ISSN 2375-091X
Research Article
African Journal of Tropical Agriculture Vol. 1 (2), pp. 014-020, October, 2013. © International Scholars Journals
Full Length Research Paper
Stable gene transformation in cowpea (Vigna unguiculata L. walp.) using particle gun method
J. Ikea1,2*, I. Ingelbrecht2, A. Uwaifo1 and G. Thottappilly2,λ
1Biochemistry Department, University of Ibadan, Ibadan, Nigeria
2International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
*Corresponding author, Present address: CSIRO Plant Industry, Black Mountain Laboratories, G.P.O Box 1600, Canberra ACT 2601, Australia. Email: j[email protected]
Accepted 18 July 2013
Abstract
We investigated the possibility of transforming and obtaining transgenic cowpea (Vigna unguiculata L Walp) plants using the particle bombardment process. Meristematic explants that could give rise to whole fertile plants were used in transformation experiments with reporter and selectable marker genes driven by a 35S CaMV promoter. Conditions for optimal delivery of DNA to explants were established based on transient gus expression assays two days after bombardment. The size of microcarriers, microflight distance and helium pressure significantly affected transient expression of reporter genes. A total of 1692 explants were bombarded with DNA-coated particles and placed on 3 mg/l bialaphos selective medium. Only 12 regenerated shoots produced seeds eventually, and all were Gus negative even though 7 gave positive PCR signals with the bar primer. Eight out of 1400 seeds from To plants were GUS positive. DNA from eight of the GUS positive seedlings were amplified with both the gus and bar primers in PCR analysis but only two gave a positive Southern signal. Only two of the 3557 T2 seedlings obtained were GUS positive. However, 3 seedlings survived Basta spray. The two GUS positive and 3 Basta surviving seedlings gave positive Southern hybridisation signals. Twelve T3 seedlings from these were GUS positive and also gave positive Southern hybridisation signals. The positive reaction of T1, T2 and T3 seedlings under Southern analysis confirms the stable integration of introduced genes and the transfer of such genes to progenies. However, the level of expression of introduced genes in cowpea cells is very low and this accounted for the high mortality rate of progenies under Basta spray.
Key words: Transformation, particle bombardment, gus assay, transient expression, reporter gene, basta, bar gene.
I. Ingelbrecht, A. Uwaifo and G. Thottappilly, J. Ikea
Page: 14 - 20
https://doi.org/10.46882/AJTA/1001Research Article
African Journal of Tropical Agriculture Vol. 1 (2), pp. 021-029, October, 2013. © International Scholars Journals
Full Length Research Paper
International institute of tropical agriculture plantain and banana programme: An insight into the contributions of farmer-to- farmer extension paradigm
B. O. Faturoti1, A. E. Agwu2*, E. M. Igbokwe2 and A. Tenkouano1
1International Institute of Tropical Agriculture, P. M. B. 5320, Oyo Road, Ibadan, Nigeria.
2Department of Agricultural Extension, University of Nigeria, Nsukka, Eungu State, Nigeria.
*Corresponding authors. E-mail: [email protected]. Tel: +234-8034024251.
Accepted 26 May, 2013
Abstract
Dissemination of research results by the International Institute of Tropical Agriculture (IITA) had been a major challenge to the Institute as inappropriate dissemination mechanism was revealed as a major constraint to her earlier efforts in disseminating cooking banana technologies between 1990 and 1994. A public-private technology delivery approach (research-farmer-to-farmer extension approach), which allows farmers to play the major role in dissemination of IITA plantain and banana based technologies was undertaken in three states of Nigeria. This study provides an insight into the contributions of this paradigm shift. The results show that farmer-to-farmer dissemination accounted for 26.6% awareness and 35.7% source of solutions to problems encountered in technology adoption at no direct cost to research and extension. Average plantain and banana hybrid adoption in the three states was 50.7%. Correlation analysis revealed that household size, ever questioned about plantain production problems, frequency of extension visits and trial experience had significant relationships with adoption. The regression analysis indicated that trial experience was the only variable with predictive value for plantain and banana hybrids adoption (R = 0.21). We concluded that free flow of information among all stakeholders is the panacea for sustained adoption and diffusion of the IITA plantain and banana based innovations.
Key words: Farmer-to-farmer extension approach, adoption, diffusion, plantain and banana hybrids, Nigeria.
E. M. Igbokwe and A. Tenkouano, A. E. Agwu*, B. O. Faturoti
Page: 21 - 29
https://doi.org/10.46882/AJTA/1003Research Article
African Journal of Tropical Agriculture Vol. 1 (1), pp. 001-006, September, 2013. © International Scholars Journals
Full Length Research Paper
Banana nectar as a medium for testing pollen viability and germination in Musa
Moses Nyine1 and Michael Pillay*2
1International Institute of Tropical Agriculture (IITA), P.O Box 7878, Kampala, Uganda.
2Vaal University of Technology Private Bag X 021 Vanderbijlpark 1900, South Africa
*Corresponding author. E-mail: [email protected].
Accepted 4 September, 2013
Abstract
A quick and reliable method for evaluating pollen quality is essential in a breeding program, especially in a crop such as banana that is characterized by high male and female sterility. In this study the germination and viability of banana pollen was evaluated in a sucrose solution and diluted banana nectar. Twenty banana accessions were used to evaluate pollen germination in the two media after 3 and 24 h. Nineteen genotypes (95%) showed significantly higher pollen germination potential (PGP) in diluted nectar than in 3% sucrose solution. The accession TMB2x 8075 - 7 showed no significant pollen germination in nectar and sucrose. Eleven genotypes (55%) showed significant increase in pollen germination by increasing the time of incubation whereas pollen germination for nine genotypes (45%) was not affected by increase in incubation time. Nectar from different banana clones influenced pollen germination suggesting a genotype effect for pollen germination in Musa.
Key words: Banana, pollen germination, sucrose solution, diluted nectar.
Michael Pillay*, Moses Nyine
Page: 1 - 6
https://doi.org/10.46882/AJTA/1007