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Production and Pathogenicity to Wheat of Pseudocercosporella herpotrichoides Conidia
Author(s) -
Higgins S.,
Fitt B. D. L.
Publication year - 1984
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/j.1439-0434.1984.tb00765.x
Subject(s) - spore , biology , conidium , germination , straw , inoculation , coleoptile , botany , horticulture , incubation , fungi imperfecti , agronomy , biochemistry
Weekly estimates of numbers of Pseudocercosporella herpotrichoides conidia on naturally infected wheat straw, made from February to July 1982, showed there were most conidia (8.1 × 10 6 per straw) in February and least (1.9 × 10 4 per straw) at the end of June. The viability of these spores remained high throughout this period, with an average of 85 % germination after 24 h. After removal of spores produced in the field, straws were incubated at 5, 10, 15, 20 or 25°C and subsequent sporulation assessed after 3 or 5 weeks. The optimum temperature for spore production was 5°C and very few spores were produced at 25°C. There was no difference in viability between spores produced at different temperatures. Wheat seedlings placed amongst infected straw collected and retained spores on the upper and lower surfaces of all leaf blades and on outer leaf sheaths. Both naturally dispersed spores and spores sprayed on to plants were not removed by subsequent rainfall. When wheat seedlings were inoculated between the coleoptile and outer leaf sheath with different numbers of P. herpotrichoides spores, lesion development was most rapid in seedlings inoculated with the greatest numbers of spores. However, after incubation for 12 weeks visible lesions were present on all plants inoculated with > c. 10 spores.