Genetic diversity and similarity in the Barbarea vulgaris complex (Brassicaceae)

TY - JOUR

T1 - Genetic diversity and similarity in the Barbarea vulgaris complex (Brassicaceae)

AU - Toneatto, Fiorello

AU - Hauser, Thure Pavlo

AU - Nielsen, Jens Kvist

AU - Ørgaard, Marian

PY - 2012/8

Y1 - 2012/8

N2 - Two subspecies of Barbarea vulgaris are taxonomically recognized as ssp. vulgaris and ssp. arcuata. In addition, two types of Barbarea vulgaris ssp. arcuata occurs in Denmark. The G-type is resistant to an herbivorous flea beetle (Phyllotreta nemorum) whereas the P-type is susceptible. A previous study suggested that the P-type evolved by a loss of resistance from a resistant progenitor. We analyzed the genetic relatedness among eight Barbarea taxa: B. vulgaris spp. vulgaris, B. vulgaris ssp. arcuata G- and P-types, hybrids between the types, B. verna, B. intermedia, B. stricta, B. orthoceras and B. australis, using AFLP and SSR markers. A clear distinction between the G- and P-types was revealed. Both were distinct from B. vulgaris ssp. vulgaris, the G-type less so than the P-type. Barbarea verna and B. intermedia formed unambiguous clusters, whereas the remaining taxa produced less discrete groupings. Possible evolutionary scenarios for flea-beetle resistance and susceptibility are discussed, including lineage sorting from a polymorphic ancestral population, and de novo loss of resistance in the P-type of B. vulgaris ssp. arcuata.

AB - Two subspecies of Barbarea vulgaris are taxonomically recognized as ssp. vulgaris and ssp. arcuata. In addition, two types of Barbarea vulgaris ssp. arcuata occurs in Denmark. The G-type is resistant to an herbivorous flea beetle (Phyllotreta nemorum) whereas the P-type is susceptible. A previous study suggested that the P-type evolved by a loss of resistance from a resistant progenitor. We analyzed the genetic relatedness among eight Barbarea taxa: B. vulgaris spp. vulgaris, B. vulgaris ssp. arcuata G- and P-types, hybrids between the types, B. verna, B. intermedia, B. stricta, B. orthoceras and B. australis, using AFLP and SSR markers. A clear distinction between the G- and P-types was revealed. Both were distinct from B. vulgaris ssp. vulgaris, the G-type less so than the P-type. Barbarea verna and B. intermedia formed unambiguous clusters, whereas the remaining taxa produced less discrete groupings. Possible evolutionary scenarios for flea-beetle resistance and susceptibility are discussed, including lineage sorting from a polymorphic ancestral population, and de novo loss of resistance in the P-type of B. vulgaris ssp. arcuata.

U2 - 10.1111/j.1756-1051.2012.01546.x

DO - 10.1111/j.1756-1051.2012.01546.x

M3 - Journal article

SN - 0107-055X

VL - 30

SP - 506

EP - 512

JO - Nordic Journal of Botany

JF - Nordic Journal of Botany

IS - 4

ER -