Conserving citrus diversity: From Vavilov’s early explorations to genebanks around the world

Authors: Volk, Gayle; GMITTER, FRED - University Of Florida; Krueger, Robert

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/6/2023
Publication Date: 2/11/2023
Citation: Volk, G.M., Gmitter, F., Krueger, R. 2023. Conserving citrus diversity: From Vavilov’s early explorations to genebanks around the world. Plants. 12(4). Article e814. https://doi.org/10.3390/plants12040814.
DOI: https://doi.org/10.3390/plants12040814

Interpretive Summary: Citrus crops are some of the most important fruits produced on a global scale. The Russian geneticist and botanist N.I. Vavilov observed wild and cultivated citrus as he traveled the world to understand the origins and distribution of plant species in the early to mid-1900s. Citrus collections now conserve and protect citrus genetic resources for current and future generations. A survey was conducted as part of the development of A Global Strategy for the Conservation and Use of Citrus Genetic Resources. The survey compiled information about the composition, management practices, and vulnerabilities of 35 citrus collections from around the world. The results of the survey are summarized in this manuscript. One of the key findings of the survey is that both human and financial resources are needed to ensure the long-term safety and security of citrus plant genetic resources. Future efforts to develop citrus genebanking communities will provide opportunities for improved conservation, as well as collaborations and training.

Technical Abstract: Citrus is among the most economically important fruit crops. Its vast species diversity and global production was observed by N.I. Vavilov during his international plant explorations in the early to mid-1900s. Currently, ex situ citrus collections located around the world conserve and protect citrus genetic resources, as revealed in a survey conducted in 2021. Responses were received from 43 collections in 27 countries, of which 35 provided data for collection composition, management practices, and security, as well as other information. The largest six citrus collections have between 1000 and 1735 accessions. The largest accession holdings were for mandarins and sweet oranges, although all fruit classes were maintained: mandarin, sweet orange, lemon, pummelo, grapefruit, hybrids, lime, sour orange, citron, kumquat, papeda, finger lime, and crop wild relatives. Collections are primarily maintained as field plantings or in screenhouse/greenhouse conditions. Phenotypic evaluations and molecular characterization efforts are ongoing, often using standardized phenotypic descriptors and some collection data are publicly available through websites. Diseases pose significant collection threats, while other collections are maintained in a clean-plant state as a result of intensive sanitation efforts. Most collections distribute materials within-country. National and regional quarantine regulations often limit the export and import of citrus, thus limiting availability of materials at an international level, with the USDA-ARS and the Queensland Department of Agriculture and Fisheries collections as the primary international providers. Resources, both financial and human, are necessary to ensure the long-term safety and security of citrus collections on a global scale. Future efforts to develop citrus genebanking communities will provide opportunities for improved conservation, as well as collaborations and training.