21. In the presence of nutrients, chlamydospores germinate by producing germ tubes that continue to grow and form mycelial masses. 22. The liberated sporangia in turn can either germinate directly with a germ tube or begin to produce biflagellate motile zoospores. 23. Most conidial spores do not germinate, and the few that do germinate in soil only have short germ tubes . 24. The filamentous fungus " Neurospora crassa " ( bread mould ) produces CATs from conidia and conidial germ tubes . 25. A conidium may form germ tubes ( germination tubes ) and / or conidial anastomosis tubes ( CATs ) in specific conditions. 26. The zoospores escape from the cyst through a germ tube ~ 4 5 micrometers in diameter and 10 15 micrometers in length. 27. Germ tubes give rise to appressorium which form haustorium and allow the pathogen to extract nutrients without penetrating the host s cell membrane.28. Once attached, the spore germinates by growing a germ tube and eventually locates a stoma by a touch responsive process known as thigmotropism. 29. In the resistant sunflower cultivars, germination was still induced but the plant's germ tube never develops after penetration by the haustorium. 30. When a conditioned seed receives a chemical signal from a host plant, it germinates, forming a germ tube which grows toward the host.
