Effects of different genotypes and gamma ray doses on haploidization with irradiated pollen technique in watermelon (Citrullus lanatus L.)

2013 ◽  
Vol 93 (6) ◽  
pp. 1165-1168 ◽  
Author(s):  
Hatıra Taşkın ◽  
Namık Kemal Yücel ◽  
Gökhan Baktemur ◽  
Songül Çömlekçioğlu ◽  
Saadet Büyükalaca

Taşkın, H., Yücel, N. K., Baktemur, G., Çömlekçioğlu, S. and Büyükalaca, S. 2013. Effects of different genotypes and gamma ray doses on haploidization with irradiated pollen technique in watermelon ( Citrullus lanatus L.). Can. J. Plant Sci. 93: 1165–1168. Two watermelon genotypes, one commercial watermelon variety (Ustun F1) and five different doses of gamma rays coming from Co60 were tested to develop useful haploidization procedures in watermelon. For this purpose, male flowers collected a day before anthesis were irradiated with 50, 150, 200, 275 and 300 Gy doses of gamma rays, and female flowers were pollinated with irradiated pollen the next day. Seeds extracted from fruits harvested 25 d later were opened individually in a laminar flow hood. Embryos obtained via embryo rescue technique were placed in glass tubes containing CP medium with 30 g L−1 sucrose, 8 g L−1 agar, 0.08 mg L−1 B12, and 0.02 mg L−1 IAA. Sixty haploid embryos were obtained from 43 watermelon fruits in this study. Genotype 1 was found to be the most successful genotype with 3.57 haploid embryos per 100 seeds. Among tested irradiation doses, 275 Gy was better than other doses, with 5.26 haploid embryos per 100 seeds. Considered together with irradiation dose and genotypes, the maximum number of haploid embryos was obtained from Genotype 1 pollinated with 275 Gy irradiation dose, with 6.25 haploid embryos per 100 seeds.

HortScience ◽  
1994 ◽  
Vol 29 (10) ◽  
pp. 1189-1190 ◽  
Author(s):  
N. Sari ◽  
K. Abak ◽  
M. Pitrat ◽  
J.C. Rode ◽  
R. Dumas de Vaulx

Parthenogenetic haploid embryos of `Crimson Sweet', `Halep Karasi', `Sugar Baby' and `Panonia F1' watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] were obtained after pollination with γ-irradiated (200 or 300 Gy) pollen. Some globular and heart-shaped embryos were observed in fruit harvested 2 to 5 weeks after pollination. The number of embryos per 100 seeds was highest for `Halep Karasi'. After in vitro culture, 17 haploid plants were obtained and doubled haploid lines were generated after chromosome doubling using colchicine.


2016 ◽  
Vol 43 (3) ◽  
pp. 235
Author(s):  
Arrin Rosmala ◽  
Nurul Khumaida ◽  
Dewi Sukma

<p>ABSTRACT</p><p>Handeuleum (Graptophyllum pictum L.Griff) is a medicinal plant widely used as a traditional medicine due to its benefecial content. Therefore, it should be developed as one of the leading Indonesian medicinal plants. The purpose of this research was to study the effect of gamma ray irradiation on morphological alteration and growth of Handeuleum accession from Bogor. The doses of gamma rays were 0, 15, 30, 45, 60, 75, 90, and 105 Gy. The results of the research showed that gamma-ray irradiation induced morphological changes and influences the growth of Handeuleum. Irradiation dose at rate of 105 Gy produced new leaf morphology in Handeuleum, namely cordate. Doses of 60, 75, 90, and 105 Gy produce stunted plants with stiff and yellowish-green leaves. The dose of 45 Gy produced relative green color index which was higher than the control plants.</p><p>Keywords: handeuleum, gamma irradiations</p>


2021 ◽  
pp. 127-133
Author(s):  
Leila Bagheri ◽  
Mahmoud Lotfi ◽  
Mansour Nori

Abstract The irradiated pollen technique (IPT) is the most successful haploidization technique within Cucurbitaceae. The influence of gamma-ray doses (250, 350, 450 and 550 Gy), genotypes and stage of development of embryos obtained by IPT on the induction of haploid embryos were studied in several Iranian melon cultivars as well as their hybrids with alien cultivars. Female flowers were pollinated using pollen that had been irradiated with gamma rays. Different shapes and stages of embryos were excised 21-25 days after pollination and cultured on E20A medium. Direct culture, liquid culture and integrated culture methods were used; integrated culture and liquid culture methods showed advantages in increasing the efficiency of haploid plant production in melon breeding programmes. Results revealed that 550 Gy of gamma irradiation was successful in inducing parthenogenesis and fruit development, whereas lower irradiation doses were not effective in inducing haploid embryos. The percentages of embryos per seed were the highest in 'Samsoori' (1.2%) and 'Saveh' (1.1%) cultivars. Some of the heart-shaped and cotyledon-shaped embryos developed into haploid plants. In total, 52 parthenogenic melon plantlets were recovered from 274 embryos via IPT. Production of haploid embryos and haploid plants was strongly influenced by gamma-ray dose, embryo stage and genotype. Indirect methods and chromosome counting performed on the root cells of regenerated plants showed that these plants were haploid (n = x = 12).


2013 ◽  
Vol 25 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Joanna Gałązka ◽  
Katarzyna Niemirowicz-Szczytt

ABSTRACT This review provides a summary of haploid induction methods and factors affecting the efficacy of specific methodologies as applied to cucumber (Cucumis sativus L.), melon (Cucumis melo L.), watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai), winter squash (Cucurbita maxima Duch. ex Lam.), summer squash (Cucurbita pepo L.) and other cucurbits. This report is focused on studies that were carried out during the last 20 years. The main objective of the research on the production of haploid cucurbit plants is to accelerate breeding programs through the use of homozygous double haploid lines (DHL) and to facilitate the selection of desired (e.g. disease-resistant) genotypes for breeding. Unfortunately, currently used protocols result in a low number of double haploids (DH). The most common and best-known method of obtaining haploid cucurbit plants is via pollination with irradiated pollen, which induces parthenogenetic development of haploid embryos in planta. The embryos are extracted from immature seeds and cultured in vitro to facilitate the maturation and development of plants. The studies described below were primarily aimed at the determination of an appropriate dose of radiation and the evaluation of the impact of the genotype and the time of year on the number of haploid embryos and plants obtained. A less popular method of haploid production - ovule and ovary culture - is based on in vitro gynogenesis. The studies related to this method concentrated on optimising the composition of the medium and pre-treatment conditions (primarily temperature) to which the flower buds were subjected. Recently, increasing attention has been paid to anther and microspore culture. As in the case of in vitro ovule and ovary culture, the medium composition and flower bud pre-treatment conditions were optimised. The most recent studies suggest that anther culture is comparable in effectiveness to the irradiated pollen technique.


OENO One ◽  
1995 ◽  
Vol 29 (1) ◽  
pp. 1
Author(s):  
A. Lima da Silva ◽  
J. P. Doazan

<p style="text-align: justify;">The efficiency of γ-irradiation as a tool for breeding grapevine rootstocks was investigated. One-bud cuttings from vitroplants of two varieties (Fercal and Gravesac) were subjected to gamma rays from Cs<sup>137</sup> source at rates from 10 to 60 Grays (Gy) at intervals of 10. All the parameters observed were affected at 20 Gy and upwards. Varietal susceptibility to irradiation was different since the maximum withstanding dose was 40 Gy for Gravesac and only 30 for Fercal. Besides, shoot development was more lowered than root development. The results showed that an increase of the irradiation dose decreased the rate of survival, the rhizogenesis and the growth of<em> in vitro</em> plants. On the V<sub>2</sub> vegetative generation ofGravesac vitroplants changes in size, in leafform, in plant habits, in growth and chlorophyll deficient mutations were recorded. Moreover, after a 30 Gy irradiation variations of growth, dry weight, leaf area, number of stomata and photosynthesis rates were shown on the V<sub>3</sub> generation. Accordingly this irradiation method is efficient to develop an <em>in vitro</em> variability. A sample of the surviving plants was established in the greenhouse for further screening.</p><p style="text-align: justify;"><br />(1) Communication faite au 6'®me Symposium International sur l'Amélioration de la Vigne, à Yalta (Crimée), Ukraine, du 4 au 10 septembre 1994</p>


1967 ◽  
Vol 31 ◽  
pp. 469-471
Author(s):  
J. G. Duthie ◽  
M. P. Savedoff ◽  
R. Cobb
Keyword(s):  

A source of gamma rays has been found at right ascension 20h15m, declination +35°, with an uncertainty of 6° in each coordinate. Its flux is (1·5 ± 0·8) x 10-4photons cm-2sec-1at 100 MeV. Possible identifications are reviewed, but no conclusion is reached. The mechanism producing the radiation is also uncertain.


1994 ◽  
Vol 144 ◽  
pp. 635-639
Author(s):  
J. Baláž ◽  
A. V. Dmitriev ◽  
M. A. Kovalevskaya ◽  
K. Kudela ◽  
S. N. Kuznetsov ◽  
...  

AbstractThe experiment SONG (SOlar Neutron and Gamma rays) for the low altitude satellite CORONAS-I is described. The instrument is capable to provide gamma-ray line and continuum detection in the energy range 0.1 – 100 MeV as well as detection of neutrons with energies above 30 MeV. As a by-product, the electrons in the range 11 – 108 MeV will be measured too. The pulse shape discrimination technique (PSD) is used.


Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1432
Author(s):  
Dmitry O. Chernyshov ◽  
Andrei E. Egorov ◽  
Vladimir A. Dogiel ◽  
Alexei V. Ivlev

Recent observations of gamma rays with the Fermi Large Area Telescope (LAT) in the direction of the inner galaxy revealed a mysterious excess of GeV. Its intensity is significantly above predictions of the standard model of cosmic rays (CRs) generation and propagation with a peak in the spectrum around a few GeV. Popular interpretations of this excess are that it is due to either spherically distributed annihilating dark matter (DM) or an abnormal population of millisecond pulsars. We suggest an alternative explanation of the excess through the CR interactions with molecular clouds in the Galactic Center (GC) region. We assumed that the excess could be imitated by the emission of molecular clouds with depleted density of CRs with energies below ∼10 GeV inside. A novelty of our work is in detailed elaboration of the depletion mechanism of CRs with the mentioned energies through the “barrier” near the cloud edge formed by the self-excited MHD turbulence. This depletion of CRs inside the clouds may be a reason for the deficit of gamma rays from the Central Molecular Zone (CMZ) at energies below a few GeV. This in turn changes the ratio between various emission components at those energies and may potentially absorb the GeV excess by a simple renormalization of key components.


Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 39-46
Author(s):  
Orhan Arslan ◽  
Şenol Bal ◽  
Nilgün Venice ◽  
Semra Mirici

SUMMARYIn this study, mitotic effects of gamma rays on Ekiz 1 variety belonging to Helianthus annuus L. (2n= 34) in the M0 (first irradiated seeds), M1 and M2 generations have been investigated. Seeds (M0) were irradiated with gamma rays at 10, 20, 30, 40 and 50 kR doses. Percentage of total abnormalities in the M0, M1 and M2 generations increased parallel to the increasing dose of radiation. These abnormalites have been observed as C-metaphase, chromosome stickiness, laggards and bridges with or without fragment. Mitotic index (M.I.) in the M0, M1 and M2 generations has decreased parallel to the dose increase. When the generations are compared, both the amounts of decrease in mitotic index and in the percentage of mitotic abnormalities were mostly observed in M0.


Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 220
Author(s):  
Emil Khalikov

The intrinsic spectra of some distant blazars known as “extreme TeV blazars” have shown a hint at an anomalous hardening in the TeV energy region. Several extragalactic propagation models have been proposed to explain this possible excess transparency of the Universe to gamma-rays starting from a model which assumes the existence of so-called axion-like particles (ALPs) and the new process of gamma-ALP oscillations. Alternative models suppose that some of the observable gamma-rays are produced in the intergalactic cascades. This work focuses on investigating the spectral and angular features of one of the cascade models, the Intergalactic Hadronic Cascade Model (IHCM) in the contemporary astrophysical models of Extragalactic Magnetic Field (EGMF). For IHCM, EGMF largely determines the deflection of primary cosmic rays and electrons of intergalactic cascades and, thus, is of vital importance. Contemporary Hackstein models are considered in this paper and compared to the model of Dolag. The models assumed are based on simulations of the local part of large-scale structure of the Universe and differ in the assumptions for the seed field. This work provides spectral energy distributions (SEDs) and angular extensions of two extreme TeV blazars, 1ES 0229+200 and 1ES 0414+009. It is demonstrated that observable SEDs inside a typical point spread function of imaging atmospheric Cherenkov telescopes (IACTs) for IHCM would exhibit a characteristic high-energy attenuation compared to the ones obtained in hadronic models that do not consider EGMF, which makes it possible to distinguish among these models. At the same time, the spectra for IHCM models would have longer high energy tails than some available spectra for the ALP models and the universal spectra for the Electromagnetic Cascade Model (ECM). The analysis of the IHCM observable angular extensions shows that the sources would likely be identified by most IACTs not as point sources but rather as extended ones. These spectra could later be compared with future observation data of such instruments as Cherenkov Telescope Array (CTA) and LHAASO.


Sign in / Sign up

Export Citation Format

Share Document