Yield response and <Emphasis Type="Italic">Stenocarpella</Emphasis> ear rot reaction among selected maize inbred lines and top cross hybrids

Stenocarpella ear rot of maize caused by Stenocarpella maydis (Berk.) Sutton is one of the most important ear rot diseases in South Africa. The objective of this study was to identify suitable maize inbred lines and top cross hybrids with Stenocarpella ear rot resistance and high grain yield. The study was conducted using 54 inbred lines and 54 top crosses with selected standard checks under natural and artificial disease inoculations. A split-plot design was used with three replications. There were considerable variations among tested inbred lines and top crosses for Stenocarpella ear rot resistance and grain yield. Two promising inbred lines GCI-35 and GCI-50 were selected possessing resistance to Stenocarpella ear rot and increased grain yield. Inbred line GCI-35 had a grain yield of 6.31 and 6.27 t/ha under natural and artificial inoculations, respectively. Line GCI-50 yielded 5.8 and 5.7 t/ha when tested under natural and artificial disease infestations, respectively. Two top cross hybrids GCT-14 and GCT-30 were selected with greater grain yield and high level of Stenocarpella ear rot resistance. Top cross entry GCT-14 yielded 7.5 and 9.33 t/ha, respectively, whereas GCT-30 had yield of 7.65 and 9.21 t/ha, respectively. The selected inbred lines and top cross hybrids will be useful in maize improvement for Stenocarpella ear rot resistance and increased grain yield in South Africa or other similar environments.     

Chemical Control of Weeds in Cotton in the Sudan Gezira

Abstract

Early work on chemical weed control in the fallow towards the end of the Second World War is reviewed briefly. Attempts to use contact residual herbicides as pre-emergence applications in the early 1950s are also described.

Pre-sowing applications of residual herbicides were found more phytotoxic to cotton than pre-emergence applications. The closer the time of pre-sowing application to cotton sowing, the more effective was suppression of weeds competing with cotton.

Mechanical cultivations and particularly disc ploughing and rotovation to a depth of more than 15 cm were found more effective in the control of Cynodon dactylon than pre-sowing herbicide applications.

Fluometuron, noruron and prometryne were found very effective as pre-emergence herbicides. Optimum rates of application were found to be only 25-50% of rates recommended for the USA and other countries. Resistant weeds included Cyperus rotundus, Cynodon dactylon, and Rhyncosia memnonia.

A large-scale trial with fluometuron, covering 125 feddans at Wad el Nairn showed that yields obtained were equal to those with normal weeding. Costs of herbicide treatments were also comparable to costs of hand-weeding in a year of exceptionally low hand-weeding costs.     

An R package for SNP marker-based parent-offspring tests

Background

With the advancement of genotyping technologies, whole genome and high-density SNP markers have been widely used for genotyping of mapping populations and for characterization of germplasm lines in many crops. Before conducting SNP data analysis, it is necessary to check the individuals to ensure the integrity of lines for further data analysis.

Results

We have developed an R package to conduct a parent-offspring test of individuals which are genotyped with a fixed set of SNP markers for further genetic studies. The program uses monomorphic SNP loci between parents and their progeny genotypes to calculate the similarity between each offspring and their parents. Based on the similarity of parents and individual offspring, the users can determine the threshold level for the individuals to be included for further data analysis. We used an F₅-derived soybean population of ‘5601T’ x PI 157440 that was genotyped with 1,536 SNPs to illustrate the procedure and its application.

Conclusions

The R package ‘ParentOffspring’ coupled with the available SNP genotyping platforms could be used to detect the possible variants in a specific cross, as well as the potential errors in sample handling and genotyping processes. It can be used in any crop which is genotyped with a fixed set of SNP markers.

     

Chemical composition of purslane (Portulaca oleracea)

Purslane (Portulaca oleracea), grown under greenhouse conditions, was harvested at three growth stages and analyzed for total solids, total protein, ash, soluble carbohydrate, and fructose/fructane in whole plants, leaves, stems, and roots. Significant increases were observed in total solids and protein during plant maturation. Leaves had the highest amount of protein in the third growth stage (44.25g/100g dry matter). Roots showed a decline in protein level as the plant aged. Soluble carbohydrate was significantly higher in growth states 1 and 3. Significant variation among growth stages was found with regard to total phosphorous, calcium, potassium, iron, managanese, and copper. Total phosphorus (P) content in leaves was significantly higher than P found in stems and roots. Iron (Fe) content varied significantly among growth stages, and roots and leaves had the highest Fe content (121.47 and 33.21 mg, respectively). Significant accumulation of managanese (Mn) was found in different growth stages. Leaves and roots had significantly higher Mn content than stems.     

Isolation of water insoluble laminaran-like polysaccharide from Sargassum linifolium

Isolation of water insoluble laminaran-like polysaccharide has been achieved fromSargassum linifolium by extraction with hydrochloric acid and oxalic acid solutions. The conditions of the extraction with both acid solutions were studied. The quality of the isolated products was also evaluated.

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Zusammenfassung AusSargassum linifolium wurden durch Extraktion mit Salzsäure und Oxalsäure wasserunlösliche Laminarin ähnliche Polysaccharide isoliert. Die Zusammensetzung und die Eigenschaften beider Extrakte wurden untersucht.

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Résumé L'isolation de l'insoluble laminarane-comme polysaccharide a été completée duSargassum linifolium par l'extraction avec les solutions de l'acide hydrochlorique et l'acide oxalique. Les conditions de l'extraction avec les solutions des deux acides ont été étudiées. La qualification des produits isolés a été encore évaluée.

     

Estimation of reference evapotranspiration for southern region of Saudi Arabia

The reference crop evapotranspiration (ET_r) for four areas in Saudi Arabia was estimated using five different methods: FAO-Penman, Jensen-Haise, Blaney & Criddle, pan evaporation, and calibrated FAO-Penman under local conditions (Penman_-SA). Comparison was also made between the estimated ET_r and the measured ET_r of alfalfa grown in lysimeters in the Riyadh area. Regression analysis revealed that estimated ET_r values were highly correlated with measured ET_r values. In addition, linear regression relationships between ET_r values estimated by the Penman_-SA method and other methods were determined. The results of this study indicated that the calibrated Penman_-SA method can be transferred successfully to other locations, and this method could be used for the estimation of ET_r values in all areas in the southern region of Saudi Arabia. Received: 16 January 1998     

Efficient and nontoxic DNA isolation method for PCR analysis

An optimized method for total DNA extraction from genetically modified sugar beet plants has been presented. Uses of high-toxic organic compounds and high-cost extraction kits for nucleic acid isolation are excluded. A comparative analysis of polymerase chain reaction products was performed with amplification of DNA obtained by two methods.     

The ant,Pachycondyla sennaarensis (Mayr) as an intermediate host for the poultry cestode,Raillietina tetragona (Molin)

The role of several species of ants as intermediate hosts for poultry cestodes in the Sudan was investigated by a search for cysticercoids in specimens from poultry houses in various localities in the country. Pachycondyla sennaarensis, Messor galla and Acantholepis sp. were the only species collected from the areas surveyed. All these ants were examined for cysticercoids of poultry tapeworms but only P. sennaarensis was found to carry cysticercoids, all of which were identical to those of the poultry cestode, Raillietina tetragona. This tapeworm was recovered from all chicks fed the cysticercoids obtained from P. sennaarensis. R. tetragona cysticercoids were present in 63.3% of the P. sennaarensis sampled with 1–40 cysticercoids per ant, which is the heaviest recorded infestation of an ant species with these cysticeroids.     

Effects of supplementing broiler diets with coriander seed powder on growth performance,blood haematology,ileum microflora and economic efficiency

A total of 480 one‐day‐old Arbor Acres broiler chicks were randomly assigned to four dietary groups, each including six replicates (n = 20/replicate). Broilers in the first group (G1) were fed a basal diet without any additives (control). Broilers in groups 2, 3 and 4 (G2, G3 and G4) were fed a basal diet supplemented with 0.1%, 0.2% and 0.4% coriander (Coriandrum sativum L.) seed powder (CSP) respectively. Feeding trials lasted for 42 days, and after that growth, carcass traits, haematological parameters, gut microbiota and economic efficiency (EE) were evaluated. Final body weight (FBW), total weight gain (TWG), total feed intake (TFI) and red blood cell (RBC) counts of broilers in the G4 and G3 treatment groups were significantly higher (p < .05) compared with broilers in the G1 treatment group. The feed conversion ratio (FCR) was better (p < .05) in the G4 treatment group (1.72) than in the G1 treatment group (1.84). Broilers in CSP treatment groups had significantly higher haemoglobin (Hb) concentrations, packed cell volume (PCV) and platelet counts, and had lower (p < .05) Escherichia coli and Clostridium perfringens counts compared with broilers in the G1 treatment group. Dressing, liver, pancreas, bursa and thymus percentages were higher (p < .05) in broilers in the G4 (70.30, 3.18, 0.31, 0.10 and 0.32% respectively) treatment group, compared with broilers in the control (G1) group (66.57, 2.37, 0.23, 0.04 and 0.21% respectively). Broilers in treatment groups G4 and G3 had lower percentages of abdominal fat and lower total bacterial counts (p < .05) than broilers in treatment groups G2 and G1. The highest economic efficiency (EE) was found in treatment group G4, and EE in this group was 13.06% greater than in the control (G1) group.