Identification of Drought, Heat, and Combined Drought and Heat Tolerant Donors in Maize

Autor: José Crossa, Jill E. Cairns, Pichet Grudloyma, Cosmos Magorokosho, Suriphat Thaitad, Sarah Hearne, Dan Makumbi, Pervez Haider Zaidi, Gary Atlin, Abebe Menkir, Marianne Bänziger, Ciro Sanchez, José Luis Araus
Rok vydání: 2013
Předmět:
Zdroj: Crop Science. 53:1335-1346
ISSN: 1435-0653
0011-183X
DOI: 10.2135/cropsci2012.09.0545
Popis: Low maize (Zea mays L.) yields and the impacts of climate change on maize production highlight the need to improve yields in eastern and south - ern Africa. Climate projections suggest higher temperatures within drought-prone areas. research in model species suggests that tol - erance to combined drought and heat stress is genetically distinct from tolerance to either stress alone, but this has not been confirmed in maize. In this study we evaluated 300 maize inbred lines testcrossed to CML539. Experiments were conducted under optimal conditions, reproduc - tive stage drought stress, heat stress, and com - bined drought and heat stress. Lines with high levels of tolerance to drought and combined drought and heat stress were identified. Signifi - cant genotype × trial interaction and very large plot residuals were observed; consequently, the repeatability of individual managed stress trials was low. Tolerance to combined drought and heat stress in maize was genetically dis - tinct from tolerance to individual stresses, and tolerance to either stress alone did not confer tolerance to combined drought and heat stress. This finding has major implications for maize drought breeding. Many current drought donors and key inbreds used in widely grown African hybrids were susceptible to drought stress at elevated temperatures. Several donors toler - ant to drought and combined drought and heat stress, notably La p osta Sequia C7-F64-2-6-2-2 and DTpYC9-F46-1-2-1-2, need to be incorpo - rated into maize breeding pipelines.
Databáze: OpenAIRE
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