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 (f_v/f_m) under suboptimal growing system. Under well-watered conditions (WW), the f_v/f_m 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 f_v/f_m 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 f_v/f_m 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 (g_s) among the varieties. There was negative correllation between f_v/f_m and stomatal conductance, high g_s was not associated with lower f_v/f_m. 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 f_v/f_m under abiotic condition.