Knowledge Center Catalog

Breeding for drought tolerance in tropical maize: Conventional approaches and challenges to molecular approaches

By: Contributor(s): Material type: TextTextPublication details: Mexico, DF (Mexico) CIMMYT : 2000ISBN:
  • 970-648-052-8
Subject(s): Summary: Most maize in the developing world is grown under rainfed conditions and annually an estimated 24 million tons of maize are lost to drought. This paper gives a brief overview of the conventional breeding approach taken by CIMMYT in developing drought tolerant maize germplasm. Typically, progenies are evaluated in replicated trials under managed drought stress, and index selection that considers primary and secondary traits is used to identify superior germplasm. Estimates of progress of selection have been calculated. They averaged around 100 kg ha-1 year-1 of improvement. Selection gains carried over from open-pollinated varieties to hybrids and they proved td be consistent across drought environments. Improved performance under drought was largely the result of improved flowering synchronization, reduced barrenness, and an increase in harvest index; associated QTL5 have been identified. Little change in water uptake and water use efficiency was found. Challenges to molecular approaches lay in (i) identifying the genes underlying known drought- adaptive traits; (ii) exploring additional traits that confer drought tolerance; and (iii) cost-effectively deploying molecular techniques that improve the drought tolerance in adapted germplasm.
Tags from this library: No tags from this library for this title. Log in to add tags.
Star ratings
    Average rating: 0.0 (0 votes)

Most maize in the developing world is grown under rainfed conditions and annually an estimated 24 million tons of maize are lost to drought. This paper gives a brief overview of the conventional breeding approach taken by CIMMYT in developing drought tolerant maize germplasm. Typically, progenies are evaluated in replicated trials under managed drought stress, and index selection that considers primary and secondary traits is used to identify superior germplasm. Estimates of progress of selection have been calculated. They averaged around 100 kg ha-1 year-1 of improvement. Selection gains carried over from open-pollinated varieties to hybrids and they proved td be consistent across drought environments. Improved performance under drought was largely the result of improved flowering synchronization, reduced barrenness, and an increase in harvest index; associated QTL5 have been identified. Little change in water uptake and water use efficiency was found. Challenges to molecular approaches lay in (i) identifying the genes underlying known drought- adaptive traits; (ii) exploring additional traits that confer drought tolerance; and (iii) cost-effectively deploying molecular techniques that improve the drought tolerance in adapted germplasm.

Global Maize Program|Research and Partnership Program

English

R99-00CIMPU|0008|EE|3

INT1888|INT2460

CIMMYT Staff Publications Collection


International Maize and Wheat Improvement Center (CIMMYT) © Copyright 2021.
Carretera México-Veracruz. Km. 45, El Batán, Texcoco, México, C.P. 56237.
If you have any question, please contact us at
CIMMYT-Knowledge-Center@cgiar.org