Anatomical Study on the Microspore Abortion in Xinli No.7(Pyrus bretschneideri)
He Tianming and Zhang Qi (College of Plant Science and Technology,Tarim Agricultural Reclamation University,Alar,Xinjiang843300)
Xinli No.7(Pyrus bretschneideri Rehd.)was used as material for studying the developmental process of microspore abortion.The results showed the anther in an embryonic form was formed in the last vegetative season.The dormant period of the flower bud was finished in next February.The meiosis of pollen mother cell occurred in middle March.Before single nu-cleus pollen formed,the way of reduction division of pollen mother cell was very regular.After tetrads were freed from the an-ther tissue,single nucleus pollen began disintegrate and dissolve.The abortion course differed from the polyploid pear whose abortion was resulted with irregular chromosomes pairing at reduction division stage.The disintegration of single nucleus pollen in Xinli No.7was correlated with the enlargement and liquidization of tapetum cell and was resulted of tapetum metabolic disorder.The kind of abortion was considered as cytoplasmic male sterility(CMS).
【CateGory Index】： S661.2