الفهرس | Only 14 pages are availabe for public view |
Abstract In the present study, some cytological and biochemical characteristics of six garlic clones were studied to estimate some of the complicated features of the garlic genome specially those of karyotype analysis. 1. Cytogenetical studies 1. 1. chromosomal aberrations Different types of chromosomal aberrations such as chromosome gap, chromatid break, centromeric attenuation and end-to-end association were scored. A highest percentage of chromosome gap was observed in EGA 2 clone. The other structural aberrations were found in different percentages. 1. 2. Secondary constrictions According to the presence and number and position of the secondary constrictions (SC) and satellites (SAT), four different categories were calculated as percentages of cells with only one SAT-chromosome (category I), with two (category II), with three (category III) and with four SAT chromosomes (category IV). Sids 40 and EGA 4 clones exhibited category I, while Baladi, AZO 3 and EGA 3 clones showed category IV. Only one clone (EGA 2) exhibited category II. Category III had the lowest percentage at all examined garlic clones when compared with the other three. 1. 3. Number of nucleoli at interphase and prophase Nucleoli number at both the interphase and the prophase showed consederable differences among the six studied 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. 1. 4. C-banding of the two garlic clones (AZO3 and EGA2) It should be prominent that C-bands were not observed around the centromeric regions on any chromosome of the chromosome complement of the two studied clones. C-bands mainly scattered on the interstitial region on the short arm of fourth, fifth and eighth chromosome. The examined metaphase cells of the two garlic clones exhibited C-banding patterns on the short arm of two homologous chromosomes of pair no.4. Almost all examined metaphase cells showed a unique, large and dark c-banding block. It was found on the interstitial region of the short arm of only a single copy of chromosome pair no.8. Two c-banding signals were observed at the interphases of the two studied garlic clones, while only one band was seen at the prophases. 2. Biochemical Evaluation Isozyme pattern of esterase, Glutamate Oxaloacetate Transaminase (GOT) and total protien were studied in six garlic clones to determine genetic variability within and between clones. Results showed that there were no differences among all tested clones by analyzing the two different isozyme pattern and the total protien. |