Optimizing the production of true shallot seed by inducing flowering in various shallot genotypes

Shallot (Allium cepa var. aggregatum) productivity can be enhanced through various methods, including using true shallot seed (TSS). Successful shallot breeding requires flowering to improve traits through gene transfer between genotypes and to produce TSS. However, one of the primary challenges in TSS production is the variability in the flowering ability of different varieties. This study aimed to examine the impact of flowering induction on flowering traits, pollen viability, and TSS production in several shallot genotypes. The study employed a randomized complete block design with two factors: shallot genotypes and induction treatments. The study found that vernalization treatment significantly increased the percentage of flowering plants in the Bauji, Bima Brebes, and Tajuk genotypes. Additionally, the combination of vernalization (V) and gibberellin (GA3) (V+G) successfully induced flowering in the Maja Cipanas genotype compared to the control. The Bima Brebes genotype exhibited the highest pollen viability following both vernalization and V+G treatment. Furthermore, vernalization also led to an increase in TSS weight in shallots. These findings suggest that vernalization could be an effective strategy for enhancing TSS production in highland areas, thereby supporting the development of high-yielding shallot varieties. Significant positive correlations were observed between TSS weight and several traits, including the percentage of flowering plants, umbel number, umbel diameter, flower number, pollen viability, percentage of plants producing TSS, capsule number, and TSS number. Keywords: Allium cepa; correlation; gibberellin; varieties; vernalization