Genotypic differences in root hydraulic conductance of rice (Oryza sativa L.) in response to water regimes

• Published in: Plant and soil 2009-03, Vol.316 (1-2), p.25-34
• Main Authors: Matsuo, Naoki, Ozawa, Kiyoshi, Mochizuki, Toshihiro
• Format: Article
• Language: English
• Subjects: Agrology; Agronomy. Soil science and plant productions; Anatomy; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Dehydration; Ecology; Fundamental and applied biological sciences. Psychology; Genotype & phenotype; Genotypes; Hydroponic culture; Hydroponics; Life Sciences; Lowland rice; Plant biology; Plant growth; Plant Physiology; Plant roots; Plant Sciences; Plants; Regular Article; Rice; Root hydraulic conductance; Soil culture; Soil hydraulic properties; Soil Science & Conservation; Soil water; Soil water regimes; Soils; Upland rice; Water stress; Water uptake; Water-saving culture
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-008-9755-5

To determine water uptake by rice in water-saving culture, we examined root hydraulic conductance (L ₀), plant growth, and root anatomy of three rice genotypes (Oryza sativa L. ssp. indica cv. Beodien, traditional upland; ssp. japonica cv. Sensho, traditional upland; ssp. japonica cv. Koshihikari, improved lowland) under three water regimes: water-saturated (hydroponic), well-irrigated aerobic (control), and water-saving aerobic in soil. In hydroponic culture, although shoot dry weight (SDW) and root number were the largest in Sensho, root L ₀ was the highest in Koshihikari. There was no significant relationship between root L ₀ and SDW in hydroponics, so root L ₀ might not limit shoot growth under flooding. Root L ₀ was much less in soil than in hydroponics, and that of Koshihikari was the lowest, especially in water-saving conditions. Root L ₀ was highly correlated with SDW under water-saving conditions but not in the control, so root L ₀ limits shoot growth under repeated water stress. Root anatomy was less affected by water regime than root L ₀ and is genetically controlled. Thus, root L ₀ may be more affected by water channels than by root anatomy.