Morpho-anatomical responses of Sertani and Trisakti upland rice genotypes to contrasting soil moisture regimes

CHAIRANI HANUM (Department of Agrotechnology, Faculty of Agriculture, Universitas Sumatera Utara. Jl. Dr. A. Sofian No. 3, Medan 20155, North Sumatra, Indonesia)
BRYAN DEVA SIMATUPANG (Department of Agrotechnology, Faculty of Agriculture, Universitas Sumatera Utara. Jl. Dr. A. Sofian No. 3, Medan 20155, North Sumatra, Indonesia)

Biodiversitas Journal of Biological Diversity
Vol. 27 No. 3 (2026)

Abstract. Hanum C, Simatupang BD. 2026. Morpho-anatomical responses of Sertani and Trisakti upland rice genotypes to contrasting soil moisture regimes. Biodiversitas 27 (3): d270334. https://doi.org/10.13057/biodiv/d270334. Water availability critically determines upland rice agronomic performance, necessitating characterization of genotypic responses across moisture gradients. This study evaluated morpho-anatomical responses of two upland rice genotypes (Sertani and Trisakti) under contrasting moisture regimes of 40%, 60%, and 80% field capacity (FC) during the vegetative phase, using a factorial Randomized Complete Block Design (RCBD) with three replications. As FC increased from 40% to 80%, both genotypes showed significant (p<0.05) progressive increases in leaf area, leaf thickness, Relative Chlorophyll Index (RCI), bulliform cell dimensions, stomatal length, stomatal width, stomatal density, root volume, and total biomass. Root volume increased nearly five-fold from 0.25 cm³ at 40% FC to 1.23 cm³ at 80% FC, while total plant dry weight increased 3.9-fold (0.20 to 0.78 g) over the same gradient. Anatomical cross-sections revealed moisture-dependent structural differentiation: at 40% FC, plants displayed reduced cortical aerenchyma with endodermal lignification, whereas at 80% FC, extensive aerenchyma development was observed; these observations are qualitative and descriptive. Observed root:shoot ratios were numerically highest at 40% FC (Sertani: 0.50; Trisakti: 0.82); however, as these represent treatment means only and were not subjected to replicate-level statistical testing, no inferential conclusion regarding biomass allocation shifts is drawn. Trisakti showed numerically higher mean values than Sertani for root volume (variety mean: 0.82 vs. 0.70 cm³) and root dry weight (0.18 vs. 0.13 g), though these differences were not statistically significant (variety main effect: F (1,15) ≤ 2.36, p>0.05). The sole trait showing a significant variety effect was RCI (F (1,15) = 5.41, p<0.05), with Trisakti recording a higher mean. These moisture-responsive morpho-anatomical plasticity patterns provide a phenotypic reference for future comparative studies of climate-adaptive upland rice germplasm.