Search results for "MICROSPORE"

Different spore structures in sympatric Isoetes histrix populations and their relationship with gross morphology, chromosome number, and ribosomal nu…

2011

Abstract Traditionally, megaspores have supplied the most relevant character for the taxonomy of Isoetes at several systematic levels, including discriminant features usually used in species identification and diagnosis. Isoetes histrix Bory is a terrestrial circum-Mediterranean quillwort characterized by dark, shiny, and persistent phyllopodia with megaspore sporangia completely covered by a velum and tuberculate megaspores. Specimens of this species from Sardinian temporary wetlands showed the sympatric presence of two kinds of individuals with correlated variation in size, ornamentation, and radial ridges of megaspores, and in ornamentation of microspores. However, they showed the same d…

Production of Haploid and Doubled Haploid Lines in Nut Crops: Persian Walnut, Almond, and Hazelnut

2021

This chapter deals with induction of haploidy via parthenogenesis in Persian walnut and via microspore embryogenesis in almond and hazelnut. Haploid induction through in situ parthenogenesis using pollination with irradiated pollen to stimulate the embryogenic development of the egg cell, followed by in vitro culture of the immature haploid embryos. Microspore embryogenesis allows the induction of immature pollen grains (microspores), to move away from the normal gametophytic developmental route in the direction of the sporophytic one, yielding homozygous organisms (embryos in this case). Unlike other fruit crops (such as Citrus), regeneration of entire plants has not yet been obtained in o…

Combined Effects of 50 Hz Electromagnetic Field and SiO2 Nanoparticles on Oxidative Stress in Plant’s Gametic Cells / Zemfrekvences (50 Hz) Elekromag…

2015

Abstract The paper presents the results of combined effects of an extremely low frequency electromagnetic field (50 Hz) (ELF EMF) and SiO2 nanoparticles on fluorescence of plant gametic cells (immature microspores). The data were recorded by a BD FACSJazz® cell sorter after cell irradiation by blue laser (488 nm). A significant difference of fluorescence was observed between gametic cells after 1 hour incubation in suspension of SiO2 nanoparticles and the control gametic cells. It was observed that fluorescence intensity of gametic cell was higher with ELF EMF treatment in comparison to control cells, but it was statistically significant only for cells treated with electromagnetic radiation…

STUDY ON ISOLATED MICROSPORE CULTURE IN CITRUS SINENSIS L. OSBECK CV. MORO, A BLOOD ORANGE CULTIVAR

2014

In vitro tissue culture represents a useful support for the advancement of Citrus breeding and propagation. Haploidy technology, that is the single-step development of complete homozygous genotypes from heterozygous parents through gametic embryogenesis, has already a huge impact on many relevant crops, representing an integral part in their breeding programmes (Germanà 2011a; 2011b). In order to increase the number of genotypes responding to gametic embryogenesis, in vitro isolated microspore culture of Citrus sinensis L. Osbeck cv. Moro, has been carried out, investigating the influence of the culture medium composition, and, particularly, of the plant growth regulator types and concentra…

Development of multicellular pollen of Eriobotrya japonica Lindl. through anther culture

2006

8 pages, 5 figures.-- Printed version published Dec 2006.

CHARACTERISATION OF MICROSPORE EMBRYOGENESIS IN ANTHER CULTURE OF CITRUS.

2002

FIRST EMBRYONIC STAGES OF CITRUS MICROSPORE DERIVED EMBRYOS.

2002

Coexistence of three microsporidia parasites in populations of the freshwater amphipod Gammarus roeseli: evidence for vertical transmission and posit…

2004

We investigated the prevalence, transmission mode and fitness effects of infections by obligatory intracellular, microsporidian parasites in the freshwater amphipod Gammarus roeseli. We found three different microsporidia species in this host, all using transovarial (vertical) transmission. All three coexist at different prevalences in two host populations, but bi-infected individuals were rarely found, suggesting no (or very little) horizontal transmission. It is predicted that vertically-transmitted parasites may exhibit sex-specific virulence in their hosts, or they may have either positive or neutral effects on host fitness. All three species differed in their transmission efficiency an…

FIRST STAGES OF MICROSPORE REPROGRAMMING TO EMBRYOGENESIS THROUGH ISOLATED MICROSPORE CULTURE IN LOQUAT

2011

The current experiments were undertaken to develop a method for regenerating doubled haploid (DH) plants of Eriobotrya japonica (Thunb.), Rosaceae, subfamily Maloideae through isolated microspore culture of nine loquat cultivars. Protocols were developed for isolation and culture of loquat microspores. Isolated microspores in vitro cultured started dividing and developing multicellular, globular and irregular structures. After 4 weeks of culture, the responding microspores produced yellowish/white callus. The embryogenic response of microspores was highly dependent on the cultivar and on the medium composition.

Early embryo achievement through isolated microspore culture in citrus clementina hort. Ex tan., cvs. 'Monreal Rosso' and 'nules'

2015

10 p.-5 fig.-3 tab.