This study addressed the differences in microsporogenesis between male sterile and fertile lines of Chinese pink. The microsporogenesis processes of male sterile and fertile lines were histologically examined in squas...This study addressed the differences in microsporogenesis between male sterile and fertile lines of Chinese pink. The microsporogenesis processes of male sterile and fertile lines were histologically examined in squashed pollen grains and in paraffin embedded sections. A stable male-sterile line （H-37B） was obtained following six generations of inbreeding in a self-fertile line, followed by two generations of backcrossing. In the corresponding fertile line, development of the mature pollen grains was followed through the initiation of the sporogenous cell, microsporocyte formation, and the tetrad developmental period. In the male-sterile line, abortion of the developing pollen grains was observed to take place at various stages, namely, sporogenous cell growth, mother cell meiosis, and tetrad transformation to the uninuclear state. The pollen grains of the fertile line were spheroid, turgid, and viable. By contrast, the male-sterile line produced pollen that was irregular in shape, empty, and nonviable. The abortion of the microspore in the male-sterile line appeared to relate to abnormal growth of the tapetum layer.展开更多
An efficient procedure was developed for in vitro callus induction, proliferation and regeneration of carnation cultivar (Dianthus caryophyllus L.) using leaf, nodal and inter-nodal explants on Murashige and Skoog’s ...An efficient procedure was developed for in vitro callus induction, proliferation and regeneration of carnation cultivar (Dianthus caryophyllus L.) using leaf, nodal and inter-nodal explants on Murashige and Skoog’s medium (MS) supplemented with exogenous plant growth regulators. For morphogenic callus induction and proliferation from various explants, MS medium supplemented with 3.0 mg/l 2,4-D was highly efficient with 100% callus induction frequency from inter-nodal explants. Leaf explants showed quicker response than nodal and inter-modal explants, for callus initiation within 6 days of inoculation. Best grown callus was obtained from leaf explant. The leaf-derived callus was maintained up to several weeks, which indicated that 8-week incubation period was the most suitable for obtaining well proliferated, morphogenic callus. Temperature variation also affected the growth of in vitro induced morphogenic callus from various explants. Results have shown that 27°C proved to be the best temperature for morphogenic callus induction and proliferation from leaf and inter-nodal explants. Among the auxin-cytokinin combination, MS medium containing 1.0 mg/l N(6)-benzylaminopurin (BAP) and 2.0 mg/l NAA showed the highest efficiency of callus initiation and proliferation from leaf, nodal and inter-nodal explants. Light conditions proved better for callogenesis and proliferation from leaf, nodal and inter-nodal explants. Regeneration response from well grown morphogenic callus was prominent on MS medium supplemented with 3.0 mg/l BAP alone and 1.0 mg/l NAA with 3.0 mg/l BAP.展开更多
文摘This study addressed the differences in microsporogenesis between male sterile and fertile lines of Chinese pink. The microsporogenesis processes of male sterile and fertile lines were histologically examined in squashed pollen grains and in paraffin embedded sections. A stable male-sterile line （H-37B） was obtained following six generations of inbreeding in a self-fertile line, followed by two generations of backcrossing. In the corresponding fertile line, development of the mature pollen grains was followed through the initiation of the sporogenous cell, microsporocyte formation, and the tetrad developmental period. In the male-sterile line, abortion of the developing pollen grains was observed to take place at various stages, namely, sporogenous cell growth, mother cell meiosis, and tetrad transformation to the uninuclear state. The pollen grains of the fertile line were spheroid, turgid, and viable. By contrast, the male-sterile line produced pollen that was irregular in shape, empty, and nonviable. The abortion of the microspore in the male-sterile line appeared to relate to abnormal growth of the tapetum layer.
文摘An efficient procedure was developed for in vitro callus induction, proliferation and regeneration of carnation cultivar (Dianthus caryophyllus L.) using leaf, nodal and inter-nodal explants on Murashige and Skoog’s medium (MS) supplemented with exogenous plant growth regulators. For morphogenic callus induction and proliferation from various explants, MS medium supplemented with 3.0 mg/l 2,4-D was highly efficient with 100% callus induction frequency from inter-nodal explants. Leaf explants showed quicker response than nodal and inter-modal explants, for callus initiation within 6 days of inoculation. Best grown callus was obtained from leaf explant. The leaf-derived callus was maintained up to several weeks, which indicated that 8-week incubation period was the most suitable for obtaining well proliferated, morphogenic callus. Temperature variation also affected the growth of in vitro induced morphogenic callus from various explants. Results have shown that 27°C proved to be the best temperature for morphogenic callus induction and proliferation from leaf and inter-nodal explants. Among the auxin-cytokinin combination, MS medium containing 1.0 mg/l N(6)-benzylaminopurin (BAP) and 2.0 mg/l NAA showed the highest efficiency of callus initiation and proliferation from leaf, nodal and inter-nodal explants. Light conditions proved better for callogenesis and proliferation from leaf, nodal and inter-nodal explants. Regeneration response from well grown morphogenic callus was prominent on MS medium supplemented with 3.0 mg/l BAP alone and 1.0 mg/l NAA with 3.0 mg/l BAP.
