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History of the invasive African olive tree in Australia and Hawaii: evidence for sequential bottlenecks and hybridization with the Mediterranean olive.

Besnard G, Dupuy J, Larter M, Cuneo P, Cooke D, Chikhi L - Evol Appl (2013)

Bottom Line: Humans have introduced plants and animals into new continents and islands with negative effects on local species.Two subspecies were introduced in Australia, and each successfully invaded a specific area: the African olive in New South Wales (NSW) and the Mediterranean olive in South Australia.Furthermore, using an approximate Bayesian computation framework, we found strong support for the serial introduction of the African olive from South Africa to NSW and then from NSW to Hawaii.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Evolution & Diversité Biologique, CNRS, UPS, ENFA, UMR 5174 Toulouse, France.

ABSTRACT
Humans have introduced plants and animals into new continents and islands with negative effects on local species. This has been the case of the olive that was introduced in Australia, New Zealand and Pacific islands where it became invasive. Two subspecies were introduced in Australia, and each successfully invaded a specific area: the African olive in New South Wales (NSW) and the Mediterranean olive in South Australia. Here, we examine their origins and spread and analyse a large sample of native and invasive accessions with chloroplast and nuclear microsatellites. African olive populations from the invaded range exhibit two South African chlorotypes hence supporting an introduction from South Africa, while populations from South Australia exhibit chlorotypes of Mediterranean cultivars. Congruently, nuclear markers support the occurrence of two lineages in Australia but demonstrate that admixture took place, attesting that they hybridized early after introduction. Furthermore, using an approximate Bayesian computation framework, we found strong support for the serial introduction of the African olive from South Africa to NSW and then from NSW to Hawaii. The taxon experienced successive bottlenecks that did not preclude invasion, meaning that rapid decisions need to be taken to avoid naturalization where it has not established a large population yet.

No MeSH data available.


Related in: MedlinePlus

Reduced median network (Bandelt et al. 1999) of the 21 chlorotypes detected in the African range of subsp. cuspidata (lineage A; Besnard et al. 2007b). Each chlorotype is represented by a dot, whose width is proportional to the number of occurrences in our sample. See Table S3 for chlorotype profiles and geographic origins. The length of branches is proportional to the number of mutational steps. The missing, intermediate nodes are indicated by small black points. For each chlorotype, the country of origin is indicated by a specific colour. The two African chlorotypes detected in NSW are indicated in red (A.1 and A.2; both were detected in the population of Cape Town, South Africa).
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fig02: Reduced median network (Bandelt et al. 1999) of the 21 chlorotypes detected in the African range of subsp. cuspidata (lineage A; Besnard et al. 2007b). Each chlorotype is represented by a dot, whose width is proportional to the number of occurrences in our sample. See Table S3 for chlorotype profiles and geographic origins. The length of branches is proportional to the number of mutational steps. The missing, intermediate nodes are indicated by small black points. For each chlorotype, the country of origin is indicated by a specific colour. The two African chlorotypes detected in NSW are indicated in red (A.1 and A.2; both were detected in the population of Cape Town, South Africa).

Mentions: In the Adelaide area (South Australia), we found three Mediterranean chlorotypes (namely E1.1, E2.2 and E3.2), while in the Sydney area (NSW), a mix of Mediterranean (E1.1 and E3.2) and African chlorotypes (A.1 and A.2) were detected as shown in Fig. 1 (see Table S3 for the profile of each chlorotype). The three Mediterranean chlorotypes have been previously reported in olive cultivars, although E2.2 is not frequent (approximately 1%) in the cultivated pool (Besnard et al. 2011, 2013). Chlorotypes A.1 and A.2 were also detected in the native range but only in the Cape region, South Africa (Table S3). These two chlorotypes are closely related (Fig. 2 and Fig. S2). In our invasive olive sample, they co-occurred only in the Harpers Hill population. Interestingly, the four herbarium African olive samples from northern New Zealand, Norfolk and Saint Helena also showed the same chlorotypes A.1 and A.2 (Fig. 1). Populations from the Cumberland Plain mainly harbour chlorotype A.1, except individual Bringelly no 21 (E1.1), Mt Annan no 17 (E3.2) and all Camden Park individuals which exhibit Mediterranean chlorotypes E1.1 or E3.2. Twenty-three of 25 individuals sampled in Camden Park displayed E3.2, and an examination of mature flowers indicates a male sterility phenotype ms2 for all of them, but one which was not flowering, as previously reported in olive cultivars exhibiting E3 chlorotypes (formerly CCK; Besnard et al. 2000).


History of the invasive African olive tree in Australia and Hawaii: evidence for sequential bottlenecks and hybridization with the Mediterranean olive.

Besnard G, Dupuy J, Larter M, Cuneo P, Cooke D, Chikhi L - Evol Appl (2013)

Reduced median network (Bandelt et al. 1999) of the 21 chlorotypes detected in the African range of subsp. cuspidata (lineage A; Besnard et al. 2007b). Each chlorotype is represented by a dot, whose width is proportional to the number of occurrences in our sample. See Table S3 for chlorotype profiles and geographic origins. The length of branches is proportional to the number of mutational steps. The missing, intermediate nodes are indicated by small black points. For each chlorotype, the country of origin is indicated by a specific colour. The two African chlorotypes detected in NSW are indicated in red (A.1 and A.2; both were detected in the population of Cape Town, South Africa).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927883&req=5

fig02: Reduced median network (Bandelt et al. 1999) of the 21 chlorotypes detected in the African range of subsp. cuspidata (lineage A; Besnard et al. 2007b). Each chlorotype is represented by a dot, whose width is proportional to the number of occurrences in our sample. See Table S3 for chlorotype profiles and geographic origins. The length of branches is proportional to the number of mutational steps. The missing, intermediate nodes are indicated by small black points. For each chlorotype, the country of origin is indicated by a specific colour. The two African chlorotypes detected in NSW are indicated in red (A.1 and A.2; both were detected in the population of Cape Town, South Africa).
Mentions: In the Adelaide area (South Australia), we found three Mediterranean chlorotypes (namely E1.1, E2.2 and E3.2), while in the Sydney area (NSW), a mix of Mediterranean (E1.1 and E3.2) and African chlorotypes (A.1 and A.2) were detected as shown in Fig. 1 (see Table S3 for the profile of each chlorotype). The three Mediterranean chlorotypes have been previously reported in olive cultivars, although E2.2 is not frequent (approximately 1%) in the cultivated pool (Besnard et al. 2011, 2013). Chlorotypes A.1 and A.2 were also detected in the native range but only in the Cape region, South Africa (Table S3). These two chlorotypes are closely related (Fig. 2 and Fig. S2). In our invasive olive sample, they co-occurred only in the Harpers Hill population. Interestingly, the four herbarium African olive samples from northern New Zealand, Norfolk and Saint Helena also showed the same chlorotypes A.1 and A.2 (Fig. 1). Populations from the Cumberland Plain mainly harbour chlorotype A.1, except individual Bringelly no 21 (E1.1), Mt Annan no 17 (E3.2) and all Camden Park individuals which exhibit Mediterranean chlorotypes E1.1 or E3.2. Twenty-three of 25 individuals sampled in Camden Park displayed E3.2, and an examination of mature flowers indicates a male sterility phenotype ms2 for all of them, but one which was not flowering, as previously reported in olive cultivars exhibiting E3 chlorotypes (formerly CCK; Besnard et al. 2000).

Bottom Line: Humans have introduced plants and animals into new continents and islands with negative effects on local species.Two subspecies were introduced in Australia, and each successfully invaded a specific area: the African olive in New South Wales (NSW) and the Mediterranean olive in South Australia.Furthermore, using an approximate Bayesian computation framework, we found strong support for the serial introduction of the African olive from South Africa to NSW and then from NSW to Hawaii.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Evolution & Diversité Biologique, CNRS, UPS, ENFA, UMR 5174 Toulouse, France.

ABSTRACT
Humans have introduced plants and animals into new continents and islands with negative effects on local species. This has been the case of the olive that was introduced in Australia, New Zealand and Pacific islands where it became invasive. Two subspecies were introduced in Australia, and each successfully invaded a specific area: the African olive in New South Wales (NSW) and the Mediterranean olive in South Australia. Here, we examine their origins and spread and analyse a large sample of native and invasive accessions with chloroplast and nuclear microsatellites. African olive populations from the invaded range exhibit two South African chlorotypes hence supporting an introduction from South Africa, while populations from South Australia exhibit chlorotypes of Mediterranean cultivars. Congruently, nuclear markers support the occurrence of two lineages in Australia but demonstrate that admixture took place, attesting that they hybridized early after introduction. Furthermore, using an approximate Bayesian computation framework, we found strong support for the serial introduction of the African olive from South Africa to NSW and then from NSW to Hawaii. The taxon experienced successive bottlenecks that did not preclude invasion, meaning that rapid decisions need to be taken to avoid naturalization where it has not established a large population yet.

No MeSH data available.


Related in: MedlinePlus