Effect of different photoperiods on the period of maturity of hot peppers (Capsicum annuum L.) and their changes in color.

• 16 h day/8 h dark can significantly shorten the maturity period in pepper. • Color in fruit skin is the combined result of various species from anthocyanins and carotenods. • Anthocyanin synthesis did not cease, and its degradation and accumulation of carotenoids proceeded simultaneously as the fruits matured. The need for a lengthy maturation period and delayed changes in color are the key factors that reduce the market value of hot peppers (Capsicum annuum L.). This study assessed the effects of different photoperiods on the reduction of the maturation period and changes in color of hot peppers. The use of a photoperiod of 16 h day/8 h night (the T4 group) resulted in a higher percentage of red hot peppers, earlier seed maturity and shorter days for the hot peppers to mature compared to the control. This suggests that the T4 group reduced the period of hot pepper maturity. An additional analysis found that the promotion of the process of changes in the color and the formation of red color in the fruits that is owing to the T4 group is the result of a combination of α-carotene, β-carotene, γ-carotene, and capsorubin. In addition, anthocyanins, including delphinidin, malvidin, and cyanidin, played a key role in the formation of purple in the hot peppers, and these pigments were related to some key differentially expressed genes. Interestingly, the biosynthesis of anthocyanins did not stop as the hot peppers matured, and the degradation and accumulation of the carotenoids proceeded simultaneously. The T4 treatment inhibited the degradation of anthocyanins, which indicated that the color of the hot peppers is owing to a mixture of anthocyanins and carotenoids. This study provides insight into the mechanism of pigment biosynthesis and the potential use of photoperiods in the process of speed breeding peppers. [ABSTRACT FROM AUTHOR]