Root-knot nematode resistance in advanced back cross populations of rice developed for water stress conditions
AbstractA number of drought tolerant introgression rice lines were screened to identify lines combining drought tolerance and resistance to root-knot nematode, Meloidogyne graminicola, for their direct utilization in water limited environments or for their indirect use in further breeding. The recurrent parent Teqing and the donors cvs Type 3, Zihui 100, Shwe Thwe Yin Hyv were resistant, while the donors cvs Binam, Khazar, Haoannong and recurrent parent cv. IR 64 were susceptible to the root-knot nematode. Though the cv. Binam was susceptible to the nematode, a number of its progenies in combination with either cv. IR 64 or cv. Teqing showed resistant reactions. Irrespective of the recurrent parent background, the percentage of resistant lines was higher in lowland stress selection compared to that in upland stress. The results revealed that the resistance to M. graminicola is not monogenic and support the multigenic nature of inheritance.