Development of a Brazilian maize core collection

Abstract

The aim of this study was to evaluate methods for developing a Brazilian maize core collection. For an initial survey of the active collection, passport information, as well as characterization and evaluation of accessions, were taken into consideration, these then being divided according to geographic region and kernel-type. Multiple sampling methods were evaluated. The strategy of constant sampling generated extensive alterations in extract accession frequency. The multivariate strategy with dispersion graphs and principal components associated with the Tocher method was considered efficient for identifying the most divergent genotypes. The multivariate strategy generated greater alterations in the variance of traits. The average number of traits revealed few modifications with the various sampling strategies used. Therefore, the active collection could be considered as possessing a satisfactory amount of information for most of its accessions. Moreover, the multivariate strategy generated modifications in the variance of the traits, independent of sampling intensity.

Characterization of Select Wild Soybean Accessions in the USDA Germplasm Collection for Seed Composition and Agronomic Traits

“…Although the use of markerassisted selection has increased the utility of wild soybean to breeders, the undesirable agronomic traits of wild soybean germplasm can be avoided during population development by backcrossing with elite cultivars and by evaluating large segregating populations (Ertl and Fehr, 1985;Carpenter and Fehr, 1986;LeRoy et al, 1991;Sebolt et al, 2000;Kabelka et al, 2006;Zhang and Huang, 2011;Akpertey et al, 2014;Shivakumar et al, 2016). Core collections were successfully developed with multiple crops including maize (Zea mays L.), rice (Oryza sativa L.), wheat (Triticum aestivum L.), and peanut (Arachis hypogaea L.) (Holbrook et al, 2000;Coimbra et al, 2009;Bordes et al, 2011;Liu et al, 2015). The selected core collection should represent the genetic diversity of the original collection with the lowest number of redundant accessions.…”

“…A core collection is easier to evaluate and more efficient to use. Core collections were successfully developed with multiple crops including maize (Zea mays L.), rice (Oryza sativa L.), wheat (Triticum aestivum L.), and peanut (Arachis hypogaea L.) (Holbrook et al, 2000;Coimbra et al, 2009;Bordes et al, 2011;Liu et al, 2015). Soybean core collections exist in East Asia (Qiu et al, 2013) and Brazil (Priolli et al, 2013).…”

“…Domesticated soybean core collections composed of a portion of the 18,480 USDA G. max accessions have also been developed using the standard 10% selection threshold (Oliveira et al, 2010). Even smaller mini-core collections that represent the most diverse 1% of the accessions have been developed for multiple crops including maize, rice, wheat, and peanut (Holbrook et al, 2000;Coimbra et al, 2009;Bordes et al, 2011;Liu et al, 2015). However, to our knowledge, there are no published core collections derived from the USDA G. soja collection.…”

Establishing an Efficient Way to Utilize the Drought Resistance Germplasm Population in Wheat

“…A valid core collection provides a high-efficient way to assess genetic diversity or to find beneficial genes [21–24]. Most core collection researches focused on finding efficient ways in sub-core collection selection [25–27]. However, there is not a widely accepted strategy for constructing sub-core collection up to now.…”

Characterization of Resistance to the Green Rice Leafhopper (<i>Nephotettix cincticeps</i> Uhler) in a Core Collection of Landraces in Rice (<i>Oryza sativa</i> L.)

“…In the concept of the core collection, it consists of a limited number of accessions represented as much as possible of the genetic diversity of the whole germplasms [10] [11]. Core collections have been developed based on the genome-wide DNA markers as well as their agronomical traits in several crop species such as rice, maize, and sorghum [12] [13] [14] [15]. Evaluations of core collections were performed in the tolerance or resistance to abiotic and biotic stresses and favorable resources have been effectively screened [16] [17].…”