African Journal of Soil Science

African Journal of Soil Science ISSN 2375-088X Vol. 5 (5), pp. 426-434, May, 2017. © International Scholars Journals

Review

Phenolics and their potential as biochemical markers for wheat rust and Russian wheat aphid resistance in South Africa

¹Henry A Njom, ²Joyce Mebalo, ²Tarekegn G Terefe, ^1,3Roland N Ndip, ¹Graeme Bradley*

¹Plant Stress Response Group, Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa,

²Agricultural Research Council, Small Grain Research Institute, Bethlehem, South Africa,

³Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Box 63, Buea, Cameroon.

*Corresponding author. E-mail: [email protected]

Accepted 27 April, 2017

Abstract

Three types of wheat rusts and Russian wheat aphid (RWA) are important constraints to wheat production in South Africa. Genetic resistance provides an effective and safe option to control these pests. However, breeding for resistance to rusts and RWA in South Africa largely depends on screening thousands of germplasm in the field at several localities. The success of such trials depends on optimum development of diseases and insects, which is mostly difficult to achieve due to seasonal variations in climatic conditions. Therefore, there is a need to improve this laborious and time-consuming screening method. Protective plant phenols, which are involved in resistance to biotic factors, are gaining more attention from plant breeders as potential biochemical markers. Such markers assist in overcoming the above limitations by allowing accurate and faster selection of resistant materials. For example, higher levels of phenolic compounds such as phytoalexins have been observed in resistant than in susceptible wheat cultivars suggesting that phenols may possibly be used as biochemical markers. This review paper discusses the different types of phenols, their significance in resistance to biotic factors and their potential application in breeding for resistance to wheat rusts and insects in South Africa.

Keywords: Phenolics, disease, resistance, breeding, South Africa.

African Journal of Soil Science ISSN 2375-088X Vol. 5 (4), pp. 420-425, April, 2017. © International Scholars Journals

Full Length Research Paper

Relationship between peach endocarp cracking and specific vascular bundle development

Zhimin Liu* and Huanpu Ma

Department of Plant Science and Technology, Beijing University of Agriculture, No. 7 Beinong Road, Huilongguan Changping, Beijing 102206, PR China.

*Corresponding authorE-mail: [email protected]. Tel.: +86 10-80799136, Fax: +86 10-80796917

Accepted 12 October, 2014

Abstract

Vascular bundles play a very important role in fruit development and quality. Each set of bundles has its own specific function. In order to know the relationship between endocarp cracking and vascular bundles, we observed specific vascular bundle development during fruit growth. The results showed that embryo bundles and ventral bundles are closely related to pit-splitting. We found that pit-splitting was caused by the occurrence of both an over-expanded seed and a weakened endocarp. The rapid development of the seed was controlled by abnormally thickened embryo vascular bundles. The weakened endocarp was caused by an abnormal thickening of the ventral vascular bundles that formed two grooves on the endocarp of the abdominal suture, thus rendering the endocarp weak and fragile. Once the expansion force of the seed is too large, the endocarp will rupture due to a weak position of the grooves, a phenomenon known as pit-splitting. Our results demonstrate that the over-development of the embryo bundle and ventral bundles is the key cause of pit-splitting. We anticipate our assay to be a starting point for more studies examining the relationship between vascular bundles and fruit quality. For example, excessive nitrogen, water and thinning can cause pit-splitting; however, the manner in which these factors influence the development of the embryo vascular bundle and abdominal vascular bundle of the endocarp is unknown. The individual and combined effect of these factors on pit-splitting could be tested and related to other fruit quality problems.

Keywords: Peach fruit, embryo and ventral vascular bundles, excessive nitrogen, split-pit.

African Journal of Soil Science ISSN 2375-088X Vol. 5 (3), pp. 410-419, March, 2017. © International Scholars Journals

Full Length Research Paper

Soil organic carbon status in a vegetable cropping systems in Southern Benin: a rapid assessment

¹Koussihouèdé Kpèdétin Inès Hermione*, ²Aholoukpè Nonwègnon Sayimi Hervé, ²Assogba Komlan Françoise Vivine, ¹Amadji Guillaume Lucien

¹UR ecopédologie; Laboratoire de Sciences du sol; Faculté des Sciences Agronomiques, Université d’Abomey-Calavi, BP 526 FSA/UAC, Cotonou, Benin.

²Centre de Recherches Agricoles Plantes Pérennes, INRAB, BP 01 Pobè, Benin.

Accepted 03 October, 2016

*Corresponding author Email: [email protected]

Abstract 

Assessing and monitoring soil organic matter (SOM) is important for determining and developing management practices that will enhance agricultural soil quality. This study is aimed at assessing soil organic carbon (SOC) stocks and pools resulting from agricultural practices in the upper soil depths (0-10 cm and 10-20 cm) in vegetable cropping systems in peri-urban areas in southern Benin. The study was conducted on plots that have been amending since 2006 with poultry manure (S+PM) and sheep dung (S+SD). Two particle-size fractions of SOM: Particulate Organic Matter (POM: 2-0.053mm) and Fine Organic Matter (FOM: 0-.053mm) were separated at 0-10 cm and 10-20cm depths and their respective carbon contents were determined through Loss On Ignition (LOI) methods. Results showed that SOC stock was the highest in fallow with 22.93 t.ha^-1and 25.87 t.ha^-1 respectively at 0–10 cm and 10–20 cm depths. The cultivation leads to a depletion in organic carbon stocks compared to the herbaceous fallow. Although no significant difference was found for SOC stocks between S+PM and S+SD for the both depths, the PM application over the time could lead to increase in SOC stocks compared to the SD application. However, their SOC distribution in fraction is similar.

Keywords: Soil Organic Carbon; agricultural practices; particle-size fractionation; vegetable cropping systems, Southern Benin.

African Journal of Soil Science ISSN 2375-088X Vol. 5 (3), pp. 378-402, March, 2017. © International Scholars Journals

Full Length Research Paper 

A study of the utilization of biomass resources, waste management and Sustainable development

Ali Abbas,  Azhar Saqib and Dev Akram

Lasbela University of Agriculture, Water and Marine Science, Uthal, Balochistan, Pakistan.

Accepted 13 January, 2017

[email protected]

Abstract

This article discusses a comprehensive review of biomass energy sources, environment and sustainable development. This includes all the biomass energy technologies, energy efficiency systems, energy conservation scenarios, and energy savings. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biomass technology. This article gives an overview of present and future use of biomass as an industrial feedstock for production of fuels, chemicals and other materials. However, to be truly competitive in an open market situation, higher value products are required. Results suggest that biomass technology must be encouraged, promoted, invested, implemented, and demonstrated, but especially in remote rural areas.

Key words: Agricultural wastes, bio-technologies, energy efficiency systems, environment.

African Journal of Soil Science ISSN 2375-088X Vol. 5 (3), pp. 367-377, March, 2017. © International Scholars Journals

Full Length Research Paper

Effectiveness of rhizobia strains isolated from South Kivu soils (Eastern D.R. Congo) on nodulation and growth of soybeans (Glycine max)

^{1, 2}Bintu Nabintu Ndusha, ¹Nancy K. Karanja, ³Paul L. Woomer, ⁴Jean Walangululu,  ²Gustave N. Mushagalusa  and Jean Marie Sanginga

¹University of Nairobi, Nairobi –Kenya, P.O. Box 29053-00100, Nairobi, ² Université Evangélique en Afrique, D.R. Congo, P.O. Box 3323, Bukavu DRC, ³N2Africa Program, International Centre for Tropical Agriculture (CIAT) 823-00621, Nairobi Kenya, ⁴Universite Catholique de Bukavu, D.R. Congo, P.O. Box 365, Bukavu DRC.

Received 11 July, 2016; Revised 10 November, 2016; Accepted 14 November, 2016 and Published 25 March, 2017

*Corresponding author mail: [email protected] or [email protected]

Abstract

Identification of effective indigenous Bradyrhizobium strains which nodulate soybean varieties could trigger development of an industry for inoculant production with use of strains adapted to local conditions. This study was conducted to identify and select effective local rhizobia strains nodulating soybean in South Kivu soils. One hundred and seven isolates collected from root nodules in South Kivu were tested in sterile sand using the modified Leonard’s jars and in potted field soils. Each jar and pot was inoculated by 1ml of broth culture concentrated at 10⁹cells per milliliter. From the first screening, only 10% of these isolates produced higher nodules number and plant shoot dry weights (p˂0.001) compared to the commercial strain USDA110 and were selected for evaluation using soils as rooting media in three liters PCV pot in the greenhouse. From the potted soils experiment, among twelve outperforming isolates, only six isolates produced higher nodules and shoots dry weight (p˂0.001) compared to the commercial strains and uninoculated controls, and were considered as effective and competitive strains. This isolates includes NAC10, NAC22, NAC37, NAC67, NAC40 and NAC75. Nodules number highly correlated with Shoot weight. There exist effective indigenous rhizobia in South Kivu soils for inoculants production.

Keywords: Indigenous rhizobia, effectiveness, selection, soja, South Kivu.