Genetic structure and differentiation among North and South European apple germplasm

The anglerfish species Lophius piscatorius and Lophius budegassa are among the most valuable fishes sought after by bottom fisheries in western and southern European waters. It is currently believed that there are two stocks for each of the two species, north and south, which determine their assessment and management. A genetic analysis using eight polymorphic microsatellite markers was carried out on samples collected from western European waters and the south-western Mediterranean Sea. The results strongly suggest that the boundary between northern and southern stocks is not genetically supported. However, populations were not genetically homogeneous. Besides a pattern of genetic differentiation between Mediterranean and the rest of the samples, the L. budegassa samples taken from the Spain Atlantic zone and from the Portugal Atlantic zone were genetically distinct, whereas the samples taken in the French Atlantic zone for the L. piscatorius species seem to be different from the rest of the samples under study. This can be indicative of a more subtle genetic structure that deserves more study for guaranteeing adequate fishery management of these species.

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The Genetic Structure of Populations of the Douglas-Fir Swiss Needle Cast Fungus Nothophaeocryptopus gaeumannii in New Zealand

Phytopathology ◽

10.1094/phyto-06-18-0195-r ◽

2019 ◽

Vol 109 (3) ◽

pp. 446-455 ◽

Cited By ~ 1

Author(s):

P. I. Bennett ◽

I. A. Hood ◽

J. K. Stone

Keyword(s):

Population Structure ◽

New Zealand ◽

Genetic Structure ◽

Random Mating ◽

Douglas Fir ◽

Needle Cast ◽

The North ◽

Genetic Structure Of Populations ◽

Swiss Needle Cast ◽

North And South

Swiss needle cast is a foliar disease of Douglas-fir (Pseudotsuga menziesii) that results in premature foliage loss and reduced growth. The causal fungus, Nothophaeocryptopus gaeumannii, was first detected in New Zealand in 1959 and spread throughout the North and South Islands over the following decades. The contemporary genetic structure of the N. gaeumannii population in New Zealand was assessed by analyzing 468 multilocus SSR genotypes (MLGs) from 2,085 N. gaeumannii isolates collected from 32 sites in the North and South Islands. Overall diversity was lower than that reported from native N. gaeumannii populations in the northwestern United States, which was expected given that N. gaeumannii is introduced in New Zealand. Linkage disequilibrium was significantly higher than expected under random mating, suggesting that population structure is clonal. Populations of N. gaeumannii in the North and South Islands were weakly differentiated, and the isolates collected from sites within the islands were moderately differentiated. This suggests that gene flow has occurred between the N. gaeumannii populations in the North and South Islands, and between the local N. gaeumannii populations within each island. Eighteen isolates of N. gaeumannii Lineage 2, which has previously been reported only from western Oregon, were recovered from two sites in the North Island and four sites in the South Island. The most likely explanation for the contemporary distribution of N. gaeumannii in New Zealand is that it was introduced on infected live seedlings through the forestry or ornamental nursery trade, as the fungus is neither seed borne nor saprobic, and the observed population structure is not consistent with a stochastic intercontinental dispersal event.

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Assessment of genetic structure among Australian east coast populations of snapper Chrysophrys auratus (Sparidae)

Marine and Freshwater Research ◽

10.1071/mf18146 ◽

2019 ◽

Vol 70 (7) ◽

pp. 964 ◽

Cited By ~ 4

Author(s):

Jess A. T. Morgan ◽

Wayne D. Sumpton ◽

Andrew T. Jones ◽

Alexander B. Campbell ◽

John Stewart ◽

...

Keyword(s):

Genetic Structure ◽

Microsatellite Markers ◽

East Coast ◽

Stock Assessment ◽

New South ◽

Recreational Fisheries ◽

South Wales ◽

Genetic Overlap ◽

Food Fish ◽

North And South

Snapper Chrysophrys auratus is a high-value food fish in Australia targeted by both commercial and recreational fisheries. Along the east coast of Australia, fisheries are managed under four state jurisdictions (Queensland, Qld; New South Wales, NSW; Victoria, Vic.; and Tasmania, Tas.), each applying different regulations, although it is thought that the fisheries target the same biological stock. An allozyme-based study in the mid-1990s identified a weak genetic disjunction north of Sydney (NSW) questioning the single-stock hypothesis. This study, focused on east-coast C. auratus, used nine microsatellite markers to assess the validity of the allozyme break and investigated whether genetic structure exists further south. Nine locations were sampled spanning four states and over 2000km, including sites north and south of the proposed allozyme disjunction. Analyses confirmed the presence of two distinct biological stocks along the east coast, with a region of genetic overlap around Eden in southern NSW, ~400km south of the allozyme disjunction. The findings indicate that C. auratus off Vic. and Tas. are distinct from those in Qld and NSW. For the purpose of stock assessment and management, the results indicate that Qld and NSW fisheries are targeting a single biological stock.A

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