Molecular mapping of the C locus for presence of pungency in Capsicum

Genome ◽  
2002 ◽  
Vol 45 (4) ◽  
pp. 702-705 ◽  
Author(s):  
Eyal Blum ◽  
Kede Liu ◽  
Michael Mazourek ◽  
Eun Young Yoo ◽  
Molly Jahn ◽  
...  

Pungency owing to the presence of capsaicinoids is a unique character of pepper (Capsicum spp.). Capsaicinoids are produced in the placenta and it has long been known that a single dominant gene, C, is required for pungent genotypes to produce capsaicinoids. We mapped C to pepper chromosome 2 in a cross between a pungent Capsicum frutescens wild accession and a non-pungent Capsicum annuum bell pepper. This position confirmed results from earlier studies. The RFLP marker TG 205 cosegregated with C and two additional RFLP markers were also located within 1 cM. The recessive allele at the C locus is used in breeding programs around the world focused on very diverse germplasm, hence any of these tightly linked markers may be of value as potential sources of useful markers for marker-assisted selection. To demonstrate this point, we developed a PCR-based CAPS (cleaved amplified polymorphic sequence) marker linked to C using the sequence of the Capsicum fibrillin gene located 0.4 cM from C. The use of molecular markers for high-throughput screening for the c allele in pepper breeding programs is discussed.Key words: pepper, pungency, marker-assisted selection.

2003 ◽  
Vol 54 (12) ◽  
pp. 1315 ◽  
Author(s):  
H. Raman ◽  
A. Karakousis ◽  
J. S. Moroni ◽  
R. Raman ◽  
B. J. Read ◽  
...  

Aluminium (Al) toxicity is one of the main factors restricting barley production in acidic soils. The utilisation of barley cultivars tolerant to Al is one of the most economic strategies for expanding barley production in these soils. Among barley genotypes, the cultivar Dayton has been reported to exhibit the highest level of Al tolerance. The gene conferring Al tolerance in Dayton, Alp, has been mapped to the long arm of chromosome 4H using RFLP markers. However, such markers are not useful for routine marker-assisted selection in breeding programs due to the cost and labour associated with their use. To increase the ease by which marker-assisted selection can be conducted for Alp, we sought to identify microsatellite markers linked to this gene. Several such markers that flank Alp were identified in a mapping population from a cross between Dayton and Harlan Hybrid. The most tightly linked microsatellite markers, HVM68 and Bmag353, flank Alp and are 5.3 cM and 3.1 cM from this locus, respectively. The linkage between Bmag353 and Alp was validated in a separate F3 population derived from the cross between Dayton and F6ant28B48-16, where this microsatellite marker was found to predict the Al tolerance phenotype with over 95% accuracy. Allele diversity for the 3 most tightly linked microsatellite markers was evaluated among 40 barley genotypes currently used in Australian barley breeding programs. The high levels of polymorphism detected among the genotypes with the markers indicated that the microsatellite markers, especially Bmag353 and Bmac310, will be broadly useful for marker-assisted selection of Alp in breeding programs seeking to improve Al tolerance.


HortScience ◽  
2010 ◽  
Vol 45 (9) ◽  
pp. 1407-1410 ◽  
Author(s):  
Longzhou Liu ◽  
Youyuan Chen ◽  
Zhenghong Su ◽  
Hui Zhang ◽  
Weiming Zhu

Melon production in China is threatened by cucurbit powdery mildew incited by Podosphaera xanthii, which can cause severe yield losses. Disease reactions of 10 melon P. xanthii race differentials indicated the presence of a unique race of P. xanthii, denoted pxCh1, in the Shanghai area. Resistance to P. xanthii race pxCh1 in melon PI 134198, which originated from India, was controlled by a single, dominant gene, designated Pm-8, in a cross with susceptible melon inbred S717. A search for a molecular marker linked to Pm-8 was initiated using the same cross. Bulk segregant analysis of their F2 progeny revealed one sequence-related amplified polymorphism (SRAP) marker of 148 bp linked to Pm-8, at 3.9 cM. The SRAP segment was recovered, cloned, and sequenced and converted into a sequence-amplified characterized region marker for marker-assisted selection of Pm-8 in breeding programs to develop melon cultivars resistant to P. xanthii race pxCh1.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nicole Pretini ◽  
Leonardo S. Vanzetti ◽  
Ignacio I. Terrile ◽  
Guillermo Donaire ◽  
Fernanda G. González

Abstract Background In breeding programs, the selection of cultivars with the highest yield potential consisted in the selection of the yield per se, which resulted in cultivars with higher grains per spike (GN) and occasionally increased grain weight (GW) (main numerical components of the yield). In this study, quantitative trait loci (QTL) for GW, GN and spike fertility traits related to GN determination were mapped using two doubled haploid (DH) populations (Baguette Premium 11 × BioINTA 2002 and Baguette 19 × BioINTA 2002). Results In total 305 QTL were identified for 14 traits, out of which 12 QTL were identified in more than three environments and explained more than 10% of the phenotypic variation in at least one environment. Eight hotspot regions were detected on chromosomes 1A, 2B, 3A, 5A, 5B, 7A and 7B in which at least two major and stable QTL sheared confidence intervals. QTL on two of these regions (R5A.1 and R5A.2) have previously been described, but the other six regions are novel. Conclusions Based on the pleiotropic analysis within a robust physiological model we conclude that two hotspot genomic regions (R5A.1 and R5A.2) together with the QGW.perg-6B are of high relevance to be used in marker assisted selection in order to improve the spike yield potential. All the QTL identified for the spike related traits are the first step to search for their candidate genes, which will allow their better manipulation in the future.


3 Biotech ◽  
2020 ◽  
Vol 10 (4) ◽  
Author(s):  
Hament Thakur ◽  
Salesh Kumar Jindal ◽  
Abhishek Sharma ◽  
Major Singh Dhaliwal

Genome ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 188-194 ◽  
Author(s):  
P. K. Subudhi ◽  
R. P. Borkakati ◽  
S. S. Virmani ◽  
N. Huang

The thermosensitive genetic male sterility (TGMS) system is considered to be a more efficient alternative to the cytoplasmic male sterility (CMS) system for hybrid rice. An F2 population from a cross between a TGMS mutant line (IR32364TGMS) and IR68 was used to map the TGMS gene tms3(t). Fertile and sterile bulks were constructed following the classification of F2 plants into true breeding sterile, fertile, and segregating fertile plants based on F3 family studies. From the survey of 389 arbitrary primers in bulked segregant analysis, four RAPD markers were identified in which three, OPF182600, OPB19750, and OPAA7550, were linked to tms3(t) in repulsion phase and one, OPAC3640, was linked to tms3(t) in coupling phase. The tms3(t) gene was flanked by OPF182600 and OPAC3640 on one side and by OPAA7550 and OPB19750 on the other side. All four markers were low-copy sequences and two of them (OPF182600 and OPAC3640) detected polymorphism when the markers were used to probe the genomic blots. Subsequently, OPAC3640 was mapped to the short arm of chromosome 6 using a mapping population available at IRRI. However, no RFLP markers from this region showed linkage to tms3(t) owing to the lack of polymorphism between the parents. All RAPD fragments were cloned and partially sequenced from both ends. Thus, PCR primers can be designed to develop PCR markers for marker-assisted breeding to facilitate the transfer of tms3(t) from one genetic background to another.Key words: bulked segregant analysis, gene tagging, marker-assisted selection, RAPD, TGMS.


Genome ◽  
1998 ◽  
Vol 41 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Ahmet Yildirim ◽  
Stephen S Jones ◽  
Timothy D Murray

The objectives of this study were to map and tag the previously undescribed eyespot resistance gene PchDv on chromosome 4V of Dasypyrum villosum in a wheat background. The 82 F2 plants used for mapping were produced from a cross between a susceptible\i wheat 'Yangmai-5' (4V(4D)) substitution line and a resistant wheat 'Chinese Spring' disomic addition line of chromosome 4V of D. villosum. Segregation for resistance and susceptibility among F2 plants was 3:1, indicating that resistance was controlled by a single dominant gene. PchDv mapped to the distal part of chromosome 4V and was bracketed by two RFLP markers, Xcdo949 and Xbcd588, in a 33-cM interval. This distance could not be reduced, owing to a lack of polymorphic loci in this region. Theoretically, double recombination in this region occurs in 3.3% of the individuals; therefore, 96.7% of the selected genotypes would have PchDv, with simultaneous selection for both flanking markers. Double recombination between the flanking markers was observed in 2 out of 82 (2.4%) F2 individuals.


Nativa ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 675
Author(s):  
Petterson Baptista da Luz ◽  
Alessandro Aparecido Brito dos Santos ◽  
Valdete Campos Ambrosio

O mercado de pimentas para fins ornamentais é um setor recém explorado, mas com grande potencial de crescimento no ramo de floricultura e paisagismo. As pimenteiras que possuem folhagem variegada, porte baixo, frutos com coloração variada em seus diferentes estádios de maturação, contrastando com as folhagens, já são utilizadas como plantas ornamentais, cultivadas e comercializadas em vasos. O presente trabalho teve como objetivo avaliar a variabilidade genética visando o potencial ornamental de acessos de Capsicum spp. através de modelos biométricos. Foram utilizados 55 acessos de Capsicum spp, e a caracterização morfoagronômica dos acessos foi realizada avaliando diferentes partes da planta. O terceiro par de correlações canônicas, com correlação de 0,51, associa plantas com área do dossel compacto-densa, com menor comprimento e largura de dossel e de pequeno porte, associado com folhagens estreitas e de pecíolo grande. Esta associação é vantajosa para ornamentação. Ficou evidenciada a presença de variabilidade genética na população, o que é bastante favorável ao melhoramento na medida em que a heterogeneidade genética possibilita a obtenção de ganhos por meio de seleção.Palavras-chave: pimenta; modelos biométricos; correlações canônicas; análise de trilha. GENETIC VARIABILITY FOCUSED ON ORNAMENTAL POTENTIAL OF A Capsicum spp. ACCESSION ABSTRACT: Pepper market for ornamental purposes is recently exploited; however, it has a great growth potential in floriculture and landscaping. Pepper with variegated foliage, small size, and varied fruit coloration at different ripening stages contrasting with leaves have already been used as ornamental plants cultivated and purchased as potted plants. This study aimed to evaluate genetic variability of Capsicum spp. focusing on its ornamental potential by means of biometric templates. Fifty-five Capsicum spp. accessions were used and a morpho-agronomic characterization of the accessions were performed by evaluating different plant parts. The third canonical correlations are 0.51 and it associates compact-dense, small, shorter length and width canopy plants with narrow foliage and large petiole, which is advantageous for ornamentation. Genetic variation was evidenced in the population being very favorable for plant breeding programs once genetic heterogeneity enables obtaining gains through selections.Keywords: pepper; biometric templates; canonic correlations; trail analysis.


2005 ◽  
Vol 95 (8) ◽  
pp. 884-889 ◽  
Author(s):  
Vihanga Pahalawatta ◽  
Xianming Chen

Most barley cultivars are resistant to stripe rust of wheat that is caused by Puccinia striiformis f. sp. tritici. The barley cv. Steptoe is susceptible to all identified races of P. striiformis f. sp. hordei (PSH), the barley stripe rust pathogen, but is resistant to most P. striiformis f. sp. tritici races. To determine inheritance of the Steptoe resistance to P. striiformis f. sp. tritici, a cross was made between Steptoe and Russell, a barley cultivar susceptible to some P. striiformis f. sp. tritici races and all tested P. striiformis f. sp. hordei races. Seedlings of parents and F1, BC1, F2, and F3 progeny from the barley cross were tested with P. striiformis f. sp. tritici races PST-41 and PST-45 under controlled greenhouse conditions. Genetic analyses of infection type data showed that Steptoe had one dominant gene and one recessive gene (provisionally designated as RpstS1 and rpstS2, respectively) for resistance to races PST-41 and PST-45. Genomic DNA was extracted from the parents and 150 F2 plants that were tested for rust reaction and grown for seed of F3 lines. The infection type data and polymorphic markers identified using the resistance gene analog polymorphism (RGAP) technique were analyzed with the Mapmaker computer program to map the resistance genes. The dominant resistance gene in Steptoe for resistance to P. striiformis f. sp. tritici races was mapped on barley chromosome 4H using a linked microsatellite marker, HVM68. A linkage group for the dominant gene was constructed with 12 RGAP markers and the microsatellite marker. The results show that resistance in barley to the wheat stripe rust pathogen is qualitatively inherited. These genes might provide useful resistance against wheat stripe rust when introgressed into wheat from barley.


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