Cold-tolerant introgression line construction and low-temperature stress responseanalysis for bell pepper

摘要

We aimed to screen cold-tolerant introgression lines (ILs) of bell pepper and investigate stress responsesof these bell peppers under low temperature.Seedlings of cold-resistant wild-type bell pepper CA157, cultivated bell pepper CA52, and their ILs wereevaluated for their tolerance to low temperature. Electrical conductivity measurement was performed onILs and two parents. Then, contents of physiological and biochemical indexes including malondialdehyde(MDA), proline, and soluble sugar content were examined. Moreover, the superoxide dismutase (SOD),catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) activities were further investigated.Finally, the chlorophyll fluorescence (PSII) parameters in all pant leaves were examined.A total of 22 ILplants showed better resistance than their recurrent parent CA52. CL122 was one of the most outstandingplants in ILs that had similar performance with wild bell pepper CA157. Cold resistance analysis based onphysiological and biochemical indexes showed that factors such as electrical conductivity, MDA, and PSIIwere closely related to cold resistance among CA157, CA52, and CL122 under low-temperature stress.In conclusion, ILs constructed in the current study might be used for cold resistance gene introgressionbetween wild and cultured species. Moreover, CL122 might be a novel bridge material for understandinglow-temperature response in bell pepper. Furthermore, electrical conductivity, MDA, and PSII might beused to identify the low-temperature resistance of bell pepper plants in a period of obviousdifferentiation.