*WATER DEFICIT STRESS IN THE REPRODUCTIVE STAGE OF
FOUR INDICA RICE (ORYZA SATIVA L.) GENOTYPES
Relative water content (RWC) in the leaf of different rice cultivars dropped significantly in
relation to reduced soil water content (SWC), especially in PT1 and IR20. In contrast, the proline
content in the leaf-blade and leaf-sheath increased when plants were subjected to 7% SWC. The
RWC was positively related to chlorophyll degradation. Chlorophyll a, chlorophyll b, total
chlorophyll, total carotenoids, maximum quantum yield of PSII, stomatal conductance and water
use efficiency in rice grown under water-deficit conditions declined significantly in comparison to
the control group, leading to a reduction in net-photosynthetic rate. In addition, when exposed to
water-deficit, panicle length and fertile grains in KDML105 and NSG19 were stabilized, leading to
greater productivity than in PT1 and IR20. These data were utilized as effective criteria for the
classification of water-deficit tolerance. From the results, KDML105 and NSG19 were identified as
water deficit-tolerant, and PT1 and IR20 as water deficit-susceptible.