Search Results

You are looking at 31 - 40 of 54 items for :

  • Anisogramma anomala x
Clear All

Eastern filbert blight (EFB), caused by the fungus Anisogramma anomala (Peck) E. Müller, is an important disease of european hazelnut (Corylus avellana L.) in the Pacific northwestern United States. In 1989, a chance seedling free of EFB was discovered adjacent to a severely diseased orchard near Troutdale, Ore. This selection, subsequently named `Zimmerman', was crossed with three susceptible selections. Based on morphological characters and incompatibility alleles, we speculated that `Zimmerman' (S1 S3) was a hybrid between `Barcelona' (S1 S2) and `Gasaway' (S3 S26). The three seedling populations were inoculated with spores of the pathogen in a greenhouse test and assayed by indirect enzyme-linked immunosorbent assay (ELISA) and by observation of canker incidence. The observed segregation fit a 3 resistant : 1 susceptible ratio in all three progenies, in contrast to the 1 : 1 ratio found when the resistant pollinizer `Gasaway' was crossed to susceptible genotypes. Random amplified polymorphic DNA (RAPD) marker UBC 152800 linked to the resistance gene in `Gasaway' co-segregated with the resistant phenotype in all three populations with 2%, 4%, and 6% recombination, respectively. Seed germination and transplanting records did not provide evidence of selection in favor of resistant seedlings. Pollen germination was 71% in `Gasaway', 29% in `Zimmerman', and 18% in `Barcelona', indicating possible selection at the gametophytic level. Subsequently 16 resistant seedlings of `Zimmerman' were crossed with the highly susceptible selection OSU 313.078. Segregation fit a 3 : 1 ratio in 14 of the 16 progenies, and showed a surplus of resistant seedlings in the other two. None showed a 1 : 1 segregation. Resistance co-segregated with two RAPD markers that flank the `Gasaway' resistance allele. To test allelism of resistance from `Gasaway' and `Zimmerman', VR 6-28 with resistance from `Gasaway' was crossed with `Zimmerman'. Eight resistant selections from this progeny were crossed with OSU 313.078. Five of the eight progenies segregated 3 : 1, two progenies segregated 1 : 1, and OSU 313.078 × OSU 720.056 gave only resistant offspring. The ratios indicate that OSU 720.056 is homozygous resistant and that `Zimmerman' and `Gasaway' share a common resistance allele. Reciprocal translocations have been reported in hazelnut cultivars, including `Barcelona', the leading cultivar in Oregon. `Zimmerman' appears to be a hybrid of `Barcelona' and `Gasaway', but because of cytogenetic abnormalities, `Zimmerman' may have inherited two copies of the chromosome region that contain the resistance locus and flanking RAPD markers. If the region containing the resistance were attached to two independent centromeres, a 3 : 1 segregation ratio for disease response and flanking markers would be expected, and we propose this as the most likely explanation. Resistance from `Gasaway' and `Zimmerman' has been called “immunity” or “complete resistance.” However, we noted a few seedlings with small cankers, nearly all of which lacked sporulating stromata. Flanking RAPD markers indicate that the resistance allele is present in these seedlings. Although not “immune” or “completely resistant,” `Gasaway' and `Zimmerman' transmit a very high level of resistance.

Free access

resistance to eastern filbert blight caused by Anisogramma anomala (Peck) E. Müller conferred by a dominant allele from ‘Gasaway’. Pollen of ‘Epsilon’ and ‘Zeta’, released in 2002 ( Mehlenbacher and Smith, 2004 ), is shed late but expresses S 1 and so is

Free access

by the fungus Anisogramma anomala (Peck) E. Müller and bud mites (primarily Phytoptus avellanae Nal.) with high nut yield, medium nut size, attractive nuts and kernels, and excellent kernel flavor. Compared with the standard ‘Barcelona’, ‘Dorris

Free access

Anisogramma anomala (Peck) E. Müller. Origin ‘Tonda Pacifica’, tested as OSU 228.084, resulted from a controlled cross of ‘Tonda Gentile delle Langhe’ (Clone O-15) and OSU 23.024 made in 1981 by Maxine M. Thompson ( Fig. 1 ). ‘Tonda Gentile delle Langhe’ is

Free access

OSU 541.147 is a new hybrid hazelnut ( Corylus ) cultivar for eastern North America. It was released by the Hybrid Hazelnut Consortium in Apr 2020 for its resistance to eastern filbert blight (EFB) caused by the fungus Anisogramma anomala

Open Access

(EFB) caused by Anisogramma anomala (Peck) E. Müller. Origin ‘Red Dragon’, tested as OSU 897.078, resulted from a cross of OSU 487.055 × OSU 367.039 ( Fig. 1 ) made in 1997. OSU 487.055 is from a cross of ‘Contorta’ (syn. Corylus avellana var

Free access

‘Sacajawea’ is a new hazelnut ( Corylus avellana L.) cultivar for the kernel market. It combines a high level of quantitative resistance to eastern filbert blight caused by the fungus Anisogramma anomala (Peck) E. Müller with excellent kernel

Free access

1995, grafted in the greenhouse, and the shoot tips of the resulting trees were inoculated with a spore suspension of Anisogramma anomala. The next winter, the inoculated shoots were tested using an enzyme-linked immunosorbent assay as described by

Free access

Anisogramma anomala (Peck) E. Müller with high nut yield, early nut maturity, high kernel percentage, and good kernel quality. Compared with ‘Barcelona’, Oregon's leading cultivar, ‘Yamhill’ has smaller trees, slightly higher nut yield, twice the nut yield

Free access

blight (EFB) caused by the fungus Anisogramma anomala (Peck) E. Müller with high nut yield, large nut size, and good kernel quality. Compared with ‘Barcelona’, Oregon's leading cultivar, ‘Jefferson’ has smaller trees, higher nut yield, and much higher

Free access