The Ultrastructure of Sporogenesis in the Pycnial Stage of Puccinia Sorghi

SUMMARY

Sporogenesis in pycnia of Puccinia sorghi is annellophoric, but at secession the spore retains the septal lamella and at least part of the lower septal wall. Pycniospores are bounded by a thin (±65 nm) wall and contain a nucleolate nucleus, endoplasmic reticulum, tubule-containing structures, several short mitochondria with predominantly platelike cristae, many ribosomes, and a few lipoid bodies. Septal pores were sectioned infrequently in pycnia, but more commonly in inter- and intracellular hyphae. All were equipped with a pulley-wheel apparatus.