Parental effects on leaf traits and correlation with yield in inter-specific backcross hybrids of Jatropha

Abstract

Selection of parental lines is an important role to Jatropha breeding. Furthermore, leaf traits might be used in selection for high yield of hybrid Jatropha. The objectives of this investigation were 1) to study the effect of parental lines to leaf and yield traits, and 2) to evaluate the relationships between leaf and yield traits in inter-specific backcross hybrids of Jatropha. Total 45 crosses of inter-specific backcross hybrids between Jatropha curcas and J. integerrima were developed from 5 female lines and 9 male lines. All of hybrids were evaluated in field trials. Data were collected for SPAD chlorophyll meter reading (SCMR), specific leaf area (SLA), leaf area average, leaf weight average and yield traits. Although the effect of female line was found on leaf and yield traits of offspring, effect of male line was not found. Moreover, effect of crosses was also found on leaf and yield traits of hybrids. There were strong negative correlation between SCMR and SLA (r = -0.73** and -0.75**), indicating SCMR could be used as a surrogate measurement of SLA. In addition, there were significant correlation between yield traits with SCMR (r = -0.36* to -0.72**), SLA (r = 0.33* to 0.66**), leaf area average (r = 0.37* to 0.69**) and leaf weight average (r = 0.33* to 0.38**). This finding suggests that these leaf parameters could be used as indirect evaluation for high yield potential of hybrid Jatropha selection.