CMS	cytoplasmic male sterility
PCD	programmed cell death
ROS	reactive oxygen species
SOD	superoxide dismutase
CAT	catalase
POD	peroxidase
APX	ascorbate peroxidase
GPX	glutathione peroxidase
ASA	ascorbic acid
GSH	glutathione
TUNEL	terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling
SEM	scanning electron microscopy
DAPI	4′,6-diamidino-2-phenylindole
TEM	transmission electron microscopy
MDA	malondialdehyde
Uby	Ubisch bodies
Ap	germination aperture
E	epidermis
En	endothecium
ML	middle layer
T	tapetum
Tds	tetrads
Msp	microspores
ER	endoplasmic reticulum
N	nucleus
Ta	tapetosome
V	vacuole
PE	primexine
Se	sexine
DM	deposit materials
PM	plasma membrane
In	intine