Assessment of Bio-physiological damages and cytological aberrations in cowpea varieties treated with gamma rays and sodium azide

The assessment of mutagen induced biological damage forms an important study in determining the mutagenic potency and genotypic sensitivity, a vital aspect in mutation breeding programs. A prior assessment of lethal dose (LD50), mutagen induced biological damage (alterations in bio-physiological traits and frequency of cytological aberrations) is a prerequisite for determining an optimum mutagen dose in a successful mutation breeding experiment. Therefore, in a multi-year project of mutation breeding, two widely cultivated varieties of cowpea viz., Gomati VU-89 and Pusa-578, were treated with gamma (gamma) rays and sodium azide (SA) doses. The results reflected a proportionate increase in bio-physiological damages with the increase in mutagenic doses and caused a substantial reduction in mean seed germination and seedling height. Different cytological aberrations such as cytomixis, univalents, chromosome stickiness, precocious separation, unequal separation, bridges, laggards, disturbed polarity, dyads, triads, and polyads were observed in both varieties. All the mutagen doses induced a broader spectrum of cytological aberrations with varying frequencies.

Automated summary

The assessment of mutagen induced biological damage is crucial for determining mutagenic potency and genotypic sensitivity in mutation breeding programs. In this study, two varieties of cowpea were treated with gamma rays and sodium azide to determine the optimal mutagen dose. The results showed that higher doses of mutagens led to increased biological damage, resulting in reduced seed germination and seedling height. Various cytological aberrations were observed in both varieties, indicating a broader spectrum of genetic alterations induced by mutagens.