Legacy genetics of Arachis cardenasii in the peanut crop shows the profound benefits of international seed exchange

Abstract

The narrow genetics of most crops is a fundamental vulnerability to food security. This makes wild crop relatives a strategic resource of genetic diversity that can be used for crop improvement and adaptation to new agricultural challenges. Here, we uncover the contribution of one wild species accession, Arachis cardenasii GKP 10017, to the peanut crop (Arachis hypogaea) that was initiated by complex hybridizations in the 1960s and propagated by international seed exchange. However, until this study, the global scale of the dispersal of genetic contributions from this wild accession had been obscured by the multiple germplasm transfers, breeding cycles, and unrecorded genetic mixing between lineages that had occurred over the years. By genetic analysis and pedigree research, we identified A. cardenasii–enhanced, disease-resistant cultivars in Africa, Asia, Oceania, and the Americas. These cultivars provide widespread improved food security and environmental and economic benefits. This study emphasizes the importance of wild species and collaborative networks of international expertise for crop improvement. However, it also highlights the consequences of the implementation of a patchwork of restrictive national laws and sea changes in attitudes regarding germplasm that followed in the wake of the Convention on Biological Diversity. Today, the botanical collections and multiple seed exchanges which enable benefits such as those revealed by this study are drastically reduced. The research reported here underscores the vital importance of ready access to germplasm in ensuring long-term world food security.

Development and Genetic Characterization of Peanut Advanced Backcross Lines That Incorporate Root-Knot Nematode Resistance From Arachis stenosperma

“…Furthermore, because of the diverse wild chromosome segments in this population, we also anticipate that it has other disease resistances and traits of value to the peanut crop. We anticipate that, over time, these backcrossed lines will impact peanut production by delivering several new traits to the peanut crop, similar to the case of North Carolina peanut lines with A. cardenasii segments that have provided resistance to late leaf spot, rust, and web blotch in numerous countries around the world ( Bertioli et al, 2021b ).…”

‘IAC SEMPRE VERDE’: a wild-derived peanut cultivar highly resistant to foliar diseases

“…ICGV 86687 derives from CS 16, a line produced in North Carolina, using a purple-seeded cultivated tetraploid peanut, A. hypogaea subsp. fastigiata (PI 261942), collected from Paraguay and the wild species A. cardenasii GKP 10017 (Bertioli et al 2021). To follow standard IAC nomenclature, the line was renamed IAC 69007 upon receipt.…”

“…Some of these lines, developed in North Carolina State University (USA) were sent to ICRISAT (International Crops Research Institute for the Semi-Arid Tropics), India, where a number of lines with resistance to LLS and rust were selected. One of these lines, ICGV 86687 was introduced to the germplasm collection of Campinas Agronomic Institute (IAC) and used as a source of resistance to foliar diseases (Bertioli et al 2021). By crossing this introgressed line with a high yielding locally-adapted cultivar, we produced 'IAC Sempre Verde' (meaning "Always Green") recommended for cultivation under "Organic" management.…”

Initiation of genomics-assisted breeding in Virginia-type peanuts through the generation of a de novo reference genome and informative markers

“…against a tetraploid reference and therefore all introgression blocks are presented in terms of tetraploid genomic coordinates, whereas prior studies have instead utilized comparisons to diploids (Bertioli et al, 2021;Clevenger et al, 2017;Lamon et al, 2020). Contextualizing results in this manner is paramount because advanced peanut cultivar development is done solely at the tetraploid level.…”

“…Out of the TAMU tetraploid route, two 'TxAG' germplasm lines were released for their resistance to root knot nematode and leaf spot foliar diseases (Simpson et al, 1993). Several A. cardenasii introgression blocks exist in cultivated peanut populations as a result of these introgression projects (Bertioli et al, 2021).…”