Physiological characterization of ‘stay green’ wheat cultivars during the grain filling stage under field growing conditions

Abstract

Rye (Secale cereale L.) chromosome arm 1RS could delay leaf senescence, and change in H 2 O 2 content is a useful index for weighing the ability to delay the senescence. Two wheat cultivars, Chuannong12 (CN12) and Chuannong 18 (CN18), harboring the wheat-rye 1BL/1RS translocated chromosome were investigated for H 2 O 2 change and physiological index after flowering under field conditions, and MY11, the agronomical parent of both CN12 and CN18, was used as the control. A combined change in the peak value of CdSe/ZnS quantum dot (QD) fluorescence and morphological observation indicated that the H 2 O 2 contents in CN12 and CN18 were generally lower than that in MY11. They both had higher values for net photosynthetic rate (P n ), stomatal conductance (G s ), F v =F 0 m F 0 v =F 0 m , and photochemical quenching of PSII (qP) than MY11 only in the late measurement stage. Some small differences were also observed, such as CN12 and CN18 wheat cultivars having higher and longer photosynthetic competence than MY11 during the grain filling stage, which perhaps resulted from a mechanism for removing oxidative species, especially H 2 O 2 .

Effects of Paraquat-induced oxidative stress on antioxidants and Chlorophyll Fluorescence in stay-green wheat (Triticum aestivum L.) flag leaves

“…To ensure efficient excitation capture of open PSII reaction centers, leaves were then measured in the light. Minimum fluorescence (F' o ) and maximum fluorescence (F' m ) values under light were read as for F o and F m (Genty et al 1989, Chen et al 2010. The maximum photochemical efficiency of PSII in the dark-adapted leaves was calculated as the ratio of variable fluorescence…”

Differential analysis of vegetative growth characters for developing stay green wheat

“…Stay-green phenotypes and broader genetic variation in senescence have been reported in hexaploid wheat (Naruoka et al, 2012). The stay-green trait has been reported to increase yields (Chen et al, 2010).…”

Stay-green: a potentiality in plant breeding

“…The senescence of tissues along with the remobilization of nutrients to younger or strategic tissues for survival / perpetuation of the plant, decreases photosystem II (PSII) activity and is associated with an increased content of reactive oxygen species (ROS) such as hydrogen peroxide (H 2 O 2 ), a marker molecule for senescence (CHEN et al, 2010). Low accumulation of reactive oxygen species such as superoxide radicals (O 2 -) and hydrogen peroxide (H 2 O 2 ) were found in mutant stay-green wheat (tasg1) compared with wild types subjected to drought stress, providing greater stability of the proteins found in the walls of thylakoids .…”