Olumayowa Olowe

Parkia biglobosa (Jacq.) is an important leguminous tree crop in the African Savannahs useful to the natives where it is found, for domestic use. Previous diversity studies on this tree crop had been majorly on morphological and biochemical analysis. In order to capture the maximum diversity not obtained by previous research, the study aimed at evaluating the genetic diversity of accessions of this crop in the different agroecological zones in Nigeria using RAPD markers. A total of 81 scorable bands with an average of 8.1 bands per primer were amplified among the accessions studied. Intrazonal genetic diversity analysis showed a percentage polymorphism with a range of 11.11% to 65.43% among the agroecological zones studied. Although, gene diversity was highest within Humid forest agroecological zone, a low genetic distance and high genetic similarity between the agroecological zones were observed. Cluster analysis indicated six main groups of which four groups had single accessions while the two groups clustered the remaining accessions, indicating a narrowed genetic base from the 23 accessions studied

Bioremediation (the use of living organism, part or their products) has been reported to be an environmental friendly and cheap remediation method which is applicable in large and small scale but, the major problem facing this mechanism is the establishment of a particular biological entity in a heavily polluted soil. The soil supplementation/amendment during bioremediation was suggested to alleviate such difficulty, compost supplements role in bioremediation is majorly 'biostimulatory' a term used to explain the addition of nutrients for effective and active biological activities. Compost supplements have been a commonly used practice in agricultural practices for ages for enhancement of soil fertility and productivity but it is now known that this practice also enriches the microbial population in soil which promotes soil remediation as they act upon the organic waste to release its nutrients. This practice as well have been reported to enhance biological degradation, mineralization or extraction of a pollutant for clean-up/remediation of a polluted soil. Today, bioremediation mechanism which combines action of two or more organisms have been gaining more interests, application of soil amendments in such setting may serve as fuel to run the system feeding both entities the nutrients, creates environment conducive for their survival and enhances tolerance as well as responses. In this chapter, we gave accounts of biostimulatory and bioaugmentation mechanisms brought about by soil amendment using composts, we considered different examples and their impacts on soil bioremediation mechanisms.

Telfairia occidentalis is highly heterozygous with continuous out-crossing. Therefore, conservation of its genetic resources will require the culture of explants from vegetative tissue rather than seeds, in order to maintain improved or superior genotypes. Experiments were carried out to establish a procedure for the sterilization of shoot tip explants from field grown seedlings and to induce organogenesis using different treatment combinations of phytohormones. Shoot tip explants obtained from 4 to 5 weeks old seedlings were surface sterilized using 3 concentrations of sodium hypochlorites (NaOCl) (0.5%, 0.75% and 1%) at 3 exposure time (10minutes, 15minutes and 20minutes). The percentage clean cultures were recorded after 4, 8 and 12 days. The lowest frequency of clean culture (0.33) was obtained when shoot tip explants were treated with 0.5% of NaOCl for 20minutes. Sterilization was most effective when shoot tip explants were treated with 1% NaOCl for 15minutes and 20minutes, after 4 and 12 days. Ninety three percent clean and viable cultures were obtained. Surface sterilized shoot tip explants were inoculated on ½ N6 media supplemented with different concentrations and combination of BAP, NAA, IAA and 2,4D. Shoot tip explants in ½ N6 media supplemented with 0.05mg/l BAP showed the highest shoot length of 1.46 cm and highest shoot number of 1.60. In all concentrations and combination of BAP and NAA, there was callus formation. In all concentrations and combination of BAP and 2,4D, calluses were formed to prevent shoot bud induction while there was induction of multiple shoot in treatment combination of 0.5mg/l BAP and 0.1mg/l 2,4D. In all concentrations and combination of BAP and IAA, there were formation of calluses, but not formed in the treatments containing 0.5mg/l BAP and 0.1mg/l IAA, while BAP 2.0mg/l and IAA 1.0mg/l induced tiny shoots.

Parkia biglobosa (Jacq.) is an important leguminous tree crop in the African Savannahs useful to the natives where it is found, for domestic use. Previous diversity studies on this tree crop had been majorly on morphological and biochemical analysis. In order to capture the maximum diversity not obtained by previous research, the study aimed at evaluating the genetic diversity of accessions of this crop in the different agroecological zones in Nigeria using RAPD markers. A total of 81 scorable bands with an average of 8.1 bands per primer were amplified among the accessions studied. Intrazonal genetic diversity analysis showed a percentage polymorphism with a range of 11.11% to 65.43% among the agroecological zones studied. Although, gene diversity was highest within Humid forest agroecological zone, a low genetic distance and high genetic similarity between the agroecological zones were observed. Cluster analysis indicated six main groups of which four groups had single accessions while the two groups clustered the remaining accessions, indicating a narrowed genetic base from the 23 accessions studied.

The reduction in the quantity and quality of maize production in
Nigeria has been attributed to some seed borne pathogens, of which strains of
Fusariumverticillioides causing ear rot infections are included. Hence, this
study investigated the resistance of six maize genotypes to strains of F.
verticillioides isolated from infected maize cobs obtained from rainforest
(Ibadan) and derived savanna (Iloora) agro ecological zones of Southwest
Nigeria. The screen house experiment was laid out in complete randomized
design. The pathogenic strains of F. verticillioides isolated from five locations
were inoculated at the silking stage (six weeks after planting) of maize
cultivars. Data collected on the growth, yield and ear rot disease assessments
were subjected to analysis of variance (ANOVA) using SAS 9.1 statistical
software. AMA TZBR YCF was the most resistant genotype to the pathogens,
followed by TZEI 25, while TZBR COMP 2-YCS 280, TZEI 22, (IBZA-EN13)
TZBR COMP 2-YCS, and TZEI 161 were most susceptible. The decreasing
order of genotypes in yield production were; AMA TZBR YCF, TZBR COMP
2-YCS 280, TZEI 25, TZEI 22, TZEI 161 and (IBZA-EN13) TZBR COMP 2-
YCS. The F. verticillioides strains isolated from Ibadan (IBD 1, IBD 2, and
IBD 3) were the most virulent in this study compared with Iloora (ILR 1 and
ILR 2) which showed moderate virulence. Therefore, AMA TZBR YCF was the
most resistant genotype to strains of F. verticillioides in this study, and could
be most suitable for cultivation in locations where Fusarium ear rot diseases
are endemic so as to ensure food security.