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.

Relationship between phenological and morphological characteristics of plant with popcorn races of a diversity microcenter in southern Brazil

“…The strategy for collecting populations considered diversity indexes from data on identification of the landraces, morphological characteristics of the grain, geographical location, and use values and conservation in the farmers' view, organized into 13 categories by Costa et al (2016). Vidal (2016) and Vidal et al (2018) chose M sampling method because it encompassed the greatest diversity with smaller sample size. This approach resulted in the popcorn collection of the Federal University of Santa Catarina (UFSC)' gene bank based on 174 populations from the FWSC.…”

“…Usually, germplasm collections prioritize geographical axes and, in cases of microregions, such as the FWSC the usual form of collection may not represent the true variability present in that area. Thus, as shown by Vidal et al (2018), the morphological diversity conserved on farm in addition with ethnobotanical information are fundamental for effective germplasm collection strategies.…”

“…Due to this diversity of local varieties and the presence of wild corn relatives, this region was indicated as a microcenter of diversity of the Zea genus (Costa, Silva, & Ogliari, 2016). After collecting populations in 2013 representing the local diversity of this microregion (Vidal, 2016, Vidal, Silva, & Ogliari, 2018, a race study based on ear and grain characteristics was carried out by Silva et al (2016), and from which they identified at least five races of popcorn, three of which were considered new.…”