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.


Illustration of the selection methods during 2009–2014.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 1: Illustration of the selection methods during 2009–2014.

Mentions: Plots were arranged in a randomized complete block design using two replications. Plants were established using intra-row spacing of 20 cm and inter-row spacing of 75 cm. Seedlings were thinned to one plant per hill after 2 weeks from planting. Weeds were controlled manually. Planting of the M1 seeds was done under normal growing conditions with supplemental irrigation during dry spell. Each row of the M1 generation contained 26 individuals, making a total of 104 plants per irradiation dose. At harvest the M2 seeds were bulked in separate bags according to irradiation doses (Figure 1). During the M2 to M5 generations’ variable number of individual plants ranging from 50 to 100 per irradiation dose were assayed for qualitative and quantitative observations.


Selection of Novel Cowpea Genotypes Derived through Gamma Irradiation.

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

Illustration of the selection methods during 2009–2014.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 1: Illustration of the selection methods during 2009–2014.
Mentions: Plots were arranged in a randomized complete block design using two replications. Plants were established using intra-row spacing of 20 cm and inter-row spacing of 75 cm. Seedlings were thinned to one plant per hill after 2 weeks from planting. Weeds were controlled manually. Planting of the M1 seeds was done under normal growing conditions with supplemental irrigation during dry spell. Each row of the M1 generation contained 26 individuals, making a total of 104 plants per irradiation dose. At harvest the M2 seeds were bulked in separate bags according to irradiation doses (Figure 1). During the M2 to M5 generations’ variable number of individual plants ranging from 50 to 100 per irradiation dose were assayed for qualitative and quantitative observations.

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.