EMS, sodium azide and gamma rays induced meiotic anomalies in Delphinium malabaricum (Huth) Munz

Abstract

Meiotic cell division is a dynamic cellular process controlled by a large number of genes that act from premeiotic to postmeiotic mitosis. Mutation in these genes may cause anomalies that impair plant fertility. In this study, an attempt has therefore been made to understand the effects of ethyl methane sulfonate (EMS), sodium azide (SA) and gamma rays on the meiotic configuration of Delphinium malabaricum. The results demonstrated that the mutagens cause various types of cytological aberrations, such as univalents, chromatin bridges, laggards, fragments, stickiness and multinucleated cells. The maximum aberrations were found at higher doses/concentrations of the mutagens. The highest percentage of pollen mother cells showing abnormalities was induced by EMS followed by gamma rays and SA. The mutagen impact on chromosomal anomalies increased the frequency of pollen sterility.

Comparative Analysis of Different Chemical Mutagens in Inducing Chromosomal Aberrations in Meiotic Cells of <i>Triticum aestivum</i> L.

“…It is interesting to note that aberrations such as chromosome stickiness or clumping, disturbed pairing, and multivalents, orientation of chromosomes, disturbed spindle functioning lead to unequal clusters of chromosomes, aberrant microspores, abnormal cytokinesis, high pollen sterility can be induced through chemical mutagenesis. Similar types of aberrations have been observed in various plants raised from seeds treated with chemical mutagens (Gulfishan et al 2012, Kolar et al 2013.…”

“…Chromosome aberrations have been used as a measure of reproductive success in plants for many years and have been correlated with morphological and taxonomical changes, fertility sterility relationships, mutations, and other characteristics. The data on mitotic and meiotic analysis is of fundamental consideration for any given species in understanding the basic structure of the genetic complement; further, the mutagen-induced aberrations of the chromosome is the primary basis of genetic variation; therefore, investigations on the mechanism of chromosome breakage, type of aberrations and their genetic consequences form an integral part of most mutation studies (Kolar et al 2013). The studies also provide information regarding the response of various genotypes to a particular mutagen and give greater chances for the selection of desired characters.…”

“…Chemically induced mutagenesis has been found to be an efficient mechanism/approach for the induction of morphological as well as genetic variabilities (Dixit et al 2013, Kolar et al 2013, Jahan et al 2020, Singh et al 2021. Chemical mutagens generate greater mutation rates as compared to physical mutagens (Kharkwal 1999) and have higher effectiveness and comparatively better specificity of mutation (Bhat et al 2005).…”

In vitro Induced Mutagenesis for Early Blight (<i>Alternaria solani</i>) Resistance in Potato (<i>Solanum tuberosum</i> L.)

“…It usually induces base substitutions (mostly induced Guanine: Cytosine → Adanine: Thyamine transitions at the 2 nd codon position) and also produce DNA single strand breaks. Kolar et al [42] reported chromosomal aberrations by using sodium azide, however, reciprocal translocations and mitotic chromosomal aberrations have also been reported by sodium azide [43]. It has also been reported as an electron transport blocker, inhibitor of the respiratory chain and its immediate effect on the meristematic region is the dropping off its progression velocity in the cell cycle [44], its exact mechanism of action as a chemical mutagen is still not clear.…”

Gamma Irradiation Induced Chromosome Aberrations in Meiotic Cells of Bread Wheat (Triticum aestivum L.)

“…Lagging of chromosomes may be either due to attachment to very weak spindle fibre or no attachment at all. Kolar et al [18] opined that due to the effect of mutagens, spindle fibres failed to carry the chromosome movement towards poles properly and resulting in the lagging chromosome appearing at anaphase. In addition, delayed terminalization, the stickiness of chromosome ends and failure of chromosomes segregation has led to laggard chromosome formation.…”