Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybush
Background The current cultivation and plant breeding of Honeybush tea (produced from members of CyclopiaVent.) do not consider the genetic diversity nor structuring of wild populations. Thus, wild populations may be at risk of genetic contamination if cultivated plants are grown in the same landsca...
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| Format: | Article |
| Language: | English |
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PeerJ Inc.
2020-09-01
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| Online Access: | https://peerj.com/articles/9818.pdf |
| _version_ | 1797423876544659456 |
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| author | Nicholas C. Galuszynski Alastair J. Potts |
| author_facet | Nicholas C. Galuszynski Alastair J. Potts |
| author_sort | Nicholas C. Galuszynski |
| collection | DOAJ |
| description | Background The current cultivation and plant breeding of Honeybush tea (produced from members of CyclopiaVent.) do not consider the genetic diversity nor structuring of wild populations. Thus, wild populations may be at risk of genetic contamination if cultivated plants are grown in the same landscape. Here, we investigate the spatial distribution of genetic diversity within Cyclopia intermedia E. Mey.—this species is widespread and endemic in the Cape Floristic Region (CFR) and used in the production of Honeybush tea. Methods We applied High Resolution Melt analysis (HRM), with confirmation Sanger sequencing, to screen two non-coding chloroplast DNA regions (two fragments from the atpI-aptH intergenic spacer and one from the ndhA intron) in wild C. intermedia populations. A total of 156 individuals from 17 populations were analyzed for phylogeographic structuring. Statistical tests included analyses of molecular variance and isolation-by-distance, while relationships among haplotypes were ascertained using a statistical parsimony network. Results Populations were found to exhibit high levels of genetic structuring, with 62.8% of genetic variation partitioned within mountain ranges. An additional 9% of genetic variation was located amongst populations within mountains, suggesting limited seed exchange among neighboring populations. Despite this phylogeographic structuring, no isolation-by-distance was detected (p > 0.05) as nucleotide variation among haplotypes did not increase linearly with geographic distance; this is not surprising given that the configuration of mountain ranges dictates available habitats and, we assume, seed dispersal kernels. Conclusions Our findings support concerns that the unmonitored redistribution of Cyclopia genetic material may pose a threat to the genetic diversity of wild populations, and ultimately the genetic resources within the species. We argue that ‘duty of care’ principles be used when cultivating Honeybush and that seed should not be translocated outside of the mountain range of origin. Secondarily, given the genetic uniqueness of wild populations, cultivated populations should occur at distance from wild populations that is sufficient to prevent unintended gene flow; however, further research is needed to assess gene flow within mountain ranges. |
| first_indexed | 2024-03-09T07:54:06Z |
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| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T07:54:06Z |
| publishDate | 2020-09-01 |
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| spelling | doaj.art-ebc786fd0ddc44fcaefffc19d87698b12023-12-03T01:23:59ZengPeerJ Inc.PeerJ2167-83592020-09-018e981810.7717/peerj.9818Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybushNicholas C. Galuszynski0Alastair J. Potts1Department of Botany, Nelson Mandela University, Port Elizabeth, Eastern Cape, South AfricaDepartment of Botany, Nelson Mandela University, Port Elizabeth, Eastern Cape, South AfricaBackground The current cultivation and plant breeding of Honeybush tea (produced from members of CyclopiaVent.) do not consider the genetic diversity nor structuring of wild populations. Thus, wild populations may be at risk of genetic contamination if cultivated plants are grown in the same landscape. Here, we investigate the spatial distribution of genetic diversity within Cyclopia intermedia E. Mey.—this species is widespread and endemic in the Cape Floristic Region (CFR) and used in the production of Honeybush tea. Methods We applied High Resolution Melt analysis (HRM), with confirmation Sanger sequencing, to screen two non-coding chloroplast DNA regions (two fragments from the atpI-aptH intergenic spacer and one from the ndhA intron) in wild C. intermedia populations. A total of 156 individuals from 17 populations were analyzed for phylogeographic structuring. Statistical tests included analyses of molecular variance and isolation-by-distance, while relationships among haplotypes were ascertained using a statistical parsimony network. Results Populations were found to exhibit high levels of genetic structuring, with 62.8% of genetic variation partitioned within mountain ranges. An additional 9% of genetic variation was located amongst populations within mountains, suggesting limited seed exchange among neighboring populations. Despite this phylogeographic structuring, no isolation-by-distance was detected (p > 0.05) as nucleotide variation among haplotypes did not increase linearly with geographic distance; this is not surprising given that the configuration of mountain ranges dictates available habitats and, we assume, seed dispersal kernels. Conclusions Our findings support concerns that the unmonitored redistribution of Cyclopia genetic material may pose a threat to the genetic diversity of wild populations, and ultimately the genetic resources within the species. We argue that ‘duty of care’ principles be used when cultivating Honeybush and that seed should not be translocated outside of the mountain range of origin. Secondarily, given the genetic uniqueness of wild populations, cultivated populations should occur at distance from wild populations that is sufficient to prevent unintended gene flow; however, further research is needed to assess gene flow within mountain ranges.https://peerj.com/articles/9818.pdfHoneybushCape floristic region (CFR)PhylogeographyNeo-cropsWild genetic resources |
| spellingShingle | Nicholas C. Galuszynski Alastair J. Potts Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybush PeerJ Honeybush Cape floristic region (CFR) Phylogeography Neo-crops Wild genetic resources |
| title | Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybush |
| title_full | Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybush |
| title_fullStr | Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybush |
| title_full_unstemmed | Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybush |
| title_short | Applied phylogeography of Cyclopia intermedia (Fabaceae) highlights the need for ‘duty of care’ when cultivating honeybush |
| title_sort | applied phylogeography of cyclopia intermedia fabaceae highlights the need for duty of care when cultivating honeybush |
| topic | Honeybush Cape floristic region (CFR) Phylogeography Neo-crops Wild genetic resources |
| url | https://peerj.com/articles/9818.pdf |
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