Comparative Mutagenic Effectiveness and Efficiency of Gamma Rays and Sodium Azide in Inducing Chlorophyll and Morphological Mutants of Cowpea

Abstract

Mutagenic effectiveness and efficiency are the most important factors determining the success of mutation breeding, a coherent tool for quickly enhancing genetic diversity in crops. However, conclusive evidence of using an effective and efficient dose of gamma (γ) rays and sodium azide (SA) for genetic improvement is scant. The present study assesses genetic diversity in M2 mutants of cowpea and evaluates mutagenic effectiveness and efficiency of the single and combination doses of γ rays and SA. In M0 generation, 7200 M1 seeds obtained by SA treatment (0.01—0.1%) and γ irradiation (100—1000 Gy) at a dose rate of 11.58 Gy/min were sown to raise M1 generation. A total of 57,620 M2 seeds were generated from the M1 generation of two varieties—Gomati VU-89 and Pusa-578, from which 47,650 seeds germinated. Moreover, plants (38,749) that survived were screened for chlorophyll and morphological mutations. Among the mutagens, SA followed by γ rays + SA and γ rays was most effective in inducing higher frequency and a broader spectrum of chlorophyll mutants. A wide range of morphological mutants affecting every growth stage was recorded with the highest frequency in 400 Gy γ rays + 0.04% SA treatment. These morphological mutants with desirable agronomic traits represent a valuable genetic resource for future breeding programs. This study revealed the potency of γ rays and SA in increasing genetic diversity and demonstrated the successful conduct of induced mutagenesis in the cowpea.

Mutagenic effect of gamma rays on induced mutation and principal component analysis of yield characters on green gram in M2 generation

“…These mutants are of no economic value but their frequency was deliberated to measure the effectiveness and efficiency of induced mutation by gamma irradiation and also served as a primary index for evaluating the genetic alteration which was caused by the mutagens. A wide spectrum of leaf mutants was found in gamma-irradiated treatment and has been reported earlier in green gram (31) and in cowpea (32). The effectiveness and efficiency of mutagens are important parameters to exploit induced mutagenesis for crop improvement.…”

Gamma ray induced positive alterations in morphogenetic and yield attributing traits of finger millet (Eleusine coracana (L.) Gaertn.) in M2 generation

“…Induced mutagenesis is an effective method for improving agronomic traits and genetic variability of important crops such as cowpea (27,28) lentil (29,30) faba bean (31,32), chickpea (33,34) urd bean (35,36), bean (37), rice (38,39) black cumin (40,41), fenugreek (42), and finger millet (43). In the present study on finger millet (Paiyur-2), all the studied morphological and quantitative traits increased in mutagenized population treated with 400 Gy to 600 Gy doses.…”

Comparative effects of caffeine and lead nitrate on the bio-physiological and yield associated traits of lentil (Lens culinaris Medik.)

“…The seed number is also an important yield attributing trait, and mutants with increased seeds per pod should be prioritized in selection programs. Earlier studies also reported increased seeds per pod in mutagenized crops [ 68 ]. In plant breeding programs, yield improvement is the ultimate aim of plant breeders and geneticists.…”