Meta-análise de Locos de Caracteres Quantitativos (QTL) para resistência à Magnaporthe oryzae em trigo

Abstract

Dated almost 10,000 years ago, the history of wheat (Triticum aestivum L.) follows that of humanity, being a fundamental food in the food chain. Although widely produced, several problems occur in its cultivation and the main obstacle, in several producing regions, is the incidence of the pathogen Magnaporthe oryzae. The current approach to overcome this obstacle is the use of genetic strategies developed by genetic breeding, where the use of genetic mapping is a promising option and has been used in the study of wheat diseases. However, what has been produced for this disease so far, are genotypes with at most moderate resistance, which have already been reported loss of resistance when subjected to more aggressive breeds. Thus, a meta-analysis was performed to consolidate Quantitative Trait Loci to wheat blast and highlight genetic characteristics of this cereal, that could be useful for breeders during the selection process of genetic plants with resistance to wheat blast. Using SNP, DART and SSR molecular marker maps, statistical analysis was applied with the LPmerge package to create a consensual map for each chromosome. Among the 30 QTL of unique lines reviewed, 29 QTL were designed covering 86,912 markers between chromosomes 1A, 2A, 2B, 3A, 4A, 4D, 5A, 5B, 6A and 7B. Some QTL stand out for acting in the resistance to the disease in two stages of the wheat plant development, in the seedling and heading phase, the case of QTL21 on chromosome 4B, QTL24 on 5A and QTL27 on 6A. Chromosome 2A showed the most promising QTL, being QTL5, QTL6, QTL7, QTL8 and QTL9.