Pathogenesis and Seedling Diseases LEARNING OBJECTIVES: The Disease Triangle Heterotrophy and Pathogenesis Saprotrophs, Necrotrophs, and Biotrophs Growth and Reproduction of Fungi in Plants Seedling Diseases Damping-off Fusarium root rot Top Blight Phytophthora root rot PLANT DISEASE TRIANGLE ENVIRONMENT PATHOGEN HOST FOMITOPSIS PINICOLA RED BELT CONK BROWN CRUMBLY ROT SAPROTROPHIC FUNGI SYCAMORE ANTHRACNOSE NECROTROPHIC PATHOGENS POWDERY MILDEW HYPHAE ASCOCARPS BIOTROPHIC PATHOGENS Growth of Fungi in Plants HYPHAE PATHOGENESIS TOXINSENZYMES GROWTH REGULATORS RHYTISMA PUNCTATUM ACER MACROPHYLLUM Cedar root rot Phytophthora lateralis Asexual Reproduction of Fungi Oomycetes- Zoospores Ascomycetes - Conidiospores SWISS NEEDLE CAST PHAEOCRYPTOPUS GAEUMANNII Sexual Reproduction of Fungi Ascospores CROP ROTATION FUMIGATION PRECISION SOWING PLANT DISEASE TRIANGLE ENVIRONMENT PATHOGEN HOST DAMPING OFF PYTHIUM a Watermold HOSTENVIRONMENT PATHOGEN SPORANGIA Release Zoospores SEXUAL OOSPORES FUSARIUM ROOT ROT or 4 TH OF JULY DISEASE FUSARIUM OXYSPORUM HOSTENVIRONMENT PATHOGEN TOP BLIGHT PHOMA, FUSARIUM HOSTENVIRONMENT PATHOGEN WINTER INJURY--ABIOTIC STORAGE BLIGHT -- ABIOTIC PHYTOPHTHORA ROOT ROT IN DOUGLAS-FIR SPORANGIA HOSTENVIRONMENT PATHOGEN OOSPORE DAMPING OFF PYTHIUM HOSTENVIRONMENT PATHOGEN SPORANGIA FUSARIUM ROOT ROT or 4 TH OF JULY DISEASE FUSARIUM OXYSPORUM