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Testcross Performance of Semiexotic Inbred Lines Derived from Latin American Maize Accessions
Author(s) -
Tarter J. A.,
Goodman M. M.,
Holland J. B.
Publication year - 2003
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2003.2272
Subject(s) - germplasm , biology , hybrid , agronomy , temperate climate , inbred strain , inbreeding , poaceae , grain yield , botany , population , genetics , demography , sociology , gene
Tropical maize ( Zea mays L.) represents the most diverse readily available source of germplasm to broaden the limited genetic base of temperate maize in the USA. One objective of this study was to determine if exotic‐derived alleles contributing to enhanced testcross agronomic performance were maintained in semiexotic lines created by inbreeding and pedigree selection. A second objective was to determine if first‐generation semiexotic lines could produce hybrids with agronomic performance comparable to commercial U.S. hybrids. One hundred sixty‐four semiexotic inbred lines were developed from crosses between temperate‐adapted inbred line Mo44 and 23 Latin American maize accessions. Mo44 and each semiexotic line were testcrossed to temperate hybrid LH132 × LH51 for evaluations. In first‐stage replicated yield trials, testcrosses of 18 semiexotic lines, representing six different races, had significantly greater grain yields than the Mo44 testcross. Advanced yield evaluations were performed on check entries and 33 selected semiexotic line testcrosses in three additional environments. Across 10 environments, 12 semiexotic line testcrosses exhibited significantly greater grain yield than the Mo44 testcross, indicating recovery of favorable exotic alleles. Semiexotic testcrosses were not competitive with commercial hybrids for grain yield but were similar to or better than commercial hybrids for grain moisture and lodging resistance. Many superior accessions represent relatively recent introductions into regions from which they were collected. Tropical landraces seem to be a good source of exotic germplasm that can be used to broaden the genetic base of modern U.S. maize production and improve productivity.