Structure and physiology Maize

planting density affects multiple aspects of maize. modern farming techniques in developed countries rely on dense planting, produces 1 ear per stalk. stands of silage maize yet denser, , achieve lower percentage of ears , more plant matter.

maize facultative short-day plant , flowers in number of growing degree days > 10 °c (50 °f) in environment adapted. magnitude of influence long nights have on number of days must pass before maize flowers genetically prescribed , regulated phytochrome system. photoperiodicity can eccentric in tropical cultivars such long days characteristic of higher latitudes allow plants grow tall not have enough time produce seed before being killed frost. these attributes, however, may prove useful in using tropical maize biofuels.

immature maize shoots accumulate powerful antibiotic substance, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (dimboa). dimboa member of group of hydroxamic acids (also known benzoxazinoids) serve natural defense against wide range of pests, including insects, pathogenic fungi , bacteria. dimboa found in related grasses, particularly wheat. maize mutant (bx) lacking dimboa highly susceptible attack aphids , fungi. dimboa responsible relative resistance of immature maize european corn borer (family crambidae). maize matures, dimboa levels , resistance corn borer decline.

because of shallow roots, maize susceptible droughts, intolerant of nutrient-deficient soils, , prone uprooted severe winds.

zea mays ottofile giallo tortonese - mhnt



zea mays strawberry —mhnt



zea mays oaxacan green mhnt



variegated maize ears



multicolored corn kernels (csiro)

while yellow maizes derive color lutein , zeaxanthin, in red-colored maizes, kernel coloration due anthocyanins , phlobaphenes. these latter substances synthesized in flavonoids synthetic pathway polymerisation of flavan-4-ols expression of maize pericarp color1 (p1) gene encodes r2r3 myb-like transcriptional activator of a1 gene encoding dihydroflavonol 4-reductase (reducing dihydroflavonols flavan-4-ols) while gene (suppressor of pericarp pigmentation 1 or spp1) acts suppressor. p1 gene encodes myb-homologous transcriptional activator of genes required biosynthesis of red phlobaphene pigments, while p1-wr allele specifies colorless kernel pericarp , red cobs, , unstable factor orange1 (ufo1) modifies p1-wr expression confer pigmentation in kernel pericarp, vegetative tissues, not accumulate significant amounts of phlobaphene pigments. maize p gene encodes myb homolog recognizes sequence cct/aacc, in sharp contrast c/taacgg bound vertebrate myb proteins.

abnormal flowers

maize flowers may exhibit mutations lead formation of female flowers in tassel. these mutations, ts4 , ts6, prohibit development of stamen while simultaneously promoting pistil development. may cause inflorescences containing both male , female flowers, or hermaphrodite flowers.