Characterization of guava (Psidium guajava L.) germplasm through morphological traits and SCoT markers

Traditional breeding programmes have been limited to the selection and introduction of genotypes with promising agronomic characteristics, but studies focused on genetic diversity in the low hills of the North West(NW) Himalayas have not been conducted, which is very important for the identification of potential parents for breeding programmes in guava. In the present study, six best performing guava cultivars/hybrids were characterised using morphological descriptors and SCoT markers. Broad phenotypic variability among the guava cultivars/hybrids was detected using morphological descriptors. A set of 36 SCoT markers were used for polymorphism, out of which 31(86.1%) markers showed polymorphism, indicating high genetic variability in the guava cultivars/hybrids. During the analysis, 291 polymorphic amplicons were obtained, ranging from four to 19, with an average of 9.4 amplicons per primer and average polymorphic information content of 0.47.The UPGMA classified hybrids and cultivars into two groups. Based on morphological and molecular performance, L-49(Sardar) was ranked as the most promising cultivar for the low hills of NW Himalayan conditions. Morphological descriptors along with SCoT markers proved efficient in detecting the levels of genetic variability among the collections maintained in the field. These results can be used as an additional source of exploitation in guava breeding programmes.