Global dependence on Corn Belt Dent maize germplasm: Challenges and opportunities

Abstract

Many changes affecting the management of genetic diversity occurred following recommendations made by the National Research Council in the aftermath of the Southern Leaf Corn blight epidemic of 1970–1971. New maize (Zea mays L.) breeding programs involving both publicly and privately funded collaborators were initiated. The number and scope of international maize breeding programs increased. Changes in germplasm usage included reduced usage of Lancaster Surecrop Oh43 and Mo17 types with increased use of Iodent. In contrast, continued and significant reliance upon Iowa Stiff‐Stalk Synthetic (BSSS) germplasm has persisted. The availability of exotic germplasm for potential use in U.S. maize breeding has increased. However, we could find no publicly available information confirming the recent deployment of exotic germplasm on U.S. farms. Estimated global dependence upon Corn Belt Dent (CBD) germplasm is highly skewed; four countries producing 55% of global maize are 84–88% reliant on CBD. The United States and China, which collectively contribute 46% of global maize production, are 92% dependent. Trends in global usage of CBD germplasm mirror those previously seen in the United States. Concerns about genetic vulnerability that were initially addressed by the U.S. National Research Council should now be considered on a global scale.

Flowered Grain Quality and Phytochemical Content of Non-Conventional Maize Hybrids from the Mexican Subtropics in Three Crop Cycles

“…In Mexico, maize genetic improvement has focused mainly on the development of dents hybrids of white grain, which are mainly used for human consumption, in the preparation of more than 600 traditional dishes [9,10]. Additionally, high-protein quality maize [11]; popcorn [12] with high oil content; and pigmented, sweet, forage maize; etc.…”

Flowered Grain Quality and Phytochemical Content of Non-Conventional Maize Hybrids from the Mexican Subtropics across Three Growing Cycles

“…In Mexico, maize genetic improvement has focused mainly on the development of dents hybrids of white grain, which are mainly used for human consumption, in the preparation of more than 600 traditional dishes [ 9 , 10 ]. Additionally, high-protein quality maize [ 11 ]; popcorn [ 12 ] with high oil content; and pigmented, sweet, forage maize; etc.…”

Assessment of Elongation of the Mesocotyl-Coleoptile and Biomass in Parents and Crosses of Corn Seedlings of the High Valleys of Mexico

“…The aforementioned studies reveal that the mesocotyl, coleoptile, roots and dry matter of corn seedlings are useful selection criteria to evaluate stress (abiotic and biotic) and the response and tolerance to deep sowing during the early stage of seedling growth. Various genetically improved corns have been generated in Mexico for different farming regions, through improvement programs at CIMMYT and institutions such as INIFAP [15,16], the public university system (UACh, COLPOS, UAAAN and UNAM) and the private sector [17,18]. Although they have made timely contributions, the demand for corn and food production has not been met, even when some of these corns have desirable agronomic traits and high yield potential [17].…”