• Several physiological and agronomical indices are considered in case of drought tolerance of a plant. For example: Leaf wilting, Fresh and dry biomass, Relative water content (RWC).
• These indices were related to stomatal conductance (gs), stomatal density, transpiration rate (E), net CO2 assimilation rate (An), and water use efficiency (WUE).

The main trait is that rice possesses C4 photosynthesis

Silica deposits in their leaves and bulliform cells which controls rolling and unrolling of leaves (presence or absence of water)

in rice plant height, chlorophyll content, root length, grain filling, can be used for drought tolerance.

Dear Junaid Iqbal ,

You can read the following article.

Article Elucidation of photosynthesis and yield performance of rice ...