Effect of soybean (Glycine max L.) on the hormonal milieu of male rats

Effect of soybean (Glycine max) on serum level of some sex hormones: testosterone, follicle stimulating hormone (FSH), luteinizing hormone/interstitial cell stimulating hormone (LH/ICSH), estradiol and prolactin in male rats was investigated. Twenty male albino rats of 12 weeks old with similar body weights were assigned to four groups of 5 rats each and treatment with soybean meal at 100, 200 and 300 mg kg(-1) body weight, respectively daily for 8 weeks. Blood samples collected through cardiac puncture were assayed for levels of hormones. There were dose-dependent effects of the soybean meal on the serum concentration of the hormones. The treatment significantly reduced the levels of testosterone and FSH in the serum while it significantly increased the levels of estradiol, LH/ICSH and prolactin. The results show that soybean (Glycine max) had strong capability to disrupt hormonal functions. Hence, its indiscriminate use could increase the risk of infertility in males.     

Assessment of age-related morphological changes in the testes of post-hatch light ecotype Nigerian indigenous chicken

The age-related morphological changes of the testes in light ecotype Nigerian indigenous chicken were evaluated in this study using gross anatomical, histological and histomorphometric techniques. The results showed that the testes of 3- to 9-month-old birds were light pink while testes of sexually mature chicken were creamy white in colour. The left and right testicular weight, length, diameter, circumference and the organosomatic indices increased significantly (p < .05) with increasing age across the groups. Although the mean tubular diameter and epithelial height of the left and right seminiferous tubules increased significantly (p < .05) with age, the tubular diameter, epithelial height and luminal diameter did not vary significantly (p > .05) between the left and right testes of all the groups. The one-cell layer thick germinal epithelium of the left testes at 3 to 6 months old showed islands of cell proliferation that contained spermatogonia and spermatocytes. At 6 to 9 months, the left testes exhibited numerous early spermatids with occasional occurrence of late stage spermatids while the right testes showed scanty early stage spermatids. At 12 to 18 months, the germinal epithelia of both left and right testes were characterized by the presence of Sertoli cells, spermatogonia, primary spermatocytes, numerous early and late stage spermatids as well as spermatozoa. In conclusion, the morphological features highlighted in the present study show that at pre-pubertal periods, the left testes may develop faster than the right testes. However, both left and right testes may participate actively in the production of spermatozoa during the post-pubertal life.     

Phytochemistry and heamatological potential of ethanol seed leaf and pulp extracts of Carica papaya (Linn.)

This study was aimed at qualitative evaluation of the ethanol seed, leaf and pulp extracts of C. papaya for bioactive compounds and also to investigate their effect on the haematology in male albino rats. A 3 x 4 factorial experimental layout using randomized complete design was adopted. Results show that the phytochemicals found in seed, leaf and pulp were almost the same but however, in varying proportions. Present result also revealed that there were significant effects (p < 0.05) of the extracts on the heamatology of the treated rats, which was blamed on the varying and different variants ofbioactive compounds found in the extracts they were administered with. Suggestively, C. papaya extracts could be used to enhance the production of selected blood parameters, taking issue of dosage into consideration.     

Estimation of genetic variability in locally grown pulses (Cajans cajan (L.) Millsp and Vigna unguiculata (L.) Walp): a panacea for sourcing superior genotypes

The negligence of breeders and farmers to explore and exploit landraces of pulses is worrisome and urgent measures needed to be set in motion to forestall major future crisis, taking into cognizance the high adaptability and nutritive values accredited to them. This study focused on the estimation of genetic variability and heritability of desirable morphological characters in Fiofio (Cajans cajan) and Olaudi and Akidi (Vigna unguiculata) with the aim of conservation. Three landraces of pulses were sown using randomized complete block design. The field experiment was carried out at the University of Calabar Experimental Farm, University of Calabar, Calabar, during 2008-2010 growing season. Phenotypic and genotypic variances and coefficients of variation and genetic advance were estimated on yield and yield-related traits. The results showed that there were considerable variations among the pulses for the traits studied. The result revealed high genetic variability in the number of leaf per plant, leaf area, number of flowers per plant, number of pods per plant and number of seeds per plant. It also showed that genetic variability in pod length and 100-seed weight was low. Heritability estimates obtained in the result were very high though the magnitude of genetic variability in the yield and yield-related traits was not proportional to the heritability estimates. The traits studied also show high genetic advance. These explicitly showed that there are sufficient genetic variations to warrant conservation and improvement in these extinction-threatened pulses studied.     

Testicular morphology and cauda epididymal sperm reserves of male rats exposed to Nigerian Qua Iboe Brent crude oil

Potential negative effects of exposure to Nigerian Qua Iboe Brent crude oil on the reproductive system of male rats was investigated. Forty Sprague-Dawley rats were used for the experiment. Exposure to Nigerian Qua Iboe Brent crude oil was achieved via oral administration of increasing doses (0.1, 0.2, and 0.4 ml/rat) every other day for 4 weeks. Cauda epididymal sperm reserves and relative weights of the testes as well as histological features of the testes of rats that received the crude oil treatment were compared to those of control rats. The results described here showed a significant (p < 0.01) dose-dependent reduction in the cauda epididymal sperm reserves of rats that received crude oil treatment relative to the control group. The morphology of testes of the crude oil-exposed rats was characterized by the presence of interstitial exudates, degeneration, and necrosis of spermatogenic and interstitial (Leydig) cells. Findings indicate that exposure of male rats to Nigerian Qua Iboe Brent crude oil may have adversely affected their reproductive systems. This may imply possible reproductive health hazards for animals and humans that may be exposed to this environmental pollutant, especially in areas where oil spillage is a common feature.     

Seasonal variations in the morphology of the seminal vesicles of the African straw-coloured fruit bat (Eidolon helvum)

The study investigated seasonal changes in the morphology of the seminal vesicles of Eidolon helvum in a typical African tropical environment. Seminal vesicles of forty-eight bats were examined during the early rainy, late rainy and peak dry seasons, using gross anatomical, histological and ultrastructural techniques. The interlobular connective tissue septa from the external capsule demarcated the glandular parenchyma into numerous lobules of tubulo-alveolar glands. A simple cuboidal epithelium of mono- or bi-nucleated cuboidal cells lined the glandular mucosa during the rainy season. This was replaced by a bistratified cuboidal epithelium, whose upper layer of cells showed evidence of degeneration, during the dry season. The PAS-positive secretory products appeared to be numerous during the rainy season, but few and clumped together during the dry season. The mean gross weight, interlobular septal thickness, acini diameter and epithelial height of the glands varied significantly with season. Ultrastructural features of the secretory cells during the rainy season showed well-developed cytoplasmic organelles, numerous electron lucid secretory vesicles and electron-dense granules. Secretory epithelial cells of the seminal vesicles are very active during the rainy season, while regeneration of degenerated epithelium in preparation for the next reproductive cycle occurs during the dry season.     

Efficacy of a new glyphosate formulation for weed control in maize in southwest Nigeria

A field trial in 2003 and 2004 assessed the efficacy of a new formulation of glyphosate, Touchdown Forte HiTech (glyphosate-TF) and two older versions, Roundup (glyphosate-RP) and Touchdown (glyphosate-TD) for weed control in Nigeria. Treatments were glyphosate-TF at 0.25–1.25 kg a.i./ha, glyphosate-RP at 1.8 kg a.i./ha, and glyphosate-TD at 1.0 kg a.i./ha. Weeded and unweeded treatments were controls. Visual evaluations of weed control at 4 and 8 weeks after treatment (WAT) in both years indicated that glyphosate-TF at all doses gave moderate to complete control of all major weeds (50–100%). At 4 WAT, control of Ageratum conyzoides L., Commelina benghalensis L., Ipomoea involucrata P. Beauv., Brachiaria comota [Hochst ex A. Rich] stapf, and Acalypha ciliata Forssk was at a level similar to that in the weeded control. In 2003, all herbicide formulations and the weeded control reduced Imperata cylindrica (L.) Beauv. shoot dry biomass to the same level at 8 WAT (91–100%) and at maize harvest (83–88%). In 2004, 0.50–1.25 kg a.i./ha of glyphosate-TF and 1.8 kg a.i./ha of glyphosate-RP gave 95% reduction at 8 WAT and 97% at harvest, similar to the weeded control. Maize grain yield in the weeded control and herbicide treatments was 2.8 times higher than that in the unweeded control in both years. These results indicate that glyphosate-TF is effective for weed control in maize at herbicide doses lower than the older formulations.     

Insight to the genetic diversity of pigeon pea Cajanus cajan (L.) Millsp. and cowpea Vigna unguiculata (L.) Walp. germplasm cultivated in Nigeria based on rbcl gene region

Genetic Resources and Crop Evolution - Pigeon pea Cajanus cajan (L.) Millsp. and cowpea Vigna unguiculata (L.) Walp. are two of the important seed legumes of Africa and are relatively more...     

Velvetbean (Mucuna spp.) suppresses speargrass (Imperata cylindrica (L.) Raeuschel) and increases maize yield

Speargrass, Imperata cylindrica (L.) Raeuschel, is a serious weed, threatening crop productivity in smallholder farms in West Africa. Since the use of more effective practices such as deep tillage and chemical control is beyond the means of resource-poor farmers who carry out most agricultural activities in this region, low-input alternative technology needs to be developed. Field studies were conducted during the 1993/1994 and 1995/1996 growing seasons to investigate the influence of three velvetbean accessions and two levels of fertilizer on the control of speargrass during the year of cover crop planting and one year later. The velvetbean accessions in 1993 were: Mucuna cochinchinensis and M. pruriens var. utilis. In 1995, M. pruriens var. IRZ was included in the study. M. cochinchinensis in 1993 and M. pruriens var. IRZ in 1995 had the highest ground cover rating early in the growing seasons whereas M. pruriens var. utilis had the lowest ground cover rating in both years. Inorganic fertilizer at30 kg ha- 1 each of N, P and K increased velvetbean ground cover by 2-22%, with M. cochinchinensis (14-22%) and M. pruriens var. IRZ (5-15%) showing the highest response in 1993 and 1995, respectively. M. pruriens var. utilis showed the least response in both years. After one growing season M. pruriens var. utilis, M. cochinchinensis, and M. pruriens var. IRZ reduced speargrass shoot density by 50, 76, and 68%, and shoot dry matter by 72, 92, and 79%, respectively. Fertilizer reduced speargrass growth in velvetbean plots, while the opposite occurred in plots without velvetbean. Velvetbean residue effectively suppressed speargrass until the beginning of the subsequent cropping season. Maize grown 1 year after velvetbean required 50% less weeding than plots without velvetbean. Maize shade reduced speargrass shoot growth by 30-80% but regrowth of the weed occurred 4 weeks before maize harvest. Maize grain yield was higher in plots previously seeded to velvetbean than in plots without velvetbean. Speargrass shoot density and dry matter were negatively correlated with maize grain yield (r =_-0.42 and r =_-0.32, respectively, P < 0.01). Although velvetbean may effectively reduce speargrass during the year of establishment and the subsequent cropping phase it has a limited effect on rhizomes and, as such, does not provide a long term control.     

Competition between Imperata cylindrica and maize in the forest savannah transition zone of Nigeria

Imperata cylindrica is a noxious weed that infests annual and perennial crops in most tropical regions. High crop densities may offer opportunities to reduce I. cylindrica competition in small‐scale farming systems. The competitive ability of maize relative to I. cylindrica was evaluated in an addition series experiment in the forest savannah transition zone in 2006 and 2007 at Ibadan, Nigeria. Maize and I. cylindrica were planted in eight monoculture densities (4, 8, 12, 16, 20, 32, 48 and 64 plants m^?2) and in a 1:1 mixture at eight total densities (2:2, 4:4, 6:6, 8:8, 10:10, 16:16, 24:24 and 32:32 maize: I. cylindrica plants m^?2) as in monoculture. Non‐linear regression models were used to relate crop and weed shoot biomass to their densities and total grain yield to maize density. In maize, intraspecific competition was more than interspecific competition; in I. cylindrica, interspecific competition was higher than intraspecific. As expected, total grain yield was lower in the mixture than in maize monoculture at all total densities. Average maize grain yield in maize monoculture differed from that in mixtures by 0.77 t ha^?1 in 2006 and 0.57 t ha^?1 in 2007. Niche differentiation indices were <1 in 2006 and >1 in 2007, indicating that both species competed for similar resources in 2006, but not in 2007. The greater competitive ability of maize over I. cylindrica may be associated with rapid growth and canopy development observed in the field.