Integrating genome size variation, ISSR-derived genetic structure, and phenotypical traits from the Southern Peruvian...

Cabanita maize is a native race with relevance for food security and economic subsistence among Southern Andean communities in Arequipa (Peru). Generally, studies are targeted to evaluate the genetic diversity of several maize races in Peru and elsewhere; however, the genetic diversity within a single maize race has not been explored yet.

This study evaluated for the first time the genetic and genome size (2C DNA) variability of 48 Cabanita maize accessions from two provinces (Castilla and Caylloma) of the Andean region of Arequipa (Peru), using 7 ISSR markers and cytometric methods. In addition, preliminary marker-phenotypical trait relationships were explored.

Despite the open-pollinated traditional cultivation of this crop, Cabanita accessions showed low genetic variability (PIC values 0.130-0.140) and low variation of their 2C DNA contents (5.35-5.65 pg). However, intra-racial genetic differences were revealed in the ISSR-based dendrogram and showed relation with the province of origin. UBC812, A5, and UBC840* markers were the most informative for evaluating genetic diversity based on their genetic diversity parameters. Castilla accessions showed slightly higher genetic diversity and 2C DNA contents and coefficients of variation (CV) than Caylloma samples. Preliminary analysis of marker-phenotypical trait relations revealed that UBC810 and UBC840* markers had relation with some Cabanita maize traits at phenotypical (kernel weight, ear length and number of rows) and chemical (free and dietary fiber-linked hydroxycinnamic acid derivative compounds) levels. However, this needs further validation through future genome-wide association studies (GWAS) to better characterize this underrepresented Andean maize race. This information would be relevant for future breeding programs at local level and product development to enable the potential designation of origin, enhancing the livelihoods of Southern Andean farmers in Peru.