Abstract:
The rice crop grown in low country wet zone of Sri Lanka, especially in river basins close to the
coastal areas, subjected to frequent flood and salinity conditions. Therefore, there is a need to
develop improved varieties for both salinity and submergence tolerance. With the objective of
salinity and submergence tolerant variety improvement, generation advancement of two crosses
(Cross 1: At 354/Bg 455, Cross 2: Ld 12-22-2-1-1/ Ld 13-5-7) were carried out at Rice Research
Station (RRS), Labuduwa, using submergence (Bg 455 and Ld 13-5-7) and salinity (At 354 and
Ld 12-22-2-1-1) tolerant parents. Estimation of genetic parameters of growth and yield
characteristics was carried out using F1 of two crosses and respective parents established at RRS
at Labuduwa during 2014/15 Maha Season. Both crosses showed positive heterosis and
heterobeltiosis in number of panicles per plants, flag leaf length, flag leaf width, number of seeds
per panicle, weight of seeds per panicle and seeds width. The estimated genetic parameters
indicated that with respect to both crosses there is a possibility to have transgressive segregants
for above mentioned important yield components of rice in subsequent generation selections.
