Corn tassel is a byproduct from hybrid corn seed production. It is also a new source of phytochemicals, including compounds with antioxidant activity. The aim of this study was to evaluate the phytochemical content and antioxidant potential of different corn tassel development stages. A 4 × 8 factorial experiment consisting of four tassel development stages and eight commercial corn varieties was carried out with a randomized complete block design with three replications. Data were collected for tassel weight, concentration and yield of total phenolics, total anthocyanin concentration, total carotenoid concentration, and antioxidant activity, as determined by the 2,2-diphenyl-1-picrylhydrazyl(DPPH^•) radical scavenging assay and Trolox equivalent antioxidant capacity(TEAC) assays. Corn varieties and tassel developmental stages showed significant variations (p ≤ 0.01) in all parameters. P4546 presented the best variety for the total phenolic content (15.8 mg GAE/g DW sample), whereas Hibrix3 had the highest phenolic yield (6.78 kg GAE/ha). KGW1, a purple waxy variety, had the highest anthocyanin content (1528.0 µg CGE/g DW sample), anthocyanin yield (753.0 g CGE/ha), carotenoid content (74.9 µg/g DW sample), and carotenoid yield (53.7 g/ha). P4546 had the highest antioxidant activity: 92.4% for DPPH^• and 76.1 µmol TE/g DW sample for the TEAC assay, respectively. The most appropriate time for tassel harvest to ensure the production of phytochemicals with high antioxidant activity should be from the 1st day of pollen shed until 50% of pollen shed. Phytochemicals and antioxidants that are extracted from corn tassel can be used as a functional food supplement, as natural pharmaceuticals, and in cosmetic products.

Corn tassel is a valuable co-product and an excellent source of phytochemicals with bioactive properties. The information on the genetic diversity in the tassel properties of waxy corn germplasm is important for creating new varieties that can have the potential for the commercial production of tassels as a co-product. Therefore, the objective of this study was to evaluate the potential of corn tassels in a set of waxy corn germplasm for the extraction of phenolic compounds with an antioxidant activity. The experiment was carried out under field conditions in the rainy season 2017 and the dry season 2017/2018. Fifty waxy corn genotypes were evaluated. Data were collected for the total anthocyanin content (TAC), total phenolic content (TPC) and the antioxidant activity was determined by the 2,2-diphenyl−1-picrylhydrazyl (DPPH) radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) assays. The season (S) had small effect on all of the parameters, accounting for 0.2–8.7% of the total variance. The genotype (G) was the largest variance component in the TAC and DPPH radical scavenging activity, accounting for 83.5–97.5% of the total variance. The G and S × G interaction contributed approximately equally to the total variance in the TPC and TEAC. Based on the TAC, TPC and antioxidant capacity variation, the genotypes were classified into seven groups. The tassels of corn genotypes belonging to three of these clusters (clusters E, F and G) had high levels of phytochemicals along with an antioxidant capacity. A significant correlation coefficient was found between the TAC and DPPH (r = 0.70 **). The TPC showed a moderate relationship with the DPPH and TEAC assays (r = 0.60 ** and 0.76 **, respectively). The information obtained from this study can be used for germplasm management and waxy corn breeding for enhancing levels of bioactive properties in waxy corn tassels.

Corn tassel is a by-product from hybrid corn seed production and a new source of phytochemicals including compounds with antioxidant activity. Four tassel development stages were evaluated in eight commercial corn varieties. Corn varieties and tassel developmental stages showed significant variations (P0.01) for all parameters. Total phenolic content and antioxidant activity were highest in field corn. KGW1, a purple waxy variety, had the highest anthocyanin content and carotenoid content at tassel development stages at 50% and 75% of pollen shed, whereas the tassel developmental stages at the 1st day of pollen shed and 50% of pollen shed had the highest of anthocyanin yield and carotenoid yield. The most suitable time for tassel harvest should be between the 1st day of pollen shed to 50% of pollen shed. Phytochemicals and antioxidants that are extracted from corn tassel can be used as a functional food supplement, natural pharmaceuticals and cosmetic products.

Doubled haploid (DH) technology accelerates maize breeding by generating completely homozygous lines within two generations, but its efficiency depends on reliable haploid identification markers. The Purple plant 1 (Pl-1) root pigmentation marker has emerged as a promising alternative to R1-Navajo (R1-nj), which suffers from frequent suppression in tropical germplasm. This study evaluated Pl-1 expression and seedling vigor in 298 diverse Thai maize genotypes across four market classes under controlled growth chamber conditions (24 ± 1 °C, 85–90% humidity, and standardized lighting), followed by testcross analysis with 89 representative genotypes crossed with BHI306 to distinguish between allelic absence and epistatic suppression mechanisms. Complete absence of Pl-1 expression was observed in 99.3% of Thai genotypes, contrasting with consistent expression in the temperate-derived control (BHI306). Testcross F₁ progeny from 89 Thai × BHI306 crosses exhibited intermediate expression levels (1.57–2.05) across all market classes, confirming allelic absence rather than suppressor-mediated inhibition. Substantial genetic diversity was detected in seedling vigor traits independent of Pl-1 status, with root length varying 43-fold and fresh weight 20-fold, showing highly significant genotypic effects. The uniform lack of Pl-1 expression across Thai germplasm eliminates background interference, highlighting its utility as a complementary marker when introgressed from inducer lines. These findings establish the genetic foundation for implementing optimized DH breeding strategies in tropical maize through marker-assisted backcrossing approaches.

The development of maternal haploid inducers adapted to tropical savanna environments is important for efficient implementation of doubled haploid (DH) tec