Speed Breeding Scheme of Hot Pepper through Light Environment Modification

Abstract

Crop breeding for high yields and quality is an important measure to ensure food security. In conventional breeding, a long generation time is required. Speed breeding could accelerate the flowering and fruiting of crops by providing suitable environmental conditions in order to reduce the generation times. This study aimed to determine a speed breeding scheme for hot peppers. Two hot pepper varieties, ‘Xiangyan 55’ and ‘Xiangla 712’, were investigated for their growth and development under different light intensities, photoperiods, and red-to-far-red ratios. Hot pepper plants bloomed at 39.88 ± 0.74 days after sowing under photosynthetic photon flux density (PPFD) 420 µmol·m−2·s−1 and a 12-h photoperiod and had seed with acceptable germination rates at 82 days after sowing. Blooming was 2–3 days earlier when the photoperiod was extended to 20 h, but the fruit and seed development were not significantly improved. Supplementation of far-red light (R:FR = 2.1) significantly accelerated the red ripening of pepper fruit and improved seed germination rates. The modification of the light environment accelerated hot pepper growth and development, reduced breeding cycles, and could produce up to four generations per year.