Pea (Pisum sativum L.) in the Genomic Era

Abstract

Pea (Pisum sativum L.) was the original model organism used in Mendel's discovery (1866) of the laws of inheritance, making it the foundation of modern plant genetics. However, subsequent progress in pea genomics has lagged behind many other plant species. Although the size and repetitive nature of the pea genome has so far restricted its sequencing, comprehensive genomic and post genomic resources already exist. These include BAC libraries, several types of molecular marker sets, both transcriptome and proteome datasets and mutant populations for reverse genetics. The availability of the full genome sequences of three legume species has offered significant opportunities for genome wide comparison revealing synteny and co-linearity to pea. A combination of a candidate gene and colinearity approach has successfully led to the identification of genes underlying agronomically important traits including virus resistances and plant architecture. Some of this knowledge has already been applied to marker assisted selection (MAS) programs, increasing precision and shortening the breeding cycle. Yet, complete translation of marker discovery to pea breeding is still to be achieved. Molecular analysis of pea collections has shown that although substantial variation is present within the cultivated genepool, wild material offers the possibility to incorporate novel traits that may have been inadvertently eliminated. Association mapping analysis of diverse pea germplasm promises to identify genetic variation related to desirable agronomic traits, which are historically difficult to breed for in a traditional manner. The availability of high throughput 'omics' methodologies offers great promise for the development of novel, highly accurate selective breeding tools for improved pea genotypes that are sustainable under current and future climates and farming systems.

Legume Crops Phylogeny and Genetic Diversity for Science and Breeding

“…This level of precision is desirable if the key alleles of genes for important agronomic traits are to be identified, but broad characterization of diversity in germplasm can be based on a pooled DNA sample and phenotyping done on the bulked landrace mixture. Multi-environment analysis of quantitative variation involving multi-trait evaluation is far more informative than a single-environment trial and potentially provides some prediction for performance in other environments (Redden et al, 2012). The challenge for gene bank curators is to strategically sample collections and maximize information from costly evaluation trials.…”

“…For cultivated pea, nuclear genome size estimates have been produced for several accessions using different methods and are estimated to be 1C = 4.4 to 4.8 pg DNA corresponding to the haploid genome size (1C) of 4.45 Gb, with a large part (75 to 97%) comprised of repetitive sequences (reviewed in Smýkal et al, 2012).…”

Assessment of field pea (Pisum sativum L.) grain yield, aerial biomass and flowering date stability in Mediterranean environments

“…In field conditions, the development of pea genotypes producing high and stable seed yield is most decisive (Cousin, 1997;Rubiales et al 2011;Smýkal et al 2012), albeit high biomass and a short phenological cycle are also generally desired characters (Hebblethwaite et al 2013). A good approach to study grain yield, aerial biomass and flowering date under field conditions is given by the use of statistic models.…”

“…Asch. and Graebn can still be found growing today (Rubiales et al 2011; and where pea once played a very important role in human diets, as witnessed by the first attested ancient DNA extraction from any legume species Medović et al 2011).In field conditions, the development of pea genotypes producing high and stable seed yield is most decisive (Cousin, 1997;Rubiales et al 2011;Smýkal et al 2012), albeit high biomass and a short phenological cycle are also generally desired characters (Hebblethwaite et al 2013). A good approach to study grain yield, aerial biomass and flowering date under field conditions is given by the use of statistic models.…”

Genetic diversity of Albanian pea (Pisum sativum L.) landraces assessed by morphological traits and molecular markers

“…The total world grain production fluctuates 10-12 million tons, with Canada as the leading producer, followed by USA, India, Russia, France and China (Smýkal et al 2012). Up to half of the area sown by pea is used for production of vegetables, green snap pea pods, green seed for fresh vegetables (fresh, frozen or canned), green leaves and for direct livestock grazing.…”