Expressão gênica de MADS-box relacionados a dormência de pereiras na região Sul do Brasil

Abstract

The pear represents a market opportunity, however, problems related to the vigor of the plant, type of rootstock, floral abortion, insufficient cold, lack of cultivars adapted to edaphoclimatic conditions, difficulties with management, among others, prevent the expansion of the crop in Brazil. Considering the difficulties of the production chain and the climatic conditions of the Southern region of the State of Rio Grande do Sul, the present study aimed to evaluate the expression of the PpDAM13-1 and PpDAM13-2 genes, which are related to dormancy, during the months from June to September 2018. For the experiment, plants of Pyrus pyrifolia (Japanese pear), cultivars Hosui and Nijisseiki, and Pyrus communis (European pear), cultivars Rocha and Santa Maria, from experimental orchards at the Federal University of Pelotas (UFPel) were used. Buds were collected from June to September and the gene expression was evaluated in RT-qPCR. The results showed that the expression of the PpDAM13-1 and PpDAM13-2 genes occurred in the four cultivars evaluated, confirming that the expression decreases according to the progression of dormancy. The cultivar Hosui for both genes and the cultivar Nijisseiki for PpDAM13-2 had high expression in the first collection, held in June, while the others cultivars showed higher values of expression between collection two and three, corresponding to the beginning and end of July. Some expression fluctuations were also observed, possibly due to temperature instability in the evaluated months. It was concluded that the expression analysis of the PpDAM13-1 and PpDAM13-2 genes can be used to asses dormancy in the evaluated conditions, with the first gene showing higher expression values.