants.Notably,a large number of genes show non-additive methylation in the endosperm of reciprocal hybrids,suggesting that endosperm might also contribute to heterosis.展开更多
The great progress in super rice breeding both in China and other countries has been made in recent years. However, there were three main problems in super rice breeding: 1) the super rice varieties were still rare...The great progress in super rice breeding both in China and other countries has been made in recent years. However, there were three main problems in super rice breeding: 1) the super rice varieties were still rare; 2) most super rice varieties exhibited narrow adaptability; and 3) current breeding theories emphasized too much on the rice growth model, but they were unpractical in guidance for rice breeding. According to the authors' experience on the rice breeding, the breeding strategies including three steps (super parent breeding, super hybrid rice breeding and super hybrid rice seed production) were proposed, and the objectives of each step and the key technologies to achieve the goals were elucidated in detail. The super parent of hybrid rice should exhibit excellent performance in all agronomic traits, with the yield or sink capacity reached the level of the hybrid rice control in regional trials. The super hybrid rice combination should meet the following criteria: good rice quality, wide adaptation, lodging resistance, resistance to main insects and diseases, and the yield exceeded above 8% over the control varieties in the national and provincial regional trials. To achieve the goal, the technical strategies, such as selecting optimal combination of the parents, increasing selection pressure, paying more attention to harmony of ideal plant type, excellent physiological traits and all the agronomic traits, should be emphasized. The yield of seed production should reach 3.75 t/ha and 5.25 t/ha for the super hybrid rice combinations derived from early-season and middle-season types of male sterile lines, respectively. The main technologies for raising seed production yield included selecting optimum seed production site, using the male sterile line with large sink capacity and good outcrossing characteristics, and improving the amount of the pollen by intensive cultivation of the male parent. According to the technologies of the three-step breeding on super hybrid rice, two super rice parents, including a male parent 996 and a thermo(photo)-genic male sterile [T(P)GMS] line C815S, were bred. Furthermore, a super early hybrid rice combination, Luliangyou 996, which could be used as a double-season early rice variety in middle and lower reaches of the Yangtze River, China, was bred by using the super rice varlet3, 996 as the male parent, and several hybrid rice combinations with higher yield than control variety in regional trials both of Hunan Province and state were bred with the T(P)GMS line C815S as the female parent.展开更多
Appropriate knowledge of the parental cultivars is a pre-requisite for a successful breeding program.This study characterized fruit yield,quality attributes,and molecular variations of ten tomato cultivars during thre...Appropriate knowledge of the parental cultivars is a pre-requisite for a successful breeding program.This study characterized fruit yield,quality attributes,and molecular variations of ten tomato cultivars during three consecutive generations under greenhouse conditions.Peto 86,Castle Rock,and Red Star cultivars showed the highest fruit yield(kg/plant),total phenolic compounds(TPC),and sap acidity.Principal component analysis categorized the evaluated fruit yield into three groups based on their quality attributes.A robust positive correlation appeared among traits inside each group.A positive correlation was likewise noticed between the first and the second groups.However,a negative correlation was detected between the first,the second and the third group.Molecular profiling,using seven inter-simple sequence repeat(ISSR)primers,produced 60 loci,including 49 polymorphic loci.The molecular analysis also pinpointed the highest genetic similarity(0.92)between P73 and Moneymaker,while the lowest genetic similarity(0.46)was observed between Castle Rock and Moneymaker.The cultivars P73 and Moneymaker showed the lowest genetic distance(2.24),while the highest genetic distance(5.92)was observed between Super Marmand and Peto86,on the one hand,and between Castle Rock and Moneymaker,on the other hand.The chemical analysis of fruit sap indicated the highest levels of TPC,total flavonoids,anthocyanin,ascorbic acid and total soluble solids in Peto 86 and Castle Rock cultivars.Phylogeny analysis of tomato cultivars based on morphological and molecular attributes indicated four distinct clades.Peto 86,Castle Rock,and Red star cultivars can be recommended for the tomato hybridization breeding programs in the future,with other tomato cultivars as potentially high-yielding parents.展开更多
The purity of hybrid rice seeds reflects the typical consistency of seed varieties in characteristics.The accuracy and reliability of seed purity detecting are of great significance to ensure the quality of seeds.In t...The purity of hybrid rice seeds reflects the typical consistency of seed varieties in characteristics.The accuracy and reliability of seed purity detecting are of great significance to ensure the quality of seeds.In this study,the feasibility of identifying the purity of hybrid rice seeds,Xinong 1A/89,by terahertz(THz)time-domain spectroscopy system combined with chemometrics was explored.Three quantitative identification models for testing the purity of Xinong 1A/89 hybrid rice seed were developed and compared by THz absorption spectroscopy with extreme learning algorithm(ELM),Principal cComponent Regression(PCR)and Partial Least Squares Regression(PLSR).Experimental results showed that comparing with classical PLSR and PCR models,ELM presents a better feasibility and stability.For the testing set,the quantitative prediction result of ELM(ELoo=2.005×10^(-5),R^(2)=96.75%)is significantly better than those of PCR(ELoo=7.346×10^(-5),R^(2)=88.10%)and PLSR(ELoo=8.007×10^(-5),R^(2)=87.03%).The results highlight the feasibility of THz spectroscopy combined with ELM as an efficient and reliable method for verification of hybrid rice seeds.展开更多
As one of the most important crops, maize not only has been a source of the food, feed, and industrial feedstock for biofuel and bioproducts, but also became a model plant system for addressing fundamental questions i...As one of the most important crops, maize not only has been a source of the food, feed, and industrial feedstock for biofuel and bioproducts, but also became a model plant system for addressing fundamental questions in genetics. Male sterility is a very useful trait for hybrid vigor utilization and hybrid seed production. The identification and characterization of genic male-sterility (GMS) genes in maize and other plants have deepened our understanding of the molecular mechanisms controlling anther and pollen development, and enabled the development and efficient use of many biotechnology-based male-sterility (BMS) systems for crop hybrid breeding. In this review, we summarize main advances on the identification and characterization of GMS genes in maize, and con struct a putative regulatory network controlling maize anther and pollen development by comparative genomic analysis of GMS genes in maize, Arabidopsis, and rice. Furthermore, we discuss and appraise the features of more than a dozen BMS systems for propagating male-sterile lines and producing hybrid seeds in maize and other plants. Finally, we provide our perspectives on the studies of GMS genes and the development of novel BMS systems in maize and other plants. The continuous exploration of GMS genes and BMS systems will enhance our understanding of molecular regulatory networks controlling male fertility and greatly facilitate hybrid vigor utilization in breeding and field production of maize and other crops.展开更多
Conversion of potato from a tetraploid, heterozygous, vegetatively propagated crop to a diploid F1hybrid, propagated via botanical seed, would constitute a considerable advance for global agriculture,but faces multipl...Conversion of potato from a tetraploid, heterozygous, vegetatively propagated crop to a diploid F1hybrid, propagated via botanical seed, would constitute a considerable advance for global agriculture,but faces multiple challenges. One such challenge is the difficulty in inbreeding potato, which involvespurging deleterious alleles from its genome. This commentary discusses possible reasons for thisdifficulty and highlights a recent sequence-based effort to classify SNP variation, in potato germplasm,according to its deleterious potential. Tools and strategies connected to this database may facilitatedevelopment of F1 hybrids.展开更多
Stigma exsertion, a key determinant of the rice mating system, greatly contributes to the application of heterosis in rice. Although a few quantitative trait loci associated with stigma exsertion have been fine map- p...Stigma exsertion, a key determinant of the rice mating system, greatly contributes to the application of heterosis in rice. Although a few quantitative trait loci associated with stigma exsertion have been fine map- ped or cloned, the underlying genetic architecture remains unclear. We performed a genome-wide associ- ation study on stigma exsertion and related floral traits using 6.5 million SNPs characterized in 533 diverse accessions of Oryza sativa. We identified 23 genomic loci that are significantly associated with stigma exsertion and related traits, three of which are co-localized with three major grain size genes GS3, GW5, and GW2. Further analyses indicated that these three genes affected the stigma exsertion by controlling the size and shape of the spikelet and stigma. Combinations of GS3 and GW5 largely defined the levels of stigma exsertion and related traits. Selections of these two genes resulted in specific distributions of floral traits among subpopulations of O. sativa. The low stigma exsertion combination gw5GS3 existed in half of the cultivated rice varieties; therefore, introducing the GW5gs3 combination into male sterile lines is of high potential for improving the seed production of hybrid rice.展开更多
基金supported by the Ministry of Science and Technology of China (2012CB944804)the National Transformation Science and Technology Program (2016ZX08001006-009)the National Key Research and Development Program of China (2016YFD0100501, 2016YFD0100902)。
文摘Heterosis is an important biological phenomenon and widely applied in agriculture.Although many studies have been performed by using vegetative organs of F_(1) hybrid plants,how heterosis (or hybrid vigor) is initiated and formed,particularly the underlying molecular mechanism,remain elusive.Hybrid contemporary seeds of rice indica varieties 9311 and PA64 were innovatively used and analysis of DNA methylome of embryo and endosperm at early developing stages revealed the globally decreased DNA methylation.Genes,especially those relate to hormones function and transcriptional regulation present non-additive methylation.Previously identified heterosis-related superior genes are non-additively methylated in early developing hybrid contemporary seeds,suggesting that key genes/loci responsible for heterosis are epigenetically modified even in early developing hybrid seeds and hypomethylation of hybrid seeds after cross-pollination finally result in the long-term transcriptional change of F_(1) hybrid vegetative tissues after germination,demonstrating that altered DNA methylation in hybrid seeds is essential for initiation regulation and maintenance of heterosis exhibiting in F_(1) hybrid plants.Notably,a large number of genes show non-additive methylation in the endosperm of reciprocal hybrids,suggesting that endosperm might also contribute to heterosis.
文摘The great progress in super rice breeding both in China and other countries has been made in recent years. However, there were three main problems in super rice breeding: 1) the super rice varieties were still rare; 2) most super rice varieties exhibited narrow adaptability; and 3) current breeding theories emphasized too much on the rice growth model, but they were unpractical in guidance for rice breeding. According to the authors' experience on the rice breeding, the breeding strategies including three steps (super parent breeding, super hybrid rice breeding and super hybrid rice seed production) were proposed, and the objectives of each step and the key technologies to achieve the goals were elucidated in detail. The super parent of hybrid rice should exhibit excellent performance in all agronomic traits, with the yield or sink capacity reached the level of the hybrid rice control in regional trials. The super hybrid rice combination should meet the following criteria: good rice quality, wide adaptation, lodging resistance, resistance to main insects and diseases, and the yield exceeded above 8% over the control varieties in the national and provincial regional trials. To achieve the goal, the technical strategies, such as selecting optimal combination of the parents, increasing selection pressure, paying more attention to harmony of ideal plant type, excellent physiological traits and all the agronomic traits, should be emphasized. The yield of seed production should reach 3.75 t/ha and 5.25 t/ha for the super hybrid rice combinations derived from early-season and middle-season types of male sterile lines, respectively. The main technologies for raising seed production yield included selecting optimum seed production site, using the male sterile line with large sink capacity and good outcrossing characteristics, and improving the amount of the pollen by intensive cultivation of the male parent. According to the technologies of the three-step breeding on super hybrid rice, two super rice parents, including a male parent 996 and a thermo(photo)-genic male sterile [T(P)GMS] line C815S, were bred. Furthermore, a super early hybrid rice combination, Luliangyou 996, which could be used as a double-season early rice variety in middle and lower reaches of the Yangtze River, China, was bred by using the super rice varlet3, 996 as the male parent, and several hybrid rice combinations with higher yield than control variety in regional trials both of Hunan Province and state were bred with the T(P)GMS line C815S as the female parent.
基金This work was supported by the Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia[Project No.GRANT805]the Princess Nourah bint Abdulrahman University Researchers Supporting Project Number(PNURSP2023R318),Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Appropriate knowledge of the parental cultivars is a pre-requisite for a successful breeding program.This study characterized fruit yield,quality attributes,and molecular variations of ten tomato cultivars during three consecutive generations under greenhouse conditions.Peto 86,Castle Rock,and Red Star cultivars showed the highest fruit yield(kg/plant),total phenolic compounds(TPC),and sap acidity.Principal component analysis categorized the evaluated fruit yield into three groups based on their quality attributes.A robust positive correlation appeared among traits inside each group.A positive correlation was likewise noticed between the first and the second groups.However,a negative correlation was detected between the first,the second and the third group.Molecular profiling,using seven inter-simple sequence repeat(ISSR)primers,produced 60 loci,including 49 polymorphic loci.The molecular analysis also pinpointed the highest genetic similarity(0.92)between P73 and Moneymaker,while the lowest genetic similarity(0.46)was observed between Castle Rock and Moneymaker.The cultivars P73 and Moneymaker showed the lowest genetic distance(2.24),while the highest genetic distance(5.92)was observed between Super Marmand and Peto86,on the one hand,and between Castle Rock and Moneymaker,on the other hand.The chemical analysis of fruit sap indicated the highest levels of TPC,total flavonoids,anthocyanin,ascorbic acid and total soluble solids in Peto 86 and Castle Rock cultivars.Phylogeny analysis of tomato cultivars based on morphological and molecular attributes indicated four distinct clades.Peto 86,Castle Rock,and Red star cultivars can be recommended for the tomato hybridization breeding programs in the future,with other tomato cultivars as potentially high-yielding parents.
基金This work is supported by Application Development Programs of Chongqing Science and Technology Commission(Grant No.cstc2014yykfA80006)Fundamental Research Funds for the Central Universities(Grant No.SWU117029)National Natural Science Foundation of China(Grant No.61401373 and 31771670).
文摘The purity of hybrid rice seeds reflects the typical consistency of seed varieties in characteristics.The accuracy and reliability of seed purity detecting are of great significance to ensure the quality of seeds.In this study,the feasibility of identifying the purity of hybrid rice seeds,Xinong 1A/89,by terahertz(THz)time-domain spectroscopy system combined with chemometrics was explored.Three quantitative identification models for testing the purity of Xinong 1A/89 hybrid rice seed were developed and compared by THz absorption spectroscopy with extreme learning algorithm(ELM),Principal cComponent Regression(PCR)and Partial Least Squares Regression(PLSR).Experimental results showed that comparing with classical PLSR and PCR models,ELM presents a better feasibility and stability.For the testing set,the quantitative prediction result of ELM(ELoo=2.005×10^(-5),R^(2)=96.75%)is significantly better than those of PCR(ELoo=7.346×10^(-5),R^(2)=88.10%)and PLSR(ELoo=8.007×10^(-5),R^(2)=87.03%).The results highlight the feasibility of THz spectroscopy combined with ELM as an efficient and reliable method for verification of hybrid rice seeds.
基金the National Transgenic Major Program of China (2018ZX0801006B,2018ZX0800922B)the National Key Research and Development Program of China (2018YFD0100806,2017YFD0102001,2017YFD0101201)+6 种基金the National Natural Science Foundation of China (31771875,31871702)the Fundamental Research Funds for the Central Universities of China (06500060FRF-BR-17-009AFRF-BR-17-010AFRF-BR-17-011A)the "Ten Thousand Plan”- National High Level Talents Special Support Plan (For X.W.)and the Beijing Science & Technology Plan Program (Z161100000916013).
文摘As one of the most important crops, maize not only has been a source of the food, feed, and industrial feedstock for biofuel and bioproducts, but also became a model plant system for addressing fundamental questions in genetics. Male sterility is a very useful trait for hybrid vigor utilization and hybrid seed production. The identification and characterization of genic male-sterility (GMS) genes in maize and other plants have deepened our understanding of the molecular mechanisms controlling anther and pollen development, and enabled the development and efficient use of many biotechnology-based male-sterility (BMS) systems for crop hybrid breeding. In this review, we summarize main advances on the identification and characterization of GMS genes in maize, and con struct a putative regulatory network controlling maize anther and pollen development by comparative genomic analysis of GMS genes in maize, Arabidopsis, and rice. Furthermore, we discuss and appraise the features of more than a dozen BMS systems for propagating male-sterile lines and producing hybrid seeds in maize and other plants. Finally, we provide our perspectives on the studies of GMS genes and the development of novel BMS systems in maize and other plants. The continuous exploration of GMS genes and BMS systems will enhance our understanding of molecular regulatory networks controlling male fertility and greatly facilitate hybrid vigor utilization in breeding and field production of maize and other crops.
基金supported by the National Science Foundation Plant Genome Integrative Organismal Systems(IOS)Grant 2310230(Characterization of Haploid Induction in Potato)Grant 1956429(Variants and Recombinants without Meiosis).
文摘Conversion of potato from a tetraploid, heterozygous, vegetatively propagated crop to a diploid F1hybrid, propagated via botanical seed, would constitute a considerable advance for global agriculture,but faces multiple challenges. One such challenge is the difficulty in inbreeding potato, which involvespurging deleterious alleles from its genome. This commentary discusses possible reasons for thisdifficulty and highlights a recent sequence-based effort to classify SNP variation, in potato germplasm,according to its deleterious potential. Tools and strategies connected to this database may facilitatedevelopment of F1 hybrids.
文摘Stigma exsertion, a key determinant of the rice mating system, greatly contributes to the application of heterosis in rice. Although a few quantitative trait loci associated with stigma exsertion have been fine map- ped or cloned, the underlying genetic architecture remains unclear. We performed a genome-wide associ- ation study on stigma exsertion and related floral traits using 6.5 million SNPs characterized in 533 diverse accessions of Oryza sativa. We identified 23 genomic loci that are significantly associated with stigma exsertion and related traits, three of which are co-localized with three major grain size genes GS3, GW5, and GW2. Further analyses indicated that these three genes affected the stigma exsertion by controlling the size and shape of the spikelet and stigma. Combinations of GS3 and GW5 largely defined the levels of stigma exsertion and related traits. Selections of these two genes resulted in specific distributions of floral traits among subpopulations of O. sativa. The low stigma exsertion combination gw5GS3 existed in half of the cultivated rice varieties; therefore, introducing the GW5gs3 combination into male sterile lines is of high potential for improving the seed production of hybrid rice.