African Journal of Agriculture

African Journal of Agriculture ISSN 2375-1134 Vol. 7 (4), pp. 001-008, April, 2020. © International Scholars Journals

Full Length Research Paper

Introgression of Pythium root rot resistance gene into Rwandan susceptible common bean cultivars

J.  Nzungize¹*, P. Gepts², R. Buruchara³, A. Male³, P. Ragama⁴, J. P. Busogoro⁵ and J. P. Baudoin¹

¹University of Liege, Gembloux Agro-Bio Tech, Belgium.

²University of California, Davis, California. USA.

³CIAT, Pan Africa Bean Research Alliance, Kampala, Uganda.

⁴National Agriculture Research Organization, Kampala, Uganda.

⁵Belgium Technical Cooperation, IPM project, Kigali, Rwanda.

Accepted 07 February, 2020

Abstract

A breeding scheme was carried out to introgress resistance genes to bean Pythium root rot in various commercial varieties grown in Rwanda. The achieved crosses were performed between three selected susceptible varieties (R617-97A, RWR 1668 and Urugezi) which are adapted to the various ecological production zones of Rwanda and two known sources of resistance to Pythium root rot (RWR719 and AND 1062). Following each inter varietal hybridization generation, a series of 4 successive back-crosses was achieved by using the susceptible parents as the initial parent lines to be improved for their respective behavior to Pythium root rot disease. At each back-cross generation, the PYAA 19₈₀₀ SCAR marker linked to Pythium root rot resistance in the two sources of resistance (varieties RWR 719 and AND 1062) was used to identify and to proceed to early selection of progenies possessing the gene of interest. The target materials serving for the molecular analyses were prepared from young trifoliate leaves of 2-weeks bean plantlets. It was observed that at each back-cross generation, there were variable proportions of plants exhibiting presence of the resistance gene according to the SCAR marker profiles. In addition to that observation mainly based to molecular profile, it was also revealed that the proportion of bean seeds having the same color as the susceptible parent line was increasing progressively. Finally, to assess if the individual plants exhibiting the SCAR marker are effectively resistant to the Pythium root rot disease, inoculation tests were carried out with a Pythium ultimum strain on each of them. This ultimate biological evaluation revealed that all the plants showing the SCAR marker were resistant to development of Pythium root rot symptoms after inoculation, confirming thus real introgression of the resistance characteristics through the breeding scheme adopted in our work.

Key words: Phaseolus, vulgaris, Pythium, molecular, root rot, bean, genotype, resistance.

African Journal of Agriculture ISSN 2375-1134 Vol. 7 (4), pp. 001-005, April, 2020. © International Scholars Journals

Full Length Research Paper

Taxonomic importance of the vegetative and pod characteristics in three Nigerian species of sesame

G. O. Alege¹, B. O. Akinyele²*, S. M. Ayodele¹ and A. V. Ogbode¹

¹Department of Biological Sciences, Kogi State University, Anyigba, Kogi State, Nigeria.

²Department of Crop, Soil and Pest Management, the Federal University of Technology, Akure, Nigeria.

Accepted 14 February, 2020

Abstract

The relevance of the vegetative and the pod characteristics to the taxonomy of three Nigerian species of sesame was investigated. The plant materials used are Sesame alatum, Sesame radiatum and Sesame indicum. After growing the plants for two years in the same environment, the seeds of each species were harvested and broadcast in a separate perforated 5 L plastic bucket filled with sandy loam soil. The buckets were kept at the nursery and watering carried out until seedlings were fully established. Two seedlings of each species were then transplanted to a 5 L plastic bucket filled with sandy loam soil and each bucket was replicated 20 times. The experimental design used was the completely randomized design (CRD). Each plant stand was thinned to one seedling two weeks after transplanting. Ten vegetative and five pod characteristics were investigated at flowering and harvest respectively. Mean values for each species were calculated and recorded from five plants randomly selected. Data were subjected to analysis of variance (ANOVA) and means separated using the least significant difference (LSD). Results revealed that the majority of the vegetative, pod and quantitative characteristics investigated show significant differences among the three species. These characteristics were used to construct a taxonomic key that facilitates the identification of the three sesame species.

Key words: Sesame, Nigeria, characteristics, taxonomy, sandy loam soil.

African Journal of Agriculture ISSN 2375-1134 Vol. 7 (4), pp. 001-006, April, 2020. © International Scholars Journals

Full Length Research Paper

Heritability and correlation coefficient analysis for yield and its components in rice (Oryza sativa L.)

M. G. Akinwale¹, G. Gregorio², F. Nwilene¹, B. O. Akinyele⁴*, S. A. Ogunbayo³ and A. C. Odiyi⁴

¹Africa Rice Center, Ibadan, Oyo State, Nigeria.

²International Rice Research Institute (IRRI), Philippines.

³Africa Rice Center, Cotonou, Benin Republic.

⁴Federal University of Technology, Akure, Ondo State, Nigeria.

Accepted 08 February, 2020

Abstract

The objectives of this study were to estimate the phenotypic and genotypic coefficients of variation, broad sense heritability, genetic gain and correlations in rice (Oryza sativa L.). The experiment was laid out in a randomized complete block design (RCBD) with three replications in the International Institute of Tropical Agriculture, Ibadan, Nigeria during 2008/2009 cropping season. Genotypes differed significantly at (p>0.001) for all the traits studied, which implies that the genotypes constitute a pool of germplasm with adequate genetic variability. Genotypic coefficients of variation were lower than the corresponding phenotypic coefficients in all the traits studied, indicating considerable influence of the environment on the expression of the traits. High to medium broad sense heritability estimates observed on days to heading, days to maturity, plant height, grain yield and number of grains per panicle, panicle weight, number of panicles per m² and panicle length suggests high component of heritable portion of variation, which is the portion exploited by breeder and that selection for these traits can be achieved directly based on their phenotypic performance. The low broad sense heritability observed for the number of tillers per plant and 1000 grain weight is indicative of the influence of the environment on these traits. Low heritability of these traits indicates the ineffectiveness of direct selection for these traits. High to medium heritability and genetic advance were recorded for the number of grains per panicle, grain yield, panicle weight and the number of panicles per plant. This suggests that these traits are primarily under genetic control and selection for them can be achieved through their phenotypic performance. Grain yield exhibited significantly positive correlation with the number of tillers per plant (r = 0.58**), panicle weight (r =0.60*) and number of grains per panicle (r= 0.52*). Therefore, the results suggest that these traits can be used for grain yield selection.

Key words: Broad sense heritability, rice, genotypic coefficient of variation, phenotypic coefficient of variation, genetic gain, rice yield, yield components.

African Journal of Agriculture ISSN 2375-1134 Vol. 7 (3), pp. 001-006, March, 2020. © International Scholars Journals

Full Length Research Paper

The Physiological responses of sunflower (HELIANTHUS ANNUUS  L.) to NiSO₄

Farzaneh Najafi¹*, Ramazan Ali Khavari-Nejad¹,² and Fatemeh Hasanjanzadeh¹

¹Department of Biology, Faculty of Science, Tarbiat Moallem University, P.O.Box 15815-3587, Tehran, Iran.

²Department of Biology, Faculty of Science, Islamic Azad University, Science and Research Branch, Tehran, Iran.

Accepted 21 February, 2020

Abstract

The effects of different concentrations of nickel sulfate (NiSO₄) on some physiological parameters in sunflower (HELIANTHUS ANNUUS L.) were studied. Sunflower plants were treated with NiSO₄ at 0, 4, 8, 16, 32 and 40 µM in Hoagland solutions. With the increasing concentrations of NiSO₄, all the growth parameters increased. The highest significant increase of NAR and RGR were obtained with 16 µM NiSO₄. Control and treated plants had similar chlorophylls and unsoluble sugars contents. Total soluble sugars and protein contents were increased in high concentrations of NiSO₄. Addition of all nickel concentrations had a significant promotive effect on Mn, Fe and Ni contents in leaves and roots as compared to that of control. Malondialdehyde (MAD) and respiration rate were significantly increased in high concentrations, however, photosynthetic rate and RWC decreased in all concentrations of NiSO₄.

Key words: Sunflower, nickel, malondialdehyde, growth parameters, gas exchange.