Physiological performance of two contrasting rice varieties under water stress

Abstract

Two rice varieties PR-115 and Super-7 were imposed to water stress and different physiological traits were monitored to evaluate the performance of these varieties under drought. Under water stress condition although the relative water content, osmotic potential, chlorophyll content, photosynthesis rate, carbon discrimination and biomass decreased in both the varieties however, the reduction was more pronounced in Super-7 variety. Oryzanol a trans-ester of ferulic acid functions as antioxidant and it increased along with total phenolic and anthocyanin content in both the varieties under drought stress. However, gallic acid, 4 hydroxy benzoic acid, syringic acid and chlorogenic acid showed differential pattern in both of the varieties under water limiting conditions. Under drought, grain yield was penalized by 17 and 54% in PR-115 and Super-7 varieties, respectively in comparison to watered plants. Super-7 variety showed pronounced electrolyte leakage and MDA enhancement under water stress condition. High non photochemical quenching and reduction in Y(NO) and Y(II) indicated balanced energy management in tolerant PR-115 variety. The studies showed that PR-115 is a drought tolerant variety while Super-7 is drought sensitive in nature.

Variation in nutritional quality of pigmented rice varieties under different water regimes

“…Significance, by analysis of variance Variety (V) P < 0.001 P < 0.01 P < 0.001 P < 0.001 Water (W) P < 0.001 P < 0.001 P < 0.001 P < 0.01 Year (Y) P < 0.001 P < 0.001 P < 0.05 P < 0.001 Variety × water P < 0.001 P < 0.001 P < 0.001 P < 0.001 Variety × year P < 0.001 P < 0.001 P < 0.001 P < 0.001 Water × year P < 0.001 P < 0.01 NS 0.05 P < 0.01 V × W × Y P < 0.001 P < 0.05 P < 0.001 P < 0.001 pigment rice varieties comparing with continuous flooding. The 10-day interval water stress condition after transplanting affected to increase anthocyanin both in drought tolerant and sensitive varieties (Khan et al, 2017). A similar response was reported by Rayee et al (2018) reporting that anthocyanin in japonica and indica rice varieties greatly enhanced by the 3-day interval of water deficit after anthesis to harvest.…”

Identification of Factors Linked to Higher Water-Deficit Stress Tolerance in Amaranthus hypochondriacus Compared to Other Grain Amaranths and A. hybridus, Their Shared Ancestor

“…Thus, the understanding of the drought tolerance mechanism(s) that operate in grain amaranth remains limited. Natural variations in WDS tolerance are common in plants, as established by copious information describing differences between natural accessions, wild populations and domesticated C3 plants, including rice [16,17,18], C3 and C4 grasses [19], different C4 subtypes [20,21], or contrasting genotypes of commercially important C3 and C4 crops [5,22,23]. Based on this evidence, and considering their different geographic origin and preferential adaptation to temperate or tropical conditions, it was hypothesized that WDS tolerance in grain amaranths and A. hybridus , their shared ancestor, would vary significantly between species.…”

Mutagenesis Reveals That the OsPPa6 Gene Is Required for Enhancing the Alkaline Tolerance in Rice

“…The content of free proline was determined as the described method by Bates et al, 1973 in. The malondialdehyde (MDA) was extracted by a previous method (Hodges et al, 1999), and separately measured at 450, 532, and 600 nm and calculated by a formula of C (μ mol g -1 FW ) = [6.45 × (OD 532 - OD 660 ) - 0.56 × OD 450 ]/(FW × 1000) (Khan et al, 2017). The osmotic potentials of leaves were measured using an osmotic pressure dew point meter (Wescor 5520, Logan, UT, United States) by a formula of Ψ s (MPa) = -C i × 0.008314 × (273+T) × 10 -3 , where C i means instrument reading and T represents environment temperature (Ball and Oosterhuis, 2005).…”