Effect of Gamma Rays on Growth and Karyokinetic Activity in <i>Trigonella foenum-graecum</i> L

Abstract

Our studies on the effect of radiation on Trigonella foenum-graecum (Raghuvan shi and Singh 1973) had indicated that seeds irradiated at 60Kr of gamma rays with cobalt 60 source though showed normal germination but there was no growth beyond two cotyledonary stage and later on these seedlings withered away. We have reported a similar pattern following colchicine treatment of dry seeds of Tri gonella foenum-graecum (Raghuvanshi and Joshi 1965). It was found that in the doses that were sufficient to induce polyploidy, germination of treated seeds was normal but no growth occurred beyond two cotyledonary stage. The present investigations were undertaken to find out the effects of higher doses on growth and karyokinetic activity. Materials and methodsDry seeds of Trigonella foenum-graecum with 6.9% moisture content were irradiated at 10, 30 and 60Kr, and germinated in petridishes. For cytological study material was fixed in 1:3 acetic alcohol, just after germination, and then after 48 hours intervals. In each set growth measurements of roots of 30 seedlings which were numbered from 1 to 30 were taken. Thus it was possible to follow growth pattern in individual seedling. Haematoxylen squashes of root tips, cotyle donary portion along with hypocotyl were prepared for chromosomal studies. Slides were later made permanent by ethanol-butanol schedule.In all, six sets were fixed at 48 hours interval. For analysing the karyokinetic activity in each set squashes of 10 root tips were prepared and from each slide 5 spots were taken at random for study. Squashes of shoot tips of both controls and irradiated ones were made for determining nuclear conditions. ObservationsGermination as indicated by emergence of radicle was first observed in 60Kr followed by 30Kr while 10Kr and controls germinated simultaneously. Maximum growth rate was recorded in 60Kr up to 3rd day ( Fig. 1) and after 3rd day, lead was taken by 30 Kr up to 7th day. The controls showed lowest growth rate up to 5th day but by 7th day they took the lead which was maintained up to last day of observa

Cyto–Genotoxic Effect Causing Potential of Polystyrene Micro-Plastics in Terrestrial Plants

“…Chromosomal breaks are formed due to the unfinished or mis-repaired DNA molecules required for linear continuity of the chromosome's structure [81], while the anaphasic bridge results from chromosomal breakage, stickiness, fusion, para-centric inversion, and altered functioning of the replication enzymes [82]. The ring chromosome can arise due to breaks in the chromosome arms and fusion of the proximal broken ends, which leads t oa loss of the distal material or rings; they can be formed by telomere dysfunction, triggering the fusion of reactive chromosome ends [52,83,84].…”

Cytological effects of some organophosphorus pesticides. I Mitotic effects.

“…Sax (1940) opined that if two breaks occur in the same chromosome, a ring chro mosome may be formed by the process of rejoining. Raghuvanshi and Singh (1976) attributed the formation of ring chromosomes in Trigonella foenum-graceum to telomeric losses.…”