Old tools as new support for on farm conservation of different types of maize

Abstract

A germplasm collection should represent the diversity of the target species and the gene pools associated with it. However, it is critical to establish collection plans which ensure such representativeness. At times it is difficult to identify the best strategy for collecting domesticated species that are conserved in situ/on farm, since, in general, the magnitude of the diversity existing in a geographical area was hitherto unknown. The Diversity Census methodology was developed for previous diagnosis of the diversity of Zea mays subsp. mays L., conserved by farmers in two municipalities in the far western region of the state of Santa Catarina, southern Brazil. The Diversity Census database allowed for the identification of the best strategy to collect different types of maize landraces. Thus, tests were carried out using two methods described for Core Collections (Modified Random Sampling and Maximization) and a third statistical method for random sampling, stratified by farm area. The Maximization method enabled the capture of all the morphological variation of the traits evaluated in the Diversity Census from the smallest sample size. The relevance of this result is the feasibility of adapting the Core Collection strategy in order to plan more efficient expeditions to collect maize landraces conserved in microregions. Such planning allows for organizing the collection work efficiently, reducing costs, simplifying the work of characterization and helping to plan integrated strategies of in situ/on fam conservation.