Single fertilization in maize

Single fertilization events were detected in seven maize lines (Zea mays L.) of different genetic background. Detection of single fertilization was achieved by a dual pollination method, that is, pollen parent 1 (y1/y1, white endosperm) was pollinated onto the silks of Oh43 (Y1/Y1, yellow endosperm) and 24 h later the same silks were pollinated with pollen of X18G (R1-scm2/R1-scm2, purple aleurone and purple embryo). Seventy-nine kernels with purple aleurone and white scutellum (Pw) were observed in 29,999 examined kernels. Determination of chromosome numbers and progeny tests revealed that 31 plants were maternal haploid, 4 were monosomics between Oh43 and X18G. 36 originated from single fertilization events by pollen parent 1 (0.4%), and 5 triploids are thought to have originated from single fertilization by a diploid sperm cell of pollen parent 1. At least one-fifth of heterofertilization events in maize can be the result of single fertilization.