Identification of QTL for resistance and susceptibility to Stagonospora meliloti in autotetraploid lucerne

Musial, J. M.; Mackie, J. M.; Armour, D. J.; Phan, H.; Ellwood, Simon R.; Aitken, Karen S.; Irwin, J. A. G.

doi:10.1007/s00122-007-0528-y

Cited by 25 publications

(23 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These complexities, and especially the fact that allele dosage is typically not known for certain, challenge genetic linkage map construction for autotetraploid alfalfa. The software "TetraploidMap" [67] can incorporate both dominant (including simplex and duplex markers) and co-dominant markers into linkage maps (Table 1) [37,54,68]. …”

Section: Genetic Linkage Map Constructionmentioning

confidence: 99%

“…Major QTL related to yield and morphological traits [37,38], fall dormancy and winter-hardiness [69,70], persistence [71], viability [53], self-fertility [72], resistance to Stagonospora melioti [68], resistance to C. trifolii [73], aluminum tolerance [57,74] and water use efficiency [75] have been mapped in alfalfa, primarily in tetraploid populations (Table 1). Several factors potentially limit the precision and power of mapping in tetraploid alfalfa.…”

Section: Characteristics Of Alfalfa Genetic Linkage Mapsmentioning

confidence: 99%

See 1 more Smart Citation

Applied Genetics and Genomics in Alfalfa Breeding

2012

View full text Add to dashboard Cite

Alfalfa (Medicago sativa L.), a perennial and outcrossing species, is a widely planted forage legume for hay, pasture and silage throughout the world. Currently, alfalfa breeding relies on recurrent phenotypic selection, but alternatives incorporating molecular marker assisted breeding could enhance genetic gain per unit time and per unit cost, and accelerate alfalfa improvement. Many major quantitative trait loci (QTL) related to agronomic traits have been identified by family-based QTL mapping, but in relatively large genomic regions. Candidate genes elucidated from model species have helped to identify some potential causal loci in alfalfa mapping and breeding population for specific traits. Recently, high throughput sequencing technologies, coupled with advanced bioinformatics tools, have been used to identify large numbers of single nucleotide polymorphisms (SNP) in alfalfa, which are being developed into markers. These markers will facilitate fine mapping of quantitative traits and genome wide association mapping of agronomic traits and further advanced breeding strategies for alfalfa, such as marker-assisted selection and genomic selection. Based on ideas from the literature, we suggest several ways to improve selection in alfalfa including (1) diversity selection and paternity testing, (2) introgression of QTL and (3) genomic selection.

show abstract

Section: Genetic Linkage Map Constructionmentioning

confidence: 99%

Section: Characteristics Of Alfalfa Genetic Linkage Mapsmentioning

confidence: 99%

Applied Genetics and Genomics in Alfalfa Breeding

2012

View full text Add to dashboard Cite

show abstract

“…Extensive research has been performed to identify markers associated with the desirable traits in crops. For the autotetra-ploid alfalfa, markers associated with disease resistance Irwin et al, 2006;Mackie et al, 2007;Musial et al, 2005Musial et al, , 2007 and yield (Brouwer et al, 2000;Musial et al, 2006) have already been discovered.…”

Section: Introductionmentioning

confidence: 99%

Association of AFLP and SCAR markers with common leafspot resistance in autotetraploid alfalfa (Medicago sativa)

Wang¹,

Bi²,

Yuan³

et al. 2012

Genet. Mol. Res.

View full text Add to dashboard Cite

ABSTRACT. To identify amplified fragment length polymorphism (AFLP) markers associated with resistance or susceptibility of alfalfa to common leafspot (CLS) caused by the fungus Pseudopeziza medicaginis (Dermateaceae), bulked segregant analysis was conducted based on an F 1(M × M) population of 93 plants and a BC 1 S population of 91 plants. Three AFLP markers, ACTCAA R206 , TAGCAC R185 , and GGACTA S264 , were found to be associated with CLS resistance or susceptibility. All three markers were found at significantly different frequencies (71.9, 80.3 and 91.8%) compared to resistant or susceptible plants in the original population. Subsequently, these three AFLP markers were converted into three SCAR markers, ACTCAA R136 , TAGCAC R128 and GGACTA S254 , which are easier to employ in breeding programs. The three SCAR markers were used in a randomly selected population with 50% resistance; the probability of finding one resistant plant was increased to 67.3, 66.7 and 90.0% with markers ACTCAA R136 , TAGCAC R128 and GGACTA S254 , independently. If two of the SCAR markers were used simultaneously, the probability would be higher than 89%. The three SCAR markers identified in this study would be applicable for selection for CLS resistance in alfalfa breeding programs. Moreover, the genetic analysis indicated that CLS resistance in alfalfa is conferred by a single dominant gene.

show abstract

“…The predominant markers used for genetic investigations include PCR-based codominant, simple-sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers and to a lesser extent restriction fragment 4 length polymorphism (RFLP) markers (Brouwer and Osborn 1999;Brummer et al 1993;Julier et al 2003; Kiss et al 1993;Musial et al 2007). Genome-wide association arrays utilising high-density chips to detect single nucleotide polymorphisms, or hybridisation arrays have been developed for M. sativa genetic investigations, with the first reports on their use appearing in 2012 (Li 2012).…”

Section: Molecular Tools Available For Lucerne Genetics and Breedingmentioning

confidence: 99%

“…M. truncatula has a fully sequenced and annotated genome and its genetics is supported by an extensive research network (Young et al 2005). Both Medicago species share the same base chromosome number (n=8) and due to the close synteny, molecular markers developed in one species will generally map to the corresponding region of the same chromosome in the other (Julier et al 2003;Musial et al 2007;Robins et al 2007a). …”

Section: Molecular Tools Available For Lucerne Genetics and Breedingmentioning

confidence: 99%

Development and validation of molecular markers for Phytophthora medicaginis resistance in lucerne

Armour¹

View full text Add to dashboard Cite

Lucerne (Medicago sativa ssp. sativa L.) is one of the most important forage legumes worldwide, and Australia's most valuable perennial forage legume. Phytophthora root rot, caused by the oomycete pathogen Phytophthora medicaginis is a lethal disease of lucerne in Australia and America. The disease is a major productivity constraint when cultivars without adequate resistance levels are grown in conditions conducive to high disease pressure. The research presented here examined Phytophthora resistance in lucerne genotypes selected from Australian cultivars, however the findings are of relevance worldwide due to the extensive use of international (USA) germplasm in Australian lucerne breeding programs in particular.A broad-based synthetic approach, first described in1942, has been the most commonly used process in lucerne breeding. However, this approach presents an inherent set of limitations which are highlighted by the yield plateau observed in lucerne in the absence of disease and pest pressures.Improved breeding strategies have been proposed to address the limitations of the current approach and the constraints imposed by lucerne biology. These improved breeding strategies utilise synthetics based on far fewer parents than are currently being used, providing greater possibilities for making genetic gain for multiple quantitatively inherited traits.However, a paucity of information exists on the number, genomic location and diversity of P. medicaginis resistance loci available in the M. sativa gene pool for breeding Phytophthora resistant lucerne. This information would underpin selection of parental genotypes in narrow-based breeding schemes aimed at addressing the current yield stagnation in lucerne. One previous report described the mapping of Phytophthora resistance loci in the lucerne genotype W116, however the molecular marker systems employed did not enable chromosome number assignment to the linkage groups generated, and the markers have limited comparative mapping potential. The research presented here sought to address the current knowledge gap in the lucerne-Phytophthora pathosystem. It determined the genetic basis for P. medicaginis resistance in lucerne clone WA272 by assigning chromosome locations to the resistance loci identified and generated an alignment of the resistance loci identified with those in W116.An autotetraploid mapping population of 182 individuals was generated and phenotyped for P. medicaginis reaction using established inoculation procedures. The population was genotyped using SSR markers from existing M. sativa and M. truncatula genetic linkage maps. Large effect QTLs iii for resistance to P. medicaginis were detected in the WA272 x D mapping population, and using the linkage map developed, these were located to WA272 linkage groups 2, 5, 6 and 7. The large effect QTL identified on linkage groups 2 and 6 through interval mapping, and the best single markers from linkage groups 5 and 7 collectively explained 94%, 92% and 76% of the phenotypic variation for the cotyledon...

show abstract

Identification of QTL for resistance and susceptibility to Stagonospora meliloti in autotetraploid lucerne

Cited by 25 publications

References 37 publications

Applied Genetics and Genomics in Alfalfa Breeding

Applied Genetics and Genomics in Alfalfa Breeding

Association of AFLP and SCAR markers with common leafspot resistance in autotetraploid alfalfa (Medicago sativa)

Development and validation of molecular markers for Phytophthora medicaginis resistance in lucerne

Contact Info

Product

Resources

About