Pyramiding novel genes for resistance to ascochyta blight from Pisum fulvum into field pea through molecular breeding

Overview
2009 to 2013

Ascochyta blight caused by Mycosphaerella pinodes (MP) is the most important pea disease in Canada and most pea growing regions in the world, often causing serious yield losses. Genetic resistance to ascochyta blight accumulated through two decades of breeding reduces disease severity, however, under cool, wet conditions, the resistance is not sufficient to prevent economic losses.  Some accessions of Pisum fulvum, a wild relative of field pea, possess a high level of resistance to ascochyta blight. This project was designed to initiate a long-term strategy for enhancement of ascochyta blight resistance in pea using an integrated genetic improvement approach through interspecific hybridization, careful phenotyping and molecular genotyping.

P. fulvum and several P. sativum subspp. elatius, transcaucasicumasiaticum, arvense and abyssinicum accessions obtained from USDA, Pullman, WA and IFAPA, Spain were evaluated.  Based on greenhouse and field experiments, 4 wild accessions namely, PI 344538 (P. sativum ssp. elatius), PI 560061 (P. fulvum), W6 15017 (P. fulvum) and P 651 (P. fulvum) were identified with substantially greater resistance than cultivar checks.  These accessions were crossed with the susceptible check cultivar Alfetta (P. sativum) and ‘inter-crosses’ were made among the four wild accessions to pyramid genes for resistance.  Crossed populations are currently in the F4 generation, and intercross populations are in the F3 generation. F6 recombinant inbred lines (RILs) generated using single seed descent from one or more of the four crossed populations, and F2-derived F4 families from the six intercross populations will be evaluated for ascochyta blight resistance in the field in summer 2012. RILs will be used for quantitative trait locus (QTL) analysis to identify markers for resistance. To obtain a preliminary indication of ascochyta blight resistance, populations were developed from backcrosses between F1 (wild parent × Alfetta) X Alfetta. These backcrossed populations (BC1F1) along with parents, F1 and F2-derived F3 families will be tested for resistance in the greenhouse in early 2012. Germplasm derived from introgression of improved ascochyta blight resistance from the wild pea accessions will serve as a resource to pea breeders attempting to increase durability of resistance and increase yield potential.

Research Area
Breeding & Genetics

Plant breeding is the art and science of changing the traits of plants in order to produce desired characteristics. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular techniques. ... [more]

 
Pathology

In the Pulse Crop Pathology Group we are interested in the biology of fungal and bacterial pathogens and their interaction with the legume host plants. The ultimate goal is to gain a better understanding of strategies employed by these pathogens to successfully invade and colonize pulse crops, and to explo ... [more]

 
Related Species

Pea (Pisum sativum L.) is one of the first domesticated crops, and was the model crop for the foundational genetic studies by Gregor Mendel, which he first reported in 1865. Pea is grown in most temperate regions of the world with annual production over the past decade of 10-12 million tonnes of field pea and 14-17 million tonnes of vegetable pea. Pea belongs to the Leguminosae family and consists of two species, P. fulvum and P. sativum with several ‘wild’ subspecies of P. sativum. Canada is the leading producer and exporter of field pea in the world. Saskatchewan is the leading province in pea production followed by Alberta and Manitoba. ... [more]

 
Sequences, Variants & Markers