Vegetative compatibility groups inVerticillium dahliae isolates from cotton in Turkey

Abstract

Verticillium dahliae Kleb. with a complicated genetic diversity is a widely distributed major pathogen resulting in cotton wilt, which causes high economic losses in cotton lint production in the cotton belt of Turkey. A collection of 70 Turkish V. dahliae isolates (68 from wilted cotton plants in 28 districts and two from watermelon plants in two districts) were tested for vegetative compatibility by observing heterokaryon formation among complementary nitrate-nonutilizing (nit) mutants. The mutants were tested against international reference tester isolates and also were paired with one another. Thirty-nine isolates were assigned to vegetative compatibility group (VCG) 2B, 19 to VCG2A and three to VCG4B. One isolate was self-incompatible and eight others could not be assigned to any of the identified VCGs because their nit mutants showed negative reactions with the tester isolates of four VCGs or their nit mutants reverted back to the wild type. This is the first report of VCGs in V. dahliae from cotton in Turkey.

Vegetative compatibility groups in Verticillium dahliae isolates from olive in western Turkey

“…Eight olive isolates (OVd151, OVd202, OVd204, OVd206, OVd208, OVd211, OVd232 and OVd234) gave a positive reaction with the Turkish testers Cy1, Ch02 and Cka1 (Dervis and Bicici 2005) along with the Israeli nit mutants ep8 and ep52 belonging to VCG2A. Isolates assigned to VCG2A did not produce any reactions with the testers of subgroup B of VCG2 or the other VCGs.…”

“…The first type was observed among all complementary nit mutants from the local isolates belonging to the same VCG and between the nit mutants from the local olive isolates and previously described Turkish cotton isolates (Dervis and Bicici 2005) as linear wild-type growth with abundant microsclerotia and dense mycelia. This type of reaction was also observed between nit mutants from T9 and local isolate CotVd19 from cotton.…”

“…In the second stage, 10 isolates belonging to local VCGs and recovered from olive trees in different (2005) Cko1 Turkey nit1 and NitM 4B Cotton Dervis and Bicici (2005) provinces of Turkey were used as the set of local tester strains (Table 3). An isolate obtained from a severely diseased cotton plant in Manisa which complemented strongly with T9 was also included in the local tester set.…”

Diversity, Pathogenicity, and Management of Verticillium Species

“…VCG3 and VCG6 (16) are comprised of only one strain each, but VCGs 1, 2, and 4 are cosmopolitan and associated with a wide host range. All VCGs exhibit broad virulence, but some show differential aggressiveness (35,42,71,72,105,125,160). VCG4 was subdivided into VCG4A and VCG4B; with the former more prevalent and damaging on potato (72,148).…”

Verticillium wilt of olive in Turkey: a survey on disease importance, pathogen diversity and susceptibility of relevant olive cultivars

“…The mutants were phenotyped (Correll et al 1987) and then used in complementation tests as described by Korolev et al (2000); nit mutants derived from international reference strains 70-21 and 131 M of V. dahliae, kindly provided by Dr. Korolev, were used as testers to identify VCG3 and VCG4A, respectively (Joaquim and Rowe 1990). Turkish local nit testers CotVd19, OVd211, OVd60 (Dervis et al 2007) and Ch03 (Dervis and Bicici 2005) were used to identify VCG1A, VCG2A, VCG4B and VCG2B, respectively. These latter testers were previously developed from local isolates and complemented with the American (VCG1A, T9 from cotton) (Joaquim and Rowe 1990) and the Israeli (VCG2A, ep8 and ep52 from eggplant; VCG2B, cot11 and cot256 from cotton; and VCG4B, Pt15M and Pt9G from potato) (Korolev et al 2000) nit testers of V. dahliae VCGs.…”