Cytological Observation on Microsporogenesis in Inter-subspecific Hybrids of Rice with Different Ploidy Level Change of callose wall synthesis during formation and development of microsporocytes in Secale cereale Meiosis and Chromosome Behavior of Microsporocytes in Populus adenopoda Maxim Study on the development correlation between male and female gametes and the induction of 2n gamete of Rongan kumquat (F.crassifolia) ULTRASTRUCTURAL INVESTIGATION OF THE INTERCELLULAR CYTOMICTIC CHANNEL IN MICROSPOROCYTES OF HIGHER PLANTS ISOLATION, CULTURE AND OBSERVATION OF CYTOMIXIS, OF MICROSPOROCYTES OF RYE