Physiological Traits of Thirty-Five Tomato Accessions (Solanum lycopersicum L.) in Response to Low Temperature

Abstract

Tomato is exposure to diverse abiotic stresses. Cold stress is one of harsh environmental 12 stresses. Abnormal low temperature affects tomato growth and development including physiolog- 13 ical disorders, flower drops, and abnormal fruit morphology, causing the decrease of tomato yield 14 and a fruit quality. It is important to identify low temperature-(LT) tolerant tomato (Solanum lyco- 15 persicum L.) cultivars. This study focused on analyzing physiological traits of thirty-five tomato ac- 16 cessions with three fruit types (cherry, medium, and large sizes) under night temperature set-points 17 of 15°C for normal temperature (NT) and 10°C for LT, respectively. Plant heights (PH) of most to- 18 mato accessions in LT were remarkably decreased compared to those in NT. The growth of leaf 19 length (LL) and leaf width (LW) was reduced depending on the genotypes under LT. The number 20 of fruits (NFR), fruit set (FS), fruit yield (FY), and marketable yield (MY) was negatively affected in 21 LT. The FS in LT was significantly correlated with FY in LT in total populations (n = 35), cherry fruit 22 sub-populations (n = 20), and medium fruit sub-populations (n = 11). Moreover, the relevance of 23 NFL in LT with FY in LT was related to total populations (n = 35), cherry fruit sub-populations (n = 24 20), but not medium fruit sub-populations (n = 11). The results indicate the physiological traits of 25 FS in LT and FY in LT are crucial factors for selecting and determining LT-tolerant cultivars for 26 breeding programs in tomato plants depending on different fruit types.