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.