Status of the Ex Situ and In Situ Conservation of Brazilian Crop Wild Relatives of Rice, Potato, Sweet Potato, and Finger Millet: Filling the Gaps of Germplasm Collections

Marcelo B Medeiros,Izulmé R I Santos,Solange C B R José,Alexandre M A Passos,Gustavo Heiden,Aluana G Abreu,José F M Valls,Suelma Ribeiro-Silva,Marília L Burle

doi:10.3390/agronomy11040638

Abstract

This study presents the status of ex situ and in situ conservation for the crop wild relatives of rice, potato, sweet potato, and finger millet in Brazil, and the subsequent germplasm collection expeditions. This research is part of a global initiative entitled “Adapting Agriculture to Climate Change: Collecting, Protecting, and Preparing Crop Wild Relatives” supported by the Global Crop Diversity Trust. Species of the primary, secondary, and tertiary gene pools with occurrences reported in Brazil were included: Oryza alta Swallen, O. grandiglumis (Döll) Prod., O. latifolia Desv., O. glumaepatula Steud., Eleusine tristachya (Lam.) Lam., E. indica (L.) Gaertn., Solanum commersonii Dunal, S. chacoense Bitter, Ipomoea grandifolia (Dammer) O’Donell, I. ramosissima (Poir.) Choisy, I. tiliacea (Willd.) Choisy, I. triloba L., and I. cynanchifolia Meisn. The status of the ex situ and in situ conservation of each taxon was assessed using the gap analysis methodology, and the results were used to plan 16 germplasm collection expeditions. Seeds of the collected material were evaluated for viability, and the protocols for seed germination and cryopreservation were tested. The final conservation score, resulting from the gap analysis and including the average of the ex situ and in situ scores, resulted in a classification of medium priority of conservation for all the species, with the exception of I. grandifolia (high priority). The total accessions collected (174) almost doubled the total accessions of these crop wild relatives incorporated in Embrapa’s ex situ conservation system prior to 2015. In addition, accessions for practically absent species were collected for the ex situ conservation system, such as Ipomoea species, Eleusine indica, and Solanum chacoense. The methods used for dormancy breaking and low temperature conservation for the Oryza, Eleusine, and Ipomoea species were promising for the incorporation of accessions in the respective gene banks. The results show the importance of efforts to collect and conserve ex situ crop wild relatives in Brazil based on previous gap analysis. The complementarity with the in situ strategy also appears to be very promising in the country.

Highlights

Introduction distributed under the terms andCrop wild relatives (CWRs) are an important source of variability for food security, and they have been used in the genetic improvement of various crops for multiple purposes [1].Despite their importance, the preservation of these genetic resources is highly threatened worldwide
Our results indicated gaps of representativeness in the ex situ collections; all species of Ipomoea and Eleusine indica were classified as high priority, while E. tristachya, Oryza alta, O. latifolia, and Solanum chacoense were classified as medium priority (Table 2)
Eleusine, and Ipomoea species were promising for the incorporation of accessions in the respective gene banks

Summary

Introduction

Introduction distributed under the terms andCrop wild relatives (CWRs) are an important source of variability for food security, and they have been used in the genetic improvement of various crops for multiple purposes [1].Despite their importance, the preservation of these genetic resources is highly threatened worldwide. To address the issue of the low representation of CWRs in ex situ germplasm collections, a global initiative entitled “Adapting Agriculture to Climate Change: Collecting, Protecting, and Preparing Crop Wild Relatives” supported by the Government of Norway and managed by the Global Crop Diversity Trust and the Millennium Seed Bank of the Royal Botanic Gardens, Kew, was established. Projects funded by this initiative, carried out by national or international gene banks, aimed to evaluate the gap of representativeness of CWRs in ex situ collections, to collect germplasm in the prioritized areas, to deposit the germplasm in national collections, and to duplicate the germplasm at the Millennium

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Results

Discussion

Conclusion