Exploring climate change impacts on morphology and phenology of common wild rice in Sri Lanka

Exploring phenotypic plasticity and adaptive potential of natural populations of wild rice is crucial because of the recent drastic climatic changes. The wild progenitors of cultivated rice (O. rufipogon and O. nivara) provide an excellent natural system for investigating the processes of phenotypic plasticity. We examine the responses of morphology and phenology of O. rufipogon and O. nivara in their respective typical natural habitats throughout the life cycle in two distinct periods, 2016 and 2020. A three-year gap was maintained to visualize the variations of traits against the continued climatic effects. Trait divergence between two years was tested using a t-test. Results revealed noticeable differences in the morphological characteristics, including the highest plant height (159.92 ± 3.52 cm), flag leaf length (21.15 ± 1.49 cm), flag leaf width (1.16 ± 0.06 cm), anther length (3.84 ± 0.06 mm), and awn length (4.10 ± 0.40 cm) of O. nivara in 2020 due to high annual precipitation. O. rufipogon showed a stable response, which inhabitant to deep water. Compared to 2016, O. nivara flowered earlier in 2020, but O. rufipogon displayed a late flowering in 2020. These findings imply that phenotypic plasticity played a significant role in environmental adaptability. These adaptive variations are crucial to adapt in climate change and species divergence, offering new avenues for understanding vital genes for breeding climate resilient rice.