Abstract:
Rice (Oryza sativa L.) is the staple food in Sri
Lanka. With the increasing population and the
changing climatic conditions, there is a need to
grow rice with increased yielding potential and
tolerance to several biotic and abiotic stresses.
Around 99 % of the total paddy production area
of the country is cultivated with newly improved
varieties, while the remaining area is adopted
with low-yielding traditional rice varieties [1].
Since rice is a semi-aquatic plant, it is usually
grown under anaerobic conditions as long as
water is available. According to recent studies,
the annual mean rainfall in Sri Lanka has
decreased throughout the country. In 2013,
about 35 % of rain-fed rice farmers in Dry and
Intermediate zones had given up their
cultivation during the Yala season compared to
the Maha, primarily due to insufficient water
availability [2]. Further, the rice production of
Yala 2019 had decreased approximately by 1.5
million metric tons than Yala 2018 season,
owing to the drought situation and pest damages
experienced in the primary rice-producing
districts [3].
The root architecture critically influences the
the yield of the crops, and improved root
characteristics help farmers grow crops tolerant
to multiple stresses and with high yield. There is
an urgent need to identify and develop drought
stress adaptable rice genotypes for rain-fed and
drought-prone areas. Therefore, the objectives
of this study were to screen three locally
available rice varieties for their root
morphology under aerobic and anaerobic
conditions and to identify best-performing
varieties with improved root traits to withstand
drought.
