David F. Farr

Fungi on Plants and Plant Products in the United States

HETEROSIS FOR WEIGHT AT 18 MONTHS AND AT SLAUGHTER IN ACLUSTER ZEBU-CROSS The objectíve of the present investigation was to evaluate the weights at 18 months and at slaughter of males crossed 114 Bos taurus (Aberdeen Angus. Holsteín. American Símmental, German Simmental) with Zebu and pure Brahman animals. Commercial Zebus and halfbreeds. To determine the influence ofdifferent genetíc and non-genetic factors on the studied characteristics. the program ofminimum squares was used. The effects mcluded in the models for weight to 18 months. weight and age to sacrifice were.· month and year at weaning. month and year at 18 months. month and year at slaughter. genetic group of the animal. ranch at 18 months. and fatteníng rancho Depending on the model considered. covariates included: weight at bírth and weaning, weight at 18 months, slaughter weight. age at 18 months and age at slaughter. Most of the factors. genetíc and non-genetíc. produced signif¡cant effects (p 0,0 1); except for weaning age. The heterosis estimaríon for each genetic group was performed once orthogonal contrasts between genetíc groups were made in each one the caracteristlCs that sígnif¡cont results. For the weíght at 18 months analysis. the mean percentage ofheterosís was 5,22%, where the 31 4 Commercial Zebu 114 Holsteín group ofanimals presented the best performance with 7.48%. Weight at sacrífice showed a mean percentage ofheterosis of3.76%. in which the 3/4 Commercial Zebu 1/4 Aberdeen Angus animals obtained the highest percentage of4.85%. For slaughter age a mean percentage ofheterosis of-5,68% was documented, m whích the 3/4 Zebu Commercial 1/4 Aberdeen Angus animals presented the highest percentage of-10.52%.

Morphological and molecular characterization of Phomopsis vaccinii and additional isolates of Phomopsis from blueberry and cranberry in the eastern United States

Forty isolates of Phomopsis were obtained from twigs and berries of highbush blueberry, Vaccinium corymbosum, and cranberry, Vaccinium macrocarpon, isolated primarily from plants grown in the eastern United States. They were characterized using conidiomatal morphology, conidial dimensions, colony appearance and growth rate, and sequences of ITS rDNA. Based on morphological and molecular similarities, most isolates grouped together with an authentic culture of Phomopsis vaccinii Shear. This taxon is described and illustrated. However, some Phomopsis isolates from Vaccinium differed in colony and conidiomatal morphology from P. vaccinii and, based on ITS sequences, were related to isolates of Phomopsis from diverse hosts. These isolates were excluded from P. vaccinii.

A new species of Phomopsis causing twig dieback of Vaccinium vitis-idaea (lingonberry)

A fungus was discovered causing a progressive twig dieback on stems of Vaccinium vitis-idaea (lingonberry) in Oregon. Both morphological and molecular data suggest that the fungus belongs in Diaporthe/Phomopsis but is distinct from P. vaccinii, cause of a dieback and fruit rot of blueberry and cranberry (Vaccinium spp.). This fungus is described and illustrated as a new species, Phomopsis columnaris. It is distinguished from other species of Phomopsis by the distinctive conidiophores that consist of vertically aligned cells lining the base and sides of the conidiomata. Another species of Phomopsis described on Vaccinium, Phomopsis myrtilli, known from V. myrtillus, is redescribed and illustrated based on authentic herbarium material.

The coelomycetous genera Chaetomella and Pilidium represent a newly discovered lineage of inoperculate discomycetes

The coelomycetous genera Chaetomella and Pilidium were determined to be closely related to each other, yet are recognized as distinct genera based on both morphological observations and rDNA sequence analyses. Analyses of the SSU and LSU of the nuclear ribosomal RNA genes suggest that Chaetomella and Pilidium along with Sphaerographium tenuirostrum and Synchaetomella lunatospora constitute a distinct lineage within the ascomycetes that is allied with the Leotiomycetes. Chaetomella and Pilidium both produce black pycnidia generally opening by a raphe, acropleurogenous conidiogenous cells, and non-septate, hyaline, usually fusiform to falcate, rarely ellipsoid, conidia. Pycnidia of Pilidium are smooth while those of Chaetomella have setae of various types. A Hainesia sporodochial synanamorph was observed in cultures of C. oblonga and C. raphigera similar to H. lythri, the synanamorph of P. concavum. Specimens of C. oblonga, type species of Chaetomella, C. acutiseta, C. circinoseta, C. raphigera, Pilidium acerinum, type species of Pilidium, and P. concavum were examined. Diagnoses and illustrations are provided for these species along with a key to the accepted species in both genera.

SEPTORIA SPECIES ON CORNUS

Five species of Septoria on Cornus are described and illustrated. A key for the identification of these species is provided. Two are found on several host species, while the remaining three are restricted to a single species of dogwood. Differences in the Septoria spp. may be correlated with proposed evolution in the genus Cornus.

Wojnowicia colluvium sp. nov. isolated from conifer litter

A coelomycetous fungus was isolated from conifer litter collected in western New Mexico and is described herein as a new species Wojnowicia colluvi- um. When grown in both nutrient media and on alfalfa twigs in water agar, the characteristics of the conidi? omata, conidiogenous cells and conidia remain rela? tively constant. A synopsis is provided of the three species accepted in Wojnowicia. Based on their de? scriptions, W. buxi is considered a synonym of W. ephedrae, and W. byrophila does not belong in Wojnow? icia.

Towards a virtual reality for plant-associated fungi in the United States and Canada

At present knowledge of fungal biodiversity in North America is scattered in diverse sources ranging from well-reviewed, comprehensive databases to unedited databases of reports from the literature, information on file cards, and uncomputerized reference collections. Resources available electronically were used to determine their relative importance in evaluating the plant-associated fungi known from the United States and to a lesser extent Canada. The results demonstrate that the literature provides the greatest information but that reference collections in the US National Fungus Collections contribute between 22–31% additional data. Little overlap exists between fungi isolated as endophytes and those reported in the literature or as reference collections. Eighty to 100% of the plant-associated fungi reported from Canada are accounted for in comprehensive resources for the United States. A comprehensive database of plant-associated fungi in Canada, the United States, and eventually Mexico would serve as a valuable resource for those making plant quarantine decisions.