scholarly journals On the effects of secretions of saprophytic bacteria on the course of mitosis in adventitious roots of Allium cepa L.

2015 ◽  
Vol 42 (1) ◽  
pp. 171-179
Author(s):  
Z. Kobierzyńska
Keyword(s):  
Allium Cepa ◽  
Chromosome Aberrations ◽  
Adventitious Roots ◽  
Bacterial Strains ◽  
Liquid Cultures ◽  
Allium Cepa L

The influence of 21 strains of saprophytic bacteria isolated from onion cultures on the course of mitosis and on the level of chromosome aberrations in adventitious roots of <i>Allium cepa</i> L. was studied. Liquid cultures of all bacterial strains caused no changes in divisions of the cells. However, ten of the strains were responsible for disturbances in this process. The nature of these disturbances depended to a large extent on the kind of medium in which the bacteria were grown.

scholarly journals Introductory studies of bacterial effects on the course of mitosis in adventitious roots of Allium cepa L.

2015 ◽  
Vol 41 (2) ◽  
pp. 205-216
Author(s):  
J. Cebrat ◽  
K. Czerwińska ◽  
K. Bohdanowicz-Murek
Keyword(s):  
Allium Cepa ◽  
Chromosome Aberrations ◽  
Adventitious Roots ◽  
Water Culture ◽  
Meristematic Cells ◽  
Allium Cepa L ◽  
Spontaneous Chromosome

The level of spontaneous chromosome aberrations and other phenomena concomitant with mitoses in the meristematic cells of <i>Allium cepa</i> L. adventitious roots grown in water, depends to a large extent on the intensity of bacteria multiplication. From the water culture two strains of bacteria, which were most numerous, were isolated - <i>Agrobacterium</i> and <i>Flavobacterium</i>. A supernatant from bacteria grown on Davis medium induced chromosome sticking together, c-mitoses and the formation of polyploid nuclei in the roots of onion.

scholarly journals Influence of 1-p-D-arabinofuranosylcytosine on mitotic activity of apical meristem of onion (Allium cepa L.) roots

2015 ◽  
Vol 47 (1–2) ◽  
pp. 173-187 ◽  
Author(s):  
M. Kuraś ◽  
A. Malinowska
Keyword(s):  
Mitotic Activity ◽  
Chromosome Aberration ◽  
Allium Cepa ◽  
Cytosine Arabinoside ◽  
Adventitious Roots ◽  
Apical Meristem ◽  
Allium Cepa L ◽  
Cells With Micronuclei

The influence of increasing cytosine arabinoside (ara-C) concentration (50, 100, 300 and 500 μg/ml) on the mitotic activity of the apical meristem of onion adventitious roots was investigated during 24-h incubation in ara-C and postincubation in water. Incubation in ara-C inhibits reversibly mitosis, the degree of inhibition being dependent on the concentration used. 50 μg/ml ara-C causes only a slight and transitional mitotic depression, while 100—500 μg/ml reduces the per cent of mitoses in various degrees after 12-h incubation whereas after 24 h all concentrations (100—500) reduce mitosis to the same level of about 2 per cent (80% inhibition). During postincubation in water there occurs after treatment with 100—500 μg/ml ara-C, a wave of highly synchronized mitoses with a peak after 12 h. The highest frequency of synchronized mitoses (60°/o) appeared in roots treated with 300 μg/ml ara-C. The main wave is preceded by a small one with a peak after 2-4 h of postincubation. This seems to be the consequence of phases S and G<sub>2</sub> inhibition by ara-C. It was found that under the influence of ara-C the per cent of mitoses with chromosome aberration and of cells with micronuclei increased only slightly.

Bacteria occurring in onion (Allium cepa L.) foliage in Puerto Rico.

1969 ◽  
pp. 199-219
Author(s):  
Juan Calle-Bellido ◽  
Lydia I. Rivera-Vargas ◽  
Myrna Alameda ◽  
Irma Cabrera
Keyword(s):  
Puerto Rico ◽  
Pseudomonas Syringae ◽  
Allium Cepa ◽  
Leaf Tissue ◽  
Field Conditions ◽  
Bacterial Strains ◽  
Burkholderia Glumae ◽  
Pathogenic Potential ◽  
Allium Cepa L ◽  
Leaf Tissues

Bacteria associated with foliar symptoms of onion (Allium cepa L.) were examined in the southern region of Puerto Rico from January through April 2004. Different symptoms were observed in onion foliage of cultivars 'Mercedes' and 'Excalibur' at Juana Díaz and Santa Isabel, Puerto Rico. Ellipsoidal sunken lesions with soft rot and disruption of tissue were the most common symptoms observed in onion foliage in field conditions. From a total of 39 bacterial strains isolated from diverse symptoms in onion foliage, 38% were isolated from soft rotting lesions. Ninety-two percent of the bacteria isolated from onion foliage was Gram negative. Pantoea spp. with 25%, was the most frequently isolated genus, followed by Pasteurella spp. and Serratia rubidae with 10% each. Fifty- six percent of the strains held plant pathogenic potential; these strains belong to the genera Acidovorax sp., Burkholderia sp., Clavibacter sp., Curtobacterium sp., Enterobacter sp., Pantoea spp., Pseudomonas spp., and Xanthomonas spp. Pathogenicity tests showed that seven out of eight tested bacterial strains evaluated under field conditions caused symptoms in onion foliage for both cultivars. Acidovorax avenae subsp. citrulli, Burkholderia glumae, Pantoea agglomerans, P. dispersa, Pseudomonas sp., Xanthomonas sp., and Xanthomonas-Wke sp. were pathogenic to leaf tissues. Clavibacter michiganensis was not pathogenic to leaf tissues. Other bacteria identified as associated with onion leaf tissue were Curtobacterium flaccumfaciens, Cytophaga sp., Enterobacter cloacae, Flavimonas oryzihabitans, Mannheimia haemolytica, Pantoea stewartii, Pasteurella anatis, P. bettyae, P. langaaensis, Photobacterium damselae, Pseudomonas syringae pv. aptata, Rhizobium radiobacter, Serratia rubidae, Sphingobacterium spiritivorum, Sphingomonas sanguinis, and an unknown strain. This paper is the first survey of bacteria associated with onion foliage in Puerto Rico. The role of non- phytopathogenic bacteria associated with the life cycle of onion under field conditions remains unknown.

scholarly journals Investigations on the cytotoxic influence of zinc on Allium cepa L. roots

2014 ◽  
Vol 51 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Halina Kocik ◽  
Barbara Wojciechowska ◽  
Alicja Liguzińska
Keyword(s):  
Mitotic Activity ◽  
Allium Cepa ◽  
Zinc Chloride ◽  
Zinc Acetate ◽  
Adventitious Roots ◽  
Apical Meristem ◽  
Root Elongation ◽  
Allium Cepa L

The influence of various (0.1, 0.08, 0.04, 0.02, 0.01, 0.005, 0.0025 and 0.00125 M) zinc chloride and zinc acetate concentrations on the mitotic activity of the apical meristem of onion adventitious roots was investigated after 24 h of incubation. It was found that the tested compounds have a mitodepressive action and distinctly inhibit root elongation. The results of topochemical analysis are reported.

scholarly journals Bacteria occurring in onion (Allium cepa L.) foliage in Puerto Rico.

1969 ◽  
Vol 96 (3-4) ◽  
pp. 199-219 ◽  
Author(s):  
Juan Calle-Bellido ◽  
Lydia I. Rivera-Vargas ◽  
Myrna Alameda ◽  
Irma Cabrera
Keyword(s):  
Puerto Rico ◽  
Pseudomonas Syringae ◽  
Allium Cepa ◽  
Leaf Tissue ◽  
Field Conditions ◽  
Bacterial Strains ◽  
Burkholderia Glumae ◽  
Pathogenic Potential ◽  
Allium Cepa L ◽  
Leaf Tissues

Bacteria associated with foliar symptoms of onion (Allium cepa L.) were examined in the southern region of Puerto Rico from January through April 2004. Different symptoms were observed in onion foliage of cultivars 'Mercedes' and 'Excalibur' at Juana Díaz and Santa Isabel, Puerto Rico. Ellipsoidal sunken lesions with soft rot and disruption of tissue were the most common symptoms observed in onion foliage in field conditions. From a total of 39 bacterial strains isolated from diverse symptoms in onion foliage, 38% were isolated from soft rotting lesions. Ninety-two percent of the bacteria isolated from onion foliage was Gram negative. Pantoea spp. with 25%, was the most frequently isolated genus, followed by Pasteurella spp. and Serratia rubidae with 10% each. Fifty- six percent of the strains held plant pathogenic potential; these strains belong to the genera Acidovorax sp., Burkholderia sp., Clavibacter sp., Curtobacterium sp., Enterobacter sp., Pantoea spp., Pseudomonas spp., and Xanthomonas spp. Pathogenicity tests showed that seven out of eight tested bacterial strains evaluated under field conditions caused symptoms in onion foliage for both cultivars. Acidovorax avenae subsp. citrulli, Burkholderia glumae, Pantoea agglomerans, P. dispersa, Pseudomonas sp., Xanthomonas sp., and Xanthomonas-like sp. were pathogenic to leaf tissues. Clavibacter michiganensis was not pathogenic to leaf tissues. Other bacteria identified as associated with onion leaf tissue were Curtobacterium flaccumfaciens, Cytophaga sp., Enterobacter cloacae, Flavimonas oryzihabitans, Mannheimia haemolytica, Pantoea stewartii, Pasteurella anatis, P. bettyae, P. langaaensis, Photobacterium damselae, Pseudomonas syringae pv. aptata, Rhizobium radiobacter, Serratia rubidae, Sphingobacterium spiritivorum, Sphingomonas sanguinis, and an unknown strain. This paper is the first survey of bacteria associated with onion foliage in Puerto Rico. The role of non- phytopathogenic bacteria associated with the life cycle of onion under field conditions remains unknown.

Effects of drought and subsequent rehydration on the structure, vitality, and permeability of Allium cepa adventitious roots

1993 ◽  
Vol 71 (5) ◽  
pp. 700-707 ◽  
Author(s):  
Elida Stasovski ◽  
Carol A. Peterson
Keyword(s):  
Allium Cepa ◽  
Lateral Root ◽  
Adventitious Roots ◽  
Free Water ◽  
Food Storage ◽  
Root Primordia ◽  
Root Cortex ◽  
Lateral Root Primordia ◽  
Allium Cepa L ◽  
Suberin Lamellae

Drought stress was induced in onion (Allium cepa L.) plants that had been sprouted from bulbs initially planted in moist vermiculite. The medium received no further water, and its free water content fell from 50 to 0% over a period of 35 d. The water stress thus imposed killed the root apices and accelerated the death of the epidermis. However, other regions, including the short cells of the dimorphic exodermis, the remainder of the cortex, and the stele (except for the mature vessels), remained alive for periods of prolonged drought (up to 200 d after cessation of watering). During this time, symplasmic continuity from the exodermis to the vascular tissues of the stele was maintained through the living cells as judged by the transport of fluorescein from an ambient solution into the stele. After the death of the epidermis, the presence of Casparian bands in all cells of the exodermis and suberin lamellae in its long cells presumably reduced the flow of water from the root to the dry external medium. A dieback pattern in which the cortex is retained would place an increased respiratory demand on the plant compared with dieback to the endodermis. However, this may be offset by positive functions such as preserving a site for future food storage and (or) providing a hospitable environment for mycorrhizae when conditions outside the root are hostile. Loss of a viable apex under conditions of drought induced the development of many lateral root primordia that did not emerge but remained dormant within the root cortex. When water was added to the growth medium, these grew out quickly and along with the new adventitious roots that sprouted from the bulbs, rejuvenated the root system. Stress periods longer than 200 d resulted in death of the majority of the roots, and the plants did not recover after watering. Key words: drought, roots, Allium cepa L., exodermis, hypodermis, dormant lateral root primordia.

Цитогенетические эффекты гамма-излучения в проростках Allium cepa L.

2018 ◽  
Vol 481 (1) ◽  
pp. 99-103
Author(s):  
А.Я. Болсуновский ◽  
Д.В. Дементьев ◽  
Е.М. Иняткина ◽  
Ю.В. Кладько ◽  
М.В. Петриченков ◽  
...  
Keyword(s):  
Allium Cepa ◽  
Allium Cepa L
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