Abstract
Perennialism is common among the higher plants, yet little is known about its inheritance. To address this, six hybrids were made by reciprocally crossing perennial Zea diploperennis Iltis, Doebley & R. Guzman with inbred lines B73 and Mo17 and Rhee Flint, a heirloom variety, of Z. mays L. ssp. mays. All the F1 plants demonstrated several cycles of growth, flowering, senescence and regrowth into normal flowering plants, indicating a dominant effect of the Z. diploperennis alleles. The regrowability (i.e. the plants' ability to regrow after senescence) was stably transmitted to progeny of the hybrids, so we focused on this trait. Segregation ratios in the F2 generations are consistent with the trait controlled by two dominant, complementary loci, but do not exclude the influence of other modifiers or environment. Genome-wide screening with genotyping-by-sequencing (GBS) indicated two major regrowth loci, regrowth 1 and regrowth 2, were on chromosomes 2 and 7, respectively. These findings lay the foundation for further exploration of the molecular mechanism of regrowth in Z. diploperennis.
Footnotes
We have reframed regrowth in our manuscript as one aspect of perennialism and focused our discussion to regrowth and regrowability instead of perennialism and perenniality. As a result, we have changed our tittle a little bit. A new QTL analysis of the SNPs without chi-square imputation has been done to explore the possibility that regrowability could be controlled by multiple QTL. The results of this analysis and the relevant discussions have been added in this revised manuscript. This new analysis strengthened our conclusion that two major loci control the regrowth in Zea diploperennis. We also removed the section about PCR marker screening and the relevant discussions from the manuscript since they are premature.