Chlorophyll content, chlorophyll fluorescence and water deficit in spring wheat

Using greenhouse techniques that nearly-simulate field water deficit would be a supplemental method for screening potential cultivars adapted to water deficit environments. The objective of this study was to determine if ther e were differential responses to water deficit in chlorophyll content and c hlorophyll fluorescence, and determine the drought susceptibility index (DS I) amongst eight genetically diverse wheat cultivars. An experiment was con ducted in three replicates where chlorophyll content and chlorophyll fluore scence were measured at 30 days after planting following (a) an early seedl ing stage water deficit treatment, and (b) a non-water-deficit treatment. A separate experiment was conducted, using a common protocol, to determine t he DSI. Water deficit decreased chlorophyll a, b, and total chlorophyll con tent in all cultivars and caused a decrease in photosynthetic efficiency (P SE) by between 44.5 and 55.7%. Results showed significant (P < 0.05) cultiv ar x water treatment interaction for chlorophyll a, total chlorophyll and P SE and cultivars differed significantly for DSI.