Development and validation of breeder-friendly KASPar markers for er1, a powdery mildew resistance gene in pea (Pisum sativum L.)

Authors: MA, YU - Washington State University; Coyne, Clarice - Clare; MAIN, DOREEN - Washington State University; PAVAN, STEFANO - University Of Bari; SUN, SULI - Chinese Academy Of Agricultural Sciences; ZHU, ZHENDONG - Chinese Academy Of Agricultural Sciences; ZONG, XUXIAO - Chinese Academy Of Agricultural Sciences; LEITAO, JOSE - Universidade Do Algarve; McGee, Rebecca

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2017
Publication Date: 11/21/2017
Citation: Ma, Y., Coyne, C.J., Main, D., Pavan, S., Sun, S., Zhu, Z., Zong, X., Leitao, J., McGee, R.J. 2017. Development and validation of breeder-friendly KASPar markers for er1, a powdery mildew resistance gene in pea (Pisum sativum L.). Molecular Breeding. 37:151. https://doi.org/10.1007/s11032-017-0740-7.
DOI: https://doi.org/10.1007/s11032-017-0740-7

Interpretive Summary: Powdery mildew is a common disease of pea (Pisum sativum L.) with worldwide distribution and can result in yield losses up to 50%. It is particularly prevalent in areas with a warm, humid climate. The first symptoms usually appear on the lowest part of the plant, with small, but distinct, spots on the leaflets. Later, these lesions grow, covering the plant surfaces and affecting the growth of the plant and the quality of harvested seeds. Given the high cost and detrimental environmental impacts associated with fungicide use, the use of powdery mildew resistant cultivars is a sustainable, efficient, and environmentally friendly method to control this disease. Marker-assisted breeding (MAB), based on DNA markers linked to loci or genes controlling phenotypes of interest, is routinely used in many crops to select for desired characteristics in the early stages of plant growth and facilitate cultivar improvement. Among DNA marker types, SNP markers are considered the ideal choice for geneticists and breeders with advantages of co-dominance, low-cost, high-throughput, and automation. In this study, eight breeder-friendly kompetitive allele-specific PCR (KASPar) markers were developed to increase the efficiency for breeding for resistance to powdery mildew in pea.

Technical Abstract: Powdery mildew of pea is caused by Erysiphe pisi DC and is a serious threat to pea (Pisum sativum L.) production throughout much of the world. Development and utilization of genetic resistance to powdery mildew is considered an effective and sustainable strategy to manage this disease. One gene, er1, conferring powdery mildew resistance, was previously cloned and sequenced, and the functional markers for each resistance allele were reported. Allele-specific DNA markers are efficient and powerful tools to facilitate crop improvement and new cultivar development in breeding programs. However, extensive application of these markers is limited by gel-associated obstacles. In this study, eight breeder-friendly kompetitive allele-specific PCR (KASPar) markers were developed to overcome the problems of gel-based markers and increase the efficiency of genotypic screening. In order to identify additional pea germplasm with powdery mildew resistance, these KASPar markers were deployed and used to genotype a pea collection derived from the USDA pea single-plant (PSP) collection. Simultaneously, a phenotypic screening and a genotypic validation using the corresponding gel-based functional markers were conducted on the PSP collection. One pea accession, PI 142775, was identified by both phenotyping and genotyping to carry the allele er1-1 for powdery mildew resistance, indicating the KASPar assay is an efficient and robust tool for breeding for powdery mildew resistance.