NOVELTY - Introgressing allele of interest of locus associated with yield trait into Zea mays germplasm, involves (a) selecting Z.mays plant comprising allele of interest of a locus associated with a yield trait, identifiable by PCR amplification of a Z.mays nucleic acid with a pair of oligonucleotides primers, and (b) introgressing the allele of interest into Z.mays germplasm that lacks the allele.    USE - The method is useful for introgressing allele of interest of locus associated with yield trait into Z.mays germplasm (claimed).    DETAILED DESCRIPTION - Method for introgressing allele of interest of locus associated with yield trait into Zea mays germplasm, involves (a) selecting Z.mays plant comprising allele of interest of a locus associated with a yield trait, identifiable by PCR amplification of a Z.mays nucleic acid with a pair of oligonucleotides primers including (1) primer pair 1 represented by a primer comprising SEQ ID NO: 52 and a primer comprising SEQ ID NO: 53, (2) primer pair 2 represented by a primer comprising SEQ ID NO: 57 and a primer comprising SEQ ID NO: 58, (3) primer pair 3 represented by a primer comprising SEQ ID NO: 62 and a primer comprising SEQ ID NO: 63, (4) primer pair 4 represented by a primer comprising SEQ ID NO: 67 and a primer comprising SEQ ID NO: 68, and (5) primer pair 5 represented by a primer comprising SEQ ID NO: 72 and a primer comprising SEQ ID NO: 73. INDEPENDENT CLAIMS are included for the following: (1) improved Z.mays plant produced by the method (M1), or portion, seed, progeny, or its tissue culture; #elite Z.mays plant produced from the improved Z.mays plant; (2) biomass produced from the improved Z.mays plant, or from its progeny plant, or from its portion, seed, or its tissue culture; and (3) isolated and purified genetic marker associated with a yield trait in Z.mays. gcgtgcgaggcatttcg (SEQ ID NO: 52), gctcgaccttggcaaccat (SEQ ID NO: 53), ctcgcccgcagtgaaatg (SEQ ID NO: 57), catatccaatcagccctggaatcc (SEQ ID NO: 58), ggcactacgtgcactgcta (SEQ ID NO: 62), cgccacgggccttgta (SEQ ID NO: 63), gttgccgctatataacaggatcca (SEQ ID NO: 67), acctaactcgtgctccttgact (SEQ ID NO: 68), ggcctgtgagggttgaatattaaca (SEQ ID NO: 72) and cgctcgaacttcaaaacaacct (SEQ ID NO: 73).