Rainfed rice - IRRI books - International Rice Research Institute

Rice Biodiversity and
Genetic Wealth
R
ice biodiversity is the varietal diversity of rice in farmers’ fields. It
provides the base for genetic improvement by pure line selection
(e.g., Basmati 370, the best known aromatic rice variety selected from
the local landrace) and hybridisation (e.g., IR8, a high-yielding, fertiliserresponsive,
dwarf variety). Also, desirable traits from local germplasm can be
transferred by using molecular techniques.
Why do farmers grow more than one
variety?
Farmers have played a major role in conserving
some of the traditional as well as improved
varieties. They have been traditionally growing
more than one variety for the following reasons:
to suit diverse, unpredictable environments
within the ecosystems;
to meet diverse household needs, e.g., food,
fodder, medicine and thatching;
to combat pests and diseases;
to suit different cropping systems;
to meet changing market demands; and
to keep the family pride and tradition.
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Remember!
Loss of biodiversity is a threat
to mankind. Save it from
extinction through farmers’
participation.
Conserve biodiversity in situ
and ex situ.
Essential varietal characteristics in
rainfed rice ecosystems
Upland – Drought tolerance
Lowland – Submergence tolerance
Flood-prone – Fast stem elongation