Screening Some Potential Potato Genotypes With an Efficient Photosynthetic System Based on Their Performance Under High Temperature and Irradiance

Sustainable potato cultivation in hot, high-light regions such as Southern Punjab, Pakistan, requires identifying genotypes with efficient photosynthetic systems. High temperatures and irradiance often reduce productivity by triggering oxidative stress and limiting photosynthesis. This study evaluated growth, photosynthesis, yield, and biochemical responses in 15 advanced potato genotypes under such conditions. Genotype BD1310-1 showed greater performance with the highest plant height (51.5 cm), leaf area index (1.47), crop growth rate (0.43 g m⁻² day⁻¹), quantum yield of Photosystem II (Φ_II; 0.75), and tuber yield (21.5 t ha⁻¹), along with the lowest oxidative stress indicators. BD1319-2 had the highest number of stems plant⁻¹ (5.3), BD1311-4 showed maximum photosynthetically active radiation absorption (430 μmol m⁻² s⁻¹), and BD1335-4 had the highest linear electron flow (209 μmol electrons m⁻² s⁻¹). Principal component analysis grouped traits into positively and negatively correlated clusters. Traits such as LAI, Φ_II, crop growth rate, and tuber yield were positively associated with photosynthetic efficiency, whereas oxidative stress markers were negatively correlated. The findings suggest that oxidative markers reflect stress, not yield potential. In conclusion, BD1310-1, BD1319-2, BD1311-4, and BD1335-4 demonstrated potential as climate-resilient cultivars suitable for high-temperature (> 40°C) and high-irradiance (> 2000 μmol m⁻² s⁻¹) environments.