Studies On Ultrastructure Feature,physiological And Biochemical Of Male Sterility In Malus Halliana

This article takes the male sterile Malus halliana and the male fertile Malus halliana var.parkmanii as the research material. We observed the characteristics of floral organs of two crabapples, the ultrastructural of anther and pollen development and the physiological and biochemical changes of two varieties of flower bud development process. The following conclusions are obtained:The morphology of floral organs showed that in the early stage of bud development, the morphology of the two crabapples was basically the same, and the development of floral organ was normal. The morphological characteristics of male sterile Malus halliana was mainly reflected in the late anther color. The Malus halliana anther is white, seemingly plump, cracked dry, no pollen attached. And the Malus halliana var.parkmanni anther is yellow, golden yellow pollen attached after cracking.Ultrastructural indicated that the pollen abortion of Malus halliana was concentrated in two period:(1) the tetrad period,(2) the microspore period. In the tetrad period, the microspore growth was not normal. Firstly, the cytoplasm of the isolated cytoplasm was solid and there were many vesicles in the endoplasmic reticulum. The nucleus gradually disappeared and microspore began to degenerate. Secondly, the tapetum did not release callose enzyme, callose wall cannot be decomposed. In the extrusion of the callose wall, the microspore disintegrated, formed callose wall wrapped hollow structure are. In the microspore period, a small part of microspore from tetrad in discrete malformation. Most of them were high electron density irregular strip material, very few were irregular microspore. According to the tapetum ultrastructure, abnormal development of tapetal cells, tapetum cells cannot provide nutrients and tapetum cells cannot form the Ubisch body were three main reasons for abortion.Comparison of soluble protein content of two varieties, we could find that Malus halliana was higher than Malus halliana var.parkmanni. In sterile period, sterility of Malus halliana protein content decreased. But Malus halliana var.parkmannnil. was higher than Malus halliana in the proline content. Three enzymes: SOD, POD, CAT, in the process of the development of the bud was not the same trend, and overall showed a downward trend. The activity of POD and SOD was higher in the Malus halliana var.parkmanni. and CAT wass the opposite trend. The production of male sterility is the result of the interaction of the three enzymes. The content of malondialdehyde was higher in Malus halliana than Malus halliana var.parkmanni. This may be a cause of Anther Abortion.