Faba Bean Breeding Programs Research Articles

Global changes in gene expression during compatible and incompatible interactions of faba bean (Vicia faba L.) during Orobanche foetida parasitism.

Orobanche foetida Poiret is the main constraint facing faba bean crop in Tunisia. Indeed, in heavily infested fields with this parasitic plant, yield losses may reach 90%, and the recent estimation of the infested area is around 80,000 ha. Identifying genes involved in the Vicia faba/O. foetida interaction is crucial for the development of effective faba bean breeding programs. However, there is currently no available information on the transcriptome of faba bean responding to O. foetida parasitism. In this study, we employed RNA sequencing to explore the global gene expression changes associated with compatible and incompatible V. faba/O. foetida interactions. In this perspective, two faba bean varieties (susceptible and resistant) were examined at the root level across three stages of O. foetida development (Before Germination (BG), After Germination (AG) and Tubercule Stage (TS)). Our analyses presented an exploration of the transcriptomic profile, including comprehensive assessments of differential gene expression and Gene Ontology (GO) enrichment analyses. Specifically, we investigated key pathways revealing the complexity of molecular responses to O. foetida attack. In this study, we detected differential gene expression of pathways associated with secondary metabolites: flavonoids, auxin, thiamine, and jasmonic acid. To enhance our understanding of the global changes in V. faba response to O. foetida, we specifically examined WRKY genes known to play a role in plant host-parasitic plant interactions. Furthermore, considering the pivotal role of parasitic plant seed germination in this interaction, we investigated genes involved in the orobanchol biosynthesis pathway. Interestingly, we detected the gene expression of VuCYP722C homolog, coding for a key enzyme involved in orobanchol biosynthesis, exclusively in the susceptible host. Clearly, this study enriches our understanding of the V. faba/O. foetida interaction, shedding light on the main differences between susceptible and resistant faba bean varieties during O. foetida infestation at the gene expression level.

Enhancing phenotyping efficiency in faba bean breeding: integrating UAV imaging and machine learning

Unmanned aerial vehicles (UAVs) equipped with high-resolution imaging sensors have shown great potential for plant phenotyping in agricultural research. This study aimed to explore the potential of UAV-derived red–green–blue (RGB) and multispectral imaging data for estimating classical phenotyping measures such as plant height and predicting yield and chlorophyll content (indicated by SPAD values) in a field trial of 38 faba bean (Vicia faba L.) cultivars grown at four replicates in south-eastern Norway. To predict yield and SPAD values, Support Vector Regression (SVR) and Random Forest (RF) models were utilized. Two feature selection methods, namely the Pearson correlation coefficient (PCC) and sequential forward feature selection (SFS), were applied to identify the most relevant features for prediction. The models incorporated various combinations of multispectral bands, indices, and UAV-based plant height values at four different faba bean development stages. The correlation between manual and UAV-based plant height measurements revealed a strong agreement with a correlation coefficient (R2) of 0.97. The best prediction of SPAD value was achieved at BBCH 50 (flower bud present) with an R2 of 0.38 and RMSE of 1.14. For yield prediction, BBCH 60 (first flower open) was identified as the optimal stage, using spectral indices yielding an R2 of 0.83 and RMSE of 0.53 tons/ha. This development stage presents an opportunity to implement targeted management practices to enhance yield. The integration of UAVs equipped with RGB and multispectral cameras, along with machine learning algorithms, proved to be an accurate approach for estimating agronomically important traits in faba bean. This methodology offers a practical solution for rapid and efficient high-throughput phenotyping in faba bean breeding programs.

English

Faba bean is an important grain legume crop in the world. Use of plant genetic breeding resources can help develop high yield and stress tolerant plant genotypes. In this study, genetic diversity of 144 faba bean accessions, collected from different parts of the world growing under Saudi Arabian conditions, was evaluated based on agro morphological basis. A wide range of variability was recorded for all the qualitative characters except growth habit (determinate 1.3% indeterminate 98.7%) and pod shattering (non-shattering 99.4%; shattering 0.6%). A high level of diversity was recorded in the qualitative characteristics including leaflet size, stipule spot pigmentation, flower ground color, intensity of streak, wing petal colors, pod colors, pod angle, hilum color, pod shattering, ground color of testa and seed shape in the tested faba bean accessions. The principal component analysis results showed that highest (95.32%) diversity came from three principal components, and dendrogram results divided faba bean into 8 distinct groups based on their origin. The cluster study of the tested faba beans accessions was based on the origin as well as on the genetic history. The extent of variability and diversity in the tested faba bean accessions indicate their potential for use in the faba bean breeding program.

Evaluating the Waterlogging Tolerance of Faba Bean Genotypes at Different Growth Stages under Field Conditions

Waterlogging stress is one of the most important abiotic stresses in Mediterranean conditions such as north of Iran. The tolerance of faba bean to waterlogging may vary between genotypes. This study investigated the effects of 10 days of waterlogging on grain yield for 21 faba bean genotypes at two stages (flowering and pod-filling stages) during 2016-2017 and 2017-2018 under farm conditions. A randomized complete block design with three replications was used at three field sites (normal and waterlogging sites). Nine indices of endurance were calculated in normal and waterlogging conditions. The results indicated that waterlogging stress reduced the faba bean grain yield. Also, the negative waterlogging effect at flowering stage is more than pod-filling stage. Correlation coefficients and principal component analysis (PCA) results revealed that mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HM), and stress tolerance index (STI) indices could be effectively used for screening of waterlogging stress tolerant genotypes. Waterlogging was caused to decrease significantly grain yield in all genotypes. According to results of three-dimensional graphs the genotypes G21, G18, G15, G6 and G2 with an average yield 4806, 4815, 4789, 4686 and 4681 kg.ha-1 , respectively, were selected as waterlogging stress tolerance and suitable grain yield under non-stress and waterlogging stress (waterlogging stress in flowering and pod-filling stages) conditions. Therefore, these genotypes can be used as source of genes in faba bean breeding programs to obtain tolerant cultivars and cultivation in the areas under waterlogging stress.

Carbon isotope and soluble metabolites reflect physiological status among contrasting faba bean genotypes in response to water deficit.

Identification and validation of biomarkers and bioindicators to select genotypes with superior tolerance to water deficit (WD) under field conditions are paramount to plant breeding programs. However, the co-occurrence of different abiotic stresses such as WD, heat, and radiation makes it difficult to develop generalized protocols to monitor the physiological health of the plant system. The study assessed the most abundant carbohydrates and sugar alcohols in five faba bean (Vicia faba) genotypes under field conditions and the abundance of naturally occurring carbon isotopes in bulk leaf material to predict water use efficiency (WUE). Plant water status and biomass accumulation were also assessed. Among the accumulated sugars, inter-specific variation in glucose was most prevalent and was found at a higher concentration (8.52 mg g−1 leaf) in rainfed trial. myo-Inositol concentrations followed that of glucose accumulation in that the rainfed trial had higher amounts compared to the irrigated trial. WUE calculated from carbon isotope abundance was consistently offset with measured WUE from measurements of leaf gas exchange. All genotypes demonstrated significant relationships between predicted and measured WUE (p < 0.05) apart from control variety PBA Warda. Thus, bulk leaf-level carbon isotope abundance can be used to calculate WUE and used as an effective selection criterion for improving WUE in faba bean breeding programs under field conditions.

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.

Adaptability and Stability of Faba Bean (Vicia faba L.) Accessions under Diverse Environments and Herbicide Treatments.

The adaptability and stability of 37 faba bean (Vicia faba L.) accessions with different levels of tolerance to metribuzin or imazethapyr was assessed across 12 season–location–herbicide experiments. Significant Genotype x environment (GE) interaction was found for the days to flowering (DFLR), plant height (PLHT) and grain yield (GY). Performance and stability of the accessions regarding PLHT and GY were assessed using four different stability parameters: cultivar superiority, static stability, Wricke’s eco-valence and Finlay and Wilkinson’s regression model. The stability parameters ranked these genotypes differently suggesting that PLHT and GY stability should be assessed not only on a single or a few stability parameters but on a combination of them. GGE biplot analysis indicated that the environments representing metribuzin treatment at Marchouch 2014–2015 and the non-treated treatment at Terbol 2018–2019 are the ideal environments for evaluating faba bean genotypes. GGE biplots showed herbicide tolerant accession IG12983 with simultaneous average PLHT, GY and stability across the environments. The performance of other tolerant accessions, namely IG13945, IG13906, IG106453, FB2648, and FB1216 was less stable but superior under specific mega environments. Therefore, utilizing these accessions in faba bean breeding programs would help broaden the adaptability to diverse locations–season–herbicide treatments.

Performance of Large Seeded Faba Bean Genotypes for Yield and Related Agronomic Traits in Different Parts of Ethiopia

Faba bean (Vicia faba L.) is a high value crop in Ethiopia and has versatile uses. The national faba bean breeding program concentrates on the three major traits (grain yield, disease resistance and seed size) of the crop for varietal release for commercial production. Hence, ten faba bean genotypes were evaluated at Adet, Areka, Bekoji, Haramaya, Holetta and Jimma during the main cropping seasons of 2018 and 2019 using a randomized complete block design with four replications with the objectives to select the genotype with best performance in terms of important agronomic traits like grain yield, disease resistance, large seed size and other desirable agronomic traits for high potential production areas in Ethiopia. The combined analysis of variance across locations revealed that there is highly significant (P &lt; 0.01) variation among the tested genotypes for grain yield, 1000-seeds weight, number of pods per plant, and days to 90% physiological maturity. The genotype EH011089-3 showed better performance than the tested genotypes having comparable grain yield performance (3803 kgha-1) with the two standard checks, Numan and Gora (3790 and 3897 kgha-1, respectively) while it had the highest 1000-seeds weight (1065 g) compared to the two standard checks, Numan and Gora (937 g and 786 g, respectively), i.e., 13.7% and 35.5% advantage, over the two standard checks, respectively. Additionally, EH011089-3 had better resistance for chocolate spot and rust diseases. Therefore, EH011089-3 was the best over the tested varieties and breeding lines. Genotype EH011089-3 is recommended for varietal release for commercial production all over in Ethiopia.

Evaluation of disease resistant and high yielding faba bean germplasm in India

Faba bean (Vicia faba L.) is one of the earliest domesticated food legumes after chickpea and pea in the world. It is been produced in many countries including China, Ethiopia, Egypt, northern Europe, the Mediterranean region, central Asia, East Asia, Latin America and as a minor crop in India. The crop is affected by many diseases and alternaria leaf blight (Alternaria spp.) is one of the serious threat to faba bean production. Twenty-five lines of faba bean were selected from three international nurseries and were evaluated at ICARDA-FLRP-Amlaha during 2016-2017 and 2017-2018, to identify resistant lines against alternaria blight disease. A wide range of variation to disease reaction was observed among faba bean genotypes. One faba bean line (S2011-134) found tolerant, six genotypes (S2011-116, FLIP15-139, FLIP15-156, FLIP15-159, FLIP15-164-S2 and FLIP15-169) were found moderately tolerant and 16 genotypes were found susceptible to alternaria blight. The faba bean genotypes showed resistance to the disease scoring (0-9) with high yield as compared to the checks, Giza and Gwalior local. The identified sources of resistance can be utilized in faba bean breeding programmes for the development of disease tolerant cultivars with high yield.

Diversity Analysis for Seed Yield and its Component Traits among Faba Bean (Vicia faba L.) Germplasm Lines

Background: Faba bean (Vicia faba L.) is one of the oldest cool season food legume crops, stands next to soybean (Glycine max L.) and pea (Pisum sativum L.). A throughout knowledge of existing genetic variation among seed yield and its component traits is essential for developing high yielding varieties in faba bean. Realizing the importance of genetic diversity in key economic traits, the present investigation planned to assess the genetic diversity in faba bean germplasm for yield improvement in faba bean breeding programme. Methods: The experimental material comprised of 80 faba bean germplasm lines, grown in RBD with three replications at Research Farm of Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar during Rabi 2015-16. The data on 10 quantitative traits was analysed for Mahalanobis D2 statistic, stepwise multiple regression and principle component analysis (PCA).Result: The present study has assessed the existed genetic variations traits among faba bean germplasm lines for seed yield and its component traits. This would certainly provide guidelines in the selection of parents as well as effective selection of promising faba bean genotypes in faba bean breeding programmes for developing high yielding varieties.

High Quantitative Trait Variability in Faba Bean Mutagenized Population for High-yielding Breeding Program in Saudi Arabia

Background: The narrow genetic base and environmental stresses are behind the low rate of faba bean yield in the past two decades. Drought stress is one of the most destructive abiotic stresses. Using induced mutagenesis on locally adapted landrace cultivar is proposed to cope with this problem. Methods: This study was conducted on faba bean landrace cultivar of Saudi Arabia, namely Hassawi 2, treated by 25 and 50 Gray gamma radiation. The genetic diversity assessment of M2 mutant populations was based on seven quantitative traits and nine Amplified Fragment Length Polymorphism (AFLP) primer combinations. Result: A total of 3419 M2 seeds were planted, of which 2782 (81.4%) seeds germinated and 2658 plants survived. A 5 to a 10-fold range of quantitative traits studied among mutant plants compared to control plants showed high variability. The number of pods per plant and seeds per plant was a valid selection criterion for a high-yielding faba bean breeding program. Nine AFLP primer combinations generated 1079 polymorphic alleles from 88 samples that comprised mutant and control plants. Shannon index (I) and expected heterozygosity (He) were 0.337 and 0.206, respectively. The AFLP results validated high variability in M2 populations. These findings will assist faba bean breeders in developing high-yielding cultivars with drought stress tolerance.

Genetic diversity in spring faba bean (Vicia faba L.) genotypes as revealed by high-throughput KASP SNP markers

Faba bean is one of the oldest legume crop grown around the world for its cheap source of protein and for being used in crop rotation with cereals to improve soil fertility through nitrogen fixation. This study was designed to determine the extent and pattern of genetic diversity and relationships among 48 Ethiopian faba bean genotypes using 37 SNPs loci based on Kompetitive allele specific PCR SNP markers. Thirty-six SNPs were found polymorphic and revealed an average of 95.6% polymorphisms. The gene diversity ranged from 0.16 to 0.50 with a mean of 0.42 and the PIC value ranged from 0.14 to 0.38 with a mean of 0.33. The Bayesian clustering model grouped the genotypes into two genetically distinct clusters with certain degree of admixture, indicating the introduction of chromosomes of different ancestry and allele frequency. The result clearly showed the presence of relatively high genetic diversity among faba bean genotypes grown in Ethiopia. Thus, these genotypes can be used in faba bean breeding programs to develop farmer preferred cultivars with desirable traits.

Genetic Analysis of Chocolate Spot and Rust Disease Resistance and Some Yield Related traits in Three Faba Bean Crosses

Breeding for high yield potential along with resistance to chocolate spot and rust diseases are the main target of most faba bean breeding programs. The five populations (P1, P2, F1, F2 and F3) of three faba bean crosses (Triple White x Ohishima Zairai), (Triple White x Giza 40) and (Triple White x Foul Sbai labiade) were evaluated during 2019 /2020 winter season at Sakha Agricultural Research Station, to study the type of gene action for foliar diseases resistance and some yield related traits. Significant differences were found among generations, i.e. P1, P2, F1, F2 and F3 for the majority of studied traits of all crosses. Significant and highly significant desirable percentages of heterosis relative to mid and better parent with favorable values for inbreeding depression for most traits. Additive gene effects were positive and highly significant for chocolate spot disease reaction, rust disease reaction. However, the dominant gene effects seem to be controlling the inheritance of yield and yield component traits. Narrow-sense heritability ranged from medium to high in most cases due to the opposite directions of dominance and dominance x dominance effects. Genetic advance from selection ranged from 7.66% for flowering date to 45.65% for No. of pods plant-1in cross 3. Finally; it could be concluded that cross 2 and cross 3 were the best for flowering date, seed yield/plant and 100-seed weight, while cross 3 was the best in resistance to chocolate spot and rust diseases. Therefore, selection in the advanced generations of both crosses could be effective.

VfODB: a comprehensive database of ESTs, EST-SSRs, mtSSRs, microRNA-target markers and genetic maps in Vicia faba.

Faba bean (Vicia faba) is an essential food and fodder legume crop worldwide due to its high content of proteins and fibres. Molecular markers tools represent an invaluable tool for faba bean breeders towards rapid crop improvement. Although there have historically been few V. faba genome resources available, several transcriptomes and mitochondrial genome sequence data have been released. These data in addition to previously developed genetic linkage maps represent a great resource for developing functional markers and maps that can accelerate the faba bean breeding programmes. Here, we present the Vicia faba Omics database (VfODB) as a comprehensive database integrating germplasm information, expressed sequence tags (ESTs), expressed sequence tags-simple sequence repeats (EST-SSRs), and mitochondrial-simple sequence repeats (mtSSRs), microRNA-target markers and genetic maps in faba bean. In addition, KEGG pathway-based markers and functional maps are integrated as a novel class of annotation-based markers/maps. Collectively, we developed 31 536 EST markers, 9071 EST-SSR markers and 3023 microRNA-target markers based on V. faba RefTrans V2 mining. By mapping 7940 EST and 2282 EST-SSR markers against the KEGG pathways database we successfully developed 107 functional maps. Also, 40 mtSSR markers were developed based on mitochondrial genome mining. On the data curation level, we retrieved 3461 markers representing 12 types of markers (CAPS, EST, EST-SSR, Gene marker, INDEL, Isozyme, ISSR, RAPD, SCAR, RGA, SNP and SSR), which mapped across 18 V. faba genetic linkage maps. VfODB provides two user-friendly tools to identify, classify SSR motifs and in silico amplify their targets. VfODB can serve as a powerful database and helpful platform for faba bean research community as well as breeders interested in Genomics-Assisted Breeding.

Physiological and Biochemical Basis of Faba Bean Breeding for Drought Adaptation—A Review

Grain legumes are commonly used for food and feed all over the world and are the main source of protein for over a billion people worldwide, but their production is at risk from climate change. Water deficit and heat stress both significantly reduce the yield of grain legumes, and the faba bean is considered particularly susceptible. The genetic improvement of faba bean for drought adaptation (water deficit tolerance) by conventional methods and molecular breeding is time-consuming and laborious, since it depends mainly on selection and adaptation in multiple sites. The lack of high-throughput screening methodology and low heritability of advantageous traits under environmental stress challenge breeding progress. Alternatively, selection based on secondary characters in a controlled environment followed by field trials is successful in some crops, including faba beans. In general, measured features related to drought adaptation are shoot and root morphology, stomatal characteristics, osmotic adjustment and the efficiency of water use. Here, we focus on the current knowledge of biochemical and physiological markers for legume improvement that can be incorporated into faba bean breeding programs for drought adaptation.

USING BIPLOT ANALYSIS OF F1 FABA BEAN DIALLEL DATA TO PREDICT COMBINING ABILITY

This study was carried out under insect cages during 2017/18 and 2018/19 seasons at Giza Research Station, ARC, Egypt to investigate the combining ability possibility prediction and relationship between biplot graph and Griffing of half diallel data, and to identify promising genotypes. Six parental faba bean genotypes and their half diallel crosses (15 F1’s) were evaluated under a randomized complete block design in three replications. The results reflected significant differences for both GCA and SCA in most traits, indicating the important role of both additive and dominant components in the inheritance. Meanwhile, Baker’s ratio emphasized the preponderant role of additive gene action in controlling the most studied traits. Simple correlation results showed that seed yield may be raised through selecting most pods and seeds per plant, which recorded the highest heritability in broad and narrow sense (hb 2 and hn 2%) estimates coupled with highest genetic advance (GA %) in faba bean. Biplot graph (innovative) and Griffing (traditional) analysis exhibited equivalent results for gca and sca effects and are meaningful for identifying Giza 843 (P1), Misr 1 (P2) and Giza 40 (P6) as the best parents and Giza 843 x Misr 1 (C12), Giza 843 x Nubaria 1 (C15), Misr 1 x Giza 3 (C24), Giza 716 x Nubaria 1 (C35) and Nubaria 1 x Giza 40 (C56) as promising five crosses. Then, GT-biplot method is considered as the best alternative analysis for giving a complete picture about the interrelationships among genotypes and traits (for relative comparing genotypes based on multiple traits). Hence, number of pods and seeds per plant traits could be used for the improvement of seed yield. Besides, five faba bean crosses were distinguished which possess genetic factors for high yield and highly promising to be employed in the development of high yielding populations of faba bean breeding programs.

Multi-locus phylogeny and pathogenicity of Stemphylium species associated with legumes in Australia

This study was initiated to elucidate the taxonomy and host range of Stemphylium species associated with leaf spot of faba bean in Australia. A three-locus phylogenetic analysis of 41 isolates collected from faba bean and other Fabaceae and Brassicaceae crops was constructed employing the internal transcribed spacers and the intervening 5.8S region of the nuclear ribosomal DNA, glyceraldehyde 3-phosphate dehydrogenase, and calmodulin sequences. The results indicated that more than one Stemphylium species occurs on faba bean (Vicia faba), chickpea (Cicer arientinum), lentil (Lens culinaris), and narrow-leafed lupin (Lupinus angustifolius) in Australia. Five Stemphylium species (S. astragali, S. beticola, S. eturmiunum, S. simmonsii, and S. vesicarium) were found associated with legume crops, of which S. astragali is a new report for Australia. Although isolates obtained from faba bean were retrieved within S. eturmiunum and S. vesicarium clades, those pathogenic to faba bean belonged to S. eturmiunum, a species not previously reported on faba bean. Interestingly, some S. eturmiunum isolates obtained from faba bean and other legumes were unable to infect faba bean, which indicated the potential presence of formae speciales within this species. The ability of S. eturmiunum isolates to cause plant death in susceptible faba bean varieties within only a few days emphasises the need for incorporation of Stemphylium blight resistance into faba bean breeding programs. Also, further research into the biology and epidemiology of the disease is warranted.

Photosynthetic and physiological responses of small seeded faba bean genotypes (Vicia faba L.) to salinity stress: identification of a contrasting pair towards salinity

In this study, we examined the behavior of six faba bean (Vicia faba L.) genotypes under salinity conditions at the seedling stage. The evaluation was assessed using 21 morphological, physiological, and photosynthetic traits under control, moderate, and severe salinity conditions. The principal component analysis (PCA) was used to identify genotypes of contrasting behavior in response to salt stress and to characterize the important traits for salt tolerance. The result of PCA analysis showed that the genotypes displayed different behavior under the saline conditions. The most discriminating quantitative characters were related to plant biomass production and photosynthesis, especially the mass of fresh root, number of leaves, water-use efficiency, and the substomatal CO2 concentration. The analysis of all parameters by PCA permits us to distinguish cv. Najeh as the most tolerant genotype for salinity conditions and cv. Chourouk as the most sensitive one. These results would be of pertinent tools in faba bean breeding programs.

Evaluation of Genetic Variability of Faba Bean (Vicia faba L.) Genotypes under Different Environments

The development of high yielding cultivars is a primary objective in most faba bean breeding program. This study is an attempte to evaluate sixty faba bean genotypes under different environment; Sids Research Station in Middle Egypt and Nubaria Research Station in North Egypt, during winter growing seasons 2014/2015 and 2015/2016.The experimental design was an alpha lattice with two replications. The combined analysis of variance over years were significant for most trait. The results for plant height showed that G2 and G50 had the tallest genotypes at Nubaria and Sids locations, respectively. The G42 recorded the highest values for number of pod, seeds and seed weight.plant-1 at Sids location, whereas, G18 genotype recoded the highest number of pods. Plant -1 at Nubaria location. G49 and G40 recorded the heaviest 100 seed weight at Sids location, while the genotype G51 had the heaviest value at Nubaria location. Regarding seed yield (ardab.Fad-1), the genotypes G27and G45 gave the highest values at Sids and Nubaria locations, respectively. The cluster analysis classified the tested genotypes in both locations to four main different groups, the first group had the highest seed yielding (ardab. fad-1), plant height and seed weight. Plant -1, followed by the third group cluster in the location Sids.

Characterization and diagnostic marker for TTG1 regulating tannin and anthocyanin biosynthesis in faba bean

Condensed tannins, found in coloured-flowering varieties of faba bean (Vicia faba L) are, after vicine and convicine, one of the major anti-nutritional factors for monogastric animals. The development of tannin-free cultivars is a key goal in breeding to broaden the use of this legume in the animal feed industry. Two recessive genes, zt-1 and zt-2, control the zero-tannin content and promote white-flowered plants. Previous studies exploiting synteny with the model Medicago truncatula reported a mutation in TTG1, a gene encoding a WD40 transcription factor located in chromosome II, as the responsible for the zt-1 phenotypes. Here a comprehensive analysis of VfTTG1 (including phylogenetic relationships, gene structure and gene expression) has been conducted to confirm the identity of the gene and to reveal structural changes that may result in different functional alleles. The results confirmed the identity of the candidate and revealed the existence of two different alleles responsible for the phenotype: ttg1-a, probably due to a mutation in the promoter region, and ttg1-b caused by a deletion at the 5′end of VfTTG1. Based on the sequencing results, an allele-specific diagnostic marker was designed that differentiate zt-1 from wild and zt-2 genotypes and facilitates its deployment in faba bean breeding programs.