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. This study shed light on such variations joined with the existence of the transposable element Ac in garlic. The examined cells exhibited different types of chromosomal aberration were recorded as percentages of the total abnormal cells. Microscopic examination of root tip cells of the (Egaseed 2) clone showed a variety of chromosomal aberrations represented as: gap, chromatid deletion, chromatid break, end-to-end association and centromeric attenuation. DNA was isolated from ten individual cloves of Egaseed 2 clone. Using Ac primer, a monomorphic fragment of 100 bp was detected in 10 cloves of the Egyptian clone (Egaseed 2) of garlic. One of the same cloves, no. 7, has an additional fragment of 300 bp. The relationship between Ac element existence and chromosomal changes occurrence was discussed.

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During the present study meiotic investigations are carried out on some members of family Convolvulaceae collected from different regions of Rajasthan. Total 19 species under 6 genera are meiotically studied. Of these, 2 species, namely, Convolvulus deserti (2n = 18) and Merremia umbellata (2n = 14) are cytologically worked out for the first time from the world and five species, namely, C. glomeratus (2n = 28), C. sabatius (2n = 22), Ipomoea cordatotriloba (2n = 30), I. triloba (2n = 30) and I. sagittifolia (2n = 30) are cytologically worked out for the first time from India.

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Gamma irradiation is one of the physical mutagens that are widely used for induced mutations, food sterilization and medicinal healing. In the present study, irradiation techniques were applied to investigate the effect of gamma irradiation on seed germination, meiotic behavior and pollen fertility of tomato (Solanum lycopersicum L.). The seeds of Solanum lycopersicum (var. Bharat ratan -221) were irradiated with different doses of gamma rays (10, 15, 20, 25, 30, 35 and 40 kR). Results showed that seed germination and pollen fertility in M1 generation reduced steadily with the increasing doses of gamma rays. During the study, increases in meiotic abnormalities with increasing doses were noticed in mutagenic population of gamma rays in M1 generation. The most common chromosome abnormalities observed include univalents, multivalents, bridges, laggards, fragments, micronuclei and disturbed polarity, etc.

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The effect of colchicine was studied from the cytological point of view to induce mutation and develop polyploidy. The present study was conducted to determine the effect of colchicine on cell division and some morphological traits. Young seedling of Chrysanthemum carinatum Schousb. (2n=18) was treated with 0.2% colchicine. During meiotic analysis, reciprocal translocation heterozygote has been isolated among population of the colchicine treated Chrysanthemum carinatum Schousb. The translocation heterozygotes showed characteristics feature such as multivalent formation (mainly quadrivalents and hexavalent), univalent formation, bivalent associations, chromatin stickiness, chromosomal laggards, fragments and multipolar PMCs. At anaphase I, some pollen mother cells (PMCs) showed abnormal 8:10 chromosomal separation in addition to normal 9:9 separation. The treated populations showed reduction in plant survivability, plant height and delayed flowering. Induction of permanent chromosomal structural changes may also sometime bring out favorable morphological variation. It is expected that the mutant, when established, could be used in further cytological and breeding programs.

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