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1.
Plant Dis ; : PDIS01200053RE, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32396052

RESUMO

Southern corn rust (SCR), an airborne disease caused by Puccinia polysora, can severely reduce the yield of maize (Zea mays L.). Using recombinant inbred lines (RILs) derived from a cross between susceptible inbred line Ye478 and resistant Qi319 in combination with their high-density genetic map, we located five quantitative trait loci (QTLs) against SCR, designated as qSCR3.04, qSCR5.07, qSCR6.01, qSCR9.03, and qSCR10.01, on chromosomes 3, 5, 6, 9, and 10, respectively. Each QTL could explain 2.84 to 24.15% of the total phenotypic variation. qSCR6.01, detected on chromosome 6, with the highest effect value, accounting for 17.99, 23.47, and 24.15% of total phenotypic variation in two environments and best linear unbiased prediction, was a stably major resistance QTL. The common confidence interval for qSCR6.01 was 2.95 Mb based on the B73 RefGen_v3 sequence. The chromosome segment substitution lines (CSSLs) constructed with Qi319 as the donor parent and Ye478 as the recurrent parent were used to further verify qSCR6.01 resistance to SCR. The line CL183 harboring introgressed qSCR6.01 showed obvious resistance to SCR that was distinctly different from that of Ye478 (P = 0.0038). Further mapping of qSCR6.01 revealed that the resistance QTL was linked to insertion-deletion markers Y6q77 and Y6q79, with physical locations of 77.6 and 79.6 Mb, respectively, on chromosome 6. Different from previous major genes or QTLs against SCR on chromosome 10, qSCR6.01 was a newly identified major QTL resistance to SCR on chromosome 6 for the first time. Using RIL and CSSL populations in combination, the SCR-resistance QTL research can be dissected effectively, which provided important gene resource and genetic information for breeding resistant varieties.

2.
Int J Mol Sci ; 20(20)2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31614814

RESUMO

Powdery mildew caused by Erysiphe pisi DC. severely affects pea crops worldwide. The use of resistant cultivars containing the er1 gene is the most effective way to control this disease. The objectives of this study were to reveal er1 alleles contained in 55 E. pisi-resistant pea germplasms and to develop the functional markers of novel alleles. Sequences of 10 homologous PsMLO1 cDNA clones from each germplasm accession were used to determine their er1 alleles. The frame shift mutations and various alternative splicing patterns were observed during transcription of the er1 gene. Two novel er1 alleles, er1-8 and er1-9, were discovered in the germplasm accessions G0004839 and G0004400, respectively, and four known er1 alleles were identified in 53 other accessions. One mutation in G0004839 was characterized by a 3-bp (GTG) deletion of the wild-type PsMLO1 cDNA, resulting in a missing valine at position 447 of the PsMLO1 protein sequence. Another mutation in G0004400 was caused by a 1-bp (T) deletion of the wild-type PsMLO1 cDNA sequence, resulting in a serine to leucine change of the PsMLO1 protein sequence. The er1-8 and er1-9 alleles were verified using resistance inheritance analysis and genetic mapping with respectively derived F2 and F2:3 populations. Finally, co-dominant functional markers specific to er1-8 and er1-9 were developed and validated in populations and pea germplasms. These results improve our understanding of E. pisi resistance in pea germplasms worldwide and provide powerful tools for marker-assisted selection in pea breeding.


Assuntos
Resistência à Doença , Genes de Plantas , Ervilhas/genética , Alelos , Ascomicetos/patogenicidade , Ervilhas/imunologia , Ervilhas/microbiologia , Banco de Sementes
3.
Int J Mol Sci ; 20(8)2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-31013701

RESUMO

Phytophthora root rot (PRR) causes serious annual soybean yield losses worldwide. The most effective method to prevent PRR involves growing cultivars that possess genes conferring resistance to Phytophthora sojae (Rps). In this study, QTL-sequencing combined with genetic mapping was used to identify RpsX in soybean cultivar Xiu94-11 resistance to all P. sojae isolates tested, exhibiting broad-spectrum PRR resistance. Subsequent analysis revealed RpsX was located in the 242-kb genomic region spanning the RpsQ locus. However, a phylogenetic investigation indicated Xiu94-11 carrying RpsX is distantly related to the cultivars containing RpsQ, implying RpsX and RpsQ have different origins. An examination of candidate genes revealed RpsX and RpsQ share common nonsynonymous SNP and a 144-bp insertion in the Glyma.03g027200 sequence encoding a leucine-rich repeat (LRR) region. Glyma.03g027200 was considered to be the likely candidate gene of RpsQ and RpsX. Sequence analyses confirmed that the 144-bp insertion caused by an unequal exchange resulted in two additional LRR-encoding fragments in the candidate gene. A marker developed based on the 144-bp insertion was used to analyze the genetic population and germplasm, and proved to be useful for identifying the RpsX and RpsQ alleles. This study implies that the number of LRR units in the LRR domain may be important for PRR resistance in soybean.


Assuntos
Resistência à Doença/genética , Interações Hospedeiro-Parasita/genética , Phytophthora , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Soja/genética , Soja/parasitologia , Mapeamento Cromossômico , Cromossomos de Plantas , Sequência Conservada , Genes de Plantas , Ligação Genética , Loci Gênicos , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Phytophthora/isolamento & purificação , Polimorfismo de Nucleotídeo Único , Soja/classificação
4.
Phytopathology ; 109(5): 804-809, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30328778

RESUMO

Pythium stalk rot caused by Pythium inflatum is becoming a more and more serious disease in maize, and it has caused severe yield loss in China in recent years. Deployment of resistant maize varieties is the most effective way to control this disease. Searching for the resistant maize germplasm and identifying the resistance genes are the vital processes in the breeding program. The maize inbred line X178 previously showed high resistance to Pythium stalk rot. Thus, this study aimed to reveal the gene(s) resistance to Pythium stalk rot in X178 by resistance inheritance analysis using the derived F2 and F2:3 genetic populations. The results showed that two independently inherited dominant genes, designated RpiX178-1 and RpiX178-2, carried by X178 are responsible for its resistance relative to the susceptible parent Ye107; they are located on regions of maize chromosome (chr.) 1 bin 1.09 and chr. 4 bin 4.08, respectively, and flanked by markers umc2047 and bnlg1671 as well as bnlg1444 and umc1313, respectively, by linkage analysis. Subsequently, RpiX178-1 was finely mapped between markers SSRZ8 and IDP2347, with genetic distances of 0.6 and 1.1 cM, respectively, and the physical distance of the target region was about 700 kb. RpiX178-2 was also further located between markers bnlg1444 and umc2041, with a genetic distance of 2.4 cM. Moreover, we confirmed that the two genes RpiX178-1 and RpiX178-2 were newly identified and different from those genes known on chrs. 1 and 4 according to results of allelism testing. Herein, we newly identified two genes resistant to P. inflatum, which provided important genetic information for resistance to Pythium stalk rot in maize.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Pythium/patogenicidade , Zea mays/genética , China , Mapeamento Cromossômico , Genes de Plantas , Marcadores Genéticos , Doenças das Plantas/microbiologia , Zea mays/microbiologia
5.
Front Plant Sci ; 9: 44, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29441079

RESUMO

Phytophthora root rot (PRR) caused by Phytophthora sojae is a major soybean disease that causes severe economic losses worldwide. Using soybean cultivars carrying a Rps resistance gene is the most effective strategy for controlling this disease. We previously detected a novel Phytophthora resistance gene, RpsZS18, on chromosome 2 of the soybean cultivar Zaoshu18. The aim of the present study was to identify and finely map RpsZS18. We used 232 F2:3 families generated from a cross between Zaoshu18 (resistant) and Williams (susceptible) as the mapping population. Simple sequence repeat (SSR) markers distributed on chromosome 2 were used to map RpsZS18. First, 12 SSR markers linked with RpsZS18 were identified by linkage analyses, including two newly developed SSR markers, ZCSSR33 and ZCSSR46, that flanked the gene at distances of 0.9 and 0.5 cM, respectively. Second, PCR-based InDel markers were developed based on sequence differences between the two parents and used to further narrow down the mapping region of RpsZS18 to 71.3 kb. Third, haplotype analyses were carried out in the RpsZS18 region using 14 soybean genotypes with whole-genome resequencing. We detected six genes with unique haplotype sequences in Zaoshu18. Finally, quantitative real-time PCR assays of the six genes revealed an EF-hand calcium-binding domain containing protein encoding gene (Glyma.02g245700), a pfkB carbohydrate kinase encoding gene (Glyma.02g245800), and a gene with no functional annotation (Glyma.02g246300), are putative candidate PRR resistance genes. This study provides useful information for breeding P. sojae-resistant soybean cultivars.

6.
Toxins (Basel) ; 10(2)2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29470401

RESUMO

Fusarium verticillioides, F. proliferatum, and F. meridionale were identified as the predominant fungi among 116 Fusarium isolates causing maize ear and kernel rot, a destructive disease in Chongqing areas, China. The toxigenic capability and genotype were determined by molecular amplification and toxin assay. The results showed that the key toxigenic gene FUM1 was detected in 47 F. verticillioides and 19 F. proliferatum isolates. Among these, F. verticillioides and F. proliferatum isolates mainly produced fumonisin B1, ranging from 3.17 to 1566.44, and 97.74 to 11,100.99 µg/g for each gram of dry hyphal weight, with the averages of 263.94 and 3632.88 µg/g, respectively, indicating the F. proliferatum isolates on average produced about an order of magnitude more fumonisins than F. verticillioides did in these areas, in vitro. Only NIV genotype was detected among 16 F. meridionale and three F. asiaticum isolates. Among these, 11 F. meridionale isolates produced NIV, varying from 17.40 to 2597.34 µg/g. ZEA and DON toxins were detected in 11 and 4 F. meridionale isolates, with the toxin production range of 8.35-78.57 and 3.38-33.41 µg/g, respectively. Three F. asiaticum isolates produced almost no mycotoxins, except that one isolate produced a small amount of DON. The findings provide us with insight into the risk of the main pathogenic Fusarium species and a guide for resistance breeding in these areas.


Assuntos
Fusarium , Micotoxinas/biossíntese , Zea mays/microbiologia , China , Contaminação de Alimentos , Fusarium/genética , Fusarium/isolamento & purificação , Fusarium/metabolismo , Genótipo , Micotoxinas/genética , Doenças das Plantas/microbiologia
7.
Theor Appl Genet ; 131(3): 525-538, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29138903

RESUMO

KEY MESSAGE: A novel Phytophthora sojae resistance gene RpsHC18 was identified and finely mapped on soybean chromosome 3. Two NBS-LRR candidate genes were identified and two diagnostic markers of RpsHC18 were developed. Phytophthora root rot caused by Phytophthora sojae is a destructive disease of soybean. The most effective disease-control strategy is to deploy resistant cultivars carrying Phytophthora-resistant Rps genes. The soybean cultivar Huachun 18 has a broad and distinct resistance spectrum to 12 P. sojae isolates. Quantitative trait loci sequencing (QTL-seq), based on the whole-genome resequencing (WGRS) of two extreme resistant and susceptible phenotype bulks from an F2:3 population, was performed, and one 767-kb genomic region with ΔSNP-index ≥ 0.9 on chromosome 3 was identified as the RpsHC18 candidate region in Huachun 18. The candidate region was reduced to a 146-kb region by fine mapping. Nonsynonymous SNP and haplotype analyses were carried out in the 146-kb region among ten soybean genotypes using WGRS. Four specific nonsynonymous SNPs were identified in two nucleotide-binding sites-leucine-rich repeat (NBS-LRR) genes, RpsHC18-NBL1 and RpsHC18-NBL2, which were considered to be the candidate genes. Finally, one specific SNP marker in each candidate gene was successfully developed using a tetra-primer ARMS-PCR assay, and the two markers were verified to be specific for RpsHC18 and to effectively distinguish other known Rps genes. In this study, we applied an integrated genomic-based strategy combining WGRS with traditional genetic mapping to identify RpsHC18 candidate genes and develop diagnostic markers. These results suggest that next-generation sequencing is a precise, rapid and cost-effective way to identify candidate genes and develop diagnostic markers, and it can accelerate Rps gene cloning and marker-assisted selection for breeding of P. sojae-resistant soybean cultivars.


Assuntos
Resistência à Doença/genética , Genes de Plantas , Doenças das Plantas/genética , Soja/genética , Sequência de Bases , Mapeamento Cromossômico , Marcadores Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Mutação INDEL , Repetições de Microssatélites , Fenótipo , Phytophthora , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Soja/microbiologia
8.
Plant Dis ; 101(1): 95-102, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30682319

RESUMO

An emerging bacterial disease with symptoms resembling those of halo blight is threatening mung bean production in China. This study was conducted to investigate the disease's geographic distribution in China using consecutive multiyear field surveys and to confirm the causative agents' identity. The surveys were conducted in 15 provinces covering seven geographic regions from 2009 to 2014. The survey results revealed that the emerging mung bean disease has rapidly spread and is prevalent in three of the main Chinese geographic regions, which contain more than 90% of the mung-bean-growing areas in China. To confirm the causal agent, diseased mung bean leaves were collected from the surveyed fields and used to isolate the pathogen. A bacterium was consistently isolated from all of the collected leaves. Based on the phenotypic characteristics, the physiological and biochemical properties, pathogenicity tests, and fatty acid composition, in combination with specific polymerase chain reactions and 16S-23S ribosomal DNA sequence analyses, the bacterium was identified as Pseudomonas syringae pv. phaseolicola. To our knowledge, this is the first report of P. syringae pv. phaseolicola causing halo blight on mung bean in China. The results indicate that P. syringae pv. phaseolicola is likely of epidemiological significance on mung bean in China.

9.
J Exp Bot ; 67(15): 4593-609, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27493226

RESUMO

Maize rough dwarf disease (MRDD) is a viral infection that results in heavy yield losses in maize worldwide, particularly in the summer maize-growing regions of China. MRDD is caused by the Rice black-streaked dwarf virus (RBSDV). In the present study, analyses of microRNAs (miRNAs), the degradome, and transcriptome sequences were used to elucidate the RBSDV-responsive pathway(s) in maize. Genomic analysis indicated that the expression of three non-conserved and 28 conserved miRNAs, representing 17 known miRNA families and 14 novel miRNAs, were significantly altered in response to RBSDV when maize was inoculated at the V3 (third leaf) stage. A total of 99 target transcripts from 48 genes of 10 known miRNAs were found to be responsive to RBSDV infection. The annotations of these target genes include a SQUAMOSA promoter binding (SPB) protein, a P450 reductase, an oxidoreductase, and a ubiquitin-related gene, among others. Characterization of the entire transcriptome suggested that a total of 28 and 1085 differentially expressed genes (DEGs) were detected at 1.5 and 3.0 d, respectively, after artificial inoculation with RBSDV. The expression patterns of cell wall- and chloroplast-related genes, and disease resistance- and stress-related genes changed significantly in response to RBSDV infection. The negatively regulated genes GRMZM2G069316 and GRMZM2G031169, which are the target genes for miR169i-p5 and miR8155, were identified as a nucleolin and a NAD(P)-binding Rossmann-fold superfamily protein in maize, respectively. The gene ontology term GO:0003824, including GRMZM2G031169 and other 51 DEGs, was designated as responsive to RBSDV.


Assuntos
Doenças das Plantas/virologia , Reoviridae/fisiologia , Zea mays/virologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/fisiologia , MicroRNAs/genética , MicroRNAs/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Zea mays/genética , Zea mays/metabolismo
10.
Toxins (Basel) ; 8(6)2016 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-27338476

RESUMO

Ear rot is a serious disease that affects maize yield and grain quality worldwide. The mycotoxins are often hazardous to humans and livestock. In samples collected in China between 2009 and 2014, Fusarium verticillioides and F. graminearum species complex were the dominant fungi causing ear rot. According to the TEF-1α gene sequence, F. graminearum species complex in China included three independent species: F. graminearum, F. meridionale, and F. boothii. The key gene FUM1 responsible for the biosynthesis of fumonisin was detected in all 82 F. verticillioides isolates. Among these, 57 isolates mainly produced fumonisin B1, ranging from 2.52 to 18,416.44 µg/g for each gram of dry hyphal weight, in vitro. Three different toxigenic chemotypes were detected among 78 F. graminearum species complex: 15-ADON, NIV and 15-ADON+NIV. Sixty and 16 isolates represented the 15-ADON and NIV chemotypes, respectively; two isolates carried both 15-ADON and NIV-producing segments. All the isolates carrying NIV-specific segment were F. meridionale. The in vitro production of 15-ADON, 3-ADON, DON, and ZEN varied from 5.43 to 81,539.49; 6.04 to 19,590.61; 13.35 to 19,795.33; and 1.77 to 430.24 µg/g of dry hyphal weight, respectively. Altogether, our present data demonstrate potential main mycotoxin production of dominant pathogenic Fusarium in China.


Assuntos
Fusarium/isolamento & purificação , Micotoxinas/biossíntese , Doenças das Plantas/microbiologia , Zea mays/microbiologia , China , Fusarium/genética , Fusarium/metabolismo , Micotoxinas/genética
11.
PLoS One ; 11(1): e0147624, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26809053

RESUMO

Pea powdery mildew, caused by Erysiphe pisi D.C., is an important disease worldwide. Deployment of resistant varieties is the main way to control this disease. This study aimed to screen Chinese pea (Pisum sativum L.) landraces resistant to E. pisi, and to characterize the resistance gene(s) at the er1 locus in the resistant landraces, and to develop functional marker(s) specific to the novel er1 allele. The 322 landraces showed different resistance levels. Among them, 12 (3.73%), 4 (1.24%) and 17 (5.28%) landraces showed immunity, high resistance and resistance to E. pisi, respectively. The other landraces appeared susceptible or highly susceptible to E. pisi. Most of the immune and highly resistant landraces were collected from Yunnan province. To characterize the resistance gene at the er1 locus, cDNA sequences of PsMLO1 gene were determined in 12 immune and four highly resistant accessions. The cDNAs of PsMLO1 from the immune landrace G0005576 produced three distinct transcripts, characterized by a 129-bp deletion, and 155-bp and 220-bp insertions, which were consistent with those of er1-2 allele. The PsMLO1 cDNAs in the other 15 resistant landraces produced identical transcripts, which had a new point mutation (T→C) at position 1121 of PsMLO1, indicating a novel er1 allele, designated as er1-6. This mutation caused a leucine to proline change in the amino acid sequence. Subsequently, the resistance allele er1-6 in landrace G0001778 was confirmed by resistance inheritance analysis and genetic mapping on the region of the er1 locus using populations derived from G0001778 × Bawan 6. Finally, a functional marker specific to er1-6, SNP1121, was developed using the high-resolution melting technique, which could be used in pea breeding via marker-assisted selection. The results described here provide valuable genetic information for Chinese pea landraces and a powerful tool for pea breeders.


Assuntos
Ascomicetos/fisiologia , Resistência à Doença/genética , Ervilhas/genética , Ervilhas/microbiologia , Doenças das Plantas/genética , Alelos , China , Doenças das Plantas/microbiologia
12.
Theor Appl Genet ; 129(5): 909-19, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26801335

RESUMO

KEY MESSAGE: A novel er1 allele, er1 -7, conferring pea powdery mildew resistance was characterized by a 10-bp deletion in PsMLO1 cDNA, and its functional marker was developed and validated in pea germplasms. Pea powdery mildew caused by Erysiphe pisi DC is a major disease worldwide. Pea cultivar 'DDR-11' is an elite germplasm resistant to E. pisi. To identify the gene conferring resistance in DDR-11, the susceptible Bawan 6 and resistant DDR-11 cultivars were crossed to produce F1, F2, and F(2:3) populations. The phenotypic segregation patterns in the F2 and F(2:3) populations fit the 3:1 (susceptible:resistant) and 1:2:1 (susceptible homozygotes:heterozygotes:resistant homozygotes) ratios, respectively, indicating that resistance was controlled by a single recessive gene. Analysis of er1-linked markers in the F2 population suggested that the recessive resistance gene in DDR-11 was an er1 allele, which was mapped between markers ScOPE16-1600 and c5DNAmet. To further characterize er1 allele, the cDNA sequences of PsMLO1 from the parents were obtained and a novel er1 allele in DDR-11 was identified and designated as er1-7, which has a 10-bp deletion in position 111-120. The er1-7 allele caused a frame-shift mutation, resulting in a premature termination of translation of PsMLO1 protein. A co-dominant functional marker specific for er1-7 was developed, InDel111-120, which co-segregated with E. pisi resistance in the mapping population. The marker was able to distinguish between pea germplasms with and without the er1-7. Of 161 pea germplasms tested by InDel111-120, seven were detected containing resistance allele er1-7, which was verified by sequencing their PsMLO1 cDNA. Here, a novel er1 allele was characterized and its an ideal functional marker was validated, providing valuable genetic information and a powerful tool for breeding pea resistance to powdery mildew.


Assuntos
Resistência à Doença/genética , Marcadores Genéticos , Ervilhas/genética , Melhoramento Vegetal , Doenças das Plantas/genética , Alelos , Ascomicetos , Sequência de Bases , Mapeamento Cromossômico , Cruzamentos Genéticos , DNA de Plantas/genética , Genes de Plantas , Ligação Genética , Dados de Sequência Molecular , Fenótipo , Doenças das Plantas/microbiologia , Análise de Sequência de DNA
13.
Mol Genet Genomics ; 290(4): 1543-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25724693

RESUMO

Stalk rots are destructive diseases in maize around the world, and are most often caused by the pathogen Pythium, Fusarium and other fungi. The most efficient management for controlling stalk rots is to breed resistant cultivars. Pythium stalk rot can cause serious yield loss on maize, and to find the resistance genes from the existing germplasm is the basis to develop Pythium-resistance hybrid lines. In this study, we investigated the genetic resistance to Pythium stalk rot in inbred line Qi319 using F2 and F2:3 population, and found that the resistance to Pythium inflatum in Qi319 was conferred by two independently inherited dominant genes, RpiQI319-1 and RpiQI319-2. Linkage analysis uncovered that the RpiQI319-1 co-segregated with markers bnlg1203, and bnlg2057 on chromosome 1, and that the RpiQI319-2 locus co-segregated with markers umc2069 and bnlg1716 on chromosome 10. The RpiQI319-1 locus was further mapped into a ~500-kb interval flanked by markers SSRZ33 and SSRZ47. These results will facilitate marker-assisted selection of Pythium stalk rot-resistant cultivars in maize breeding. To our knowledge, this is the first report on the resistance to P. inflatum in the inbred line Qi319, and is also the first description of two independently inherited dominant genes conferring the resistance of Pythium stalk rot in maize.


Assuntos
Resistência à Doença/genética , Genes de Plantas/genética , Doenças das Plantas/genética , Zea mays/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , DNA de Plantas/genética , Genes Dominantes/genética , Ligação Genética , Marcadores Genéticos/genética , Interações Hospedeiro-Patógeno , Endogamia , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase , Pythium/fisiologia , Zea mays/microbiologia
14.
Plant Pathol J ; 31(1): 67-71, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25774112

RESUMO

During late August and early September 2011, stem rot symptoms were observed on adzuki bean plants (Vigna angularis) growing in fields located in Beijing and Hebei Province, China, respectively. In this study, four isolates were obtained from infected stems of adzuki bean plants. Based on their morphology, and sequence and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses of the ribosomal DNA internal transcribed spacers (rDNA-ITS) region, the four isolates were identified as Rhizoctonia solani in anastomosis group (AG) 4 HGI. Pathogenicity tests showed that all isolates were strongly pathogenic to adzuki bean and resulted in serious wilt symptoms which was similar to observations in the fields. Additionally, the isolates infected several other crops and induced related rot on the roots and basal stems. To our knowledge, this is the first report of Rhizoctonia solani AG 4 HGI causing stem rot on adzuki bean.

15.
PLoS One ; 9(5): e95458, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24835431

RESUMO

BACKGROUND: The adzuki bean weevil, Callosobruchus chinensis L., is one of the most destructive pests of stored legume seeds such as mungbean, cowpea, and adzuki bean, which usually cause considerable loss in the quantity and quality of stored seeds during transportation and storage. However, a lack of genetic information of this pest results in a series of genetic questions remain largely unknown, including population genetic structure, kinship, biotype abundance, and so on. Co-dominant microsatellite markers offer a great resolving power to determine these events. Here, we report rapid microsatellite isolation from C. chinensis via high-throughput sequencing. PRINCIPAL FINDINGS: In this study, 94,560,852 quality-filtered and trimmed reads were obtained for the assembly of genome using Illumina paired-end sequencing technology. In total, the genome with total length of 497,124,785 bp, comprising 403,113 high quality contigs was generated with de novo assembly. More than 6800 SSR loci were detected and a suit of 6303 primer pair sequences were designed and 500 of them were randomly selected for validation. Of these, 196 pair of primers, i.e. 39.2%, produced reproducible amplicons that were polymorphic among 8 C. chinensis genotypes collected from different geographical regions. Twenty out of 196 polymorphic SSR markers were used to analyze the genetic diversity of 18 C. chinensis populations. The results showed the twenty SSR loci were highly polymorphic among these populations. CONCLUSIONS: This study presents a first report of genome sequencing and de novo assembly for C. chinensis and demonstrates the feasibility of generating a large scale of sequence information and SSR loci isolation by Illumina paired-end sequencing. Our results provide a valuable resource for C. chinensis research. These novel markers are valuable for future genetic mapping, trait association, genetic structure and kinship among C. chinensis.


Assuntos
Distribuição Animal , Besouros/genética , Fabaceae/parasitologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Repetições de Microssatélites/genética , Sementes/parasitologia , Animais , Sequência de Bases , China , Análise por Conglomerados , Primers do DNA/genética , Genética Populacional , Dados de Sequência Molecular
16.
J Econ Entomol ; 107(5): 1992-9, 2014 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-26309291

RESUMO

In total, 339 faba bean (Vicia faba L.) and 100 pea (Pisum sativum L.) accessions were screened for their ability to resist Callosobruchus chinensis L. in free choice laboratory tests. Four, 15, and 43 faba bean varieties were highly resistant, resistant, and moderately resistant to C. chinensis, respectively. Three immune, three highly resistant, and six resistant accessions were discovered among the pea germplasm. The faba bean and pea varieties presented a hundred-kernel weight reduction varied from 0.18 to 35.36% for faba bean varieties and 0 to 56.53% for pea varieties. Varieties with brown and black seed color had significantly fewer wormholes and higher C. chinensis resistance than varieties with light-color seeds. Resistance to C. chinensis showed a significant, positive correlation with catechin, total polyphenol, and γ-aminobutyric acid contents, but a significant, negative correlation with oligosaccharide content. Correlation coefficients (r) between infestation rate of faba bean and total phenol, catechin, and oligosaccharide contents were -0.9723, -0.8071, and 0.7631, respectively. The values of r for pea resistance and total phenol, catechin, and oligosaccharide content were -0.8846, -0.7666, and 0.8308, respectively. The results suggest that quality components in faba bean and pea have a great role in resistance against C. chinensis.


Assuntos
Antibiose , Besouros/fisiologia , Herbivoria , Ervilhas/fisiologia , Vicia faba/fisiologia , Animais , Besouros/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ervilhas/genética , Melhoramento Vegetal , Vicia faba/genética
17.
PLoS One ; 8(7): e69799, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23936102

RESUMO

Resistance to Phytophthora sojae isolate PsMC1 was evaluated in 102 F2∶3 families derived from a cross between the resistant soybean cultivar Wandou 15 and the susceptible cultivar Williams and genotyped using simple sequence repeat (SSR) markers. The segregation ratio of resistant, segregating, and susceptible phenotypes in the population suggested that the resistance in Wandou 15 was dominant and monogenic. Twenty-six polymorphic SSR markers were identified on soybean chromosome 17 (Molecular linkage group D2; MLG D2), which were linked to the resistance gene based on bulked segregation analysis (BSA). Markers Sattwd15-24/25 and Sattwd15-47 flanked the resistance gene at a distance of 0.5 cM and 0.8 cM, respectively. Two cosegregating markers, Sattwd15-28 and Sattwd15-32, were also screened in this region. This is the first Rps resistance gene mapped on chromosome 17, which is designated as Rps10. Eight putative genes were found in the mapped region between markers Sattwd15-24/25 and Sattwd15-47. Among them, two candidate genes encoding serine/threonine (Ser/Thr) protein kinases in Wandou 15 and Williams were identified and sequenced. And the differences in genomic sequence and the putative amino acid sequence, respectively, were identified within each candidate gene between Wandou 15 and Williams. This novel gene Rps10 and the linked markers should be useful in developing soybean cultivars with durable resistance to P. sojae.


Assuntos
Genes de Plantas , Genoma de Planta , Phytophthora/crescimento & desenvolvimento , Doenças das Plantas/genética , Imunidade Vegetal/genética , Soja/genética , Sequência de Aminoácidos , Mapeamento Cromossômico , Estudos de Associação Genética , Ligação Genética , Marcadores Genéticos , Técnicas de Genotipagem , Repetições de Microssatélites , Dados de Sequência Molecular , Doenças das Plantas/imunologia , Alinhamento de Sequência , Soja/imunologia
18.
Theor Appl Genet ; 126(6): 1555-61, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23467992

RESUMO

Phytophthora root rot (PRR), caused by Phytophthora sojae Kaufmann & Gerdemann, is one of the most destructive diseases of soybean [Glycine max (L.) Merr.]. Deployment of resistance genes is the most economical and effective way of controlling the disease. The soybean cultivar 'Yudou 29' is resistant to many P. sojae isolates in China. The genetic basis of the resistance in 'Yudou 29' was elucidated through an inheritance study and molecular mapping. In response to 25 P. sojae isolates, 'Yudou 29' displayed a new resistance reaction pattern distinct from those of differentials carrying known Rps genes. A population of 214 F2:3 families from a cross between 'Jikedou 2' (PRR susceptible) and 'Yudou 29' was used for Rps gene mapping. The segregation fit a ratio of 1:2:1 for resistance:segregation:susceptibility within this population, indicating that resistance in 'Yudou 29' is controlled by a single dominant gene. This gene was temporarily named RpsYD29 and mapped on soybean chromosome 03 (molecular linkage group N; MLG N) flanked by SSR markers SattWM82-50 and Satt1k4b at a genetic distance of 0.5 and 0.2 cM, respectively. Two nucleotide binding site-leucine rich repeat (NBS-LRR) type genes were detected in the 204.8 kb region between SattWM82-50 and Satt1k4b. These two genes showed high similarity to Rps1k in amino acid sequence and could be candidate genes for PRR resistance. Based on the phenotype reactions and the physical position on soybean chromosome 03, RpsYD29 might be a novel allele at, or a novel gene tightly linked to, the Rps1 locus.


Assuntos
Resistência à Doença/genética , Genes de Plantas/genética , Phytophthora/patogenicidade , Doenças das Plantas/microbiologia , Soja/genética , Sequência de Aminoácidos , Sequência de Bases , China , Mapeamento Cromossômico , Análise por Conglomerados , Cruzamentos Genéticos , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Análise de Sequência de DNA , Homologia de Sequência , Soja/microbiologia , Virulência
19.
J Econ Entomol ; 100(4): 1450-5, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17849901

RESUMO

Laodelphax striatellus Fallén (Homoptera: Delphacidae), is a serious pest in rice, Oryza sativa L., production. A mapping population consisting of 81 recombinant inbred lines (RILs), derived from a cross between japonica' Kinmaze' and indica' DV85' rice, was used to detect quantitative trait loci (QTLs) for the resistance to L. striatellus. Seedbox screening test (SST), antixenosis test, and antibiosis test were used to evaluate the resistance response of the two parents and 81 RILs to L. striatellus at the seedling stage, and composite interval mapping was used for QTL analysis. When the resistance was measured by SST method, two QTLs conferring resistance to L. striatellus were mapped on chromosome 11, namely, Qsbph11a and Qsbph11b, with log of odds scores 2.51 and 4.38, respectively. The two QTLs explained 16.62 and 27.78% of the phenotypic variance in this population, respectively. In total, three QTLs controlling antixenosis against L. striatellus were detected on chromosomes 3, 4, and 11, respectively, accounting for 37.5% of the total phenotypic variance. Two QTLs expressing antibiosis to L. striatellus were mapped on chromosomes 3 and 11, respectively, explaining 25.9% of the total phenotypic variance. The identified QTL located between markers XNpb202 and C1172 on chromosome 11 was detected repeatedly by three different screening methods; therefore, it may be important to confer the resistance to L. striatellus. Once confirmed in other mapping populations, these QTLs should be useful in breeding for resistance to L. striatellus by marker-assisted selection of different resistance genes in rice varieties.


Assuntos
Hemípteros/fisiologia , Oryza/genética , Locos de Características Quantitativas , Animais , Mapeamento Cromossômico , Marcadores Genéticos , Endogamia , Oryza/parasitologia , Recombinação Genética
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