Host range, symbiotic effectiveness and nodulation competitiveness of some indigenous cowpea bradyrhizobia isolates from the transitional savanna zone of Ghana

To identify indigenous rhizobia with potential as inoculants for increasing cowpea (Vigna unguiculata) yields, we have assessed the host range, symbiotic effectiveness and competitiveness for noduleoccupancy among five (AII-2-1, AII-5-2, AI-4-3, AII-3-4 and BIII-2-2) indigenous cowpea bradyrhizobia isolates from the transitional savanna zone of Ghana. ERIC-PCR DNA fingerprinting patterns were used to identify the isolates occupying nodules. All the isolates nodulated cowpea, groundnut (Arachis hypogeae) and mungbean (Vigna radiata), but only AII-2-1, AII-3-4 and BIII-2-2 nodulated soybean (Glycine max). Apart from cowpea where all the isolates were effective, there were significant differences in the symbiotic effectiveness of the isolates on the other host legumes. Out of a total of about 250 cowpea nodules that were screened for each inoculum-mix, isolate AII-5-2 was the most competitive for nodule occupancy whilst AII-3-4 was the least. Isolate AII-5-2 occupied 71% of the nodules in an inoculum-mix consisting of equal proportions of AII-2-1, AII-5-2 and AI-4-3 (a 3-isolatemix) and 60% of nodules in an inoculum-mix consisting of equal proportions of all the five isolates (a 5- isolate-mix). Therefore, among the isolates tested, AII-5-2 has the best potential for use as inoculant formaximizing cowpea yield in N2- deficient agro-ecological zones of Ghana

Field assessment of soil water storage and actual evapotranspiration of rainfed maize (Zea mays L.) genotypes in a coastal savannah environment

A field experiment was carried out in a coastal savannah agro-ecological zone of Ghana to assess the dynamics of stored soil water and actual evapotranspiration (AET) of three maize genotypes (Obatanpa, Mamaba, and Golden Crys- tal) grown under rainfed conditions. Access tubes were installed to a depth of 120 cm for soil water content monitoring using a neutron probe meter. The soil water balance model of plant root zone was used to estimate AET at different crop growth stages. On average, the rate of AET for Obatanpa, Mamaba, and Golden Crystal maize genotypes were estimated as 4.32, 4.46, and 3.72 mm·day−1, respectively, for the major cropping season as against corresponding values of 3.88, 4.00 and 3.72 mm day−1 for the minor cropping season. Mamaba had higher values of AET from 42 DAE (days after emergence) to 84 DAE during the minor cropping season while it had low AET values during the major cropping season. The positive balance in stored soil water in the root zone of Obatanpa was the highest from 42 DAE to 84 DAE followed by Mamaba and Golden Crystal during the major cropping season. Mamaba, on the other hand, had the high- est AET from 70 DAE to 84 DAE. Obatanpa used 55.6% of stored soil water for AET, which was the highest among the maize genotypes during the major cropping season. Golden Crystal and Mamaba followed with 53.3% and 51.5%. For the minor cropping season, 48.5% of stored soil water was used by Mamaba for AET, followed by Obatanpa, (46.4%) and Golden Crystal (43.2%). A strong positive significant (p ≤ 0.05) linear correlation existed between AET and precipitation with the coefficient of determination (R2) being 69.2 for Obatanpa, 88.5 for Mamaba and 82.8 for Golden Crystal for the major cropping season. Higher R2 values (98.0, for Obatanpa, 94.1 for Mamaba and 98.9 for Golden Crystal) were, however, obtained for the minor cropping season. Additionally, a strong linear relationship was found between AET and precipitation, suggesting the need to formulate strategies for enhancing effective use of pre- cipitation in sustained rainfed maize production.Justice Okona Frimpong, Marcus Quaynor Addy, Emmanuel Ofori Ayeh, Harry Mensah Amoatey, Jacob Teye Kutufam, Bertrand Quaye, Joshua Osei Sintim, Daniel Kwasi Asar

Mutation detection analysis of a region of 16S-like ribosomal RNA gene of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii

<p>Abstract</p> <p>Background</p> <p>The level of intra-species genetic variation in <it>Entamoeba histolytica, Entamoeba dispar </it>and <it>Entamoeba moshkovskii </it>populations in a localized geographic area, like Puducherry, India, remains unknown.</p> <p>Methods</p> <p>In the present study the existence of genetic variation in the nested multiplex polymerase chain reaction (NM-PCR) amplified region of the 16S-like ribosomal RNA genes of <it>E. histolytica, E. dispar </it>and <it>E. moshkovskii </it>was investigated by riboprinting and single strand conformation polymorphism (SSCP) analysis.</p> <p>Results</p> <p>We found that 70 stool specimens were positive for <it>E. histolytica</it>, 171 stool specimens were positive for <it>E. dispar</it>, and 37 stool specimens were positive for <it>E. moshkovskii </it>by NM-PCR. Ninety liver abscess pus specimens, 21 urine specimens, and 8 saliva specimens were positive for <it>E. histolytica </it>by NM-PCR. Riboprinting analysis detected a mutation in the PCR product of only one <it>E. histolytica </it>isolate from a stool specimen. However, SSCP analysis detected mutations in the PCR products of five <it>E. histolytica </it>isolates and three <it>E. moshkovskii </it>isolates from stool specimens, and one <it>E. histolytica </it>isolate from a saliva specimen. The mutations detected by riboprinting and SSCP analysis were confirmed by sequencing. All the nucleotide sequences showing mutations in this study have already been deposited into the NCBI GenBank database under accession numbers [GenBank: <ext-link ext-link-type="gen" ext-link-id="EF682200">EF682200</ext-link> to GenBank: <ext-link ext-link-type="gen" ext-link-id="EF682208">EF682208</ext-link>].</p> <p>Conclusion</p> <p>The present study has revealed the subsistence of mutations in the ribosomal RNA genes of <it>E. histolytica </it>and <it>E. moshkovskii</it>, which points towards the existence of intra-species genetic variation in <it>E. histolytica </it>and <it>E. moshkovskii </it>isolates infecting humans.</p

Analysis of leaf parameters of rain-fed maize cultivars

Leaf area index (LAI), specific leaf area (SLA) and leaf dry matter content (LDMC) are plant/crop physiological variables which could be used to differentiate among and select maize cultivars suitable for specific environmental conditions, particularly in rain-fed agriculture. The leaf area index, SLA, LDMC and total dry matter (TDM) were estimated for the three rain-fed maize cultivars (Golden Crystal, Mamaba and Obatanpa) during the major and minor cropping seasons. The experimental design used was the completely randomized block design in four replicates, with maize cultivars as treatments. This study was undertaken to assess differences or similarities in the time course of LAI, SLA and LDMC as an assessment of the response of the three maize cultivars to rain-fed conditions during the major and minor cropping seasons in a coastal savannah agro-ecological environment. Additionally, the linear correlation analysis was used to assess the association between LAI and SLA, LAI and LDMC, SLA and LDMC, SLA and LDMC, TDM and LAI as well as between TDM and LDMC for the three rain-fed maize cultivars. Generally, Obatanpa and Mamaba maize cultivars produced comparatively higher LAI which peaked at about 1.30 and 2.00 on 84 DAE during the major and minor cropping seasons, respectively. The maize cultivars had mean peak SLA values of 1.20 m^2g^-1 on 14 DAR and 1.60 m^2g^-1 on 28 DAE during the major and minor cropping seasons, respectively. With regards to LCMD, all the maize cultivars had peak values on 28 DAE, with the value of Golden Crystal being 0.70 g g^-1 during the major season and 0.65 g g^-1 for Mamaba during the minor cropping season. During the major cropping season the linear regression between SLA and LDMC for Obatanpa (R = 0.948) and for Mamaba (R = 0.222) were positive but positive and poor for Golden Crystal (R = 0.059). For the minor cropping season, the correlation between SLA and LDMC remained positive and fairly good for Obatanpa (R = 0.702), Mamaba(R = 0.861) and positive but poor for Golden Crystal (R = 0.363). However the combined cropping seasons, R value was positive and good for Obatanpa (R = 0.701) and Mamaba (R = 0.861) while that for Golden Crystal was poor (R = 0.363). Such a poor linear correlation between SLA and LDMC for Golden Crystal is an indication that the maize cultivar is poorly adapted to the rain-fed coastal savannah agro-ecological environment and, therefore, not suitable for the cropping environment. Additionally, the correlation between TDM and LAI was positive but poor in all the crop growing seasons, with R values ranging from 0.423 for Obatanpa, 0.524 for Mamaba and 0.562 for Golden Crystal. Furthermore, R value was 0.507 for the combined cropping seasons and all the maize cultivars. Analyses of leaf paramaters have provided insight into the different responses of these maize cultivars to rain-fed conditions in a coastal savannah agro-ecological environmentD.K. Asare, J.O. Frimpong and E.O. Aye

Productivity and soil water use by rainfed maize genotypes in a coastal savannah environment

Polish title as appears on publisher's website: poprzedni artykuł wróć do listy artykułów następny artykułTotal aboveground biomass, grain yield and actual evapotranspiration data were used to estimate water use efficiency by the maize genotypes in terms of total dry matter and grain yield production. Grain yield and its associated water use efficiency were significantly different (P≤0.05) among the maize genotypes during the major cropping season, with Mamaba producing the highest grain yield of 7 250 kg ha-1 and water use efficiency of 13.2 kg ha-1 mm-1. For the minor season, however, no significant difference was observed in grain yield which ranged between 5 800 and 7 200 kg ha-1, with Obatanpa producing the highest grain yield. Similarly, no significant difference was observed in water use efficiency during the minor cropping season which ranged between 14.6 kg ha-1 mm-1 and 19.1 kg ha-1 mm-1, with Obatanpa having the highest water use efficiency. Maize genotypes Mamaba and Obatanpa were identified suitable for the rainfed conditions at the study area because of their comparatively high grain yield and better use of soil moisture for grain yield production.J.O. Frimpong, H.M. Amoatey, E.O. Ayeh, and D.K. Asar