Insight into genetic relation and diversity of cultivated and semi-domesticated under-utilized Crotalaria species gained using start codon targeted (SCoT) markers

• Genetic variation in cultivated and semi-domesticated Crotalaria species were evaluated using SCoT markers.
• SCoT markers have high resolving power with ability to reveal high polymorphism in Crotalaria.
• Rich genetic diversity was observed in cultivated Crotalaria juncea and semi-domesticated species Crotalaria pallida and Crotalaria spectabilis.
• Conservation of Crotalaria germplasm and their use in population improvement should be given priority.

To augment conventional crop improvement approaches in cultivated sunnhemp (Crotalaria juncea L.) and other under-utilized Crotalaria species, genetic diversity of 94 genotypes from seven Crotalaria species was studied using 20 Start Codon Targeted (SCoT) markers. High allele number (1.32), polymorphism information content (0.37) and resolving power (6.59) established SCoT as a reliable marker system for genetic analysis in Crotalaria. All the species except Crotalaria retusa L. exhibited high number of SCoT amplicons. Analysis of molecular variance revealed significant variability between (24.0%) the species as well as within species (76.0%). A cluster analysis identified distinct groups corresponding to the seven species and also identified sub-groups within the species. The sunnhemp cultivars were distant from the landraces, suggesting the need of population improvement using distantly related genotypes. Species relationship identified Crotalaria pallida Aiton to be a close relative of C. juncea. The results of principal coordinate analysis were comparable to that of cluster analysis, revealing high genetic variability in sunnhemp and other semi-domesticated Crotalaria species. The study further suggests some measure for conservation of genetic resources and genetic improvement of these species based on the results of diversity analysis.

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