Florogenesis is one of the most complicated and interesting processes in the nature. This process involves developmental, physiological and molecular events leading to transformation from vegetative to reproductive ph...Florogenesis is one of the most complicated and interesting processes in the nature. This process involves developmental, physiological and molecular events leading to transformation from vegetative to reproductive phase for optimal seed production and the continuation of species. The basic knowledge about flowering processes, male and female sexual systems support basic and applied research and breeding programs. Most of the onion varieties from India are short day varieties, more diverse than other exotic germplasm and useful as a source of new alleles for supporting breeding programs. The present investigation was focused to study for the first time florogenesis process by scanning electron study for the first time florogenesis process by scanning electron microscopy (SEM) and development of female gametophytes by light microscopy in order to acquire basic knowledge useful for optimizing in vitro process to produce gynogenic haploid to support and speed breeding program in short-day onion Allium cepa L. cv. Krishnapuram (KP) or Bangalore Rose. This study revealed that shoot primordium differentiated into inflorescence meristem in the month of December, while seeds were planted in the field in the September. The individual florets are preceded by a variying number of floral initials. The female gametophyte developed from chalazal side megaspore. The embryo sac development is a bisporic Allium type showing short-lived antipodals. The histological study suggests that the use of big or preanthesis flower buds with embryo sac for production of gynogenic haploids to support breeding program in onion cv. Krishnapuram (KP). However further studies are needed for confirmation of this observation.展开更多
The present study describes the anatomy, distribution, morphology and ultrastructure of laticifer system in the phylloclades of Euphorbia caducifolia Haines (Family Euphorbiaceae), a potential biofuel yielding, Crassu...The present study describes the anatomy, distribution, morphology and ultrastructure of laticifer system in the phylloclades of Euphorbia caducifolia Haines (Family Euphorbiaceae), a potential biofuel yielding, Crassulacean Acid Metabolism (CAM) plant for the first time using light and transmission electron microscopy (TEM). Histochemical tests were performed to identify the principal components of latex using a variety of stains. In cross section, the phylloclade is composed of four distinct regions: the epidermis, cortex, vascular cylinder and pith. The phylloclade anatomy indicated xeromorphic characters and provided an insight about its capacity to grow with very little rainfall and/or inputs on dry or marginal lands. Non-articulated laticifers are present in the cortex, vascular cylinder and pith, but their frequency varies with the tissue type. Highest laticifer frequency was observed in vascular cylinder (9.6%) followed by cortex (3.9%) and pith regions (1.9%). In contrast, laticifer index was found to be higher in the pith (12.7%) followed by cortex (3.8%) and vascular cylinder (2.3%). The discovery of a system of laticifers in E. caducifolia not described earlier could also be of taxonomic value. The histo-chemical tests revealed the presence of lipids, phenols, flavonoids, protein and starch in laticifer. As described by TEM observations laticifers contained distinct cell wall, nucleus and cytoplasm with ribosomes, small and big vacuoles, mitochondria, endoplasmic reticulum, plastids and osmophilic bodies. The lipophilic compounds present in the latex of this species could be used as chemical feedstock for the production of biofuels.展开更多
文摘Florogenesis is one of the most complicated and interesting processes in the nature. This process involves developmental, physiological and molecular events leading to transformation from vegetative to reproductive phase for optimal seed production and the continuation of species. The basic knowledge about flowering processes, male and female sexual systems support basic and applied research and breeding programs. Most of the onion varieties from India are short day varieties, more diverse than other exotic germplasm and useful as a source of new alleles for supporting breeding programs. The present investigation was focused to study for the first time florogenesis process by scanning electron study for the first time florogenesis process by scanning electron microscopy (SEM) and development of female gametophytes by light microscopy in order to acquire basic knowledge useful for optimizing in vitro process to produce gynogenic haploid to support and speed breeding program in short-day onion Allium cepa L. cv. Krishnapuram (KP) or Bangalore Rose. This study revealed that shoot primordium differentiated into inflorescence meristem in the month of December, while seeds were planted in the field in the September. The individual florets are preceded by a variying number of floral initials. The female gametophyte developed from chalazal side megaspore. The embryo sac development is a bisporic Allium type showing short-lived antipodals. The histological study suggests that the use of big or preanthesis flower buds with embryo sac for production of gynogenic haploids to support breeding program in onion cv. Krishnapuram (KP). However further studies are needed for confirmation of this observation.
文摘The present study describes the anatomy, distribution, morphology and ultrastructure of laticifer system in the phylloclades of Euphorbia caducifolia Haines (Family Euphorbiaceae), a potential biofuel yielding, Crassulacean Acid Metabolism (CAM) plant for the first time using light and transmission electron microscopy (TEM). Histochemical tests were performed to identify the principal components of latex using a variety of stains. In cross section, the phylloclade is composed of four distinct regions: the epidermis, cortex, vascular cylinder and pith. The phylloclade anatomy indicated xeromorphic characters and provided an insight about its capacity to grow with very little rainfall and/or inputs on dry or marginal lands. Non-articulated laticifers are present in the cortex, vascular cylinder and pith, but their frequency varies with the tissue type. Highest laticifer frequency was observed in vascular cylinder (9.6%) followed by cortex (3.9%) and pith regions (1.9%). In contrast, laticifer index was found to be higher in the pith (12.7%) followed by cortex (3.8%) and vascular cylinder (2.3%). The discovery of a system of laticifers in E. caducifolia not described earlier could also be of taxonomic value. The histo-chemical tests revealed the presence of lipids, phenols, flavonoids, protein and starch in laticifer. As described by TEM observations laticifers contained distinct cell wall, nucleus and cytoplasm with ribosomes, small and big vacuoles, mitochondria, endoplasmic reticulum, plastids and osmophilic bodies. The lipophilic compounds present in the latex of this species could be used as chemical feedstock for the production of biofuels.
