Identification of Selection Criteria for Improving Potato Yield Using Genotypic Path Coefficient Analysis under Multi-Location Field Conditions in Iraq

• Sawsan F. Fawaz1*

  Author

A field experiment was conducted in the spring season of 2023 by planting eight potato genotypes (3P29, 3P30, 3P31, 3P32, 3P35, 3P33, 3P34, and 3P36) in a Randomized Complete Block Design (RCBD) with three blocks in three locations: Bazian in Sulaymaniyah, Bardarash in Erbil, and Al-Qubba in Mosul. The aim was to determine the genotypic path coefficient of traits on total yield to determine the best criterion for selection. A set of growth and yield traits were studied. The path coefficient analysis results indicate that the number of marketable tubers showed the highest and most significant genetic correlation with total yield. It also exhibited a very high positive indirect effect on total yield through the number of main stems. Moreover, the number of main stems was highly and significantly correlated with total yield and showed a very high positive direct effect. These traits therefore represent key selection criteria that can be adopted in breeding programs to improve the productivity of the potato genotypes under study in Sulaymaniyah Governorate. The traits of tuber dry weight and number of main stems were among the most important traits at the Erbil location, as they recorded the highest genetic correlation and the highest positive indirect effect through tuber weight. Therefore, emphasis should be placed on these traits in selection, as they represent effective selection indicators for improving total yield. The traits of tuber dry weight and number of main stems were among the most important traits at the Mosul location, as they recorded the highest genetic correlation and the highest positive indirect effect through tuber weight. Therefore, they can be considered key selection criteria in breeding and improvement programs at this location.

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