STABILITY OF TUBER YIELD OF POTATO GENOTYPES (SOLANUM TUBEROSUM L.)

Abstract

In the Mexican Highlands and mountain ranges there are serious problems in the supply of potato seed (Solanum tuberosum L.) of good quality for high yielding and stable varieties. The identification of genotypes bearing these characters might be a very important solution for these problems. In this study we estimated the tuber yield and stability of 10 potato genotypes by means of 11 univariate methods. The genotypes were evaluated in a randomized complete block design with four replications in each environment. Statistical significance (P ≤ 0.01) for environments (E), genotypes (G), and G x E interaction was found. The tuber yield averaged over five environments ranged from 13.28 to 25.04 t ha^-1. The genotypic stability parameter λ_i of Tai classified the genotypes in similar order that Wricke’s ecovalence (W_i), Shukla’s stability (σ_i² ), Huehn’ s nonparametric measures (S_i⁽¹⁾ and S_i⁽²⁾) and Eberhart and Russell’s stability parameters. The correlations of parameters α_i with b_i , λ_i with Sd_i , W_i with σ_i² , and S_i⁽¹⁾ with S_i⁽²⁾, were almost 1(r ≥ 0.99). The Francis and Kannenberg’s coefficient of variation, and Lin and Binns’ superiority measure for cultivar, allowed to identify varieties ‘Gigant’ and 776943 as high yielding and stable genotypes, while the method of Lin and Binns included the varieties ‘Alpha’, 750660 y 779040 into this group.