Core Collections: Is There Any Value for Cotton Breeding?

Abstract

Global plant breeding activities are reliant on the available genetic variation held in extant varieties and germplasm collections. Throughout the mid- to late 1900s, germplasm collecting efforts were prioritized for breeding programs to archive precious material before it disappeared and led to the development of the numerous large germplasm resources now available in different countries. In recent decades, however, the maintenance and particularly the expansion of these germplasm resources have come under threat, and there has been a significant decline in investment in further collecting expeditions, an increase in global biosecurity restrictions, and restrictions placed on the open exchange of some commercial germplasm between breeders. The large size of most genebank collections, as well as constraints surrounding the availability and reliability of accurate germplasm passport data and physical or genetic characterization of the accessions in collections, limits germplasm utilization by plant breeders. To overcome these constraints, core collections, defined as a representative subset of the total germplasm collection, have gained popularity. Core collections aim to increase germplasm utilization by containing highly characterized germplasm that attempts to capture the majority of the variation in a whole collection. With the recent availability of many new genetic tools, the potential to unlock the value of these resources can now be realized. The Commonwealth Scientific and Industrial Research Organisation (CSIRO) cotton breeding program supplies 100% of the cotton cultivars grown in Australia. The program is reliant on the use of plant genetic resources for the development of improved cotton varieties to address emerging challenges in pest and disease resistance as well as the global changes occurring in the climate. Currently, the CSIRO germplasm collection is actively maintained but underutilized by plant breeders. This review presents an overview of the Australian cotton germplasm resources and discusses the appropriateness of a core collection for cotton breeding programs.

Characterization of agronomic traits and genomic diversity in a newly assembled radish core collection

“…Plant germplasm collections store seeds or breeding materials to conserve genetic variation in the form of plant varieties, landraces, and wild species related to specific crops. Germplasms have been collected by gene banks worldwide; however, they often become so large that the scale of their success is limited by inefficient data management (Egan et al., 2022). One method proposed for the management of large germplasm collections is the development of a core collection, which is defined as a limited set of accessions representing the genetic diversity of a crop species and its wild relatives (Frankel, 1984; van Hintum et al., 2000).…”

“…A primary goal of the core collection is the effective utilization of available genetic resources (Odong et al., 2013; van Hintum et al., 2000). To date, several core collections have been developed from diverse crop taxa, including peanut (Holbrook et al., 1993), annual Medicago (Diwan et al., 1994), Capsicum (Zewdie et al., 2004), safflower (Dwivedi et al., 2005), pearl millet (Bhattacharjee et al., 2006), cowpea (Mahalakshmi et al., 2007), wild mustard (Zhao et al., 2010), rice (S. Kumar et al., 2020; H. Zhang et al., 2011), Australian bermudagrass (Jewell et al., 2012), cotton (Egan et al., 2022), soybeans (N. Jeong et al., 2019; Nair et al., 2022), and Brassica (Witzel et al., 2021). A core collection also provides opportunities for marker development, phytochemical profiling, and gene discovery.…”

Core Germplasm Construction Based on Genetic and Phenotypic Diversity of Buffalograss (Bouteloua dactyloides (Nutt.) Columbus) from the Great Plains of America

“…This work can be grouped into two general areas. Firstly, there are ongoing discussions concerning the purposes, strategies, and methods of core collection construction for plants of different breeding systems, geographical distributions, and economic impacts [7][8][9][10]. Secondly, advancement in molecular biotechnology allows for reevaluation of the efficacy and diversity of existing collections [11,12].…”

Variability in Maturity, Oil and Protein Concentration, and Genetic Distinctness among Soybean Accessions Conserved at Plant Gene Resources of Canada

“…Many core sets of germplasm have been developed from large germplasm collections [3][4][5][6]. These representative accessions have facilitated germplasm management and enhanced germplasm utilization [7][8][9][10]. However, many collections are not adequately evaluated and characterized, as evaluation and characterization efforts require substantial resources and funding support [11,12].…”