Haploid induction in tropical supersweet corn and ploidy determination at the seedling stage

Abstract

The objective of this work was to determine the possibility of haploid induction in tropical supersweet corn (Zea mays L. var. saccharata) using a maternal inducer, as well as to identify alternative methods for haploid selection. A single-cross hybrid of field corn and 11 tropical supersweet corn populations were crossed with the haploid inducer. The haploids were pre-selected using the R1-navajo marker and were differentiated into haploids or false positives at the V2-V3 stage, based on the color of the first leaf sheath and on the length of stomata guard cells. The obtained results are indicative of the possibility of inducing maternal haploids in populations of tropical supersweet corn. However, a large number of false-positive haploids were incorrectly selected by the R1-navajo marker. The color of the first leaf sheath was efficient for haploid identification in supersweet corn populations, and the method based on stomata morphometry can be used when there is no color distinction on the first leaf sheath.

Are stomatal area and stomatal density reliable traits for identification of doubled haploids in maize?

“…Choe et al (2012) found that the mean length of the stomatal guard cells is an efficient trait for differentiation of haploid and diploid plants in maize. Sekiya et al (2020) evaluated samples of maize leaves collected in the V2/V3 stages and found that the morphometry of the stomata is an efficient methodology for distinction between haploids and false positives in sweet corn. Thus, our study confirms the efficiency of evaluation of stomatal density for distinction of DH and FP and for selection of DH.…”