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Showing 3 results for Ovule

Parisa Jonoubi, Ahmad Majd, Aref Marouf, Shahla Amini,
Volume 2, Issue 3 (12-2015)
Abstract

Pimpinella anisum L. belongs to Apiaceae family. The samples of vegetative and reproductive organs at different stages of development were gathered and investigated by cell-histology methods. The investigation of the anatomical structure of vegetative organs showed that the secretory ducts are arranged between the parenchymal tissues of the leaf. Section of flower buds revealed that anthers had 4 pollen sacs, the division of pollen mother cell was of the simultaneous type, microspore tetrads were of tetragonal type and the tapetum layer was secretory. The study of the ultrastructure of pollen grains with SEM showed that they had 3 pores. The ovary was found to be two-chambered and two-carpeled the ovule to be anatropous and to have one membrane. In embryogenic investigation it was found that the embryos were globular, cotyledonary and torpedo-shaped and the transition between globular embryos to cordate embryos was found. The vegetative organs were observed to have the general structure of dicotyledons. The development patterns of ovule and embryo sac follow the Polygonum type. Tetrahedral microspore tetrads were observed. The ultrastructure of pollens was found to be similar to those of Smyrnium, a genus of Apiaceae family. All stages of embryogenesis were covered in this study. 


Maryam Behnam, Seyed Javad Davarpanah, Ramin Karimian,
Volume 3, Issue 3 (12-2016)
Abstract

Cotton (Gossypium hirsutum L.) is an important crop in the world and increasing its fiber quality is very cr-ucial for textile industries. Spider silk is the strongest and most elastic fiber ever known in the nature. Cotton is one of the main crops in the world and increasing its fiber quality is very important for textile industries. In this regard, a synt-hetic construct has been designed to offer spider silk quality to cotton fibers by fiber-specific expression of Major am-pullate spidroin1 (MaSp1) gene under control of core sequence of GaRD22-like1 promoter. The synthetic construct was double digested by the EcoRI and NheI and sub-cloned in pCAMBIA1304 binary vector. E.coli DH5α was transformed using new plasmid namely pCSP. Ligation and intact backbone of plasmid was conformed using MaSp1 and hygrom-ycin re-sistance genes specific primers and finally with EcoRI/NheI double digestion. Agrobacterium tumefaciens LBA4404 was transformed with pCSP to transform cotton ovules of Varamin cultivar. The expression of MaSp1 in co-tton ovules and fibers showed that this synthetic sequence had been successfully expressed under control of GaRDL1 core promoter and this construct without codon optimization could be used for cotton transformation and its fiber qual-ity manipulation.


Fateme Mousavi, Ahmad Majd,
Volume 6, Issue 2 (8-2019)
Abstract

Simaroubaceae is a monophyletic family in the order Sapindales with 22 genera and 109 species. Ailanthus altissima (Mill) Swingle, also known as the tree of heaven, is a highly invasive species, which systematically belongs to Simaroubaceae. Reproductive characteristics are essential for the deployment and maintenance of invasive species in new environments and examination of the reproductive system of these species is interesting. To date, no embryological investigations had been directed to A. altissima and our knowledge on the embryology of this species was very limited. A study was carried out on the embryology of A. altissima and the comparison of anther development in male and female flowers in order to gain insights into defining embryological features in this species. According to the results of histological analysis, male flowers have rudimentary gynoecia and anthers are tetrasporangiate. Cytokinesis in meiosis is simultaneous resulting in tetrahedral tetrads. Anther wall development follows the dicotyledonous type and the tapetum is secretory. Female flowers have staminodes and microspore mother cells are degraded too early before entering the course of meiosis. Ovules are anatropous, bitegmic, and crassinucellate. The development of the embryo sac follows the polygonum type. Embryos follow the Onagrad type. The endosperm development is nuclear type. A well-developed hypostase is present and a nucellar cap is formed. These observations will advance our understanding of embryology and embryo anatomy in A. altissima as an invasive species.
 
 

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