Onasanya A.,Africa Rice Center |
Onasanya A.,Federal University of Technology Akurre |
Basso A.,Africa Rice Center |
Basso A.,French National Institute for Agricultural Research |
And 13 more authors.
Biotechnology | Year: 2010
A combined molecular diagnostic and DNA fingerprinting PCR technique for Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas oryzae pv. oryzicola (Xoc), Pseudomonas fuscovaginae (Pf) and Pseudomonas syringae pv. syringae (Pss) pathogens from rice has been developed in Africa by this study, using four primer pairs designed from Xoo (NC-007705.1), Xoc (NZ-AAQN01000001.1), Pf (AB021381.1) and Pss (NC-007005.1) complete genome sequence. Molecular PCR diagnostic showed that the presence of at least a band indicates positive detection of a bacterial pathogen and absence of a band indicates negative for no bacterial pathogen detected, while in the same PCR assay the presence of one or more band at different position revealed the DNA fingerprint of a bacterial pathogen. Out of 95 bacterial cultured isolates analyzed, 84 contained Xoo, 50 contained Xoc, 19 contained Pf and 16 contained Pss pathogens. DNA fingerprinting of the 84 Xoo pathogens revealed seven Xoo genotypes, four Xoc genotypes were identified from 50 Xoc pathogens and 19 Pf pathogens produced three Pf genotypes while 16 Pss pathogens formed three Pss genotypes. Development of a reliable molecular technique for Xoo, Xoc, Pf and Pss identification and differentiation is a prerequisite into understanding the genetics of Xoo, Xoc, Pf and Pss population structure in Africa and deployment of durable resistance cultivars. © 2010 Asian Network for Scientific Information.
Zandjanakou-Tachin M.,International Institute Of Tropical Agriculture |
Zandjanakou-Tachin M.,University of Lomé |
Ojiambo P.S.,International Institute Of Tropical Agriculture |
Ojiambo P.S.,North Carolina State University |
And 4 more authors.
Plant Pathology | Year: 2013
Mycosphaerella species that cause the 'Sigatoka disease complex' account for significant yield losses in banana and plantain worldwide. Disease surveys were conducted in the humid forest (HF) and derived savanna (DS) agroecological zones from 2004 to 2006 to determine the distribution of the disease and variation among Mycosphaerella species in Nigeria. Disease prevalence and severity were higher in the HF than in the DS zone, but significant (P<0·001) differences between agroecological zones were only observed for disease severity. A total of 85 isolates of M. fijiensis and 11 isolates of M. eumusae were collected during the survey and used to characterize the pathogenic structure of Mycosphaerella spp. using a putative host differential cultivar set consisting of Calcutta-4 (resistant), Valery (intermediate) and Agbagba (highly susceptible). Area under disease progress curve (AUDPC) was higher on all cultivars when inoculated with M. eumusae than with M. fijiensis, but significant (P<0·05) differences between the two species were only observed on Valery. Based on the rank-sum method, 8·3% of the isolates were classified as highly aggressive and 46·9% were classified as aggressive. About 11·5% of all the isolates were classified as least aggressive, and all of these were M. fijiensis. The majority of M. eumusae isolates (seven out of 11; 64%) were classified as aggressive. A total of nine pathotype clusters were identified using cluster analysis of AUDPC. At least one M. fijiensis isolate was present in all the nine pathotype clusters, while isolates of M. eumusae were present in six of the nine clusters. Isolates in pathotype clusters III and V were the most aggressive, while those in cluster VIII were the least aggressive. Shannon's index (H) revealed a more diverse Mycosphaerella collection in the DS zone (H=1·81) than in the HF (H=1·50) zone, with M. fijiensis being more diverse than M. eumusae. These results describe the current pathotype structure of Mycosphaerella in Nigeria and provide a useful resource that will facilitate screening of newly developed Musa genotypes for resistance against two important leaf spot diseases of banana and plantain. © 2012 The Authors. Plant Pathology © 2012 BSPP.
Oluwafemi S.,Bowen University |
Alegbejo M.D.,Ahmadu Bello University |
Onasanya A.,Africa Rice Center |
Olufemi O.,Central Biotechnology Laboratory
African Journal of Agricultural Research | Year: 2011
Maize streak virus (MSV; family Geminiviridae, genus Mastrevirus) is the most important virus of maize (Zea mays L.) in sub-Saharan Africa. The relatedness of this virus to others showing streak symptoms from grasses on or near maize fields from five ecological areas of Nigeria was studied using genetic scanning analyzer. The relationship dendogram showed 50-95% variations as the 30 isolates were grouped into two main clusters at 0.50 coefficient of variation, five subgroups at 0.06 and 25 at 0.95 coefficient of variation, respectively. The dendogram suggests five family trees at 60% similarity. Split decomposition data showed three clusters implying three evolutionary trees among the streak isolates in Nigeria, as indicated by the three major groupings. The first cluster had four subgroups. MSV (IITA) is within the first tree, which also had 14 other grass isolates. The second tree comprised only three isolates, which were all transmissible to maize and produced typical or severe symptoms in their grass hosts. The third tree had 12 isolates, which were diverse from each other. Despite basic differences in the theoretical background of UPGMA cluster analysis and Split Decomposition, these two approaches of phylogeny reconstruction yielded similar results. © 2011 Academic Journals.
Ajevar G.,Indian Veterinary Research Institute |
Muthu S.,Central Biotechnology Laboratory |
Sarkar M.,Indian Veterinary Research Institute |
Kumar H.,Indian Veterinary Research Institute |
And 2 more authors.
Veterinary Research Communications | Year: 2014
Endometritis is one of the leading causes of infertility in the cattle and buffalo and innate immune mechanism plays an important role in clearing the infection. In this regard, endometrial expression and function of Toll Like Receptors (TLR) are focus of investigation in the recent years. In this study, we report the transcriptional profiles of TLR4 and 5 in the buffalo endometrium during the follicular, early, mid and late luteal phases of estrous cycle and 'subclinical and clinical endometritis' and also at true anestrus (n = 10 for each stage) using RT-PCR and qRT-PCR as they are the ligands for the lipopolysaccharide and flagellin components of E.coli, the most common cause of postpartum endometritis. We found a significant positive correlation between TLR4 and 5 in all the groups (r = 0.696-0.803; P < 0.05) except late luteal phase (r = 0.522; P > 0.05). Chi-square analysis showed that the qualitative expression of endometrial TLR4 and 5 transcripts was significantly associated with the phase of estrous cycle and also with uterine infection (P < 0.05). Further, using true anestrus category as a calibrator group, relative quantitation of TLR4 and 5 revealed that the transcriptional expression of TLR4 and 5 genes were highly upregulated (24.6-83.3 folds) during endometritis conditions and moderately upregulated during mid-luteal phase (6.8-16.2) of the estrous cycle (P < 0.05). The results suggested a role of progesterone in the expression of TLR4 and 5. © 2014 Springer Science+Business Media.
Akanji B.O.,Federal University of Technology Akurre |
Ajele J.O.,Federal University of Technology Akurre |
Onasanya A.,Federal University of Technology Akurre |
Onasanya A.,Afnca Rice Center |
Oyelakm O.,Central Biotechnology Laboratory
Biotechnology | Year: 2011
Genetic fingerprinting of 30 Pseudomonas aeruginosa (Pa) isolates from three types of nosocomial infection cases from two Osun State Teaching Hospitals was compared using RAPD-PCR markers. Ten out of 50 operon primers tested showed polymorphism with reproducible results among the isolates and produced 131 bands of which 74 were polymorphic with sizes ranging between 200 and 3,000 bp. Cluster analysis using the 74 polymorphic markers classified the 30 Pseudomonas aeruginosa isolates into two (PgA and PgB) genetic groups. Comparing isolates proportion in each genotype based on their site of infection, antibiotics resistance pattern and geographical location, it was revealed that the proportion of urinary tract infection isolates in PgA genotype was significantly less than those in PgB genotype (z = -1.195, p<0.05) while the proportion of septicaemia isolates in PgA genotype was significantly higher than its proportion in PgB genotype (z = 1.348, p<0.05). However the proportion of wound infection isolates of PgA andPgB genotypes were significantly the same (z = -0.278, p>0.05). The PgA genotype contained few isolates with increased virulence and resistance to new antimicrobial modules and could possibly be new emerging P. aeruginosa strains from PgB genotype population. The study has critically revealed the genetic diversity and distribution among P. aeruginosa isolates in Osun State. © 2011 Asian Network for Scientific Information.