[P3] Abiotic Stress for Crop Production

[P3-14] Root and Leaf Plasticity in Response to Soil Moisture Fluctuation in Rice

*Nominated for Presentation Awards

^○Yasutaka Noda^1.2, Mana Kano-Nakata², Shiro Mitsuya¹, Akira Yamauchi¹ (1.Graduate School of Bioagricultural Sciences, Nagoya University, Japan, 2.International Center for Research and Education in Agriculture (ICREA), Nagoya University, Japan)

Drought and soil moisture fluctuation (SMF) stress negatively affect plant growth and development in rainfed rice ecosystem. In our previous study, CSSL47 (chromosome segment substitution line derived from Nipponbare and Kasalath crosses) and KDML105 showed high root plasticity in response to SMF (Suralta et al. 2010; Owusu-Nketia et al. 2018). Also, leaf morphoanatomical plasticity in response to environmental stresses has been reported. This study aimed to evaluate the leaf morphoanatomical response in relation to root plasticity expression under SMF conditions and those contribution to dry matter production using Nipponbare, CSSL47 and KDML105. We hypothesized that root plasticity exhibited more in mild drought-SMF than severe drought-SMF. Rice plants were grown under waterlogged conditions (Control), 20% of soil moisture content as mild drought to waterlogged (SMF20) and 10% of soil moisture content as severe drought to waterlogged (SMF10) in root box (L × W × H = 25 cm × 2 cm × 40 cm) under glasshouse conditions. CSSL47 and KDML105 showed greater shoot dry matter production than Nipponbare under SMF, which was attributed to the greater root system and stomatal number per plant resulting the maintenance of water uptake. However, there was no difference in stomatal density among the three varieties. Also, more plasticity was exhibited in SMF20 than in SMF10. These results implied that CSSL47 and KDML105 can increase leaf area and the number of stomata per plant and contributed to the increase in dry matter production under SMF with mild drought to waterlogged.