ABSTRACT
Immature maize shoots accumulate a powerful antibiotic substance, 2, 4-dihydroxy-7-methoxy-1, 4-benzoxazin-3-one (DIMBOA). A maize mutant (bx) lacking DIMBOA is highly susceptible to be attacked by aphids and fungi. Some of the maize chromosomes have chromosomal knobs highly repetitive heterochromatic domains that stain darkly. Individual knobs are polymorphic among strains of both maize and teosinte. Maize is still an important model organism for genetics and developmental biology today. The teosintes are wild grasses native to Mexico and Central America and have limited distribution. Teosinte species show little tendency to spread beyond their natural range and distribution is restricted to North, Central and South America. The genus Tripsacum is comprised of about 12 species that are mostly native to Mexico and Guatemala but are widely distributed throughout warm regions in the USA and South America, with some species present in Asia and Southeast Asia. All species are perennial and season grasses.
