Relation of Root Growth of Rice Seedling with Nutrition and Water Use Efficiency Under Different Water Supply Conditions

The arid/semiarid regions contribute the forty- three percent of crop planted each year. In these regions, rice is mostly grown under rainfed conditions, where the chances plants to face drought are during the growing season. The primary determinant of cr…

Relation of Root Growth of Rice Seedling with Nutrition and Water Use Efficiency Under Different Water Supply Conditions

Water deficiency is one of the primary yield-limiting factors in rice. In plants, the nutrition and water use efficiency depend on root growth efficiency under different water supply conditions (WSC). Three rice genotypes, Azucena (an upland japonica), IR1552 (a lowland indica) and Jia 9522 (a lowland japonica), were grown under different WSC with 0 cm (submerged), 40 cm and 80 cm groundwater levels below the soil surface to investigate the root parameters, water use efficiency, nitrogen, phosphorous and potassium contents, net photosynthetic rate and transpiration rate of the rice plant. The relative parameters were defined as the ratio of the parameters under submerged conditions (0 cm groundwater level below soil surface) to these under upland conditions (40 cm and 80 cm groundwater levels below soil surface). The results indicated that different genotypes showed different relative root parameters and relative nutrition content and water use efficiency under different WSC. The length and number of adventitious root are more important than seminal root length in water and nutrition uptake, and maintaining the grain yield and increasing dry matter, but the adventitious root number could not be served as an index for screening drought-resistant genotypes. Furthermore, different drought-resistant genotypes have been also found, and Azucena was resistant to drought, IR1552 sensitive to drought and Jia 9522 neither sensitive nor resistant to drought.