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Performance of Single and Double Cross Autotetraploid Maize Hybrids with Different Levels of Inbreeding
Author(s) -
Sockness Bradley A.,
Dudley J. W.
Publication year - 1989
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/cropsci1989.0011183x002900040006x
Subject(s) - inbreeding , biology , inbred strain , population , zea mays , hybrid , genetics , botany , agronomy , gene , demography , sociology
In autotetraploids (4N's), theory suggests that double crosses (DC) should outperform single crosses (SC) if the parents of the SC's are inbred. To evaluate the importance of this theory, experiments using 4N maize ( Zea mays L.) were designed to determine the relative performance of 4N SC's and DC's from parents with different levels of inbreeding. The parental lines were derived from three 4N maize synthetics (B,CD, and OP). The study was divided into three experiments grown in central Illinois in from 2 to 4 environments. In one experiment grown at 2 locations in 1986, between population SC's (B ✕ OP, B ✕ CD, CD ✕ OP)and DC's [(B ✕ OP)(BOP), (B ✕ CD)(B ✕ CD), (CD ✕ OP)(CD ✕ OP)] produced S 1 parentalines were compared to within population SC's (B ✕ B, CD ✕ CD, OP ✕ OP) and their between population DC's [(B B)(CD ✕ CD), (B ✕ B)(OP ✕ OP), (CD ✕ CD)(OP a second experiment grown at 2 locations in 1987, the within population SC's and between population DC's produced from S 1 lines were compared to the same SC's and DC's produced from S 3 parental lines. In a third experiment, within population SC's and DC's produced from 16 essentially homozygous lines from Syn. OP were evaluated. Double cross yields from S 2 , S 3 , and homozygous parents were similar, but SC yields decreased as the parents became more inbred. Thus, it may be possible to use relatively inbred parents to produce autotetraploid maize DC's without significant loss of productivity. Results agreed with theory in that for most traits DC's outperformed SC's, the performance was linearly related to the inbreeding coefficient (F), and genetic variancestimates among SC's were larger than among DC's.