Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Life Sciences
Host Resistance To Monilinia Vaccinii-Corymbosi In Flowers And Fruits Of Highbush Blueberry, Jeffery S. Lehman, Suzu Igarashi, Peter V. Oudemans
Host Resistance To Monilinia Vaccinii-Corymbosi In Flowers And Fruits Of Highbush Blueberry, Jeffery S. Lehman, Suzu Igarashi, Peter V. Oudemans
Biology and Earth Science Faculty Scholarship
Monilinia vaccinii-corymbosi, the causal agent of mummy berry disease, infects blueberry flowers via the gynoecial pathway. To describe the expression of host resistance in highbush blueberry (Vaccinium corymbosum), fungal growth in the styles and colonization of the locules were compared among five blueberry cultivars in a series of controlled greenhouse experiments. Styles were harvested 1 and 4 days postinoculation, and the length colonized by hyphae was determined using fluorescence microscopy. At 8 weeks after inoculation, fruit were harvested and scored for the presence of hyphae in the locules. The infection frequency of styles ranged from 0.33 to 0.71, and only …
Relationships Between Blueberry Flower Age, Pollination, And Conidial Infection By Monilinia Vaccinii-Corymbosi, Jeffery S. Lehman, Henry K. Ngugi, Harald Scherm
Relationships Between Blueberry Flower Age, Pollination, And Conidial Infection By Monilinia Vaccinii-Corymbosi, Jeffery S. Lehman, Henry K. Ngugi, Harald Scherm
Biology and Earth Science Faculty Scholarship
Monilinia vaccinii-corymbosi infects open blueberry flowers via the gynoecial pathway, leading to mummification of the developing fruit. To determine the effect of flower age on infection, stigmata were inoculated with conidia of M. vaccinii-corymbosi between 0 and 5 days after anthesis, fungal growth rates through the stylar canal were measured in detached flowers in the laboratory, and fruit disease incidence was determined in plants grown in the greenhouse. Hyphal growth rates were greatest in flowers inoculated on the day of anthesis, declined linearly with increasing flower age at inoculation (r = 0.921; P < 0.0001; n = 12), and were unaffected by the presence or absence of pollen applied at the time of inoculation. In greenhouse-grown plants, the percentage of infected fruit decreased exponentially with increasing flower age at inoculation (R = 0.878; P = 0.0057; n = 10), with disease incidence ranging from 76.4% for flowers inoculated on the day of anthesis to 15.5% for those inoculated 4 days later. Fruit disease incidence in the greenhouse was linearly correlated with hyphal growth rates in detached flowers (r = 0.985; P < 0.0001; n = 9), justifying the use of detached flowers when investigating gynoecial infection by M. vaccinii-corymbosi. In separate experiments, the effects of timing and sequence of pollination and inoculation on hyphal growth rates through the stylar canal and on disease incidence were investigated. Application of pollen to detached flowers 1 or 2 days before inoculation reduced hyphal growth rates by between 14.0 and 42.9% compared with flowers that received pollen and conidia simultaneously. Similarly, reductions in fruit disease incidence by between 9.5 and 18.3% were observed on greenhouse-grown plants for pollination-to-inoculation intervals ranging from 1 to 4 days. These results document that newly opened flowers are most susceptible to infection by M. vaccinii-corymbosi and that fruit disease incidence is reduced if pollination occurs at least 1 day before inoculation. Strategies that lead to early pollination of newly opened flowers may be useful for managing mummy berry disease in the field.
Variation And Heritability Of Phenology In The Fungus Monilinia Vaccinii-Corymbosi On Blueberry, Jeffery S. Lehman, Peter V. Oudemans
Variation And Heritability Of Phenology In The Fungus Monilinia Vaccinii-Corymbosi On Blueberry, Jeffery S. Lehman, Peter V. Oudemans
Biology and Earth Science Faculty Scholarship
The germination of field-collected pseudosclerotia and the development of apothecia from eight New Jersey populations of the mummy berry fungus Monilinia vaccinii-corymbosi were evaluated under controlled conditions in the greenhouse. Development data for apothecia were used to describe the timing of apothecium formation and to estimate broad- and narrow-sense heritabilities of fungal phenology. Mean development times for the formation of apothecia ranged from 35.4 to 54.7 days. The mean development times for populations collected from early-season cv. Weymouth ranged from 35.4 to 39.6 days and were significantly shorter than the development times for three of the four populations collected from …
Phenology Of Apothecium Production In Populations Of Monilinia Vaccinii-Corymbosi From Early- And Late-Maturing Blueberry Cultivars, Jeffery S. Lehman, Peter V. Oudemans
Phenology Of Apothecium Production In Populations Of Monilinia Vaccinii-Corymbosi From Early- And Late-Maturing Blueberry Cultivars, Jeffery S. Lehman, Peter V. Oudemans
Biology and Earth Science Faculty Scholarship
Pseudosclerotia were evaluated for differences in timing of apothecium development in four controlled experiments conducted over a 2-year period. In a separate experiment, conidia from 10 randomly selected isolates from both of the fungal populations were used to inoculate open flowers. Germination of pseudosclerotia produced from these artificial inoculations also was evaluated. The timing and rate of shoot elongation for cvs. Weymouth and Jersey were assessed in one greenhouse and two field experiments. Average development times for the fungal population from cv. Weymouth were 8 to 15 days earlier or 33 to 42% less than those for the population from …