Biofortification of common bean as a complementary approach to addressing zinc deficiency in South Africans
Rebahlotse Mapula Molotoa, Lesiba Harry Moremib, Puffy Soundya and Sipho Thulane Masekoa
aDepartment of Crop Sciences, Tshwane University of Technology, Pretoria, South Africa; bWaterberg Technical and Vocational Education and Training College, Mokopane, South Africa
ABSTRACT
Deficiencies of vitamin A, iodine, iron and zinc (Zn) in humans are caused partly by the consumption of food that has insufficient quantities of these. Their deficiency has a negative impact on the health, wellbeing, social and economic status of human beings. A national survey conducted in 2012 identified deficiencies of vitamin A, Fe, and Zn among other nutrients in South Africans
and regarded the deficiencies of vitamin A and Fe as a moderate but not Zn. This review discusses causes of Zn prevalence in low-income South Africans and that it is largely caused by the low content of Zn in their diets. Initiatives to reduce Zn deficiency include fortification of wheat products and maize meal which has failed to address it successfully. Weaknesses of fortification include high cost of fortified food products to low-income populations, poor regulation in ensuring compliance in fortification, non-fortification of sorghum meal, and leaching of fortified nutrients during processing. This review suggests Zn-biofortification of locally-preferred common bean cultivars as an alternative strategy to compliment fortification. The review also discusses advantages of adopting biofortified Nutritional Andean common beans. Furthermore, the review suggests initiatives including evaluation of the common bean genotypes’ adaptation to different agro-ecologies.
KEYWORD S
Biofortification; fortification; zinc deficiency; zinc; South Africa
Changes in the weed communities as affected by different primary soil tillage and deep loosening
Regina Skuodienė , Danutė Karč auskienė , Regina Repš ienė and Gintaras Š iaudinis
Vėž aič iai Branch, Lithuanian Research Centre for Agriculture and Forestry, Gargž dų , Lithuania
ABSTRACT
Long-term soil cultivation at the same depth affects soil characteristics and crop productivity. The aim of the study was to investigate the impact of a long-term different intensity soil tillage methods and deep loosening on weed number, weed agrobiological group and soil seed bank changes in till Bathygleyic Dystric Glossic Retisol soil under the climatic conditions of the Western Lithuania (geographical coordinates 55°43 ′38 ′′N, 21°27 ′43 ′′E). The study included different soil tillage methods (conventional ploughing, shallow ploughing and shallow ploughless tillage) and deep loosening. During investigational years, the greatest weed number in crops and the greatest weed seed number in the seed bank were determined in the soil reduced tillage (shallow ploughing and shallow ploughless tillage). The weed number in crops of conventional ploughing soil was 35.8% lover compared to reduced tillage soil. The weed seed number in the seed bank of conventional ploughing was 49.6% lover compared to reduced tillage Decreasing soil tillage intensity resulted in weed seeds concentration in the upper topsoil. A one-time deep loosening had a significant effect during the crop rotation: the weed number in crops and weed seed number in the seed bank were determined to have increased by 26.6% and 51.6% in conventional ploughing soil and by 11.9% and 23.2% shallow ploughless soil respectively. However, after deep loosening, the number of Poa annua in crops decreased 2.9 times in plots
of conventional ploughing and 1.7 times – in plots of shallow ploughing soil.
KEYWORD S
Intensive tillage; reduced tillage; weed number; weed agrobiological group; soil seed bank
Effect of soil sterilisation on biological control of Fusarium oxysporum f. sp. lycopersici and Meloidogyne javanica by antagonistic fungi and organic amendment in tomato crop
M. W. Mwangia, W. M. Muirua, R. D. Narlaa, J. W. Kimenjua and G. M. Kariukib
aDepartment of Plant Science and Crop Protection, University of Nairobi, Nairobi, Kenya; bDepartment of Agricultural Science and Technology, Kenyatta University, Nairobi, Kenya
ABSTRACT
One of the major challenges in the application of biological control agents into the soil is their inability to withstand competition from natural microflora. In this study a management programme involving fungal biological control agents Trichoderma harzianum (TH) and Purpureocillium lilacinium (PL), and the organic amendment neem was carried out for the control
of Meloidogyne javanica and Fusarium oxysporum f. sp. lycopersici (FOL). The experiment was carried out in sterile and non-sterile soil in order to test the efficacy of biological control in natural soil conditions. This experiment was repeated twice. A Wilcoxon’s Signed-Rank test indicated there were no significant (P < 0.05) differences in fusarium wilt control in sterile and
non sterile soils in the treatments PL neem and TH neem, but there was significantly (P < 0.05) higher control of M. javanica in the same treatments in sterile soils compared to non sterile soils. The combinations of fungal antagonists and neem were effective in non sterile as in sterile soils in the control of fusarium wilt, while being less effective in the control of M. javanica. Thus the
biological control agents can be very effective in the control of fusarium wilt in natural conditions where the soil is not sterilised, but be less effective in the control of M. javanica in the same conditions. There is therefore potential of integrated management of fusarium wilt and root-knot nematodes (RKN) by these biological control agents in natural soil field conditions as an alternative to using chemicals.
KEYWORD S
Antagonistic fungi; biological control; Fusarium oxysporum f. sp. lycopersici; Meloidogyne javanica; non sterile; sterile
Establishment of seed germination and micropropagation protocols for Senegalia nigrescens, a potential anti-virulent species
Olusola Bodedea, Shakira Shaikb and Roshila Moodleya
aSchool of Chemistry, University of KwaZulu-Natal, Durban, South Africa; bSchool of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
ABSTRACT
This study describes seed germination and micropropagation of Senegalia nigrescens, an economic, medicinal and nitrogen-fixing species of South Africa. Seeds of S. nigrescens were subjected to presowing treatments including soaking in cold water for 24 h, sulphuric acid (H2SO4) or hydrochloric acid (HCl) for 4, 8 and 12 min and mechanically scarifying seeds before sowing on Petri plates with filter paper. Mechanically-scarified seeds were also sown aseptically on a filter paper bridge, plain agar, ½ or full strength Murashige and Skoog (MS) basal medium. Single nodal explants from MS-derived seedlings were grown on MS media supplemented with 0.0, 0.5, 1.0 and 2.0 mg L −1 of benzylaminopurine (BAP) or kinetin (KIN) and a combination of 0.5 mg L −1 of BAP and KIN to investigate shoot multiplication. No significant differences were observed in the number of shoots produced across all treatments. However, the treatment containing 1.0 mg L −1 KIN produced a significantly higher shoot length (14.17 ± 5.20 mm) than 0.5, 1.0 and 2.0 mg L −1 BAP (7.67 ± 3.87, 6.75 ± 2.93 and 8.70 ± 3.56 mm, respectively). The highest rooting rate (16.7%) was obtained on ¼ strength MS supplemented with either indole-3-acetic acid (IAA) or indole-3- butyric acid (IBA) at concentrations 1.0 and 0.5 mg L −1 , respectively. Rooted plantlets were successfully acclimatised with a 66.7% survival rate. The findings from this study would be of great benefit for the commercial propagation of S. nigrescens.
KEYWORD S
Acacia; dormancy; presowing; in vitro regeneration; scarification
From soil to rice – a typical study of transfer and bioaccumulation of heavy metals in China
Qiubei Gua, Zhongfang Yanga,b, Tao Yua,b, Qiong Yanga, Qingye Houa and Qizuan Zhangc
aSchool of Earth Sciences and Resources, China University of Geosciences, Beijing, People’s Republic of China; bKey Laboratory of Ecological Geochemistry, Ministry of Land and Resources, Beijing, People’s Republic of China; cGuangxi Bureau of Geology & Mineral Prospecting & Exploitation, Nanning, People’s Republic of China
ABSTRACT
For the purpose of studying the contamination, bioaccumulation and transfer of heavy metals and understanding the effects of soil properties on these, the work was carried out on a regional scale. A total of 30 sets of soil and pairing rice tissues samples (root, straw and grain) were collected in Xiangzhou of Guangxi, China; soil properties and Cd, Cu, Pb and Zn of different rice tissues were analyzed. The mobility and bioaccumulation of Cd, Cu, Pb and Zn were assessed by transfer coefficients and bioaccumulation factors of them. The results indicated that the excess proportions of Cd and Pb were 50%, 3.33% and 30%, 6.67% in soil and rice grain, respectively, according to Chinese maximum permitted concentrations of heavy metals. Cd and Zn showed stronger bioaccumulation and mobility capability; the bioaccumulation and transfer of Cu were slightly lower than Cd and Zn; Pb had the weakest mobility. The bioaccumulation and mobility of heavy metals from soil to rice were restrained by soil pH, CaO, SOC, Fe oxides and Mn.
KEYWORD S
Heavy metal; contamination; transfer; bioaccumulation
Genetic differentiation among selected tepary bean collections revealed by morphological traits and simple sequence repeat markers
Zinhle Babongile Mhlabaa,b, Beyene Ameleworkc, Hussein Shimelisa,b,c, Albert Thembinkosi Modia,b and
Jacob Mashiloa,b,c
aDiscipline of Crop Science, University of KwaZulu-Natal, Pietermaritzburg, South Africa; bSchool of Agricultural, Earth and Environmental , University of KwaZulu-Natal, Pietermaritzburg, South Africa; cAfrican Centre for Crop Improvement (ACCI), University of KwaZuluNatal, Pietermaritzburg, South Africa
ABSTRACT
Understanding the genetic relationship of crop ideotypes is essential for genetic analysis and breeding. The objective of this study was to determine genetic differentiation present among 20 selected tepary bean (Phaseolus acutifolius A. Gray) genotypes using morphological traits and simple sequence repeat (SSR) markers in order to identify genetically unique parental lines to
develop breeding populations. Phenotypic diversity was estimated using Shannon-Weaver diversity index (H’), principal component analysis (PCA) and cluster analysis (CA). Genotypic diversity was estimated using Jaccard’s genetic distances and CA. Shannon-Weaver diversity index values for the studied morphological traits ranged from 0.89 to 0.99, with a mean of 0.95
revealing high phenotypic differences among test genotypes. PCA identified four useful principal components (PC’s) which contributed to 73% of the total phenotypic variation of collections. PC1 accounted for 28% of the total variation correlated to dry shoot mass and number of pods per plant. PC2 correlated with number of seeds per pod, grain yield and harvest index and
contributed to 21% of total variation. The mean observed (Ho) and expected (He) heterozygosity values were 0.45 and 0.51, respectively revealing moderate genetic differentiation among genotypes. The mean polymorphic information content was 0.52, suggesting efficient discriminatory power of the SSR loci useful in future tepary bean genetic diversity analysis. The
current study revealed moderate genetic differentiation among the studied tepary bean genotypes. Morphological traits and SSR markers well-correlated in allocating the tepary bean genotypes. The following genotypes were genetically distinct: G40201, G40237, G40068, G40033 and G40063 which are recommended for further crosses, selection and population development.
KEYWORD S
Breeding; genotype; phenotype; P. acutifolius; tepary bean; microsatellite markers
Impact of variety and farming practices on growth, yield, weed flora and symbiotic nitrogen fixation in faba bean cultivated for fresh seed production
Georgia Ntatsia, Anestis Karkanisb, Dionisios Yfantopoulosa, Margit Ollec, Ilias Travlosa, Ricos Thanopoulosd, Dimitrios Bilalisa, Penelope Bebelia and Dimitrios Savvasa
aDepartment of Crop Science, Agricultural University of Athens, Athens, Greece; bDepartment of Agriculture Crop Production and Rural Environment, University of Thessaly, Volos, Greece; cEstonian Crop Research Institute, Jogeva alevik, Estonia; dFarm & Agricultural Enterprises Management, Agricultural University of Athens, Athens, Greece
ABSTRACT
The main objective of this study was to investigate the performance of faba bean landraces originating from different regions of Greece under both organic and conventional farming systems focusing mainly on yield, biological nitrogen fixation (BNF), and competitiveness to weeds. Faba bean exhibited a high ability to fix nitrogen from the atmosphere, as indicated by the percentage of N2 derived from the atmosphere which exceeded 75% in all evaluated varieties, and the total amount of biologically fixed N up to full anthesis, which fluctuated from 118.5 to 193.9 kg ha −1 in the various cropping systems and cultivars. The weed density was appreciably higher in the organic plots, without significant differences among the faba bean cultivars, while wild mustard and corn poppy were the most competitive weeds. The application of inorganic starter fertiliser in the conventionally-treated plots had no negative effect on biologically-fixed nitrogen by faba bean plants, while the herbicide pendimethalin had no negative impact on the nodulation process. Protein concentrations in faba bean cultivars fluctuated from 27.3% to 31.4%. The evaluated landraces could be utilised in breeding programmes due to their earliness, and their high performance in terms of protein content, BNF
ability, and productivity.
KEYWORD S
Biological nitrogen fixation; protein; soil fertility; weed density; Vicia faba L; legumes
Micro-nutrient composition and end-user acceptable quality in potato in Ethiopia
Asrat Asfaw a,b, Gebremedhen Woldegiorgisc, Semagn A. Kolechd, Gedif Mulugetab, Dinka Mulugetac, Abigail Ngugib, Gabriela Burgose, Thomas zum Feldee and Merideth Bonierbalee
aInternational Institute of Tropical Agriculture (IITA), Abuja, Nigeria; bInternational Potato Centre (CIP), Sub-Saharan Africa Regional Program, Nairobi, Kenya; cEthiopian Institute of Agricultural Research (EIAR), Addis Ababa, Ethiopia; dAmhara Regional Agricultural Research Institute (ARARI), Bahir Dar, Ethiopia; eInternational Potato Center (CIP), Lima, Peru
ABSTRACT
Micronutrient deficiencies in diets, including iron (Fe) and zinc (Zn), are an important public health problem across population in Ethiopia. Potato is a modest source of dietary nutrients. The purpose of this study was to assess the mineral (Fe & Zn) composition of potato germplasm in Ethiopia and grower’s willingness to try new potato types. The Fe and Zn contents were assessed in peeled tubers of popular farmer varieties, and newly introduced Andean diploid group Phureja accessions and improved tetraploid clones grown in multi-location trials. Grower’s preferences for the new potato types was assessed using a participatory approach. Significant variations in mineral and tuber yield traits exist among the germplasm assessed and broad-sense heritability appears to be high for most traits measured, suggesting that progress through breeding can be made among these materials. However, the slightly negative correlation of tuber yield with Fe and Zn content and user appreciation traits found in this study suggests that progress in improving crops for yield and enhanced Fe and Zn concentrations with end-user acceptable
quality will be challenging. The results from this study provide baseline information on Fe and Zn composition of many popular farmer varieties in Ethiopia and end-user preference criteria for evaluating new potato varieties that would help to orient the biofortification breeding to the conditions and preference of farmers.
KEYWORD S
Biofortification; Phureja; Fe and Zn profiling; user trait elicitation
