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Phenotypic stability of potato (Solanum tuberosum L.) cultivars grown under different environmental conditions in the Southern Region of the State of Minas Gerais, Brazil^*

Ronan Gualberto; César Augusto Brasil Pereira Pinto

Departamento de Biologia, Escola Superior de Agricultura de Lavras, Caixa Postal 37, 37200-000 Lavras, MG, Brasil. Send correspondence to C.A.B.P.P.

ABSTRACT

We evaluated the phenotypic stability of 14 potato cultivars (Achat, Agria, Apuã, Baraka, Baronesa, Bintje, Bronka, Clarissa, Dunja, Frisia, Itararé, Monalisa, Radosa, and Ruta) for marketable tuber yield and its components (number of marketable tubers per plot and mean tuber weight). The contribution of environmental effects to the genotype x environment interaction was also evaluated. Trials were carried out in nine environments (locations, years and planting dates) in a fully randomized block design with four replications. The cultivars Bronka, Monalisa and Clarissa were the most stable for marketable yield. Cultivars Baraka, Bronka and Monalisa were the most stable for mean marketable tuber weight. Bintje and Achat, which are among the three cultivam most frequently planted in the region, proved to be highly unstable both for yield and for mean tuber weight. For number of marketable tubers per plot, the regression model was not satisfactory to evaluate the phenotypic stability of cultivam due to the low values for the determination coefficients (average r² - 0.47). Among the environmental effects that contributed to the genotype x environment interaction, planting date was more important than location and the effect of location was greater than years. Mean marketable tuber weight was the trait least affected by genotype x environment interaction.

Keywords: phenotypic; potato; cultivars grown; environmental conditions.

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* Part of a thesis presented by R.G. to Escola Superior de Agricultura de Lavras (ESAL) in partial fulfillment of the requirements for the Master's degree.