Genetic components of potato chip quality evaluated in three environments and under various storage regimes

Abstract

A diallel series of crosses was made between parents with good processing quality and nonprocessing but well-adapted varieties and breeding clones to study the inheritance of chipping quality and tuber yield in potatoes. The progeny of the crosses were assessed in three widely differing growing environments and chipped from a range of storage environments. Principal component analysis for chip color indicated that the first (PCA1) and second (PCA2) principal components accounted for 84.4 and 5.0% of the total variability, respectively. PCA1 scores were highly correlated (P < 0.01) with the mean chip color scores of the 20 crosses measured over the 11 environments, whereas PCA2 scores were highly correlated (P < 0.01) with the standard deviations of the chip scores over storage environments. These results provide new information that supports the recently proposed concept of two genetically independent systems determining chip color, i.e., "overall chipping quality" and "chipping stability". Highly significant (P < 0.01) general combining-ability and nonsignificant specific combining-ability effects suggest additive genetic factors and high narrow-sense heritability for specific gravity. Combining-ability effects for yield traits were generally nonsignificant, which probably reflects the selection of parents with proven breeding value.Key words: Solanum tuberosum, stability, yield, specific gravity