Evaluation of drought tolerance of Triticum araraticum and Triticum timopheevii: A neglected GGAA genome

Wheat is an essential cereal crop, and its production is limited by several biotic and abiotic stress factors, specifically drought. Climate change and depletion of groundwater due to erratic rainfalls have increased the severity and intensity of drought stress. Genetic erosion in domesticated wheat and increased drought stress highlight the need to evaluate the potential of wheat wild relatives. Thus, two different approaches, i.e., a PEG-induced drought stress experiment at the seedling stage and a two-year field experiment under rainfed conditions, were conducted in the molecular genetics lab and research and application area of the Field Crops Department of Çukurova University, respectively, to decipher the potential of an overlooked GGAtAt genome of Triticum araraticum. A panel of 90 Triticum araraticum genotypes was used in both experiments 15 Triticum dicoccoides genotypes, and five commercial cultivars of durum wheat were used in the drought stress experiment for comparison. The findings of the seedling stage experiment revealed that drought stress significantly affected all the studied traits, with the maximum effect on mean seminal root length (42.26%), followed by shoot length and total root length (40.34 and 40.32, respectively) and the minimum effect on total root number (9.50%). On the other hand, the results of the field experiment revealed significant variations among genotypes for all the traits under investigation, while the genotypic response for most of the traits was constant in response to the change in environment. The results revealed valuable genetic diversity among the genotypes that can be used in wheat breeding programs. Moreover, based on the results of the seedling stage experiment, some promising T. araraticum genotypes (TR60, TR14, TR41, TR1, TR45, TR62, TR103, TR96, TR38, TR97, TR55, TR30, TR7) were identified and it was observed that T. araraticum showed comparable performance with T. dicoccoides. Therefore, it is concluded that T. araraticum holds significant potential for drought stress tolerance in wheat and should be utilized in wheat breeding programs to develop drought-tolerant wheat cultivars. Keywords: Drought stress, Wheat, Triticum araraticum, Shoot length, Total root length