Abstract:
Photosynthesis serves as the primary source of dry matter production,
determining biomass and grain yield in rice. The objectives of this research
were to compare leaf photosynthetic traits among six elite rice varieties
released by the Department of Agriculture in Sri Lanka and to identify the
best-performing variety. A pot experiment was conducted with six rice
varieties grown in soil media, arranged in a completely randomized block
design, and replicated five times in a plant net house facility. The collected
data included chlorophyll content, quantum yield efficiencies, stomatal
conductance, and relative water content in rice leaves. The results revealed
significant variation in chlorophyll content, with the highest value observed
in BW 367 (37.0) and the lowest recorded in BG-310 (29.1) compared to the
control variety AT-362. Chlorophyll fluorescence measurements of 0.74 were
recorded in BW-360, while the lowest was found in BG-360 (0.67) compared
to the control variety AT-362 (0.73). In the 11th week after planting, stomatal
conductance showed significance, exhibited highest value was observed in
BW-367 (570.38), and the lowest in BG-403 (189.99). Comparing relative
water content among the six varieties revealed significant differences
between treatments (P < 0.05), with the highest value measured in BG-360
(89.66%) and the lowest in BG 379-2 (62.66%). According to these findings,
BG 360 and BW 367 exhibited superior performance compared to the control
variety AT-362 under net house conditions.
