Chlorophyll Fluorescence and Stomatal Conductance of Ten Sugarcane Varieties under Waterlogging and Fluctuation Light Intensity

Abstract

Under natural conditions, plants are often subjected to waterlogging due to poor soil drainage and or exessive rainfall. This condition leads to reduced maximum quantum yield of photosystem II (fv/fm) under suboptimal growing system. Under well-watered conditions (WW), the fv/fm of ten varieties of sugarcane were maintained at more than 0.78. However, following waterlogging for 4 days and a constant light of 3000 mmolmol-1 for 60s, the fv/fm of ten varieties of sugarcene varied from 0.587 in PS882 (V4) to 0.740 in GMP2 (V9). Meanwhile, under fluctuating light intensity from dark to highlight of 1600 mmolmol-1, the fv/fm of all varieties decreased to below of 0.1 except in the genotype PSJK922 (V5) at 28 DAT (day after treatment) of waterlogging. This difference was then further examined through measurements of stomatal conductance (gs) among the varieties. There was negative correllation between fv/fm and stomatal conductance, high gs was not associated with lower fv/fm. Dendrogam analyses showed the variety of PS881 (V1), PS864 (V3) and Kidang Kencana (KK) were highly sensitive to waterlogging. These results suggest potential screening of plants based on improve fv/fm under abiotic condition.

Agronomic parameters of sugarcane under planting densities in different cultivation cycles

“…Moreover, sugarcane grown without irrigation in Northeastern Brazil has low productivity in relation to irrigated areas, directly reflecting on the reduction of plant physiological performance and sugarcane yield, since the occurrence, intensity and duration of abiotic stresses, such as water deficit, cause morphophysiological changes in the plant, with reduced gas exchange, greater sensitivity in stomatal conductance (gs), leaf transpiration (E), liquid photosynthesis (A), in water use efficiency (Marchiori et al, 2017), lower growth of leaf area, reduction in the appearance of new leaves and increase in leaf abscission due to a higher concentration of abscisic acid in the plant, which is associated with the amount of light absorbed and the total photosynthetic activity of the plant, reducing the production of photoassimilates (Smit and Singels, 2006;Lawson, 2009;Soleh et al, 2018).…”