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.

Effect of Temperature induction response on Cell viability, Cell Survivability, Malondialdehyde content and total soluble protein content of cotton (Gossypium hirsutum L.) genotypes

“Temperature Induction Response” (TIR) technique was employed to investigate the effect of temperature on popular 20 cotton (Gossypium hirsutum L.) genotypes in a laboratory experiment conducted at the Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore during 2020-2021. Identical sized ten days old cotton seedlings were selected and subjected to inductive temperature (gradual temperature raised from 28 to 40℃) for 4 h and non-inductive temperature (46℃ for 3 h, 47℃ for 3 h, 48℃ for 3 h and 48℃ for 4 h) for specific time duration. KC3 and SVPR6 recorded highest thermotolerance among the genotypes and TSH325 and TSH357 showed moderate thermotolerance while TSH375 and TSH383 were sensitive, in terms of seedling survival, cell viability, total soluble protein and malondialdehyde compared to remaining genotypes under non-inductive temperature