Architecture of rice root system as affected by tillering characteristics and N
1997
Kondo, M. | Aguilar, A. (International Rice Research Inst., P.O. Box 933, Manila (Philippines))
Root distribution is a critical factor in determining water-capturing capacity in upland rice. The plasticity of architecture of the root system as affected by genotypic variation and cultural conditions is to be clarified. The plasticity of the root components, nodal root, and lateral root was examined in pot and hydroponic cultures with different tillering characteristics. Nodal root number is positively related to tiller number in general, although there are some genotypic differences in this relationship. Based on tiller and nodal root number, the varieties used can be classified into three groups-lowland varieties, improved upland varieties, and traditional upland varieties. Nodal root length is negatively related to tiller number and, more closely with nodal root number. However, a nodal root length was strongly affected by N levels and O2 supply. High N level strongly inhibited elongation under submerged condition with limited O2 supply, while inhibition was to a lesser extent under aerated condition. This indicates interaction between N and O2 upon nodal root elongation. The density of the thick lateral roots varied based on genotype and N and O2 supply levels. Different parameters of root components varied in different degrees according to genotype and environmental factors. The environmental factors affect root morphologies directly and indirectly through tillering traits
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