Chromosomal and biochemical assessments of six garlic clones

Abstract

Garlic (Allium sativum L.) is a commonly used Allium crop worldwide. It might be expected that garlic would show some intraspecific variations because of its vegetative reproduction. The main goal of this study was to examine the chromosomal aberrations and the relationship between secondary constrictions and nucleolus organizing regions in six garlic clones. Moreover, the biochemical assessments of total protien, esterase and glutamate gxaloacetate transaminase (GOT) were also carried out. Different types of chromosomal aberrations such as (i.e.) chromosome gap, chromatid break, centromeric attenuation and end-to-end association were scored. Data showed that the highest percentage of chromosome gap (15%) was observed in EGA 2 clone. The other structural aberrations were found in different percentages. According to the presence, number and position of the secondary constrictions (SC) and satellites (SAT), four different categories for six garlic clones studied could be identified. Nucleoli number at both interphase and prophase showed consederable differences among the six clones. For instance, percentage of nucleoli at interphase varied from 94% to 97% (one nuclelus) in Sids 40 and EGA4, respectively. No cells was detected at the prophase containing four nucleoli. A strong relationship was observed between existence of the structural chromosomal aberrations and numbers and position of some cytological markers such as satellites, secondary constrictions and nucleoli. No differences were founed among all studied cloves of the six garlic clones by using total protien, esterase and GOT. In the present work, the relationship between the assessed biochemical markers and the scored chromosomal aberrations couldn't be proved.

Variation of Karyotype Formula, and Asymmetry Between Individual Plants of Garlic and Its Relationship With Ac Transposon

“…Otherwise, the examined cells even within the same root exhibited five different SC or SAT chromosome forms with different percentages and approximately distributed in all chromosome pair. These data is in accordance with those previously reported (Elmamlouk et al, 2002;Yüzbaşioğlu and Unal, 2004;Ata, 2005;Osman et al, 2007;Ata and Osman, 2009;Anwar and Ata, 2017;Mahmoud et al, 2017 andHelmy, 2020).…”

“…In spite of using the conventional chromosome staining, the applying of fine and digital micro-photography with recent karyogram analysis might allow to detect the minute differences of karyotypic formula and asymmetry within and between cloves and bulbs of the same genotype. The hypothesis that accumulation of somatic chromosome mutations (particularly those of structural aberrations) caused M 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 100 bp 500 bp alterations of chromosome morphology (that might be quantified in terms of karyotype formula and asymmetry) between garlic genotypes was previously accepted (Bozzini and De Luca, 1991;Elmamlouk et al, 2002;Yüzbaşioğlu and Unal, 2004;Ata, 2005;Osman et al, 2007;Ata and Osman, 2009;Ata et al, 2010;Mukherjee and Roy, 2012;Ramesh, 2015;Anwar and Ata, 2017;Mahmoud et al, 2017 andHelmy, 2020). However, the interpretation of the given variation in karyotype formula and karyotypic asymmetry within and between cloves and bulbs in this study is still problematic.…”

“…The eight pairs of chromosomes tend to fall into three distinct groups, A) 5 "long" pairs, B) 2 satellited pairs, and C) the shortest pair. Examinations of the meiotic chromosomes pairing particularly those with nucleolar regions have clearly shown that several types of structural aberrations were frequently occurred during gametogenesis (Anwar and Ata, 2017). Surprisingly, almost all examined PMCs couldn't exhibit normal or regular chromosome pairing (primary association of the eight chromosome pairs).…”

“…Allium is the largest genus of the family Amaryllidaceae which comprises more than 800 species of monocotyledonous perennial, mostly bulbous flowering and economically important plant species (Fritsch et al, 2001 andRicroch et al, 2005;Anwar et al, 2017), including bulb onion (Allium cepa, 2n=2x=16), Japanese onion (Allium fistulosum, 2n=2x=16), leek (A. porrum, 2n=4x=32), and garlic (A. sativum, 2n=2x=16). Chromosome numbers are known for only about one-third of them and detailed cytological data are very limited (Ramesh, 2015).…”

“…Chromosome numbers are known for only about one-third of them and detailed cytological data are very limited (Ramesh, 2015). A single garlic accession frequently displays a high degree of phenotypic plasticity that is likely to be dependent upon soil type, moisture, and altitude (Fritsch and Friesen, 2002, Usman et al, 2016and Anwar et al, 2017. Karyotype of A. sativum comprises 16 chromosomes and could be, with difficulties, arranged into 8 pairs (Verma and Mittal, 1978;Elmamlouk et al, 2002;Ata, 2005;Osman et al, 2007;Ata and Osman, 2009;Ata, 2017 andMahmoud et al, 2017).…”