CYTOLGICAL AND ISOZYMES STUDIES OF GARLIC CULTIVATED IN EGYPT.

Abstract

Generally It has been accepted that the apomictic nature of nature of garlic clones could affect its cytological and genetical features as a result of accumulation of certain somatic mutations. Thus, the aim of this study is to examine some of the cytological (karyotyping, mitotic index and mitotic abnormalities) and isozyme characteristics of five garlic genotypes cultivated in Egypt (Baladi , Chinese , Chinese , 30-4 , Chinese 31-1and Chinese 31-3).Relative chromosome lengths and centromere position of these genotypes revealed insignificant difference in their karyotype formula (5 large , 2 medium from submetacentric pair and one large metacentric pair no. 5). The percentage of mitotic index of Baladi genotype (8.28%) was not very much different from that of Chinese (12.08%) whereas it was significantly lower than those of Chinese 30-4 (15.6%),Chinese 31-1(18.18%)and Chinese 31-3 (16. 8%). Means of total chromosomal abnormalities (including anuepliody, break and stickiness) were remarkably lower in genotypes Baladi (7.64%) and Chinese (9.38%)than those of Chinese 30-4 (11.94%), Chinese 31-3 (11.2%). Statistical analysis revealed that there was a high correlation (0.77) between the mitotic index and the percentage of mitotic chromosome abnormalities. Isozymes [Acid phosphatase, Glutamate Oxaloacetate Transaminase (GOT), Peroxidase and Esterase) banding patterns were qualitatively compared. The banding patterns of esterase (2bands) and GOT (one band) were similar in all five genotypes. As for Pyroxidase, the four genotypes of the Chinese origin had two bands, whereas only one band was shown by the genotype Baladi that was similar in molecular weight to small band of Chinese genotypes. All studies genotypes of acid phosphatase showed one band, which was of a low molecular weight in all except in Chinese genotype where it was a high molecular weight and Chinese 31-1 in which both low and high molecular weight bands were found.