Genotypic Variation in Biomass Production at the Early Vegetative Stage among Rice Cultivars Subjected to Deficient Soil Moisture Regimes and Its Association with Water Uptake Capacity

Genotypic Variation in Nitrogen Uptake during Early Growth among Rice Cultivars under Different Soil Moisture Regimes

“…The plants used in the present study were the same as those used previously (Matsunami et al, 2012): RDRS developed by NIAS as a global rice core collection (NIAS Genebank, 2010) and a high drought-tolerant japonica cultivar Azucena (Sangam et al, 2010). RDRS consists of 69 cultivars, including 22 indica I types, 33 indica II types and 14 japonica types (personal communication with Dr. Ebana, NIAS) collected from 19 countries, and developed based on a genome-wide RFLP polymorphism survey of 332 accessions, which were selected on the basis of the passport data of all collections stored at the Genebank of the NIAS, and holds 91% of the alleles identified in these accessions (Kojima et al, 2005).…”

“…The amount of water uptake was estimated from the daily reduction in pot weight and the amount of evaporation. Further details of cultural methods and soil properties were as described previously (Matsunami et al, 2012).…”

“…In this regard, we previously examined the genotypic variation in early growth of the rice diversity research set of germplasm (RDRS), which was developed by the National Institute of Agrobiological Sciences (NIAS, Tsukuba, Japan) under different soil moisture conditions, and revealed their wide genotypic diversity in biomass production and water uptake capacity (Matsunami et al, 2012). Genetic improvement of N uptake ability and N use efficiency will contribute to the efficient recovery of N input, and the amount of chemical N applied can be reduced and thereby alleviate environmental pollution.…”

Root development and the expression of aquaporin genes in rice seedlings under osmotic stress

“…We previously examined the genotypic variation in biomass production under different soil moisture conditions using a rice diversity research set of germplasm developed by the National Institute of Agrobiological Science and found that an indica rice cultivar 'Puluik Arang' exhibited great water uptake, resulting in large biomass production under unflooded conditions (Matsunami et al, 2012). It was hypothesized that better development of the root system, especially lateral root development, contributed to the greater water uptake by the cultivar 'Puluik Arang' under conditions of low water availability.…”

Agronomic Traits for High Productivity of Rice Grown in Aerobic Culture in Progeny of a Japonica Cultivar and a High-Yielding Indica Cultivar

“…The favorable traits include high root growth Matsunami et al, 2012), high transpiration and root exudation rates (Matsunami et al, 2010), high stomatal conductance and leaf elongation rates (Nguyen et al, 2009), rapid leaf area growth (Okami et al, 2011), large individual shoot size (Okami et al, 2012), and high radiation-use efficiency Katsura et al, 2010). In these studies, many rice cultivars with widely different genetic backgrounds were used.…”