Recovery of Valencia Groundnut (Arachis hypogaea L.) Traits in Early Segregating and Promising Late Leaf Spot Resistant Populations

Abstract

Abstract. In Uganda, there are no Valencia varieties that are resistant to leaf spot diseases. Introgression of
resistance genes into elite lines is always associated with the transfer of undesirable traits from the donor
parents. Knowledge of the degree of genetic relationship provides breeders with a more efficient way to
identify populations of potential relevance for their plant improvement programs. The objective of this study
was to determine the recovery of Valencia groundnut traits in the early segregating and promising late leaf spot
(LLS) resistant populations. Four crosses between Valencia lines (P1) and donor lines (P2) were made. The
populations that included F1, F2, BC1P1 and BC1P2, together with their parents (P1and P2) of each of the
four crosses namely, Valencia C (P1) × ICGV-SM 02501 (P2), Valencia C (P1) × SGV-07009 (P2), NuMexM3 (P1) × ICGV-SM 02501 (P2) and Redbeauty (P1) × ICGV-SM 03590 (P2) were evaluated. Cluster
analysis revealed differences among the generations for the traits analysed with major and sub-clusters,
implying that the generations of crosses formed a genetically diverse population that offers possible
opportunity for selection. In the cross between NuMex-M3 X ICGV-SM 02501, the populations BC1P1 and
F2, exhibited higher (80 %) recovery of the recurrent parental (NuMex-M3) traits. Similarly, the backcross
population (BC1P1) to the susceptible elite variety of the Valencia C X ICGV-SM 02501 cross recovered
approximately 75% of the recurrent parental traits Valencia C with lower LLS disease score. Such populations
could result in higher gain in Valencia traits and LLS resistance when utilized the breeding program. For
maximum gain in LLS resistance and recovery of Valencia traits, more selfing and backcrossing can be
performed to fix the genes for LLS resistance as well those of Valencia characteristics