Correlation and path coefficient analysis for total soluble solids in tomato (Lycopersicon esculentum Mill) fruit

Abstract

Path coefficients are standardized versions of linear regression coefficients that can be used  in partitioning correlation coefficients into direct and indirect effects of various traits towards dependent variable. This study was carried out in the years 2014 and 2015 at the
Laboratory of the Department of Food Science and Technology, Federal University of Agriculture, Abeokuta, to investigate the relationship of some processing quality traits of tomato and their contributions to Total Soluble Solids (TSS), a vital trait in the tomato
processing industry. Tomato fruits on which the processing quality traits were evaluated were derived from plants cultivated at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta, Nigeria. Pearson‟s correlation analysis and Path
coefficient analysis were carried out to examine relationships between traits and describe the effects of traits measured on TSS. Positive and highly significant correlations were observed between Total Soluble Solids (TSS) and pH, lycopene content and vitamin C while moisture content and titrable acidity had negative and highly significant correlation with TSS. Vitamin C content and pH showed positive and direct effects on TSS, while fruit firmness, moisture content, titratable acidity and lycopene content had direct but negative effect on TSS. Vitamin C content had the highest direct effect on TSS. It is concluded that an effective selection for high TSS in tomato fruit would not single out any of the traits with direct effects on TSS, rather screening of tomato genotypes using a combination of these traits as selection indices is recommended for tomato fruits total soluble solids.

Keywords: Beske, Direct effect, Lycopene, Processing quality, Roma VF and Total Soluble Solids