Breeding of a New Upland Rice Variety "Yumenohatamochi" with High Drought Resistance and Good Eating Quality.

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

“…Regarding rice root morphology, which is adaptable to flooded conditions, Yamauchi et al (1987Yamauchi et al ( , 1988 speculated that those cultivars with a concentrated type of root system, which results in a large number of short individual crown roots, might be more adaptable to flooded conditions, because such a root system might be capable of supplying adequate oxygen to the root apex which requires a large amount of oxygen for cell division. In contrast, root penetration into a deeper soil layer (Araki and Iijima, 1998;Hirasawa et al, 1998;Kato et al, 2006aKato et al, , 2007, or lateral root development (Kano et al, 2006;Suralta et al, 2008), was indicated as a critical root trait for adaptability to water-deficient conditions. Furthermore, the plasticity of root development was emphasized as an important trait for the adaptability to soil moisture changes (Kano et al, 2011).…”

Growth of Rice (Oryza SativaL.) Cultivars Under Upland Conditions With Different Levels of Water Supply3. Root System Development, Soil Moisture Changeand Plant Water Status

“…On the other hand, in the field experiment, RLD at 30-60 cm depth did not differ among cultivars after the heading stage ( Table 1). The deep root traits of YHM are derived from a tropical deep rooted rice cultivar, JC81 (Hirasawa et al, 1998), and it might be more affected by low air temperatures and low levels of solar radiation during the panicledevelopment stage in the field experiment, compared with LMT and NPB, resulting in lower RLD and RWD at 0-60 cm in YHM ( Table 1). Greater distribution of roots in deeper soil layers was necessary for the development of a deep root system in the field, which confirms the results of Azhiri-Sigari et al (2000) in pot experiments.…”

Growth of Three Rice (Oryza sativaL.) Cultivars under Upland Conditions with Different Levels of Water Supply

“…YHM is an upland japonica cultivar with a deep root system, which has been recently bred in Japan, and often performs better than other upland cultivars under upland conditions in dry years in Japan (Hirasawa et al, 1998). LMT is a lowland japonica cultivar developed in the United States (Bollich et al, 1985), and has a deep root system under fl ooded lowland conditions in Japan (Morita et al, 1995).…”