Polyploidy,or whole-genome duplication,is an important evolutionary process that has shaped the genomes and traits of many plants,including numerous important crops.The Brassica genus,which includes diverse vegetables...Polyploidy,or whole-genome duplication,is an important evolutionary process that has shaped the genomes and traits of many plants,including numerous important crops.The Brassica genus,which includes diverse vegetables and oilseeds,is a key model system for studying how polyploidy affects plant diversification and domestication.This review summarizes the current understanding of how multiple rounds of ancient and more recent polyploidization events laid the foundation for the wide diversity seen in Brassica.We discuss the key outcomes through which polyploidy facilitates the accumulation of genetic variation,including genomic buffering that enables mutation retention.Furthermore,we explore the significant roles of interspecies and interploidy introgression in introducing external genetic novelty.We highlight homoeologous exchange(HE)as a critical mechanism unique to allopolyploids,driving substantial genomic rearrangements including presence-absence variations and gene dosage alterations that directly contribute to significant phenotypic innovation and adaptation in Brassica.Together,these polyploidy-associated processes have led to the extensive range of genomic variations that shaped great morphological diversification in the domestication of Brassica.By integrating insights from genomics,genetics,and evolutionary biology,this review shows how polyploidy has been central to Brassica's success and agricultural value.We also suggest future research areas to better understand polyploid evolution and improve crop breeding.展开更多
The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops ...The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops variabilis Eig. (or rye), a significant increase in the chiasmata of homoeologous pairing was shown by the phKL+Ph2(-) plants with respect to their phKL+Ph2 sibs, which indicates that Ph2-deficiency and phKL showed an additive effect on promoting pairing. The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents, of which, reduction of univalents was mainly due to the increment of rod bivalents. The combined lines are probably more desirable materials for alien gene transferring than phKL or Ph2(-) lines alone. In comparison with that of ph1b X Ae. variabilis (or rye), phKL+Ph2(-) X Ae. variabilis (or rye) show higher (or similar) numbers of rod bivalents, while the total chromosome pairing level significantly reduced that ascribed to the decrement in ring bivalents and multivalents. These results probably indicate the different genetic mechanisms for Ph1 and Ph2 or phKL on controlling homoeologous pairing.展开更多
The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characterist...The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characteristics of homoeologous pairing and recombination induced by phKL.In KL haploids,the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring(CS)haploids.There was a clear preference for A–D pairing and less frequent for A–B and B–D,reflecting the higher levels of affinity between genomes A and D in wheat.The characteristics of pairing were affected by temperature and magnesium ion supplementation.The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues:2Sv-2B,2Sv-2D,and 2RL-2BL.The recombination rates were 1.68%,0.17%,and 0%,respectively.The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present,both in wheat haploids and hexaploids.The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree,permitting homoeologous crossing over but only between closely related chromosomes;there was no crossing over between more differentiated chromosomes.Therefore,the phKL system(QPh.sicau-3A)can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.展开更多
Wheat 1BL/1RS translocations are widely planted in China as well as in most of the wheat producing area in the world for their good qualities of disease resistance and high yield. 1BL/1RS translocations are however po...Wheat 1BL/1RS translocations are widely planted in China as well as in most of the wheat producing area in the world for their good qualities of disease resistance and high yield. 1BL/1RS translocations are however poor in bread making, partially caused by a family of small monomeric proteins, ω-secalins, which are encoded by genes on 1RS. Based on published sequence of a rye ω-secalin gene we designed a pair of primers to cover the whole mature protein coding sequence. A major band could be amplified from 1BL/1RS translocations but not from euploid wheat. Using this primer set we conducted PCR amplification by using high fidelity Pfu polymerase on the genomic DNAs and cDNAs purified from a 1BL/1RS translocation Lankao 906. Sequencing analysis indicated that this gene family contains several mem- bers of 1150 bp, 1076 bp, 1075 bp, 1052 bp and 1004 bp genes, including two pseudogenes and three active genes. The gene transcripts were differentially expressed in developing seeds.展开更多
Hordeum californicum （2n = 2x = 14, HH） is resistant to several wheat diseases and tolerant to lower nitrogen. In this study, a molecular karyotype of H. californicum chromosomes in the Triticum aestivum L. cv. Chin...Hordeum californicum （2n = 2x = 14, HH） is resistant to several wheat diseases and tolerant to lower nitrogen. In this study, a molecular karyotype of H. californicum chromosomes in the Triticum aestivum L. cv. Chinese Spring （CS）-H. californicum amphidiploid （2n = 6x = 56, AABBDDHH） was established. By genomic in situ hybridization （GISH） and multicolor fluorescent in situ hybridization （FISH） using repetitive DNA clones （pTa71, pTa794 and pSc119.2） as probes, the H. californicum chromosomes could be differentiated from each other and from the wheat chromosomes unequivocally. Based on molecular karyotype and marker analyses, 12 wheat--alien chromosome lines, including four disomic addition lines （DAH1, DAH3, DAH5 and DAH6）, five telosomic addition lines （MtH7L, MtHIS, MtH1L, DtH6S and DtH6L）, one multiple addition line involving H. californicum chromosome H2, one disomic substitution line （DSH4） and one translocation line （TH7S/1BL）, were identified from the progenies derived from the crosses of CS-H. californicum amphidiploid with common wheat varieties. A total of 482 EST （expressed sequence tag） or SSR （simple sequence repeat） markers specific for individual H. californicum chromosomes were identified, and 47, 50, 45, 49, 21, 51 and 40 markers were assigned to chromosomes H1, H2, H3, H4, H5, H6 and H7, respectively. According to the chromosome allocation of these markers, chromosomes H2, H3, H4, H5, and H7 of H. californicum have relationship with wheat homoeologous groups 5, 2, 6, 3, and 1, and hence could be designated as 5Hc, 2He, 6Hc, 3Hc and 1Hc, respectively. The chromosomes H1 and H6 were designated as 7Hc and 4Hc, respectively, by referring to SSR markers located on rye chromosomes.展开更多
The purpose of this study was to characterize Ta14 S homoeologs and assess their functions in wheat seed development.The genomic and c DNA sequences of three Ta14 S homoeologous genes encoding 14-3-3 proteins were iso...The purpose of this study was to characterize Ta14 S homoeologs and assess their functions in wheat seed development.The genomic and c DNA sequences of three Ta14 S homoeologous genes encoding 14-3-3 proteins were isolated.Sequence analysis revealed that the three homoeologs consisted of five exons and four introns and were very highly conserved in the coding regions and in exon/intron structure,whereas the c DNA sequences were variable in the 5′ and 3′-UTR.The three genes,designated as Ta14S-2A,Ta14S-2B and Ta14S-2D,were located in homoeologous group 2 chromosomes.The polypeptide chains of the three Ta14 S genes were highly similar.These genes were most homologous to Hv14 A from barley.Real-time quantitative PCR indicated that the three Ta14 S genes were differentially expressed in different organs at different developmental stages and all exhibited greater expression in primary roots of 1-day-old germlings than in other tissues.Comparison of the expression patterns of the three homoeologous genes at different times after pollination also revealed that their expression was developmentally regulated.The transcription of Ta14S-2B was clearly higher during seed germination,whereas expressions of Ta14S-2A and Ta14S-2D were up-regulated at the beginning of seed imbibition(0–12 h),but declined thereafter.The results suggested that the three Ta14 S homoeologous genes have regulatory roles in seed development and germination.展开更多
While Upland cotton(Gossypium hirsutum L.) represents 95% of the world production,its genetic improvement is hindered by the shortage of effective genomic tools and resources.The
Homoeologous recombination(HR),the exchange of homoeologous chromosomes,contributes to subgenome adaptation to diverse environments by producing various phenotypes.However,the potential relevance of HR and innate immu...Homoeologous recombination(HR),the exchange of homoeologous chromosomes,contributes to subgenome adaptation to diverse environments by producing various phenotypes.However,the potential relevance of HR and innate immunity is rarely described in triploid cyprinid fish species.In our study,two allotriploid genotypes(R_(2)C and RC_(2)),whose innate immunity was stronger than their inbred parents(Carassius auratus red var.and Cyprinus carpio L.),were obtained from backcrossing between male allotetraploids of C.auratus red var.×C.carpio L.and females of their two inbred parents,respectively.The work detected 140 HRs shared between the two triploids at the genomic level.Further,transcriptions of 54 homoeologous recombinant genes(HRGs)in R_(2)C and 65 HRGs in RC_(2) were detected using both Illumina and PacBio data.Finally,by comparing expressed recombinant reads to total expressed reads in each of the genes,a range of 0.1%-10% was observed in most of the 99-193 HRGs,of which six recombinant genes were classified as"response to stimulus".These results not only provide a novel way to predict HRs in allopolyploids based on cross prediction at both genomic and transcriptional levels,but also insight into the potential relationship between HRs related to innate immunity and adaptation of the triploids and allotetraploids.展开更多
With the long-term support by the National Natural Science Foundation of China,Ministry of Agriculture,and Science and Technology Department of Zhejiang Province,the research team led by Prof.Zhang Mingfang(张明方)at ...With the long-term support by the National Natural Science Foundation of China,Ministry of Agriculture,and Science and Technology Department of Zhejiang Province,the research team led by Prof.Zhang Mingfang(张明方)at Zhejiang University,assembled an allopolyploid B.juncea genome and uncovered differential homoeolog gene expression influencing selection,which was published in Nature展开更多
Allopolyploids often exhibit advantages in vigor and adaptability compared to diploids.A long-term goal in the economically important Brassica genus has been to develop a new allohexaploid crop type(AABBCC)by combinin...Allopolyploids often exhibit advantages in vigor and adaptability compared to diploids.A long-term goal in the economically important Brassica genus has been to develop a new allohexaploid crop type(AABBCC)by combining different diploid and allotetraploid crop species.However,early-generation allohexaploids often face challenges like unstable meiosis and low fertility,and the phenotypic performance of these synthetic lines has rarely been assessed.This study analyzes agronomic traits,fertility,and genome stability in ArArBcBcCcCc lines derived from four crosses between B.carinata and B.rapa after 9–11 selfing generations.Our results demonstrate polyploid advantage in vigor and seed traits,considerable phenotypic variation,and high fertility and genome stability.Meanwhile,parental genotypes significantly influence outcomes in advanced allohexaploids.Structural variants,largely resulting from A–C homoeologous exchanges,contribute to genomic variation and influence hexaploid genome stability,with the A sub-genome showing the highest variability.Both positive and negative impacts of SVs on fertility and seed weight are observed.Pseudo-euploids,frequently appearing,do not significantly affect fertility or other agronomic traits compared to euploids,indicating a potential pathway toward a stable allohexaploid species.These findings provide insights into the challenge and potential for developing an adaptable and stable Brassica hexaploid through selection.展开更多
Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,a...Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.展开更多
Barley yellow dwarf virus(BYDV),vectored by several aphid species,is the most significant viral pathogen of wheat and other grain cereals.Significant economic losses resulting from BYDV in wheat,barley and oats have b...Barley yellow dwarf virus(BYDV),vectored by several aphid species,is the most significant viral pathogen of wheat and other grain cereals.Significant economic losses resulting from BYDV in wheat,barley and oats have been reported in many countries.The most economic means of controlling BYDV is to develop wheat varieties with resistance to BYDV. So far no BYDV resistance has been described in wheat collections except one gene in some cultivars tolerant to BYDV. However, Thinopyrum intermedium ,two octoploids Zhong 4 awnless and TAF46,and the disomic addition lines,L1,Z1,Z2 and Z6 all showed resistance to BYDV. We developed several wheat Th.Intermedium translocation lines, Yw642, Yw443 and Yw243 etc., showing good BYDV resistance from L1 by inducing homologous pairing using CS Ph1 mutant. It was found that their BYDV resistance was controlled by a single dominant gene. Characterization of these wheat lines was carried out by GISH and RFLP analysis. The results of GISH showed that the lines, Yw642, Yw443 and Yw243 etc., were homozygous wheat Th.intermedium translocation lines containing 20 pairs of wheat chromosomes and 1 pair of wheat Th.intermedium translocation chromosomes,in which the chromosome segments of Th intermedium were transferred to the distal end of a pair of wheat chromosomes. RFLP analysis indicated that the translocation chromosome of the wheat lines was T7DS·7DL 7XL translocation. The breakpoint of translocation is located on the distal end of 7DL,between Xpsr965 and Xpsr680,about 90 99 cM from the centromere. The BYDV gene is located on the distal end of 7XL around Xpsr680,Xpsr687 and Xwg380.The RFLP markers of psr680,psr687 and wg380 co segregated with the BYDV resistance and could be used for marker assisted selection(MAS)in wheat breeding program for BYDV resistance.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2021YFF1000104)the Agricultural Science and Technology Innovation Program(ASTIP),Beijing Municipal Science and Technology Project(Grant No.Z231100003723009)+4 种基金the Central Public-interest Scientific Institution Basal Research Fund(Grant No.Y2023PT16)TKI project(Grant No.KV1605-004)support from the China Scholarship Councilthe NPO bursary funding from Wageningen universitythe scholarship from Institute of vegetables and flowers,CAAS.
文摘Polyploidy,or whole-genome duplication,is an important evolutionary process that has shaped the genomes and traits of many plants,including numerous important crops.The Brassica genus,which includes diverse vegetables and oilseeds,is a key model system for studying how polyploidy affects plant diversification and domestication.This review summarizes the current understanding of how multiple rounds of ancient and more recent polyploidization events laid the foundation for the wide diversity seen in Brassica.We discuss the key outcomes through which polyploidy facilitates the accumulation of genetic variation,including genomic buffering that enables mutation retention.Furthermore,we explore the significant roles of interspecies and interploidy introgression in introducing external genetic novelty.We highlight homoeologous exchange(HE)as a critical mechanism unique to allopolyploids,driving substantial genomic rearrangements including presence-absence variations and gene dosage alterations that directly contribute to significant phenotypic innovation and adaptation in Brassica.Together,these polyploidy-associated processes have led to the extensive range of genomic variations that shaped great morphological diversification in the domestication of Brassica.By integrating insights from genomics,genetics,and evolutionary biology,this review shows how polyploidy has been central to Brassica's success and agricultural value.We also suggest future research areas to better understand polyploid evolution and improve crop breeding.
文摘The combined lines having both phKL and Ph2-deficiency were obtained in the genetic background of common wheat (Triticum aestivum L.) landrace. These lines had normal fertility. In the wheat combined lines X Aegilops variabilis Eig. (or rye), a significant increase in the chiasmata of homoeologous pairing was shown by the phKL+Ph2(-) plants with respect to their phKL+Ph2 sibs, which indicates that Ph2-deficiency and phKL showed an additive effect on promoting pairing. The effects were shown in the increment of rod bivalents, ring bivalents and trivalents and reduction of univalents, of which, reduction of univalents was mainly due to the increment of rod bivalents. The combined lines are probably more desirable materials for alien gene transferring than phKL or Ph2(-) lines alone. In comparison with that of ph1b X Ae. variabilis (or rye), phKL+Ph2(-) X Ae. variabilis (or rye) show higher (or similar) numbers of rod bivalents, while the total chromosome pairing level significantly reduced that ascribed to the decrement in ring bivalents and multivalents. These results probably indicate the different genetic mechanisms for Ph1 and Ph2 or phKL on controlling homoeologous pairing.
基金supported by the National Natural Science Foundation of China(31971884,31601300,32172020)USDANIFA(#CA-R-BPS-5411-H)to AJL+1 种基金Natural Science Foundation of Sichuan Province(2022NSFSC1696,2019YJ0415)the National Key Research and Development Program of China(2016YFD0102000)。
文摘The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characteristics of homoeologous pairing and recombination induced by phKL.In KL haploids,the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring(CS)haploids.There was a clear preference for A–D pairing and less frequent for A–B and B–D,reflecting the higher levels of affinity between genomes A and D in wheat.The characteristics of pairing were affected by temperature and magnesium ion supplementation.The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues:2Sv-2B,2Sv-2D,and 2RL-2BL.The recombination rates were 1.68%,0.17%,and 0%,respectively.The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present,both in wheat haploids and hexaploids.The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree,permitting homoeologous crossing over but only between closely related chromosomes;there was no crossing over between more differentiated chromosomes.Therefore,the phKL system(QPh.sicau-3A)can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.
基金supported by the National Basic Research Program of China(973)(No.2004CB117200).
文摘Wheat 1BL/1RS translocations are widely planted in China as well as in most of the wheat producing area in the world for their good qualities of disease resistance and high yield. 1BL/1RS translocations are however poor in bread making, partially caused by a family of small monomeric proteins, ω-secalins, which are encoded by genes on 1RS. Based on published sequence of a rye ω-secalin gene we designed a pair of primers to cover the whole mature protein coding sequence. A major band could be amplified from 1BL/1RS translocations but not from euploid wheat. Using this primer set we conducted PCR amplification by using high fidelity Pfu polymerase on the genomic DNAs and cDNAs purified from a 1BL/1RS translocation Lankao 906. Sequencing analysis indicated that this gene family contains several mem- bers of 1150 bp, 1076 bp, 1075 bp, 1052 bp and 1004 bp genes, including two pseudogenes and three active genes. The gene transcripts were differentially expressed in developing seeds.
基金supported by the Technology Support Program of Jiangsu Province (No. BE2012306)the Program of Introducing Talents of Discipline to Universities (No. B08025)+1 种基金the Project No.7 from Science and High-Tech Based Major Program of Agriculture Committee of Shanghai Municipal Administration (No.20127)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Hordeum californicum （2n = 2x = 14, HH） is resistant to several wheat diseases and tolerant to lower nitrogen. In this study, a molecular karyotype of H. californicum chromosomes in the Triticum aestivum L. cv. Chinese Spring （CS）-H. californicum amphidiploid （2n = 6x = 56, AABBDDHH） was established. By genomic in situ hybridization （GISH） and multicolor fluorescent in situ hybridization （FISH） using repetitive DNA clones （pTa71, pTa794 and pSc119.2） as probes, the H. californicum chromosomes could be differentiated from each other and from the wheat chromosomes unequivocally. Based on molecular karyotype and marker analyses, 12 wheat--alien chromosome lines, including four disomic addition lines （DAH1, DAH3, DAH5 and DAH6）, five telosomic addition lines （MtH7L, MtHIS, MtH1L, DtH6S and DtH6L）, one multiple addition line involving H. californicum chromosome H2, one disomic substitution line （DSH4） and one translocation line （TH7S/1BL）, were identified from the progenies derived from the crosses of CS-H. californicum amphidiploid with common wheat varieties. A total of 482 EST （expressed sequence tag） or SSR （simple sequence repeat） markers specific for individual H. californicum chromosomes were identified, and 47, 50, 45, 49, 21, 51 and 40 markers were assigned to chromosomes H1, H2, H3, H4, H5, H6 and H7, respectively. According to the chromosome allocation of these markers, chromosomes H2, H3, H4, H5, and H7 of H. californicum have relationship with wheat homoeologous groups 5, 2, 6, 3, and 1, and hence could be designated as 5Hc, 2He, 6Hc, 3Hc and 1Hc, respectively. The chromosomes H1 and H6 were designated as 7Hc and 4Hc, respectively, by referring to SSR markers located on rye chromosomes.
基金financially supported by the Key Transgenic Breeding Program of the Ministry of Agriculture of China(No.2014ZX0800205B-003)the National Natural Science Foundation of China(No.30771332)
文摘The purpose of this study was to characterize Ta14 S homoeologs and assess their functions in wheat seed development.The genomic and c DNA sequences of three Ta14 S homoeologous genes encoding 14-3-3 proteins were isolated.Sequence analysis revealed that the three homoeologs consisted of five exons and four introns and were very highly conserved in the coding regions and in exon/intron structure,whereas the c DNA sequences were variable in the 5′ and 3′-UTR.The three genes,designated as Ta14S-2A,Ta14S-2B and Ta14S-2D,were located in homoeologous group 2 chromosomes.The polypeptide chains of the three Ta14 S genes were highly similar.These genes were most homologous to Hv14 A from barley.Real-time quantitative PCR indicated that the three Ta14 S genes were differentially expressed in different organs at different developmental stages and all exhibited greater expression in primary roots of 1-day-old germlings than in other tissues.Comparison of the expression patterns of the three homoeologous genes at different times after pollination also revealed that their expression was developmentally regulated.The transcription of Ta14S-2B was clearly higher during seed germination,whereas expressions of Ta14S-2A and Ta14S-2D were up-regulated at the beginning of seed imbibition(0–12 h),but declined thereafter.The results suggested that the three Ta14 S homoeologous genes have regulatory roles in seed development and germination.
文摘While Upland cotton(Gossypium hirsutum L.) represents 95% of the world production,its genetic improvement is hindered by the shortage of effective genomic tools and resources.The
基金supported by the National Natural Science Foundation of China(31702334,31730098,U19A2040 and31430088)the Key Research and Development Program of Hunan Province(2018NK2072 and 2017NK1031)+4 种基金the Earmarked Fund for China Agriculture Research System(CARS-45)111 Project(D20007)High-Level Talent Agglomeration Program of HunanChina(2019RS1044)the Cooperative Innovation Center of Engineering and New Products for Developmental Biology of Hunan Province(20134486)。
文摘Homoeologous recombination(HR),the exchange of homoeologous chromosomes,contributes to subgenome adaptation to diverse environments by producing various phenotypes.However,the potential relevance of HR and innate immunity is rarely described in triploid cyprinid fish species.In our study,two allotriploid genotypes(R_(2)C and RC_(2)),whose innate immunity was stronger than their inbred parents(Carassius auratus red var.and Cyprinus carpio L.),were obtained from backcrossing between male allotetraploids of C.auratus red var.×C.carpio L.and females of their two inbred parents,respectively.The work detected 140 HRs shared between the two triploids at the genomic level.Further,transcriptions of 54 homoeologous recombinant genes(HRGs)in R_(2)C and 65 HRGs in RC_(2) were detected using both Illumina and PacBio data.Finally,by comparing expressed recombinant reads to total expressed reads in each of the genes,a range of 0.1%-10% was observed in most of the 99-193 HRGs,of which six recombinant genes were classified as"response to stimulus".These results not only provide a novel way to predict HRs in allopolyploids based on cross prediction at both genomic and transcriptional levels,but also insight into the potential relationship between HRs related to innate immunity and adaptation of the triploids and allotetraploids.
文摘With the long-term support by the National Natural Science Foundation of China,Ministry of Agriculture,and Science and Technology Department of Zhejiang Province,the research team led by Prof.Zhang Mingfang(张明方)at Zhejiang University,assembled an allopolyploid B.juncea genome and uncovered differential homoeolog gene expression influencing selection,which was published in Nature
基金supported by the Sino-German Research Project(GZ 1362)Grains Research and Development Corporation International Visiting Fellowship(UWA2406-010BGX)+1 种基金the National Natural Science Foundation of China(32171982)the Fundamental Research Funds for the Central Universities of the Chinese Government(2662023PY004).
文摘Allopolyploids often exhibit advantages in vigor and adaptability compared to diploids.A long-term goal in the economically important Brassica genus has been to develop a new allohexaploid crop type(AABBCC)by combining different diploid and allotetraploid crop species.However,early-generation allohexaploids often face challenges like unstable meiosis and low fertility,and the phenotypic performance of these synthetic lines has rarely been assessed.This study analyzes agronomic traits,fertility,and genome stability in ArArBcBcCcCc lines derived from four crosses between B.carinata and B.rapa after 9–11 selfing generations.Our results demonstrate polyploid advantage in vigor and seed traits,considerable phenotypic variation,and high fertility and genome stability.Meanwhile,parental genotypes significantly influence outcomes in advanced allohexaploids.Structural variants,largely resulting from A–C homoeologous exchanges,contribute to genomic variation and influence hexaploid genome stability,with the A sub-genome showing the highest variability.Both positive and negative impacts of SVs on fertility and seed weight are observed.Pseudo-euploids,frequently appearing,do not significantly affect fertility or other agronomic traits compared to euploids,indicating a potential pathway toward a stable allohexaploid species.These findings provide insights into the challenge and potential for developing an adaptable and stable Brassica hexaploid through selection.
基金funded by the Natural Science Foundation of Sichuan Province for Young Scholars(2024NSFSC1218)the HighLevel Talent Introduction Project of Sichuan Academy of Agricultural Sciences(NKYRCZX2024022)+1 种基金the Accurate Identification Project of Crop Germplasm from Sichuan Provincial Finance Department(1+3 ZYGG001)the Strategic Scientist Studio of Sichuan Academy of Agricultural Sciences.
文摘Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.
文摘Barley yellow dwarf virus(BYDV),vectored by several aphid species,is the most significant viral pathogen of wheat and other grain cereals.Significant economic losses resulting from BYDV in wheat,barley and oats have been reported in many countries.The most economic means of controlling BYDV is to develop wheat varieties with resistance to BYDV. So far no BYDV resistance has been described in wheat collections except one gene in some cultivars tolerant to BYDV. However, Thinopyrum intermedium ,two octoploids Zhong 4 awnless and TAF46,and the disomic addition lines,L1,Z1,Z2 and Z6 all showed resistance to BYDV. We developed several wheat Th.Intermedium translocation lines, Yw642, Yw443 and Yw243 etc., showing good BYDV resistance from L1 by inducing homologous pairing using CS Ph1 mutant. It was found that their BYDV resistance was controlled by a single dominant gene. Characterization of these wheat lines was carried out by GISH and RFLP analysis. The results of GISH showed that the lines, Yw642, Yw443 and Yw243 etc., were homozygous wheat Th.intermedium translocation lines containing 20 pairs of wheat chromosomes and 1 pair of wheat Th.intermedium translocation chromosomes,in which the chromosome segments of Th intermedium were transferred to the distal end of a pair of wheat chromosomes. RFLP analysis indicated that the translocation chromosome of the wheat lines was T7DS·7DL 7XL translocation. The breakpoint of translocation is located on the distal end of 7DL,between Xpsr965 and Xpsr680,about 90 99 cM from the centromere. The BYDV gene is located on the distal end of 7XL around Xpsr680,Xpsr687 and Xwg380.The RFLP markers of psr680,psr687 and wg380 co segregated with the BYDV resistance and could be used for marker assisted selection(MAS)in wheat breeding program for BYDV resistance.
