Limits...
Selection of Novel Cowpea Genotypes Derived through Gamma Irradiation.

Horn LN, Ghebrehiwot HM, Shimelis HA - Front Plant Sci (2016)

Bottom Line: Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought.Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors.The selected promising mutants' lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments.

View Article: PubMed Central - PubMed

Affiliation: School of Agricultural, Earth and Environmental Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-NatalPietermaritzburg, South Africa; Directorate of Research and Training, Plant Production Research, Ministry of Agriculture, Water and ForestryWindhoek, Namibia.

ABSTRACT
Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes after mutagenesis using gamma irradiation. Seeds of three traditional cowpea varieties widely grown in Namibia including Nakare (IT81D-985), Shindimba (IT89KD-245-1), and Bira (IT87D-453-2) were gamma irradiated with varied doses and desirable mutants were selected from M2 through M6 generations. Substantial genetic variability was detected among cowpea genotypes after mutagenesis across generations including in flowering ability, maturity, flower and seed colors and grain yields. Ten phenotypically and agronomically stable novel mutants were isolated at the M6 each from the genetic background of the above three varieties. The selected promising mutants' lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments. The novel cowpea genotypes selected through the study are valuable genetic resources for genetic enhancement and breeding.

No MeSH data available.


Related in: MedlinePlus

Some common abnormalities at M3 observed at Bagani Research Station. (A) spinach-like leaves, (B) Short-pods, (C) broad-dark leaves, (D) chlorophyll mutant, -single stem (E,F) observed at Omahenene research Station.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4834446&req=5

Figure 2: Some common abnormalities at M3 observed at Bagani Research Station. (A) spinach-like leaves, (B) Short-pods, (C) broad-dark leaves, (D) chlorophyll mutant, -single stem (E,F) observed at Omahenene research Station.

Mentions: During the M1 and M2 generations the percentage field establishment (ES) ranged between 79 to 89%, respectively (Table 2). Nakare and Shindimba mutants had ES of 0% at irradiation does of 250, 300, and 400 Gy. Phenotypic abnormalities such as albinism, leaf deformity, single stem, seedless pods or short pod sizes were invariably observed at the following doses and genotypes: 450 and 600 Gy (Bira); 150 and 200 Gy (Nakare); and 100, 150, and 200 Gy (Shindimba) (Figure 2). Segregation of FC (white and purple) were observed at the M2 with the following doses and genotypes: 300, 450, and 600 Gy (Bira), 100 and 200 Gy (Nakare), and 100, 150, and 200 Gy (Shindimba) (Figure 3). SC variations were observed during the M2 (Figure 4). White, brown, red, and cream SC were common in Bira mutants across all irradiation doses. In addition to these Nakare and Shindimba had speckled, chocolate, light brown, black, mixed and dark brown SC when subjected to irradiation doses of 100, 150, and 200 Gy (Table 2 and Figure 4). Bira mutants displayed relatively high seed yields varying from 98 to 200 g/plant at 0 and 600 Gy, respectively (Table 2).


Selection of Novel Cowpea Genotypes Derived through Gamma Irradiation.

Horn LN, Ghebrehiwot HM, Shimelis HA - Front Plant Sci (2016)

Some common abnormalities at M3 observed at Bagani Research Station. (A) spinach-like leaves, (B) Short-pods, (C) broad-dark leaves, (D) chlorophyll mutant, -single stem (E,F) observed at Omahenene research Station.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834446&req=5

Figure 2: Some common abnormalities at M3 observed at Bagani Research Station. (A) spinach-like leaves, (B) Short-pods, (C) broad-dark leaves, (D) chlorophyll mutant, -single stem (E,F) observed at Omahenene research Station.
Mentions: During the M1 and M2 generations the percentage field establishment (ES) ranged between 79 to 89%, respectively (Table 2). Nakare and Shindimba mutants had ES of 0% at irradiation does of 250, 300, and 400 Gy. Phenotypic abnormalities such as albinism, leaf deformity, single stem, seedless pods or short pod sizes were invariably observed at the following doses and genotypes: 450 and 600 Gy (Bira); 150 and 200 Gy (Nakare); and 100, 150, and 200 Gy (Shindimba) (Figure 2). Segregation of FC (white and purple) were observed at the M2 with the following doses and genotypes: 300, 450, and 600 Gy (Bira), 100 and 200 Gy (Nakare), and 100, 150, and 200 Gy (Shindimba) (Figure 3). SC variations were observed during the M2 (Figure 4). White, brown, red, and cream SC were common in Bira mutants across all irradiation doses. In addition to these Nakare and Shindimba had speckled, chocolate, light brown, black, mixed and dark brown SC when subjected to irradiation doses of 100, 150, and 200 Gy (Table 2 and Figure 4). Bira mutants displayed relatively high seed yields varying from 98 to 200 g/plant at 0 and 600 Gy, respectively (Table 2).

Bottom Line: Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought.Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors.The selected promising mutants' lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments.

View Article: PubMed Central - PubMed

Affiliation: School of Agricultural, Earth and Environmental Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-NatalPietermaritzburg, South Africa; Directorate of Research and Training, Plant Production Research, Ministry of Agriculture, Water and ForestryWindhoek, Namibia.

ABSTRACT
Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes after mutagenesis using gamma irradiation. Seeds of three traditional cowpea varieties widely grown in Namibia including Nakare (IT81D-985), Shindimba (IT89KD-245-1), and Bira (IT87D-453-2) were gamma irradiated with varied doses and desirable mutants were selected from M2 through M6 generations. Substantial genetic variability was detected among cowpea genotypes after mutagenesis across generations including in flowering ability, maturity, flower and seed colors and grain yields. Ten phenotypically and agronomically stable novel mutants were isolated at the M6 each from the genetic background of the above three varieties. The selected promising mutants' lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments. The novel cowpea genotypes selected through the study are valuable genetic resources for genetic enhancement and breeding.

No MeSH data available.


Related in: MedlinePlus