Meiotic Analysis of Induced Translocation Heterozygotes In Lathyrus sativus L.

Abstract

Summary During the meiotic analysis of gamma ray treated sets, two induced translocation heterozygotes (P-1 and P-8) were cytologically isolated at 200 Gy and 400 Gy doses in Lathyrus sativus L. var. Pusa-24. However, both translocation heterozygotes (P-1 and P-8) exhibited the formation of a ring and chain of multivalents in majority of PMCs at diakinesis and metaphase-I. At anaphase-I, both the translocation heterozygotes displayed various abnormalities as well, although some PMCs showed normal 7 : 7 separations but the most common and frequent separation to be encountered in these two variants was 6 : 8 separation. Pollen fertility was found to decline to 41.32% in P-1 and 39.46% in P-8 against 98.92% in the control sets.

Gamma Ray Induced Chromosomal Interchange in Safflower (Carthamus tinctorius L.)

“…Translocation heterozygotes have been of interest as they represent a model of surveying genic and chromosomal changes and provide novel gene linking by breaking undesirable associations (Tripathi and Kumar 2009). Chromosome interchanges involving the exchange of chromosome segments have been produced in a large number of plant species using ionizing radiation (Gill et al 1980, Kumar andSingh 2003).…”

“…Among the various crop plants known, the genetics of reciprocal translocation has been studied by many workers viz. in soybean by Mahama et al (1999), in Phaseolus vulgaris by Ashraf and Bassett (1987), in grass pea by Talukdar and Biswas (2006) and by Tripathi and Kumar (2009). The segregation pattern of these translocation heterozygotes has been lacking in safflower, however, due to poor staining ability and the problem of chromosome stickiness.…”

Determination of optimum dose based of biological responses of lethal dose (LD25, 50, 75) and growth reduction (GR25, 50, 75) in ‘Yaghouti’ grape due to gamma radiation

“…Moreover, Sparrow 30 , who studied the cytological effects of radiation, concluded that these cytological alterations, including chromosomal damage, slowed mitosis, nuclear deterioration, cell expansion, and others, cause the reduction in vegetative traits such as leaf area. Nee Tripathi and Kumar 31 reported that higher doses of γ-ray lead to various drastic physiological effects, including changed protein biosynthesis, change in water transport, modified leave gas exchange, and hormones and enzymes imbalance. Moreover, Kovacs and Keresztes 32 reported that continuous short-wave radiation exposure would restrict vegetative development due to the gradual leaf elongation rate, resulting in lesser fully expanded leaves.…”

Meiotic abnormalities affect genetic constitution and pollen viability in dicots from Indian cold deserts

“…Occurrence of univalents and multivalents in complex and instable polyploid genome of Erigeron annuus (2n=27; 3x), Carduus nutans (2n=40; 4x), Geranium pratense (2n=56; 4x), and Taraxacum officinale (2n=32; 4x) with distorted behaviour during gamete formation led to low reproductive success. Such chromosomal associations occur in nature at a low rate, may arise spontaneously or induced by a variety of factors including chemical or irradiation treatments [18]. The inverse correlation between frequency of chromosome associations and pollen fertility also reported in Hyoscyamus muticus [19] and Brassica campestris var.…”