Question

"Diameter of penetration peg is smaller than the normal hypha" why?​

Answer 1

Answer:

• Most fungi form an appressorium at the end of germ tube, it being bulbous or cylindrical with a flat surface in contact with the surface of the host plant.
• Then a penetration peg grows from the flat surface of the appressorium towards the host and pierces the cuticle and cell wall.
• The penetration peg grows into the small hyphae generally much smaller in diameter than the normal hyphae of the fungus and regains its normal diameter once inside the cell.
• Parasitic higher plants also form an appressorium and penetration peg and the point of contact of the radical with the host plant; and penetration is similar to that in fungi.
• Direct penetration in nematodes is accomplished by repeated back and forth thrusts of their stylets. Such thrusts finally create fine opening in the cell wall. It then inserts its stylet into the cell so the entire nematode enters the cell.