VARIABILITY, CHARACTER ASSOCIATION AND PATH ANALYSIS OF YIELD AND YIELD RELATED TRAITS IN SWEET POTATO (Ipomoea batatas (L.) LAM.)

Abstract

An experiment conducted to study the genetic variability and inheritance based on different yield contributing traits of sweet potato genotypes in Sher-E-Bangla Agricultural University, Dhaka-1207, and Bangladesh during Rabi season (2015). Among the analyzed genotypes, G1 (IB001) showed the best performance having variation in fourteen traits followed by G4 (IB004), G2 (IB002) and G3 (IB003). The Highest range of variation was observed in individual root weight (375.0- 614.50) g with the highest average mean of 459.92 g. Narrow gap between GCV and PCV was found in ten characters, leaf areal above-ground dry matter content, root number per plant, root length, individual root weight, root fresh yield per plant, root dry matter content, root dry yield per plant, root fresh yield per plot and root fresh yield per hectare suggesting minor environmental influence on gene expression controlling those traits. High heritability coupled with high genetic advance in percent of mean was observed in many traits, viz., vine length, leaf area, above ground fresh weight per plant, above ground dry weight per plant, root number per plant, root length, root diameter, individual root weight, root fresh weight per plant, root dry matter content, root dry yield per plant, root fresh yield per plot and root fresh yield per ha explaining high heritable nature. Heritability of these traits is most likely due to additive gene effects. This study serves wide opportunity for improvement through effective selection of these traits in early generation. The highly significant positive correlation with yield per hectare was observed with vine internode diameter, leaf area, above ground fresh weight per plant, root number per plant, root length, root diameter, individual root weight, root fresh yield per plant, root dry matter content, root dry yield per plant and root fresh yield per plot. Path co-efficient analysis indicated that all the characters except vine length, vine internode diameter, leaf area, above ground dry matter content, root diameter and root fresh yield per plant had the direct positive effect on yield. The positive significant indirect effect was also found by above-ground dry matter content on yield per plot.