Physiological quality and gene expression during the development of habanero pepper (Capsicum chinense Jacquin) seeds

Abstract

Phytohormones have different characteristics and functions, and they may be subject to changes in their gene expression and synthesis during seed development. In this study, we evaluated the physiological qualities of habanero peppers (Capsicum chinense Jacquin) during seed development and the expression of genes involved in germination. Seeds were obtained from fruits harvested at different stages of development [i.e., 14, 21, 28, 35, 42, 49, 56, 63, and 70 days after anthesis (DAA)]. Immediately after harvesting, the seeds were subjected to various tests to determine moisture content, germination, first count germination, and seedling emergence. Real-time polymerase chain reaction was used to evaluate the expression of various genes, including MAN2, NCED, B73, ICL6, and GA3ox. Electrophoresis was used to assess the expression of various enzymes, including α-amylase, isocitrate-lyase, and endo-β-mannanase. Habanero peppers harvested at 70 DAA and subjected to 7 days of rest exhibited higher germination rates and vigor compared to those harvested at all other developmental stages. Peppers harvested at 63 DAA without drying exhibited higher α amylase and AmyB73 gene expression levels. Peppers harvested at 70 DAA with 7 days of rest exhibited higher endo-β-mannanase expression levels. MAN2 gene expression increased during the development of non-dried seeds until 70 DAA. Peppers harvested at 42 DAA exhibited the highest isocitrate-lyase and ICL6 gene activity levels in comparison to those at all other developmental stages.