Biochemical and physiological evaluations of common bermudagrass [Cynodon dactylon (L.) Pers.] Iranian accessions under cold stress

Abstract

In this study, one foreign cultivar and forty-nine common bermudagrass
accessions were collected from 18 provinces of Iran. Turfgrasses were
grown at four temperature regimes (24/17, 7.5/0, -7.5/-12 and 15/-15°C
day/night cycles) in a factorial experiment based on the completely randomized design with three replications. Physiological traits were evaluated to categorize all accessions as either cold sensitive or tolerant using Hierarchical Clustering with Ward’s method in SPSS software. Our results revealed that cold-tolerant common bermudagrass accessions showed higher proline, protein, antioxidant enzymes, color, visual quality and chlorophyll content and cold-sensitive accessions showed more severe cell membrane damage (EL) under cold stress conditions. Fall in temperature from 24°C severely decreased chlorophyll content, visual quality and color in all accessions. The highest antioxidant enzymes activity, chlorophyll content, color and visual quality at -7.5°C were observed in Taft, foreign cultivar, Naein, Malayear, Aligoudarz, Safashahr and Gorgan accessions. The increase in POD, SOD, CAT and APX activity
observed in this study led to protection against oxidative damage caused due to high ROS levels. The most cold-tolerant accessions at -15°C were Taft, Naein and Malayear. Great variations in freezing tolerance were observed between Iranian accessions of common bermudagrass. Further molecular studies are needed to clarify better these findings.