Abstract: The study involved cell morphological observation and comparison of biochemical characteristics of the new male sterile materials H9A and its maintainer H9B by means of optical and electron microscopy and measurement of biochemical indexes. Microspore abortion of H9A occurred in the early uninucleate stage. The tapetum cells were in extreme hypertrophy so that tetrads were extruded to crack and break down and could not form normal uninucleate pollen grains; the abortion type was sporophyte. During this period, the buds were 0.526–0.572 cm long and 0.318–0.372 cm in diameter; the corolla was about one quarter the length of the calyx. The peroxidase activities in the flower buds of H9A were significantly greater than that in the maintainer line beginning at the tetrad stage, and the content of free proline in the flower bud of the maintainer line H9B was significantly higher than that of H9A in the mononuclear microspore stage. The soluble protein content during the stages of microspore development in H9A was significantly lower than that in H9B, but malonaldehyde (MDA) content was higher than that in the maintainer line.

Key words: biochemical characteristics, cytomorphology, male sterile