Major Faba Bean Research Articles

Faba bean chocolate spot and factors affecting disease intensity in major faba bean growing districts of North Shewa, central highlands of Ethiopia

Faba bean chocolate spot and factors affecting disease intensity in major faba bean growing districts of North Shewa, central highlands of Ethiopia

Influence of Environment by Spacing and Phosphorus Fertilizer Interaction on the Productivity of Faba Bean (Vicia faba L.) in the Major Nitisol Production Areas in Ethiopia

Though Faba bean is an important pulse crop grown in the highlands of Ethiopia, its productivity is far below its potential due to several constraints, such as optimum plant density and fertilizer rates meant for major faba bean growing areas. Hence, a field experiment was conducted to determine the appropriate seeding and fertilizer rates for faba bean production at Holeta, Jima, Kulumsa, and Sinana areas during the 2019 to 2021 main cropping seasons. Factorial combinations of phosphorus fertilizer (23, 46, and 69 kg P2O5/ha), intra-row spacing (7, 10, and 13 cm), and inter-row spacing (30, 40, and 50 cm) were laid out in a randomized complete block design with three replications. Due to the non-homogeneity of variances across locations, a separate combined ANOVA was done for Kulumsa and Jimma that were found homogeneous. Similarly, a separate combined ANOVA over years was done for Holeta. On the other hand, Sinana's two-year data lacked homogeneity across years and with either of the other testing sites. Hence, results of each year presented. Based on the ANOVA results, the lowest fertilizer rates of 23 kg P2O5/ha together with 10 cm intra-row spacing and 40 cm inter-row spacing, were found to be optimum for the study areas around Kulumsa and Jimma while, the highest fertilizer rate of 69 kg P2O5/ha together with 10 cm intra-row spacing and 40 cm inter-row spacing, were found to be economically optimal for faba bean production in West Shewa acidic nitisols. On the other hand, to get reliable results, the experiment should be repeated at least once in one growing season at Sinan testing sites.

Spatial distribution pattern of Rhizobium leguminosarum bv. vicieae across legume growing areas of Tigray region

Introduction: Several research findings stated that, faba bean had phenotypically diverse and symbiotically effective in Tigray, Ethiopia. However, limited researches were conducted in the region regarding biological nitrogen fixation with local varieties and races. Objective: To address the limitations Spatial Distribution Pattern of Rhizobium leguminosarum bv. Vicieae across legume growing areas of Tigray region was investigated. Methodology: A total of 112 root nodules with (107.9 average) nodules plant-1 were collected from 15 major faba bean growing districts of the region for isolation and characterization of indigenous root nodulating bacteria of the host plant. A serious of methods and procedures were undertaken to confirm the presumptive, eco-physiological and morphological characteristics of the isolated Rhizobium bacteria in triplicates. Results: All the tested isolates were presumptively gram -ve, raised, translucent and white in color, failed to grow on peptone glucose agar, keto lactose test and Hofer’s alkaline test. Phenotypically, 75% of the isolated candidates were appearing large mucoid and morphologically >80% of them were recorded more than 2mm colony diameter. Physiologically, 100 % of the isolates were grown well at a temperature range between 20℃ and 30℃, pH values between 6 and 8, and in the range of 0.1 and 2.5% (w/v) NaCl concentrations. In addition to this, a faba bean nodulating bacterium uses a broad range (90-100%) of carbohydrate utilization. The effectiveness of the candidates confirms 65%, 18.33%, 15% and 1.6% were recorded as highly effective, effective, less effective and ineffective. Moreover, the highest and lowest symbiotic effectiveness was scored 457% and 21% respectively.

Effect of Fungicide Application Rate and Frequency on development of Major Faba bean Diseases, Grain Yield and Yield Components of Faba Bean (Vicia Faba L.) at Southeastern Oromia, Bale

The experiment was conducted at Sinana and Agarfa to determine the application rate and frequency of MATICO. Randomized Complete Block Design with three replications was used to lay out the experiment. Logistic model (ln[y/ (1-y)]) was used to estimate r. Correlation and regression analysis were employed to find the relationship between diseases’ severity, yield, and yield-related traits. Analysis of Variance (ANOVA) for diseases parameters has shown significant differences (p<0.05) between treatments. The highest diseases parameters were recorded from unsprayed and plots sprayed with lower rates and frequency and the lowest was recorded from plots sprayed four tines at 2.5 kg/ha. ANOVA for yield and yield-related traits has shown significant variations (P<0.05) among treatments. The highest pods per plant (21), thousand Kernel Weight (664.7g), and grain yield (3319.4kg/ha) were recorded from plots sprayed four times at 2.5 kg/ha. Simple linear regression has revealed a significant association (P<0.0001) between grain yield and diseases severity and the Correlation of grain yield with diseases severity has depicted a significant negative correlation. The highest marginal rate of return (2126.31%) was obtained from plots sprayed twice at 2.5kg/ha. Therefore, two times application of MATICO WP at a rate of 2.5 kg/ha is recommended.

Genetic diversity and population structure of Moroccan Botrytis spp. strains, causing chocolate spot disease in faba bean

Chocolate spot (Botrytis spp.) is one of the most important foliar diseases limiting the yield and seed quality of faba bean (Vicia faba L.) worldwide. Knowledge of the population structure of the pathogen is key to developing appropriate breeding strategies for disease management. This study aims to assess the genetic diversity and population structure of 75 Botrytis spp. isolates collected from seven major faba bean growing regions in Morocco. Genetic diversity was assessed using 30 Sequence Related Amplified Polymorphism (SRAP) primer combinations. Eight primer-combinations generated 118 polymorphic alleles and had discriminated between different isolates with an average PIC value of 0.28. The Moroccan Botrytis spp. populations presented a high genetic diversity that was more distributed within populations (99%) than among populations. Population structure analysis revealed that the genetic diversity was not linked to geographic locations, indicating limited geographic delimitation and significant gene flow. The data will be useful to improve the faba bean breeding program to develop effective resistant cultivars. To our knowledge, this is the first study carried out on the genetic variability of Botrytis spp. Isolates from faba bean In Morocco.

Pathogenic Specialization in Uromyces viciae-fabae in Australia and Rust Resistance in Faba Bean.

The pathogen Uromyces viciae-fabae causes rust (a fungal disease) on faba bean (Vicia faba). This disease limits faba bean production in Africa, Asia, Europe, and Australia. The development of resistant cultivars to U. viciae-fabae is the optimal solution for sustainable disease management. However, unknown virulence in Australian U. viciae-fabae populations has confounded resistance breeding. This study examined differences in virulence among Australian U. viciae-fabae isolates collected from various locations and established a differential set of faba bean genotypes. Ten rust isolates were collected from the major faba bean growing regions in Australia and single spore cultures produced. These cultures were subsequently used for assessing virulence on 40 diverse faba bean genotypes. Based on the host-pathogen interactions, 12 putative host genotypes were identified as a differential set. A nomenclature system was subsequently developed using the binary pathotype naming system. Based upon host-pathogen interactions, nine virulence patterns were detected, and the isolates were named using the new nomenclature. We report characterization and naming of U. viciae-fabae pathotypes using differential genotypes in Australia. This differential set will help identify and track the evolution of new virulence in pathogen population and will assist pyramiding of rust resistance genes.

Recent advances in faba bean genetic and genomic tools for crop improvement.

Faba bean ( Vicia faba L.), a member of the Fabaceae family, is one of the important food legumes cultivated in cool temperate regions. It holds great importance for human consumption and livestock feed because of its high protein content, dietary fibre, and nutritional value. Major faba bean breeding challenges include its mixed breeding system, unknown wild progenitor, and genome size of ~13 Gb, which is the largest among diploid field crops. The key breeding objectives in faba bean include improved resistance to biotic and abiotic stress and enhanced seed quality traits. Regarding quality traits, major progress on reduction of vicine‐convicine and seed coat tannins, the main anti‐nutritional factors limiting faba bean seed usage, have been recently achieved through gene discovery. Genomic resources are relatively less advanced compared with other grain legume species, but significant improvements are underway due to a recent increase in research activities. A number of bi‐parental populations have been constructed and mapped for targeted traits in the last decade. Faba bean now benefits from saturated synteny‐based genetic maps, along with next‐generation sequencing and high‐throughput genotyping technologies that are paving the way for marker‐assisted selection. Developing a reference genome, and ultimately a pan‐genome, will provide a foundational resource for molecular breeding. In this review, we cover the recent development and deployment of genomic tools for faba bean breeding.

Genetic Diversity of Orobanche crenata Populations in Ethiopia Using Microsatellite Markers.

Orobanche crenata is a parasitic weed that causes considerable yield losses on food legumes in Ethiopia and the Mediterranean region. Understanding the genetic diversity of Orobanche crenata using molecular techniques generate useful information in managing the weed through resistance breeding. This study aimed at assessing the genetic diversity of O. crenata populations collected from major faba bean growing areas of Ethiopia. A total of 96 samples were collected from the Orobanche-infested faba bean farmer field. The genetic diversity of the population was studied using 30 O. cumana SSR markers. The results showed that 11 SSRs were functional and transferable markers to study the diversity of O. crenata populations. The average number of alleles, gene diversity, heterozygosity, and polymorphic information content values for the SSR loci were 9.6, 0.82, 0.38, and 0.80, respectively. The pairwise genetic similarity analysis showed the lowest genetic distance between samples collected from South Gondar and South Wollo (0.12) while the highest genetic distance (0.48) was found between South Gondar and North Wollo. The analysis of molecular variance result indicated that the variation among individuals was a major source of genetic variation (55%) followed by within individuals (43%) and among populations (2%) variation. The output of population genetic structure analysis indicated the presence of two major groups irrespective of the area of collection or region of origin. Besides, the outcome of the spatial autocorrelation computation indicated a significant and positive genetic correlation between samples collected under a 28 km radius. In general, the absence of geographic region based genetic structure presumably demonstrates the expansion of the parasitic weed between farming sites upon its recent introduction to the country. Thus, the clear absence of population differentiation warrants screening faba bean population in hot spot area.

Identification and Quantification of Major Faba Bean Seed Proteins

Faba bean (Vicia faba L.) holds great importance for human and animal nutrition for its high protein content. However, better understanding of its seed protein composition is required in order to develop cultivars that meet market demands for plant proteins with specific quality attributes. In this study, we screened 35 diverse Vicia faba genotypes by employing the one-dimensional sodium dodecyl sulfate–polyacrylamide gel electrophoresis (1D SDS-PAGE) method, and 35 major protein bands obtained from three genotypes with contrasting seed protein profiles were further analyzed by mass spectrometry (MS). Twenty-five of these protein bands (MW range: ∼ 9–107 kDa) had significant (p ≤ 0.05) matches to polypeptides in protein databases. MS analysis showed that most of the analyzed protein bands contained more than one protein type and, in total, over 100 proteins were identified. These included major seed storage proteins such as legumin, vicilin, and convicilin, as well as other protein classes like lipoxygenase, heat shock proteins, sucrose-binding proteins, albumin, and defensin. Furthermore, seed protein extracts were separated by size-exclusion high-performance liquid chromatography (SE-HPLC), and percentages of the major protein classes were determined. On average, legumin and vicilin/convicilin accounted for 50 and 27% of the total protein extract, respectively. However, the proportions of these proteins varied considerably among genotypes, with the ratio of legumin:vicilin/convicilin ranging from 1:1 to 1:3. In addition, there was a significant (p < 0.01) negative correlation between the contents of these major fractions (r = −0.83). This study significantly extends the number of identified Vicia faba seed proteins and reveals new qualitative and quantitative variation in seed protein composition, filling a significant gap in the literature. Moreover, the germplasm and screening methods presented here are expected to contribute in selecting varieties with improved protein content and quality.

Impact Assessment of Abiotic Production Constrains of Faba Bean (Vicia faba L.) and Breeding Mechanisms for Acid Soil, Drought and Waterlogging Affected Environments

Faba bean is one of the oldest crops grown in Ethiopia. It is used as a source of protein in human diets, as fodder and a forage crop for animals and for soil fertility improvement. Its production in Ethiopia is totally rainfed on nitosols, cambisol and vertisol. Ethiopia is the second largest faba bean producer next to China. However, its productivity has remained very low compared to the potential due to biotic and abiotic stresses coupled with poor crop management practices provided by farmers. Thus, this review deals with impacts of abiotic stress on the growth and performance of faba bean and its remedial measures for continues production. Among the abiotic stresses soil acidity, drought and waterlogging provide a hostile environment for faba bean growth. Both soil acidity and drought are worldwide problem and sensitivity to acid soils limits the usage of faba bean in some cropping systems. Hence, the low production of faba bean is attributed by high moisture stress in the northern block of the country and soil acidity in the western and central highlands of Ethiopia. As chocolate spot the major faba bean disease it can be aggravated by any abiotic stress. To overcome low production of faba bean on acidic soils liming is an immediate option but choice of acid-tolerant varieties may further reduce the amounts of lime requirement and makes farming more attractive. Likewise, terminal drought can be managed by early planting and use of early varieties. Additionally, physiological traits like deep root, stomatal conductance and osmoregulation enables as drought resistant mechanisms. Breeding faba bean for acid soil, drought and water logging problem areas is the best option for sustainable production of the crop and to address the resource poor farmers that produce faba bean in their cropping system. Keywords: Abiotc stress, Breeding, Drought, Faba bean, soil acidity, Waterlogging DOI: 10.7176/JBAH/10-11-06 Publication date: June 30 th 2020

The Species Composition and Relative Abundance of Insect Pests of Stored Faba Bean in Farta District of South Gondar Zone of North Western Ethiopia

Faba bean contributes to meet the basic dietary needs of millions of people and animals around the world, including Ethiopia, pertaining to its high protein, carbohydrate, dietary fibers and micronutrients. Nevertheless, insect pests have been reported to cause significant loss of it under traditional farmers’ storages. Accordingly, survey involving sampling of stored faba bean from a total of 162 farmers stores selected in nested design was conducted from 4, September 2019 – 15, May 2020 in six major faba bean producing peasant associations of Farta District. Accordingly, a total of 10 species of insect pests viz Acanthoscelides obtectus, Callosobruchus sp., Callosobruchus chinensis, Zabrotes subfasciatus, Callosobruchus muculutus, Bruchus sp. and Bruchidius sp. were recorded from stored faba bean of the study area. 90% of which was belonging to order Coleoptera with in two families i.e., Bruchidae and Nitidulidae, while one species (10%) was from order Psocoptera of the family Liposcelididae. In terms of their relative abundance the species were in the following order Acanthoscelides obtectus &gt; Callosobruchus sp. &gt; Callosobruchus chinensis &gt; Zabrotes subfasciatus &gt; Callosobruchus muculutus &gt; Carpophilus sp. &gt; C. dimidatus &gt; Liposcelis sp. &gt; Bruchus sp. &gt; Bruchidius sp. Accordingly, the presence of great infestation of the faba bean grain by pests was suggested. As a result, the traditional practices used by farmers were ineffective for satisfactory protection of the stored faba bean grains. Therefore, designing effective management strategies against insect pests of stored faba bean in the study area is urgently needed.

Genetic Diversity Assessment of Portuguese Cultivated Vicia faba L. through IRAP Markers

Faba bean have been grown in Portugal for a long time and locally adapted populations are still maintained on farm. The genetic diversity of four Portuguese faba bean populations that are still cultivated in some regions of the country was evaluated using the Inter Retrotransposons Amplified Polymorphism (IRAP) technique. It was shown that molecular markers based on retrotransposons previously identified in other species can be efficiently used in the genetic variability assessment of Vicia faba. The IRAP experiment targeting Athila yielded the most informative banding patterns. Cluster analysis using the neighbor-joining algorithm generated a dendrogram that clearly shows the distribution pattern of V. faba samples. The four equina accessions are separated from each other and form two distinct clades while the two major faba bean accessions are not unequivocally separated by the IRAP. Fluorescent In Situ Hybridization (FISH) analysis of sequences amplified by IRAP Athila revealed a wide distribution throughout V. faba chromosomes, confirming the whole-genome coverage of this molecular marker. Morphological characteristics were also assessed through cluster analysis of seed characters using the unweighted pair group method arithmetic average (UPGMA) and principal component analysis (PCA), showing a clear discrimination between faba bean major and equina groups. It was also found that the seed character most relevant to distinguish accessions was 100 seed weight. Seed morphological traits and IRAP evaluation give similar results supporting the potential of IRAP analysis for genetic diversity studies.

Application of benzothiadiazole and Trichoderma harzianum to control faba bean chocolate spot disease and their effect on some physiological and biochemical traits

Chocolate spot disease is the most prevalent and important disease in the major faba bean growing regions in the world. Different concentrations of the abiotic inducer (0.3 and 0.5 mM benzothiadiazole) and the biotic inducer (1 × 107 and 2 × 107 spore/ml Trichoderma harzianum) were used alone or in combination to study their efficiency against faba bean chocolate spot disease caused by Botrytis fabae and Botrytis cinerea and their effect on some chemical analyses (phenylalanine ammonia lyase activity, total flavonoids and peroxidase isozymes, pectin and lignin content and total chlorophyll content). Application of the tested inducers as foliar treatment significantly reduced the severity of chocolate spot disease as compared with untreated infected plants. The reduction in disease severity was associated with a gradual increase in phenylalanine ammonia lyase activity. Maximum increase was recorded at 72 h after inoculation with B. fabae and B. cinerea. In addition, the levels of flavonoids in induced infected leaves recorded a sharp increase at 24 h after inoculation with B. fabae or B. cinerea. Also, pectin and lignin contents in the cell wall of induced infected plants were significantly increased as compared with untreated infected plants. Beside the induction of resistance, the tested inducers markedly increased total chlorophyll content in treated infected plants as compared with untreated infected plants. Isozymes analysis revealed that new peroxidase bands were induced only in treated faba bean leaves in response to infection with B. fabae or B. cinerea.

Genetic diversity of faba bean (Vicia faba L.) populations revealed by sequence specific amplified polymorphism (SSAP) markers

This study used sequence specifc amplifcation polymorphism (SSAP) markers to investigate the genetic diversity and population genetic structure of nine Tunisian Vicia faba populations belonging to the minor and major faba bean’s sub-species. Three primers were used (PDR1, Tps19 and Tvf4 ) in this study. These primers gave good SSAP marker profiles, high number of bands obtained per gel and a high percentage of polymorphic bands as confirmed in a previous study. Indeed, these primers provided a total of 173 amplified bands, with 123 of them being polymorphic. Shannon indexes ranges from 0.166 to 0.248 with an average of 0.207. The genetic diversity within population of 0.743 was clearly higher than that of among population genetic diversity (Dst = 0.138), indicating an out-crossing predominance in the studied populations. The Dst value showed that 15.6% of the total genetic variation resided among populations, a little lower than that of out-crossing species. The dendrogram grouping the populations by unweighted pair-group method with arithmetic averages (UPGMA) method revealed three main clusters. The local major faba bean ‘Batata’ was the most divergent population and was separated from other population.

Yield stability of faba bean lines under diverse broomrape prone production environments

Faba bean ( Vicia faba L.) is one of the important pulse crops grown in many parts of the world. Its production and productivity are affected by different biotic and abiotic stresses. Broomrape ( Orobanche and Phelipanche spp.) causes yield losses of 7– 80% in major faba bean growing countries mainly in the Mediterranean Basin and Nile Valley countries. Host plant resistance is found to be the most effective and economic method of broomrape control. Efforts made at the International Center for Agriculture Research in the Dry Areas over many years to develop advanced breeding lines with acceptable resistance and tolerance levels to broomrape have resulted in the identification of several useful breeding lines. These lines were shared with National Agricultural Research Systems (Egypt, Sudan, Tunisia and Portugal) as part of the Faba Bean Orobanche International Nursery, in order to test their stability across three seasons (2005, 2006 and 2007). The results showed that Orobanche plant number, dry weight, Orobanche index, flowering date, maturing date and grain yield were significantly different among lines and locations. AMMI analysis showed that some lines derived from hybrid bulk populations “HBP/DS0/2000” and “HBP/ES0/2000” showed acceptable levels of yield stability in the presence of Orobanche infections across all environments compared with susceptible check. In highly infested soils, the tolerant and resistant lines gave acceptable levels of yield compared with the susceptible check. However, the yield potential of resistant and tolerant lines in non-infested soils was lower than the highly susceptible check.

Identification and genetics of resistance to cercospora leaf spot (Cercospora zonata) in faba bean (Vicia faba)

The fungal disease cercospora leaf spot CLS (Cercospora zonata) has affected major faba bean (Vicia faba) production regions in southern Australian in the last several years. This study offers the first report of sources of resistance to CLS in faba bean and describes techniques to evaluate resistance to C. zonata in faba bean genotypes within a controlled environment. The method was rapid (43 days), repeatable (R 2 > 0.74) and demonstrated positive correlations (R 2 > 0.45–0.80) to data collected from field disease nurseries under naturally established CLS epiphytotics. All faba bean cultivars currently adopted by the Australian industry were found to be susceptible to CLS and defoliation was found to be an important component of disease expression. Genetic analysis of segregation patterns in F 2 derived F 3 families of 1322/2*Farah (resistant*susceptible) showed the mode of inheritance of resistance to C. zonata was monogenic dominant. F 3 families were shown to segregate in the ratio of 1:2:1 for homozygous resistant: heterozygous: homozygous susceptible (χ 2 2 = 2.78; P > 0.05) and individual plants within heterozygous F 3 families segregated in the ratio of 3:1 for resistant: susceptible responses (χ 1 2 = 2.93; P > 0.05). Monogenic dominant inheritance also explained the change in frequency of resistant and susceptible plants within a population of cv. Cairo following one generation of self-pollination (χ2 = 0.88, 0.3 < P < 0.5). The sources of resistance identified in this study are being used to transfer CLS resistance to adapted faba bean genotypes for future cultivar releases to the southern Australian industry.

The Effect of Indigenous Root-Nodulating Bacteria on Nodulation and Growth of Faba Bean (Vicia Faba) in the Low-Input Agricultural Systems of Tigray Highlands, Northern Ethiopia

This study was initiated to isolate and characterize indigenous rhizobia nodulating faba bean, and evaluate symbiotic characteristics between the crop and the rhizobia in major faba bean producing areas in Tigray highlands. Field crops were also surveyed for nodulation in selected sites of seven (7) faba bean growing districts. A total of 44 rhizobial strains were isolated and their symbiotic properties (nodule number, fresh weight, color and plant growth) were recorded. A total of 12 strains with good symbiotic properties were characterized for their morphological and physiological traits on Yeast Extract Manitol Agar (YMA) medium. The result of the study showed the presence of diversity in morphological, physiological and symbiotic properties among the rhizobial strains. There was statistically significant difference in nodule number, fresh weight and shoot height (p< 0.05) and great variation in nodule color within and among the districts. Nodulation status of the field crops was poor except Ofla, D/Temben and Alaje districts. Though the presence of diversity among the strains revealed the possibility of getting potentially effective adaptable rhizobial strains that enhance faba bean productivity, the weak symbiotic properties observed during isolation and nodulation status survey might partly be responsible for yield variation and reduction in low input cropping systems of Tigray. Hence, studies on a need for inoculation and factors responsible for poor nodulation need to be undertaken to realize the role of biological nitrogen fixation in Tigray cropping systems. Key words: Biological nitrogen fixation, Faba bean, Nodulation, Rhizobia, Symbiotic Effectiveness, Tigray.