Articles

Variability and mechanisms of drought tolerance in maize populations from Honduras


Abstract


Maize breeding for drought tolerance requires searching mechanisms and sources of drought tolerance. We assessed drought tolerance at juvenile stages of development in a collection of open-pollinated maize populations from a dry area of Honduras. Eighteen Honduran populations were evaluated for the response of morphological, physiological and photosynthetic traits to increasing levels of water stress during germination, seedling and early growth. Water stress was imposed by using solutions of polyethylene glycol6000. The population Natual Olote Gordo faced drought by increasing root elongation; the population Langueño was able to maintain natural photosynthetic traits under drought conditions at a reasonable level; Capulin was drought tolerant at germination and early growth, and Maicito Montecristo maintained root biomass at seedling and early growth stages. At early growth, Castaño Sur, Maicito Montecristo, Negrito, Sangre de Cristo, and Tuy showed diminished conductance while there was no significantreduction in Langueño. Considering photosynthetic performance, the response to drought can be classifiedas resistance (Langueño) or tolerance (Capulín). Therefore, diverse mechanisms of drought adaptation are displayed by these populations depending on the feature measured and the stage of development. Different adaptive traits to drought at early stages of development could be combined by crossing the appropriate populations.

Keywords

Zea mays L.; germplasm; water stress; photosynthesis; arid areas.

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Maydica - A journal devoted to maize and allied species

ISSN: 2279-8013