Screening of pepper (Capsicum l.) seedlings tolerance to low temperature

Abstract

This study was conducted on screening for 21 pepper genotypes tolerant to low temperature and their duration for survival in 3-4 (38 days after sowing), and 4-6 (47 days after sowing) true leaf seedling growth stages (LS). It was detected that response of seedlings on low temperature were different and ranged among the genotypes depends on growth stages. Seedlings in early 3-4 LS growth stage were more susceptible than 4-6 LS seedlings, where the first symptoms of leaf cold damages (LCD) were revealed within 7 days after transplanting (DAT) and 12 DAT in pepper seedlings, respectively. There were identified that the susceptible genotypes in 3-4 LS can be tolerant in 4-6 LS, or show opposite pattern, where tolerant one in next the growth stage, plant becomes susceptible. Low temperature negative impact on chlorophyll content (CHL) in leaves, however depends on seedling growth stage and genotype might be ranged. The lowest content of CHL were observed in early growth 3-4 LS seedlings than 4-6 LS. And, it was revealed that cold susceptible pepper genotypes in which CHL reduced significantly during cold treatment, showed good ability to recovery of CHL after treatment of seedlings in NT condition, whereas cold tolerant genotypes with high CHL content during low treatment, can reduce significantly of CHL after transfer of seedlings to NT condition for recovery. According to screening were selected relatively cold tolerant pepper genotypes LT8 and LT9 in early 3-4 LS, and LT8, LT13, LT18, LT20 and LT21 in 4-6 LS, where LCD were below 45 and 10%, respectively.