Seleção assistida por marcadores de clones de batata com os alelos de resistência aos vírus PLRV, PVY e PVX

Abstract

Potato’s low productive potential (Solanum tuberosum L.) in Brazil is due to the tropical climate since the crop produces better in a climate with a milder temperature. The Brazilian climate contributes to the spread of diseases, especially those of a viral nature. There are three economically important viruses for the crop: Potato leafroll virus (PLRV), Potato virus Y (PVY) and Potato virus X (PVX). Breeding programs seek genetic resistance to these viruses through molecular techniques in order to benefit the national productive chain. This work was carried out with the objective of generating clones and detecting the simultaneous presence of Rladg, Ryadg and Rx1 alleles, which confer resistance to PLRV, PVY, and PVX, respectively, by means of molecular markers. Crosses were made in the form of a partial diallel between materials called OGC (presenting the Rladg allele) and MLG (presenting the Ryadg and Rx1 alleles) of the UFLA’s Potato Planting Breeding Program, with a total of twelve families, designated as RPC. A field trial with the first clonal generation was conducted in the winter crop in Lavras/2018. The experiment was carried in an augmented block design, with plots of one meter long containing three plants. As common treatments, the cultivars Agata, Asterix, Taurus, and Cupido were used. The clones have gone through mass selection for tuber appearance, evaluation of the agronomic characteristics and then submitted to the identification of the presence of the Rladg allele. The clones that presented this allele, in addition, were submitted to the analysis of the presence of the other alleles, Ryadg and Rx1 that confer resistance to PVY and PVX. The data were submitted to the individual analysis of variance and averages clustered by Scott & Knott test (5% probability level). The clones RPC 01-06, RPC 03-18, RPC 08-21 and RPC 09-05, possessing the Rladg and Ryadg alleles which confer resistance to the PLRV and PVY viruses, respectively, were selected. Two of them (RPC 03-18 and RPC 09-05) also presented the Rx1 allele, which confers resistance to PVX.