Vol. 8, Special Issue 12, Part R (2024)

Rice is a primary nutritional source for a significant portion of the global population. Despite notable advancements in rice production and productivity over the past five decades, a substantial portion of the annual yield is lost due to various biotic and abiotic stress factors. Among these, bakanae disease has emerged as a serious threat to rice cultivation. Stress factors significantly impact physiological parameters such as leaf gas exchange activities in rice plants. This study investigated the effects of bakanae disease on leaf gas exchange activities in two contrasting rice genotypes, one resistant and the other susceptible. The results revealed that pathogen inoculation inhibited germination, increased plant height in the susceptible genotype, while the resistant genotype remained largely unaffected. Initially, photosynthesis rates increased in inoculated plants but subsequently declined compared to control plants, with a more pronounced reduction observed in the susceptible genotype. Similar trends were observed in transpiration rates and stomatal conductance. In control plants of both genotypes, no significant changes in these parameters were observed over time. Further research is essential to elucidate the mechanisms underlying these physiological responses, which could provide valuable insights into the complex nature of host resistance.