Genetic Behaviour of Induced Translocation Heterozygote in Poppy

Abstract

Summary From among the population obtained from gamma irradiated seeds, a plant having segmental exchanges between heterologous chromosomes was isolated. Gamma ray-induced translocations have been reported in many plant species; however, there is no previous report of the occurrence of induced translocation in poppy. Chromosomal associations in rings and chains along with bivalents and univalents were observed in pollen mother cells (PMCs) during microsporogenesis. In a number of PMCs, only a few bivalents and a high frequency of univalents have also been observed. Various anaphasic anomalies were also taken into account including chromatid bridges, laggards and unequal separations etc. Later stages of meiosis were also found to be highly disturbed. Owing to the high frequency of chromosomal aberrations, the pollen fertility was considerably reduced. Phenotypically, the plant was shorter in height and weaker in comparison to the control population. The study furthermore deals with a brief investigation on the genetic behaviour of this peculiar anomaly and the probable cause of its occurrence.

Cytogenetical Investigation of a Translocation Heterozygote Induced by Gamma Rays in <i>Coriandrum sativum</i> L.

“…This led to much higher pollen sterility and a concomitant decrease in seed production. Induction of translocation heterozygotes through gamma rays was known in many plant species, e.g., Pennisetum typhoides (Pantulu 1967), Vicia faba (Sjodin 1971), Vinca rosea (Sudhakaran 1971), Oryza sativa (Reddi and Redi 1975), Plantago (Padha et al 1998) and poppy (Kumar and Naseem 2012). We have reported translocation heterozygosity for the first time in coriander, it is of immense interest to study whether this characteristic will pass on to successive generation or remain as recessive.…”

Meiotic analysis of induced translocation heterozygotes in Lepidium sativum Linn.

“…Abnormalities like laggards, bridges, and micronuclei are the consequence of unequal or difficulty in accurate segregation of chromosomes at Anaphase I/II of Telophase I/II. High possibility of formation of laggards presenting unequal and delayed separation is mainly contributed by alternate orientation (Kumar et al, 2012). Elevated meiotic disturbances via unequal segregation of the number of translocated chromosomes and the consequent increased pollen fertility are the consequences of the involvement of a greater number of different non-homologous chromosomes.…”

“…Therefore, semisterile individuals is a unique feature for creating variations in the Lepidium which may be utilized by plant breeders to develop mutant lines. Gamma irradiations have been successful in inducing translocation heterozygosity in plant species like Pennisetum typhoids (Pantulu et al, 1967), Vicia faba (Sjodin et al, 1971), Pisum sativum (Verma et al, 2012), Safflower (Verma et al, 2014), Vinca rosea (Sudhakaran et al, 1971), Plantago (Padha et al, 1998) and papaver somniferum (Kumar et al, 2012).…”

Genetic behavior of induced translocation heterozygote in Artemisia annua L.

“…Induction of translocation heterozygotes through gamma rays is known in many plant species, e.g. Pennisetum typhoides (Pantulu 1967), Vicia faba (Sjodin 1971), poppy (Kumar and Naseem 2012) etc. The actual cause for induction of translocation by gamma rays is yet unknown, but perhaps gamma radiation ionizes the DNA directly or by reacting with the cell water content and producing free radicals that induce translocation in Artemisia annua L. The application of gamma rays might be the probable cause of physiological imbalance in the cells, producing some chemical substances that disrupt the synthesis of DNA in the cells following breakage and restitution of the broken segments, thus resulting in chromosome associations (Basi et al 2006).…”

“…The occurrence of anaphasic anomalies like laggards, bridges and unequal separations can be explained to be due to the inability of the multivalent to separate properly (Kumar and Singh 2003). Adjacent orientations were mainly responsible for the formation of laggards because here there are always possibilities of unequal and delayed separation (Kumar and Naseem 2012). Bridges might be formed due to delayed chiasma termilnalization.…”