MALE AND FEMALE GAMETOPHYTE DEVELOPMENT OF FLUE-CURED TOBACCO NANJIANG 3

Flue-cured Tobacco Nanjiang 3 was a kind of main cultivated varieties in Guizhou province. Its anatomical structure of microsporogenesis, megasporogenesis and development of male and female gametophyte were observed by paraffm section method. The results showed that, the anther wall is defined as basic development type with glandular tapetum. Microspore mother cell undergoes simultaneous division with two kinds of tetrad arrangements: tetrahedral or decussate type. The mature pollens belong to 2 cells type and have three or four apertures. The ovule of Flue-cured Tobacco Nanjiang 3 is anatropous and thin nucellus. The archesporial cell develops to megaspore mother cell directly and has larger volume. Four megaspore cells form a linear tetrad. The development pattern of embryo sac is Polygonum type, finally forms 7-celled and 8-nucleate mature embryo sac. Stamens develop earlier than gynoecium and the period of microsporogenesis, megasporogenesis and development of male and female gametophyte can be judged by appearance of the flower bud.