Seed coat color, weight and eye pattern inheritance in gamma-rays induced cowpea M2-mutant line

Abstract

Gamma radiation is a very effective tool for inducing genetic variation in characters of many plants. Black seeds of M2 mutant were obtained after exposure of an Egyptian cowpea cultivar (Kaha 1) to a low dose of gamma rays. Segregation of seed coat color, weight of 100 seeds and seed eye pattern of the black seeds of this mutant line were further examined in this study. Four colors were observed for seed coat in the M3 plants ranging from cream to reddish brown and three eye patterns were distinguished from each other. SDS–PAGE of the seed storage proteins showed 18 protein bands; five of these bands disappeared in the seeds of M3 plants compared to M2 and M0 controls while other 5 protein bands were specifically observed in seeds of M3 plants. PCR analysis using twelve ISSR primers showed 47 polymorphic and 8 unique amplicons. The eight unique amplicons were characteristic of the cream coat color and brown wide eye pattern (M03-G10) while the polymorphic bands were shared by 6 coat-color groups. A PCR fragment of 850 bp was amplified, using primer HB-12, in M3-G04 which showed high-100 seed weight. These results demonstrated the mutagenic effects of gamma rays on seed coat color, weight of 100 seeds and eye pattern of cowpea M3 mutant plants.

Development of new cowpea (Vigna unguiculata) mutant genotypes, analysis of their agromorphological variation, genetic diversity and Population structure

“…Our results showed that, in general, the gene 562 diversity and the PIC were close (Fig 5), suggesting the evenness of allele's frequencies in the 563 mutant populations as reported by Shete values ranging from 0.25 to 0.5 and slightly informative at less than 0.25. Based on this, the 566 ISSR827, ISSR844, ISSRHB9, ISSR17899B and ISSR809 were moderately informative, the 567 remaining markers were slightly informative which were higher than the scores recorded in 568 the cowpea mutant population developed by Gaafar et al [12]. These differences could be 569 attributed to the low irradiation dose (50 Gy) used which might induce less mutations and less 570 variability compared to the 300 Gy and 340 Gy employed in this study.…”

“…These differences could be 569 attributed to the low irradiation dose (50 Gy) used which might induce less mutations and less 570 variability compared to the 300 Gy and 340 Gy employed in this study. In addition, Gaafar 571 and coworkers [12] used ethidium bromide for DNA staining which is less sensitive than 572…”

“…89 ISSR are useful to study genetic diversity, genome mapping or evolutionary biology in many 90 crop species and they overcome the limitations of other markers, such as low reproducibility 91 of RAPD and high cost of AFLP (Amplified fragment length polymorphic) and the use a 92 single primer during the amplification processes [18,19]. ISSR combine the advantages of 93 SSR, AFLP and RAPD markers which do not require prior genome sequence information and 94 are efficient to detect genetic variation among cowpea varieties [20,21] or mutant lines 95 [10,12]. ISSR primers can be unanchored with 1 to 4 degenerate nucleotides at 3' or 5' end to 96 avoid their slippery within the repeat units and smears apparition during amplification but 97 previous studies showed that primers anchored at 3' gave more clear bands [22,12].…”

“…ISSR combine the advantages of 93 SSR, AFLP and RAPD markers which do not require prior genome sequence information and 94 are efficient to detect genetic variation among cowpea varieties [20,21] or mutant lines 95 [10,12]. ISSR primers can be unanchored with 1 to 4 degenerate nucleotides at 3' or 5' end to 96 avoid their slippery within the repeat units and smears apparition during amplification but 97 previous studies showed that primers anchored at 3' gave more clear bands [22,12]. 98…”

Physiological and molecular studies on ISSR in two wheat cultivars after exposing to gamma radiation

“…These inter repeats are highly polymorphic in their sizes even among closely related genotypes as the result of the deficiency of evolutionary functional constraints in these functioning regions. Also, it is a technique that is widely used for assessing the alteration in DNA sequences induced by mutagenic agents such as gamma rays 5 . Additionally, ISSRs have been used successfully in genome mapping for a variety of crop species including maize, rice, barley and wheat 6,7 .…”