Impact of elevated temperature on root traits and microbial interaction in cotton (Gossypium hirsutum L.) genotypes

Climate change mainly alters the plant phyllosphere and rhizosphere resource allocations. Compared with shoot parameters, there is less information about how roots, especially root system architecture (RSA) and their interactions with others, may respond to elevated temperature changes. These responses could greatly influence different species acquisition of resources and their competition with their neighbours. The main aim of this experiment was to evaluate the effects of ambient temperature (T1) and elevated temperature (+4oC) (T2) in Open-top chamber (OTC) on root traits and microbial interaction changes in cotton (Gossypium hirsutum L.). A pot experiment was conducted at the Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore, during 2020-2021 to investigate the root traits and microbial interactions. Cotton varieties, namely KC3, SVPR6, TSH325, TSH357 and TSH375 were screened at the seedling level for cellular thermo tolerance and further, at the root level, these selected varieties were studied against the elevated temperature condition for 10 days in OTC during the stage of flowering to boll development period along with control temperature condition. Root interactions' intensity and direction may fluctuate as a result of variations in RSA responses between species. Negative root interactions could become more intense under high temperature circumstances and species with bigger roots and greater early root growth had stronger competitive advantages. The present findings showed that elevated temperatures promote various microbial growths in the geothermal regions, enhancing the root angle and root length of cotton species. Among the genotypes, KC3 and SVPR6 performed better under elevated temperatures.