AFLP-based genetic diversity analysis distinguishes apomictically and sexually reproducing Cenchrus species

Abstract

Analysis of genetic diversity is important for plant breeders to breed new and improved cultivars with desirable characteristics. Since DNA-based molecular markers are not affected by environmental factors, they can be utilized to assess genetic diversity among species and to develop molecular markers for breeding programmes. Out of the 25 Cenchrus species, only eight are available in the Indian germplasm collections, and only four of them are grown in sown pastures for their high forage value, while the remaining four species are used for basic and applied studies. This study aimed at assessing genetic diversity and relatedness of the apomictic and sexual Cenchrus species available in the Indian germplasm collection using AFLP-based molecular markers. Based on the genetic dissimilarity matrix phylogenetic analysis, 36 accessions of eight Cenchrus species were observed to be clustered in four groups. All apomictic C. ciliaris L. accessions clustered within a group, while the other three apomictic Cenchrus spp. grouped separately. Similarly, the rare accessions of sexual C. ciliaris grouped separately from the sexually reproducing Cenchrus spp. However, Bayesian cluster analysis grouped the 36 accessions in three clusters only. Clustering of the accessions of phylogenetic Groups 1 and 2 was similar in Bayesian cluster analysis, while the accessions of Groups 3 and 4 clustered together. Some of the AFLP markers were observed to delineate the apomictic and sexual species/accessions of Cenchrus. The gathered information has the potential to be used for genetic improvement of Cenchrus species through cross-hybridization to exploit hybrid vigour as well as for introgression of desirable traits.