Kartikaningrum et al. 2025_Supplementary information of "Identification of heat-tolerant Impatiens genotypes: morphological responses and stress tolerance indices under elevated temperatures"

This study aimed to identify Impatiens (balsam plant) genotypes that exhibit superior heat tolerance traits and explore how temperature affects plant morphology. The research compared ten Impatiens genotypes under heat stress and normal conditions. Measurements were taken during the vegetative and generative stages and at the end of the observation period. Results revealed significant genotype-specific responses to temperature with genotype and temperature interactions. Some genotypes exhibited superior plant height, leaf number, and flower production traits. However, under heat stress, many traits generally declined, including plant height and flower number, while some traits, like leaf length and width, increased. We found the darker colors in leaves, stems, and flowers under heat stress compared to control conditions. We also calculated heat tolerance indices. Thecorrelation and biplot analyses found that heat tolerance (TOL) often indicates susceptibility, while the stress tolerance index (STI), mean productivity (MP), and the geometric mean of productivity (GMP) reflect stress tolerance and yield performance under stress. STI, MP, and GMP are the most effective tools for selecting heat stress-tolerant for our Impatiens genotypes. The identified specific genotypes with high STI, MP, and GMP and low TOL, such as 22.04.16 and 22.04.08, exhibit resilience and robust performance under heat stress.