Association analysis for yield and yield contributing components in potato, Solanum tuberosum

Correlation and path analysis studies are of considerable importance in breeding programme. In present study a set of fifty two potato genotypes based on fourteen yield attributing characters were included. The marketable tuber yield/plot showed a significant and positive association with weight of tubers/plant, total tuber weight/plot, number of leaves/plant 45 days after planting (DAP) and at maturity, number of marketable tubers/plant and number of unmarketable tubers/plant. Thus improvement in marketable tuber yield of potato can be ascertained by direct selection for these traits. Path coefficient analysis revealed that number of marketable tubers/plant, number of leaflets/leaf at 45 DAP, number of unmarketable tubers/plant, plant height at flowering stage, number of leaves/plant at maturity and plant emergence had high positive and direct influence on marketable tuber weight. Thus direct selection for these traits would be worthwhile. The genotypic path analysis also indicated that biological yield and harvest index showed positive and significant correlation. Therefore these characters are more important than other traits for the genetic improvement of potato. Genotypic correlation coefficient was found to be higher in magnitude than that of phenotypic correlation coefficient which clearly indicated the presence of inherent association among various characters. Tuber yield was positively correlated with plant height, biological yield, harvest index and big tuber percentage at both the phenotypic and genotypic levels. In contrast it was negatively correlated with small and medium tuber percentage at both levels.