Breeding Maize

field of maize in liechtenstein

maize reproduces sexually each year. randomly selects half genes given plant propagate next generation, meaning desirable traits found in crop (like high yield or nutrition) can lost in subsequent generations unless techniques used.

maize breeding in prehistory resulted in large plants producing large ears. modern breeding began individuals selected highly productive varieties in fields , sold seed other farmers. james l. reid 1 of earliest , successful developing reid s yellow dent in 1860s. these efforts based on mass selection. later breeding efforts included ear row selection, (c. g. hopkins ca. 1896), hybrids made selected inbred lines (g. h. shull, 1909), , highly successful double cross hybrids using 4 inbred lines (d. f. jones ca. 1918, 1922). university supported breeding programs important in developing , introducing modern hybrids. (ref jugenheimer hybrid maize breeding , seed production pub. 1958) 1930s, companies such pioneer devoted production of hybrid maize had begun influence long term development. internationally important seed banks such international maize , wheat improvement center (cimmyt) , bank @ maize genetics cooperation stock center university of illinois @ urbana-champaign maintain germplasm important future crop development.

since 1940s best strains of maize have been first-generation hybrids made inbred strains have been optimized specific traits, such yield, nutrition, drought, pest , disease tolerance. both conventional cross-breeding , genetic modification have succeeded in increasing output , reducing need cropland, pesticides, water , fertilizer.

global maize program

panorama of cornfields in nan province, thailand

cimmyt operates conventional breeding program provide optimized strains. program began in 1980s. hybrid seeds distributed in africa drought tolerant maize africa project.

genetic modification

genetically modified (gm) maize 1 of 26 gm crops grown commercially in 2016. grown since 1997 in united states , canada, 92% of maize crop genetically modified in 2016 , 33% of worldwide maize crop gm in 2016. of 2011, herbicide-tolerant maize varieties grown in argentina, australia, brazil, canada, china, colombia, el salvador, european union, honduras, japan, korea, malaysia, mexico, new zealand, philippines, russian federation, singapore, south africa, taiwan, thailand, , usa, , insect-resistant corn grown in argentina, australia, brazil, canada, chile, china, colombia, czech republic, egypt, eu, honduras, japan, korea, malaysia, mexico, netherlands, new zealand, philippines, romania, russian federation, south africa, switzerland, taiwan, usa, , uruguay.

in september 2000, $50 million worth of food products recalled due presence of starlink genetically modified corn, had been approved animal consumption , had not been approved human consumption, , subsequently withdrawn market.