Browsing by Author "Gallegly, Mannon E."

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    The avocado subgroup of Phytophthora citricola constitutes a distinct species, Phytophthora mengei sp. Nov.
    Hong, Chuanxue; Gallegly, Mannon E.; Browne, Greg T.; Bhat, Ravindra G.; Richardson, Patricia A.; Kong, Ping (Mycological Society of America, 2009-07)
    Isolates from avocado tree cankers have been recognized as a distinct subgroup within the P. citricola complex since 1974, both morphologically and molecularly (isozyme and amplified fragment length polymorphism [AFLP] analyses). This sub-group is formally separated from P. citricola after comparative DNA Fingerprinting and sequence analyses of the ITS region, as well as by morphological examinations. This new taxon is homothallic, produces plerotic oospores with paragynous antheridia and noncaducous semipapillate sporangia. Morphologically it differs from Other species of Waterhouse group III by producing many large bizarre-shaped sporangia and smaller oogonia with asymmetric capitate antheridia. It belongs to clade 2 and is phylogenetically closer to A siskiyouensis, P. capsici and P. tropicalis than to P. citricola. P. mengei can be easily differentiated from its relatives in the same clade and other species of this morpho-group by DNA fingerprints and sequence analysis. This new taxon is named Phytophthora mengei sp. nov.
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    A high-temperature tolerant species in clade 9 of the genus Phytophthora: P-hydrogena sp nov
    Yang, Xiao; Gallegly, Mannon E.; Hong, Chuanxue (Mycological Society of America, 2014-01)
    A previously unknown Phytophthora species was isolated from irrigation water in Virginia, USA. This novel species produces abundant noncaducous and nonpapillate sporangia in soil water extract solution. It sometimes produces chlamydospores and hyphal swellings in aged cultures and in Petri's solution. This species has optimum vegetative growth at 30 C and grows well at 35 C. The lowest and highest temperatures for growth are 5 and 40 C. All isolates examined in this study are compatibility type A1 and produce mostly plerotic oospores when paired with an A2 mating-type tester of P. cinnamomi. Sequence analyses of the rDNA internal transcribed spacer (ITS) regions and the mitochondrially encoded cytochrome c oxidase 1 (cox 1) gene placed this species in clade 9 of the genus Phytophthora. These characteristics support the description of this taxon as a new species for which we propose the name P. hydrogena sp. nov. Further phylogenetic and physiological investigations of clade 9 species revealed a high-temperature tolerant cluster including P. hydrogena, P. aquimorbida, P. hydropathica, P. irrigata, P. chrysanthemi, P. insolita, P. polonica and P. parsiana. These species all grow well at 35 C. The monophyly of the species in this heat-tolerant cluster except P. insolita and P. polonica is highly supported by the maximum-likelihood analyses of the ITS and cox 1 sequences.
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    Phytophthora pini Leonian resurrected to distinct species status
    Hong, Chuanxue; Gallegly, Mannon E.; Richardson, Patricia A.; Kong, Ping (Mycological Society of America, 2010-10)
    Phytophthora pini was named by Leonian in 1925, but this species was largely ignored until 1956 and then merged with P. citricola by Waterhouse in 1963. This study compared the ex-type and exauthentic cultures of these two species with isolates of P. plurivora and the P. citricola subgroups Cil I and 111 reported previously. Examination of these isolates revealed that the ex-type culture of P. pini is identical to P. citricola I. Phytophthora pini Leonian therefore is resurrected to distinct species status and redescribed here with a Latin description, replacing P. citricola I. Molecular, physiological and morphological descriptions of this species are presented. The molecular description includes DNA sequences of five nuclear and mitochondria] regions as well as PCR-SSCP fingerprints. The relationship among the above species and other species recently segregated from the P. citricola complex also is discussed.