How can breeding contribute to more productive and sustainable rainfed lowland rice systems?

Abstract

The contributions to this special issue have examined our current understanding of the adaptation of rainfed lowland rice to the abiotic stresses associated with drought, submergence and low soil fertility. Genetic variation has been identified for both broad adaptation across target rainfed lowland environments and specific adaptations to some of the abiotic stress environments, e.g. late season drought, and submergence during vegetative development. However, in general progress in genetic improvement of adaptation that contributes to higher and more stable yields has been extremely slow. The opportunities for increasing the rate of genetic improvement of grain yield is examined under the four headings: (1) the complexity of the target genotype–environment system; (2) the genetic resources available to the breeding programs; (3) clarity of the breeding objectives, capacity of the adopted breeding strategy to achieve the necessary genetic modifications and selection strategy; and (4) the physical and human resource capability to implement, evaluate and manage the necessary breeding strategies. Recommendations are made on priority research areas that are required to integrate the growing understanding of rainfed lowland rice adaptation and the needs of the breeding programs.