title: Dissection of the genetic basis of heterosis in an elite maize hybrid by QTL mapping in an immortalized F2 population.
abstract: The genetic basis of heterosis for grain yield and its components was investigated at the single- and two-locus levels using molecular markers with an immortalized F(2) (IF(2)) population, which was developed by pair crosses among recombinant inbred lines (RILs) derived from the elite maize hybrid Yuyu22. Mid-parent heterosis of each cross in the IF(2) population was used to map heterotic quantitative trait loci. A total of 13 heterotic loci (HL) were detected. These included three HL for grain yield, seven for ear length, one for ear row number and two for 100-kernel weight. A total of 143 digenic interactions contributing to mid-parent heterosis were detected at the two-locus level involving all three types of interactions (additive x additive = AA, additive x dominance = AD or DA, dominance x dominance = DD). There were 25 digenic interactions for grain yield, 36 for ear length, 31 for ear row number and 51 for 100-kernel weight. Altogether, dominance effects of HL at the single-locus level as well as AA interactions played an important role in the genetic basis of heterosis for grain yield and its components in Yuyu22.
authors: National Maize Improvement Center of China, China Agricultural University, 100193 Beijing, China.
authors: Jihua
authors: J
authors: Tang
authors: Jianbing
authors: J
authors: Yan
authors: Xiqing
authors: X
authors: Ma
authors: Wentao
authors: W
authors: Teng
authors: Weiren
authors: W
authors: Wu
authors: Jingrui
authors: J
authors: Dai
authors: Baldev S
authors: BS
authors: Dhillon
authors: Albrecht E
authors: AE
authors: Melchinger
authors: Jiansheng
authors: J
authors: Li
mesh_terms: D002874:Chromosome Mapping; D008040:Genetic Linkage; D005819:Genetic Markers; D006823:Hybrid Vigor / Q000235:genetics*; D006824:Hybridization, Genetic; D040641:Quantitative Trait Loci; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development
chemical_list: D005819:Genetic Markers