Practice question

Ustilago tritici incites loose smut of wheat, a systemic floral smut where entire inflorescence except rachis converts into powdery olive-black mass of teliospores initially enclosed by delicate grayish peridium. Teliospores germinate in soil producing basidium bearing haploid basidiospores infecting coleoptile of germinating wheat seedling; dikaryotic mycelium grows intercellularly, remains dormant within embryo, proliferates vigorously at heading stage replacing ovaries. Spore masses disperse openly via wind, lacking persistent covering membrane unlike covered smut. Distinction from rusts which produce rusty pustules not smutted grains is evident.