Quality assessment of Urochloa (syn. Brachiaria) seeds produced in Cameroon

Urochloa (syn. Brachiaria) is the most popular fodder of livestock farmers in Cameroon for hay and seed productions. Farmers in Cameroon have been producing Brachiaria seeds for decades for own uses and surplus are sold to neighbours, and to traders from Cameroon and neighbouring countries. However, there is no information available about qualities of these seeds. Fifteen Urochloa seeds samples were collected from farmers and/or government stations in five regions (Adamaoua, East, North, North West, and West) and analysed for major seed quality parameters along with seeds of improved Urochloa cultivar Basilisk imported from Brazil as a check. Study showed significant differences among treatments for various seed quality parameters tested (P < 0.0001). The highest thousand grains weight was recorded in Basilisk (5.685 g), followed by W12 (3.555 g), A05 (3.153 g) and N01 (2.655 g). Caryopsis number and caryopsis weight were highest in Basilisk followed by E09, A06, and W12. Of three conditions tested for seed germination, mean germination was the highest in greenhouse (7.39%) where Basilisk had the highest germination (25.5%) followed by N01 (18.50%), A05 (14.50%) and W12 (12.75%). The seed viability ranged from 18% (E09) to 81% (N01), and there were a positive and highly significant relationships between seed germination and viability traits (r = 0.883; P < 0.0001). This study showed a marked difference in seed quality parameters of Urochloa grass seeds produced in Cameroon, and the potential of developing Urochloa grass seed business in the Northern, Adamaoua and Western regions of Cameroon.

Comparative TMT Proteomic Analysis Unveils Unique Insights into Helicoverpa armigera (Hübner) Resistance in Cajanus scarabaeoides (L.) Thouars

Pigeonpea [Cajanus cajan (L.) Millspaugh] is an economically important legume playing a crucial role in the semi-arid tropics. Pigeonpea is susceptible to Helicoverpa armigera (Hübner), which causes devastating yield losses. This pest is developing resistance to many commercially available insecticides. Therefore, crop wild relatives of pigeonpea, are being considered as potential sources of genes to expand the genetic base of cultivated pigeonpea to improve traits such as host plant resistance to pests and pathogens. Quantitative proteomic analysis was conducted using the tandem mass tag platform to identify differentially abundant proteins between IBS 3471 and ICPL 87 tolerant accession and susceptible variety to H. armigera, respectively. Leaf proteome were analysed at the vegetative and flowering/podding growth stages. H. armigera tolerance in IBS 3471 appeared to be related to enhanced defence responses, such as changes in secondary metabolite precursors, antioxidants, and the phenylpropanoid pathway. The development of larvae fed on an artificial diet with IBS 3471 lyophilised leaves showed similar inhibition with those fed on an artificial diet with quercetin concentrations with 32 mg/25 g of artificial diet. DAB staining (3,3′-diaminobenzidine) revealed a rapid accumulation of reactive oxygen species in IBS 3471. We conclude that IBS 3471 is an ideal candidate for improving the genetic base of cultivated pigeonpea, including traits for host plant resistance.

Comparative Analysis Delineates the Transcriptional Resistance Mechanisms for Pod Borer Resistance in the Pigeonpea Wild Relative Cajanus scarabaeoides (L.) Thouars

Insect pests pose a serious threat to global food production. Pod borer (Helicoverpa armigera (Hübner)) is one of the most destructive pests of leguminous crops. The use of host resistance has been an effective, environmentally friendly and sustainable approach for controlling several agricultural pests. The exploitation of natural variations in crop wild relatives could yield pest-resistant crop varieties. In this study, we used a high-throughput transcriptome profiling approach to investigate the defense mechanisms of susceptible cultivated and tolerant wild pigeonpea genotypes against H. armigera infestation. The wild genotype displayed elevated pest-induced gene expression, including the enhanced induction of phytohormone and calcium/calmodulin signaling, transcription factors, plant volatiles and secondary metabolite genes compared to the cultivated control. The biosynthetic and regulatory processes associated with flavonoids, terpenes and glucosinolate secondary metabolites showed higher accumulations in the wild genotype, suggesting the existence of distinct tolerance mechanisms. This study provides insights into the molecular mechanisms underlying insect resistance in the wild pigeonpea genotype. This information highlights the indispensable role of crop wild relatives as a source of crucial genetic resources that could be important in devising strategies for crop improvement with enhanced pest resistance.

Metagenomic Analysis of Plant Virus Occurrence in Common Bean (Phaseolus vulgaris) in Central Kenya

Two closely related potyviruses, bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV), are regarded as major constraints on production of common bean (Phaseolus vulgaris L.) in Eastern and Central Africa, where this crop provides a high proportion of dietary protein as well as other nutritional, agronomic, and economic benefits. Previous studies using antibody-based assays and indicator plants indicated that BCMV and BCMNV are both prevalent in bean fields in the region but these approaches cannot distinguish between these potyviruses or detect other viruses that may threaten the crop. In this study, we utilized next generation shotgun sequencing for a metagenomic examination of viruses present in bean plants growing at two locations in Kenya: the University of Nairobi Research Farm in Nairobi's Kabete district and at sites in Kirinyaga County. RNA was extracted from leaves of bean plants exhibiting apparent viral symptoms and sequenced on the Illumina MiSeq platform. We detected BCMNV, cucumber mosaic virus (CMV), and Phaseolus vulgaris alphaendornaviruses 1 and 2 (PvEV1 and 2), with CMV present in the Kirinyaga samples. The CMV strain detected in this study was most closely related to Asian strains, which suggests that it may be a recent introduction to the region. Surprisingly, and in contrast to previous surveys, BCMV was not detected in plants at either location. Some plants were infected with PvEV1 and 2. The detection of PvEV1 and 2 suggests these seed transmitted viruses may be more prevalent in Eastern African bean germplasm than previously thought.

Development of Microsatellite Markers and Analysis of Genetic Diversity and Population Structure of Colletotrichum gloeosporioides from Ethiopia

Twenty three polymorphic microsatellite markers were developed for citrus plant pathogenic fungus, Colletotrichum gloeosporioides, and were used to analyze genetic diversity and population structure of 163 isolates from four different geographical regions of Ethiopia. These loci produced a total of 118 alleles with an average of 5.13 alleles per microsatellite marker. The polymorphic information content values ranged from 0.104 to 0.597 with an average of 0.371. The average observed heterozygosity across all loci varied from 0.046 to 0.058. The gene diversity among the loci ranged from 0.106 to 0.664. Unweighted Neighbor-joining and population structure analysis grouped these 163 isolates into three major groups. The clusters were not according to the geographic origin of the isolates. Analysis of molecular variance showed 85% of the total variation within populations and only 5% among populations. There was low genetic differentiation in the total populations (FST = 0.049) as evidenced by high level of gene flow estimate (Nm = 4.8 per generation) among populations. The results show that Ethiopian C. gloeosporioides populations are generally characterized by a low level of genetic diversity. The newly developed microsatellite markers were useful in analyzing the genetic diversity and population structure of the C. gloeosporioides populations. Information obtained from this study could be useful as a base to design strategies for better management of leaf and fruit spot disease of citrus in Ethiopia.

Interspecific hybridization and bioactive alkaloid variation increases diversity in endophytic Epichloë species of Bromus laevipes

Studying geographic variation of microbial mutualists, especially variation in traits related to benefits they provide their host, is critical for understanding how these associations impact key ecological processes. In this study, we investigate the phylogenetic population structure of Epichloë species within Bromus laevipes, a native cool-season bunchgrass found predominantly in California. Phylogenetic classification supported inference of three distinct Epichloë taxa, of which one was nonhybrid and two were interspecific hybrids. Inheritance of mating-type idiomorphs revealed that at least one of the hybrid species arose from independent hybridization events. We further investigated the geographic variation of endophyte-encoded alkaloid genes, which is often associated with key benefits of natural enemy protection for the host. Marker diversity at the ergot alkaloid, loline, indole-diterpene, and peramine loci revealed four alkaloid genotypes across the three identified Epichloë species. Predicted chemotypes were tested using endophyte-infected plant material that represented each endophyte genotype, and 11 of the 13 predicted alkaloids were confirmed. This multifaceted approach combining phylogenetic, genotypic, and chemotypic analyses allowed us to reconstruct the diverse evolutionary histories of Epichloë species present within B. laevipes and highlight the complex and dynamic processes underlying these grass-endophyte symbioses.

Symptoms Analysis of Obsessive-Compulsive Disorder in Adolescents and Adults in a Teaching Hospital

INTRODUCTION

Obsessive-compulsive disorder has a broadly diverse clinical expression that reflects heterogeneity. Several studies have identified consistent symptom dimensions of obsessive-compulsive disorder. The purpose of this study was to conduct an exploratory symptoms analysis of obsessive-compulsive symptoms in adolescents and adults with obsessive-compulsive disorder.

METHODS

This was a cross-sectional study conducted in the Department of Psychiatry, National Medical College. This study examined lifetime occurrence of obsessive-compulsive symptoms included in the 13 symptom categories of the Yale-Brown Obsessive Compulsive Scale. Symptoms analysis was performed on 60 patients with obsessive-compulsive disorder. Eight categories of obsessions and six categories of compulsions from Yale-Brown Obsessive Compulsive Scale were included in the analyses. SPSS software package (version 16) was used to analyze the data and shown in the table.

RESULTS

Of 60 adolescents and adults, female and male were in the ratio of 1.2:1. Contamination was the most common occurring obsession followed by aggressive obsession. The most common occurring compulsion was checking followed by washing. Only a minority of patients (13.33%) presented predominantly with obsessions however 18.33% patients presented predominantly with compulsions. Certain obsessions and compulsions co-occur to form a cluster.

CONCLUSIONS

In adolescents and adults, obsessive-compulsive disorder is a multidimensional disorder. Symptom dimensions are predominantly congruent with those described in similar studies of adults with obsessive-compulsive disorder.

Phytophthora hedraiandra Detected from Irrigation Water at a Perennial Ornamental Plant Nursery in Virginia

Water survey for Phytophthora spp. by baiting with rhododendron leaves in April 2006 at a perennial ornamental plant nursery in Virginia detected five isolates showing a unique, previously unknown single-strand conformation polymorphism (SSCP) fingerprint (1). These cultures were isolated from two reservoirs at different depths of water column from surface to 2 m. They were homothallic and produced smooth-surfaced spherical oogonia with an average diameter of 27 μm on 10% V8 agar. Oospores were aplerotic. The paragynous antheridia were averaging 12 μm in diameter. Sporangia were papillate, spherical to ovoid, averaging 39 by 28 μm (length by width). They were caducous with short (<4 μm) pedicels. Chlamydospores and hyphal swellings were not observed. Two isolates were sequenced for rDNA internal transcribed spacer (ITS) 1 and 2 regions and cytochrome oxidase subunit 1 (Cox 1) gene. ITS sequences of both isolates (GenBank Accession Nos. JN376065 and JN376066) were identical to that of Phytophthora hedraiandra type culture (GenBank Accession No. AY707987). Also, the Cox 1 sequence of an isolate (Accession No. JN376067) had 99% homology with that of the type culture (GenBank Accession No. AY69115). Pathogenicity of both isolates was tested on Rhododendron catawbiense and Viburnum tinus, two known hosts of P. hedraiandra (2). For each isolate and host, five leaves and stems on potted plants were wounded by needles and then inoculated by placing over each wound a 5-mm² mycelial plug from a 7-day-old culture and securing with Parafilm. V8 agar was used instead of mycelial plugs on control plants. After inoculation, each plant was enclosed in a plastic bag for 1 day and then incubated at 22°C with a 12-h photoperiod. Distilled water was sprayed daily for 5 days postinoculation (dpi) until disease symptoms were observed. At 15 dpi, 3 of the 10 inoculated rhododendron leaves and 6 of the 10 stems showed leaf lesions, wilting, dieback, and cankers, eventually leading to rhododendron death. Two of the 10 viburnum leaves and 4 of the 10 stems showed similar symptoms. Leaf lesions were approximately 3 to 5 cm in diameter. P. hedraiandra was recovered from diseased tissues and all resulting cultures showed an identical SSCP fingerprint to tested isolates as well as a P. hedraiandra isolate from Minnesota (3). No symptom developed on control plants. To our knowledge, this is the first report of P. hedraiandra in Virginia. Considering neither host plant has been grown or bought for resale by this nursery, this study indicates that P. hedraiandra may have a wider host range than is currently known. This possibility and the importance of water dispersal for P. hedraiandra in disease epidemiology warrant further investigation. References: (1) P. Kong et al. Fungal Genet. Biol. 39:238, 2003. (2) W. A. Man in't Veld et al. Eur. J. Plant Pathol. 117:25, 2007. (3) B. W. Schwingle et al. Plant Dis. 90:109, 2006.

Phytophthora aquimorbida sp. nov. and Phytophthora taxon 'aquatilis' recovered from irrigation reservoirs and a stream in Virginia, USA

Two distinct subgroups (L2 and A(-2)) were recovered from irrigation reservoirs and a stream in Virginia, USA. After molecular, morphological and physiological examinations, the L2 subgroup was named Phytophthora aquimorbida and the A(-2) designated as Phytophthora taxon 'aquatilis'. Both taxa are homothallic. P. aquimorbida is characterized by its noncaducous and nonpapillate sporangia, catenulate and radiating hyphal swellings and thick-walled plerotic oospores formed in globose oogonia mostly in the absence of an antheridium. P. taxon 'aquatilis' produces plerotic oospores in globose oogonia mostly with a paragynous antheridium. It has semi-papillate, caducous sporangia with variable pedicels, but it does not have hyphal swelling. Analyses of ITS, CO1, β-tubulin and NADH1 sequences revealed that P. aquimorbida is closely related to P. hydropathica, P. irrigata and P. parsiana, and P. taxon 'aquatilis' is related to P. multivesiculata. The optimum temperature for culture growth is 30 and 20 C for P. aquimorbida and P. taxon 'aquatilis' respectively. Both taxa were pathogenic to rhododendron plants and caused root discoloration, pale leaves, wilting, tip necrosis and dieback. Their plant biosecurity risk also is discussed.

Enhancement of switchgrass (Panicum virgatum L.) biomass production under drought conditions by the ectomycorrhizal fungus Sebacina vermifera

Experiments were conducted to examine the effects of cocultivating the important bioenergy crop switchgrass with the ectomycorrhizal fungus Sebacina vermifera under severe drought conditions. Plants cocultivated with the fungus produced significantly higher biomass and had a higher macronutrient content than uninoculated control plants under both adequately watered and drought conditions.

Effect of maternal alcohol consumption on cerebellum of rat pups: a histological study

Consumption of alcohol during pregnancy results in fetal alcohol syndrome (FAS) in newborn affecting the central nervous system which is more sensitive to deleterious effect of alcohol. This study was conducted to observe the histological alterations in cerebellum of rat pups born to alcohol consuming mother rats. Virgin female albino rats were given 20.0% (v/v) alcohol through oral route two weeks prior to mating and continued till the weaning of their offspring. On postnatal day 27 (PND27), rat pups were sacrificed. Their brains were collected and weighed. The cerebellums were isolated and processed for histological study. The diameter of Purkinje cell and width of molecular and granular layers of the cerebellar hemisphere were measured. Results showed significantly decreased brain weight in rat pups of experimental group when compared to control. The diameter of Purkinje cells, width of molecular and granular layers were also found to be decreased in the experimental group. These results suggest that the maternal consumption of alcohol affects the brain growth and induces significant alterations in the histological architecture of cerebellum of growing rats.

Effect of prenatal exposure of alcohol in the morphology of developing rat embryo

The objective this study was to observe the morphological changes in developing rat embryo exposed to alcohol in utero. Virgin female Wistar rats in experimental group (n=15) were given 20% (v/v) alcohol two weeks before mating and throughout the gestational period through oral route. The controls (n=15) were also maintained and were given the tap water. On gestational day 15 (GD15) and 19 (GD19), five rats from each group were sacrificed by cervical dislocation and the abdomen was incised to expose the uterine horn. The number of implantation sites and resorptions were counted and recorded. The body weight and length of the fetuses were also recorded. The litter size and body weight of the newborn were also recorded at the time of birth from the remaining dam. The incidence of resorption was higher in alcohol treated group than in control which was found to be 25% and 8.7% at days 15 and 19 respectively. The body weight and length of fetuses were found to be decreased and was significant at GD15 (p<0.001 for weight and p<0.05 for length). Similarly, the litter size and body weight of newborn were also found to be decreased significantly (p<0.05 for litter size and p<0.01 for body weight). The present study shows that the maternal consumption of alcohol during pregnancy has adverse effect on fetal viability and development of growing embryo.

Utility of phenotypic dermal indices in the detection of Down syndrome patients

Down syndrome (DS) is the most common cause of mental retardation. The frequency of DS patients is about 1:800 and is mainly because of the presence of extra copy of chromosome number 21. Dermatoglyphic has been well established as a diagnostic aid in number of diseases having hereditary basis. Dermatoglyphic data was obtained by the use of ink and prints on a paper, from 15 cytogenetically confirmed patients of Down syndrome attending to the genetic clinic at BPKIHS. The data were correlated and compared with equal number of controls. Dermatoglyphic prints were used to evaluate the variation in the fingerprint patterns, the presence of simian crease and the difference in 'atd' 'dat' and 'adt' angles between the control and the DS patients. The results showed that both the 'atd' and 'adt' angles differed significantly from the control group. The dactylography study revealed higher incidence of loops and lower incidence of whorls in the DS patients as compared with the controls. This method is non-invasive and cost effective. The observed changes in the 'atd' and 'adt' angles plus the fingerprint patterns in the dermatoglyphic study proved that this simple technique could be a valuable tool for selecting patients of DS for cytogenetics analysis.

Variations in the Phytophthora infestans Population in Nepal as Revealed by Nuclear and Mitochondrial DNA Polymorphisms

ABSTRACT Phytophthora infestans isolates collected from potato and tomato crops from various parts of Nepal during the 1999 and 2000 crop seasons were characterized for nuclear and mitochondrial DNA polymorphisms using restriction fragment length polymorphism markers. The nuclear DNA probe RG57 detected 11 multilocus genotypes among 280 isolates. Three genotypes were detected 21 times or more, constituting 94% of the total population, whereas frequencies of other genotypes ranged from 0.004 to 0.014. The overall genotypic diversity as estimated by the Gleason index was 1.78. Most of the overall diversity was present at the highest level (i.e., interregional, 46%), indicating limited gene flow among regions. Cluster analysis of multilocus genotypes derived from RG57 and mating type data for Nepalese isolates and representative isolates worldwide showed Nepalese isolates grouping into four clusters. Characterization of 67 isolates for mitochondrial DNA polymorphisms revealed the presence of two mt-haplotypes, Ia and Ib with the proportions of 0.88 and 0.12, respectively. Polymorphisms in nuclear and mitochondrial DNA revealed a moderate level of diversity in this population. Genotype NP3 had an identical RG57 fingerprint to US1 and had mt-haplotype Ib, confirming the presence of an old population in Nepal. Most of the genotypes had a different RG57 fingerprint than that of US1 and mt-haplotype Ia, the common characteristics of new populations. The presence of a new population at high proportions in Nepal was consistent with the global trend of mt-haplotype distribution, and suggests the displacement of old populations. This study indicates at least three possible introductions of P. infestans to Nepal.