Screening different cold-resistant sugarcane (Saccharum ssp. L) genotypes using morphological and biochemical indices

Sugarcane is cultivated in different parts of the world up to a latitude of about 32 degrees north and south. The resistance of this plant to cold is low. Considering the sensitivity of sugarcane to cold, in order to identify the pathways and genes by differential expression in sugarcane cultivars during cold stress and employ them in sugarcane plant breeding programs, 454 sugarcanes were investigated using morphological and biochemical indices, in the Research Farm of Khuzestan Sugarcane Research Institute following the incidence of -1.2 ℃ temperature in the region in December 2015. In the first stage, the cold-tolerant or sensitive cultivars were selected using morphological indices. In the second stage, biochemical indices such as proline and malondialdehyde were measured in the tolerant cultivars (selected at the first stage) after a cold stress period in 2016, which showed increases in comparison with susceptible cultivars. According to the data obtained at the two stages, two cultivars, namely BR00-01 and TUC66-107, were identified as the most tolerant and sensitive to cold, respectively. Based on the results of morphological studies, the cultivars with a higher tolerance to cold stress were also hose with higher proline and MDA levels in the biochemical study stage compared with the sensitive cultivars. There was also a high correlation between morphological traits and biochemical indicators in terms of cold resistance. Therefore, by measuring morphological and biochemical indices, it is possible to determine to a large extent the type of reaction of a sugarcane cultivar to cold stress before doing molecular analysis and spending huge sums of money, and to select superior clones when sifting sugarcane clones at different breeding stages.