2017 ASHS Annual Conference

Kikuyugrass (Pennisetum clandestinum Hochst. Ex Chiov.) is a warm-season species introduced into California in the 1920s for soil stabilization. Today it is considered either an invasive weed or the desired species on many golf courses and other turf areas along coastal and inland regions. Currently, there are no active kikuyugrass breeding programs in the United States. To assess the extent of genetic variation present among available accessions of kikuyugrass, local populations were sampled from throughout California, as well as from the collections at the University of California, Riverside (UCR), Hawaii and Australia. A total of 20,000 single nucleotide polymorphism (SNP) makers were discovered using the Diversity Arrays Technology sequencing (DArTseq) platform. The hierarchical plot, gap statistics, and the principal coordinate analysis all showed that the 336 accessions in the study separated into three main clusters. Seventy-seven percent of the total genetic variation was due to within population variation, while 23% represented among population variation. The main axis of the principal coordinate analysis accounted for 33% of the total variation. Accessions from California showed the least genetic variation with all but six located in the same cluster. Accessions from Australia and Hawaii showed a much broader degree of genetic diversity and would be valuable stock for breeding should such efforts become feasible and the exchange of germplasm possible. Meanwhile, breeding toward new turf-type cultivars must be limited to available germplasm within the UCR collection with select accessions from around the State.