In this study, two species belonging to the genus Allium and distributed in Turkey are investigated. A thick cuticle is observed on the epidermis of the scapes of the species. The epicuticular layer is not evident in Allium scorodoprasum ssp. rotundum (L.) Stearn. Secretory cavities have been formed in the pith region of the species. Vascular bundles are in the form of two rings, one above and one below the sclerenchymatic ring. The cross- section of the leaf of Allium brevicaule Boiss. & Balansa is circular, unlike A. scorodoprasum ssp. rotundum. In both species, the stomata are located lower than the epidermis cells. The seeds of A. brevicaule are smaller than in A. scorodoprasum ssp. rotundum and they are polygonal shaped. The testa cells of A. brevicaule seeds have scalariform and tuberculate ornamentation. A. scorodoprasum seeds have reticulate sculpture testa. The species have sulcate pollen types. The pollen form of A. brevicaule is perprolate, and that of A. scorodoprasum ssp. rotundum is subprolate. The apertures in both species are monosulcus. In A. brevicaule, the sulcus does not extend to the poles at the proximal end. Therefore, the differences in the scape and leaf anatomy, as well as in palynology and micromorphology, can be used to distinguish Allium species.

In this study, genotoxic potential of industrial waste water (IWW) samples was investigated using Allium cepa assay. The root tips were treated with different IWW samples (A, B and C) for 48 hours. The effects of IWW oncytological effects were determined. It was found that all IWW samples significantly increased the percentage of total abnormality. Mitotic chromosomal abnormalities such as irregular metaphase, stickiness, c-mitosis, micronucleus,vagrant chromosomes and bridges were determined. Furthermore, a significant reduction for the mitotic index that isindicative of cellular toxicity was observed in root tips cells, which were treated with IWW samples. A. cepa assaycan be used as useful tool for the detection of genotoxic and cytotoxic potential of IWWs.

In two field experiments, the effect of some weed control treatments (citric acid at the rate of 10, 15 and 20%, acetic acid at the rate of 20, 30 and 40%, oxadiargyl, oxyflurfen, rice straw mulch, hand hoeing and an unweeded check control treatment) on weed growth and onion productivity in sandy soils at the Agricultural Experimental Station of the National Research Centre, Egypt was studied. The results indicated that all weeded treatments reduced the dry weight of broadleaf, grassy and total weeds as compared with the weedy check. Oxadiargyl, followed by two hand hoeing, rice straw mulch and acetic acid 40% recorded the greatest weed control efficiency. Insignificant differences were noticed between these treatments. Applying rice straw mulch increased bulb length, bulb diameter, bulb weight and onion yield by 67.52, 57.55, 45.74 and 66.22% over the weedy check, respectively. The highest values of N, P and K were obtained from rice straw mulch treatment followed by hand hoeing, oxadiargyl and acetic acid 40% treatments. It may be concluded that farmers can certainly depend on mulching or acetic acid at 40% instead of using chemical herbicides especially in organic farm systems for controlling onion weeds.

Three plant extracts viz. bulbs of Allium sativum L. (Liliaceae), seeds of Annona squamosa L. (Annonaceae) and leaves of Vitex negundo L. (Verbenaceae) were evaluated against cowpea wilt pathogen, Fusarium oxysporum f. sp. ciceris by mycelial dry weight method under laboratory condtions. The mean mycelium dry weights of F. oxysporum of methanol and benzene extracts of A. sativum obtained from 125 g of crused dry plant material (bulbs) were 0.0113 and 0.0174 mg, respectively. This was followed by methanol and petroleum ether extracts of A. squamosa (0.2396 and 0.2381 mg). They effectively controlled mycelial growth of cowpea wilt pathogen, however V. negundo extracts did not cause any significant mycelium growth inhibition when compared to other plant extracts tested. Among the three plant extracts, methanol extracts of A. sativum bulbs could possibly be used for controlling F. oxysporum.

Arbuscular mycorrizal (AM) fungi may enhance plant growth and polyphenol production, however, there have been limited studies on the relationships between root colonization of different fungal species and polyphenol production on cultivated Allium porrum (garden leek). The effects of inoculation of AM fungi spores from Rhizophagus intraradices, Giga -spora margarita, Glomus geosporum, Paraglomus occultum, Claroideoglomus claroideum, and Glomus species on colonization of garden leek roots and symbiotic changes in polyphenol production and plant growth were evaluated in greenhouse experiments. There were significant differences (p < 0.05) in colonization of leek roots by AM fungi species. The greatest level of root colonization was recorded on plants inoculated with R. intraradices (73%) and the lowest level on C. claroideum (3.2%). Significant differences (p < 0.05) in plant height were recorded between AM inoculated plants and the controls. Polyphenol levels differed significantly (p < 0.05) between garden leek plants inoculated with AM fungi and the non-inoculated controls. The percentage increases in polyphenol (a derivative of kaempferol) on garden leeks inoculated with G. geosporum relative to the untreated controls ranged from 28 to 1123%. Due to symbiosis with different AM species, other polyphenols decreased in some instances (negative values) and increased in others for values of up to 590%. Results showed that AM fungi species exhibited remarkable differences in polyphenol levels in garden leeks. The high polyphenol production by garden leek plants inoculated with G. geosporum, and Glomus species could be exploited for enhanced resistance of garden leeks to insects and diseases. This research highlights an understudied area, notably the relationships between AM fungal inoculations, root colonizations and polyphenol production in garden leeks. The findings can be utilized to improve pest resistance and the quality of garden leek plants.

We made interspecific crosses to facilitate the introgression of desirable traits of Allium roylei into the Alliumcepa genome. After hand-pollination, 906 interspecific F1Allium cepa × A. roylei plants were obtained by in vitro culture via embryo rescue. Nuclear DNA analysis showed that 97.6% of the regenerants were interspecific F1Allium cepa × A. roylei hybrids. Genomic in situ hybridization (GISH) showed that each hybrid had 16 chromosomes, eight of which were identified as A. cepa and eight as A. roylei chromosomes.

Triploid viviparous onions [Allium x cornutum Clementi ex Visiani 1842, syn Allium cepa L. var. viviparum Metzg. (Alef.), auct.] (2n = 3x = 24), are known in some countries only as rare relict crops. In other parts of the world they are still traditionally or even commercially cultivated. In previous cytogenetic studies of the Croatian triploid viviparous onion Ljutika, Giemsa C-banding, chromosome pairing analysis during meiosis, and genomic hybridization in situ indicated a complex hybrid with highly heterozygous karyotype structure, with possible triparental genome organization. This study continues an analysis of the karyotype structure of Ljutika. Staining with fluorochromes CMA3 (Chromomycin A3) and Dapi (4,6-diamidino-2-phenylindole) confirmed previous results from Giemsa C-banding and revealed GC-rich heterochromatic regions associated mainly with chromosome ends and nucleolus organizing regions (NORs), and only a few interstitial bands. Fish mapping of the ribosomal 18S-5.8S-26S genes revealed two major rDNA signals on the short arms of two subtelocentric satellite chromosomes in almost all metaphase plates of Ljutika. The largest subtelocentric chromosome lacked rDNA signals. A significantly smaller rDNA signal was occasionally located on one small submetacentric chromosome. These results are in agreement with previously published results from identification of NORs by silver-staining technique, which confirmed a maximum three nucleoli in interphase nuclei. We discuss the molecular mechanisms underlying rearrangements and activity of ribosomal genes in the triploid karyotype.