Allelic variation in candidate genes associated with QTL for the maize anther culture response

Anther culture could be an efficient means to produce homozygous maize bree ding lines if more genotypes were responsive. To better understand the maiz e anther culture response (ACR) allele-specific single-strand conformation polymorphism (SSCP) markers were developed for ACR candidate genes, anther ear1, knotted1, tasselseed2, viviparous1, and ZAG1. Individuals from H99xPa 91 and Pa91xFR16 F-2:4 families were rested for ACR and haplotyped for cand idate genes. Ar least two alleles were detected among parental lints FR16, H99, and Pa91 for all genes except anther ear1. Most polymorphisms affected single nucleotides. Some were within exons and would affect the predicted amino acid residues. Other lines (B73, LH59, and Mo17) had a 313-nucleotide insertion in intron 2 of viviparous1. The insertion has sequence similarit y to fragments of maize oleosin-3, a polyamine oxidase, and allele B-M033 o f the b gene. There were associations of ACR with SSCP markers for H99 vivi parous1 and FR16 knotted1 alleles. The associations may be due to alleles o f these genes or favorable alleles of linked genes. Identification of favor able ACR alleles may help define culture conditions favoring ACR, enable in trogression of small chromosome segments with favorable ACR-related alleles , and ultimately help make anther culture reliable for production of maize breeding lines.