Faba bean is grown mostly in cool season climates but also in sub-tropical regions over winter or spring [56]. It usually produces relatively high biomass as compared to other pulses and is typically more prone to moisture stress, particularly from the onset of flowering in shorter growing seasons [57]. Dryland production of faba bean is thus less reliable in climates that experience significant transient moisture stress or drought during vegetative growth. Under these conditions, the crop is short and produces only a few reproductive nodes [58].

Faba bean is highly responsive to irrigation [59] and relatively tolerant to water logging [60] compared to other pulse species. In Australia, this allows faba bean to be sown earlier in higher rainfall temperate climates to extend the length of the growing season and in wetter areas with duplex soils that are prone to water logging.

In Mediterranean and sub-tropical climates which have a short growing season, early sowing is essential to minimise yield losses from moisture- and high temperature-stress [61] during reproductive development. Early maturing cultivars are now available that can better avoid such stresses. In Mediterranean and temperate climates the crop is highly reliant on the in-season rainfall, whereas in sub-tropical farming systems sub-soil moisture can often supply sufficient water until at least the onset of flowering stage and early podding [62].

Genetic improvement has focused on directly screening for yield responsiveness and yield potential in water limiting environments. Physiological traits such as earliness to flower, higher harvest index and better disease resistance can improve tolerance to moisture stress during the reproductive period [63]. As the crop is very leafy, variation for better leaf turgor [64] may contribute to higher drought tolerance per se but needs to be better understood. There also may be potential to produce growth types that are more determinate in flowering (i.e., ti types) to reduce competition between reproductive tissue and the growing vegetative apex for assimilates [65].

In many dryland cropping regions, the utilisation of sub-soil water for plant growth and grain yield is compromised by increasing sodicity and soil salinity. Useful variation for tolerance to salinity appears to be present in faba bean [66,67] that could improve water use efficiency in the soil compared to other pulses. Faba bean does not appear to be as sensitive to high soil boron (commonly found in alkaline sub-soils) in terms of plant injury or biomass reduction [68] and hence, improved tolerance is not an objective of breeding programs.

Faba bean is grown widely across both low and high pH soil types and associated micro-nutrient deficiencies (e.g., Zn, Fe, Mo, Mg) can sometimes occur. Although genetic variation may exist for tolerance to such deficiencies, breeding is limited to evaluation in target environments as sufficient micro-nutrients are typically applied in fertiliser at sowing or later with foliar applications if symptoms appear.

As a cool season legume, high temperatures at flowering are likely to reduce pollen viability in faba bean, and interact with moisture stress to cause flower, ovule and pod abortion [69]. Potentially useful variation may be present at different reproductive growth stages following exposure to high temperature [70].

Faba bean pod walls are thick enough to protect developing ovules from cold injury which has allowed breeders to breed for earliness for autumn sown varieties. Vegetatively the crop can suffer physical cold injury and this is considered to be one of the main abiotic constraints for growing autumn-sown faba beans in cool temperate climates [71]. Screening in the field is difficult, but achievable with a reliable cold environment [72]. However, controlled environment screening may also be useful [71].

Faba bean is widely grown for both human consumption and stock feed. Export of dry grain is dominated by Australia, France and the UK. The import market of dry grain for human consumption is relatively small (the sum of world imports is less than 300,000 tonnes/year) compared to other pulses such as chickpea, lentil and field pea.

Dry faba bean grain is used for human consumption in diverse cuisines either as a whole or processed product such as medamis (stewed beans), falafel (deep fried bean/vegetable mix), bussara (bean paste) and nabet soup (boiled germinated grain). By far the main importer of dry grain for human consumption is the Middle East-Mediterranean region, particularly Egypt. However, faba bean is an important food in China, which is the largest consumer of the crop but mostly as a vegetable (i.e., green seed and pods), and across the Latin based cultures of the south Americas.

Grain is processed to produce canned, crushed, dehulled, split or flour products all of which have different grain quality requirements and end-uses. Flour can be used as a source of vegetable protein in meat extenders and starch is extracted to make vermicelli, noodles, dumplings and steamed bread in Asia. Whole dry grain is also sprouted in some Asian countries for consumption as a vegetable or used as whole grain in cooking.

For canning uniform grain size and high hydration capacity are needed to produce a high quality product. The preferred grain size is driven by regional preference. For example, the Egyptian market prefers the larger size of Australian product compared to that from the UK or France. However, Saudi Arabia prefers small sized grain. Though broad bean is a large sized dry grain imported by Mediterranean countries (e.g., Italy, Spain) at a premium price, the market size is relatively very small.

Seed coat colour can be important as grain is traded initially on visual appearance, even though it is of little significance for end use quality per se. A lighter colour (i.e., light buff) is generally preferred and discoloration caused by age of the grain (i.e., darkening) or weather or disease damage is poorly perceived and can lead to discounted prices or market rejection. Low light and temperature storage conditions for dry grain can delay the darkening discoloration [73]. However, useful genetic variation has also been identified in breeding. Variation for the unique bean flavour and interaction with growing environment is sometimes referred to by trade for regional markets. However, the merit of targeting this in breeding is questionable. Tannin free types are accepted for dry grain human consumption markets but are likely to taste (e.g., less astringent) and cook differently (i.e., hydrate quicker) to traditional types consumed and imported historically.

The animal feed markets use faba bean as a source of protein and energy [74]. Feeding studies show that faba bean is a good poultry feed with addition of supplemental methionine. The grain is also regularly used in feeding rations for pigs, dairy, beef cattle and sheep. Commercial faba bean grain has a protein content of around 24 to 30%, and there is scope for genetic improvement [75]. Variation for sulphur content of methionine and cysteine is low and there is a negative genetic correlation with seed protein content [76] limiting the effectiveness of classical breeding.

In Europe, the absence of polyphenolic substances (commonly known as tannins), as well as vicine and convicine, are breeding priorities because they decrease digestibility and biological value of the protein in animal feeding [77,78]. Dehulling is used to eliminate tannin mostly present in the seed coat and is of less importance than vicine and convicine which are thermostable and difficult to breakdown in processing. These glucosides can also trigger haemolytic anaemia or favism in humans that inherit Glucose-6-phosphate dehydrogenase (G6PD) deficiency. However, G6PD deficiency helps to protect against malaria [79].

Screening for zero-tannin genotypes is relatively easy as the absence of tannin in the seed coat is coded by two recessive genes, which act to block the synthesis of anthocyanin or anthocyanin’s precursors, and plants that are homozygous recessive at either locus, produce white-flowers and zero-tannin seed. Zero-tannin cultivars are now available in Europe (e.g., ‘Gloria’). However, the lack of plant anthocyanin may increase disease sensitivity of the crop at establishment and fungicidal seed dressing is needed [19].

Low vicine cultivars have been developed (e.g., ‘Mélodie’). The trait is monogenetic recessive and a morphological marker (white hilum) is known.

Breeding for animal nutrition is focused in Europe where subsidies aim to increase faba bean production and decrease imports of vegetable protein, particularly soybean, whereas higher value human consumption markets and reliable production are a greater priority in Australia.

Progenies from two faba bean crosses (Vf6 × Vf136 and 29H × Vf136) have been used to identify QTLs affecting ascochyta blight resistance. Vf136 is susceptible, Vf6 partially resistant and 29H resistant to ascochyta blight. Analysis of cross Vf6 × Vf136 against one isolate of A. fabae indicated a polygenic control determined by at least two QTLs (Af1 and Af2), assigned to chromosomes III and II that explained 21 and 25% of the variability, respectively [88]. In a parallel study, in cross 29H × Vf136, 6 QTLs named Af3 to Af8 were detected for resistance against two different isolates of A. fabae in stems and leaves. However, only Af3 and Af4 were effective against both isolates on both stems and leaves [89]. Interestingly, Af1 [90] and Af3 [89] were both assigned to chromosome III and might correspond to the same genomic regions.

QTL mapping studies should be independently confirmed in different genetic backgrounds and environments to demonstrate that DNA markers identified in one population are useful in different pedigrees [83]. To date, only a small fraction of the QTLs identified for important plant traits have been independently tested for confirmation. The validation may involve replication studies in independent populations (in particular, recombinant inbred lines, RILs), constructed from the same parental genotypes or with closely related genotypes used in the primary QTL mapping study [94]. In faba bean, this approach was recently carried out by studying 165 RILs developed by single-seed descent from the cross Vf6 × Vf136 [91]. The new molecular map allowed detecting Af1 and Af2 on the same chromosomes, explaining a similar percentage of the phenotypic variation. Fifteen common markers facilitated the comparison of homologous regions between maps and confirmed the occurrence of QTLs for ascochyta blight resistance in independent populations (F₂ and F₆) for the first time.

The prospects of MAS for ascochyta resistance in faba bean breeding programs will depend on the extent to which QTL results can be extrapolated from one population to another. This fact is being pursued by developing a new map in the RIL population from the cross 29H × Vf136. A number of common standard markers (SSRs and gene based markers) are being genotyped, in order to confirm the QTLs across generations (F₂ and RIL) and further to validate additional QTLs across different genetic backgrounds. Moreover, regions bearing stable QTLs are being saturated in both maps as a first step towards the development of reliable molecular markers useful for disease resistance selection.

Rust resistance is race-specific and monogenic, implying that the use of single resistance genes in cultivars would likely result in non-durable resistance [32,95]. Gene pyramiding of different sources into a single cultivar is known to increase the durability of this type of resistance [96]. MAS of markers tightly linked to different resistant genes would greatly facilitate this process. Bulked segregant analysis has been used to detect RAPD markers tightly linked to the gene causing hypersensitive resistance to rust (race 1) in the inbred line 2N52 [87]. Three RAPD markers (OPD13₇₃₆, OPL18₁₀₃₂ and OPI20₉₀₀) in coupling phase with the gene (Uvf-1) were mapped in 55 F₂ plants. No recombinants between OPI20₉₀₀ and Uvf-1 were detected. Two additional markers (OPP02₁₁₇₂ and OPR07₉₃₀) were linked to the gene in repulsion phase at a distance of 9.9 and 11.5 cm, respectively [87]. However, these markers have not been adopted in any breeding programs.

The first study to identify QTLs controlling broomrape resistance in faba bean was conducted using an F₂-derived population of a cross between the resistant line Vf136 and the susceptible line Vf6 [97]. Vf136 derives from a cross between the Spanish cultivar “Alameda” and Vf1071, a resistant line selected from Giza 402 and one of the main sources of broomrape resistance [98,99]. Three QTLs (named Oc) were identified, suggesting that broomrape resistance in faba bean is a polygenic trait with major effects from a few single genes. Oc1, Oc2 and Oc3 were assigned to chromosome I, chromosome VI and linkage group 11, respectively, and collectively explain 74% of the total phenotypic variance (37.3%, 11.3% and 25.5%, respectively). All the resistance-enhancing alleles originated from the resistant parent Vf136. Oc1 and Oc3 had considerable dominant effects, whereas Oc2 displayed purely additive gene action [3].

In order to validate the QTLs identified in the F₂ population, 165 RILs (F₆ generation) from the cross Vf6 × Vf136 were used to construct a new linkage map with a wide genome coverage [91]. To confirm the position and effects of the three QTLs identified in F₂, validation experiments were carried out using the F₆ progeny in three environments. Oc1, the major QTL identified in F₂ and explaining the highest percentage of the phenotypic variance, was not further detected in the RILs in any of the environments [91]. This is probably due to overdominance displayed by the QTL in the F₂. Dominance ebly due to overdominance displayed by the QTs generation but are absent in RILs. Moreover, some QTLs detected in early generations of maximum linkage disequilibrium are indeed due to multiple linked genes that may be separated via recombination [100], which could also explain this outcome. Indeed, two additional QTLs (Oc4 and Oc5) with small effects (17% and 9%) were detected in the same linkage group as Oc1, which is ascribed to chromosome I. Both QTLs were only expressed in one of the environments. Variations in the level of infestation and/or weather conditions could have contributed to differences in gene expression between environments.

In contrast to Oc1, both Oc2 and Oc3 showed consistency between F₂ and F₆ generations [3] since they were detected in at least two of the three environments confirming their environmental stability and pointing to their suitability as future targets for MAS [91].

The information available so far, especially that for resistance to Ascochyta and crenate broomrape, reveals the potential use of molecular markers for indirect selection for resistance in faba bean. Depending on their relative effects and position, some of the QTLs could be used in MAS approaches, after saturation of target regions to refine QTL position and identify the marker most closely linked to the resistance genes. Recent unpublished advances are integrated in Table 1.

Vicine-convicine content may decrease up to 20 times due to the presence of the vc-allele that is linked to colourless hilum in the seeds [101]. RAPD markers linked to the recessive allele (vc-) were identified by analysing an F₂ population derived from a cross between Vf6 and the vc-genotype [102]. Two RAPDs linked in coupling and repulsion phase to the vc-allele were identified and converted into SCARs (Sequence Characterized Amplified Regions). The loss of the initial polymorphism between pools was resolved by restriction analysis with HhaI for SCAR SCH01₆₂₀ and RsaI for SCAR SCAB12₈₅₀, polymorphic between the parental lines. The simultaneous use of these CAPS (Cleavage Amplification Polymorphic sequences) allowed the accurate fingerprinting of the vc-allele in faba bean lines and could facilitate the development of cultivars with low vicine-convicine content and improved nutritional value although the simple visual assessment of hilum colour would remain as most cost effective (Table 1).

Tannin: Two recessive genes, zt-1 and zt-2, control the absence of tannins in faba bean seeds, generating white flower plants [103,104]. Four RAPD loci (OPC5₅₅₁, OPG15₆₀₀, OPG11₁₁₇₁ and OPAF20₇₇₆) were identified that are tightly linked to zt-1 [13]. Two SCARs were developed, SCC5₅₅₁ associated to white flowers and zero tannin content and SCG11₁₁₇₁ linked to coloured flowers and high tannin content. The genotyping of both markers in 37 faba bean lines differing in flower colour and tannin content resulted in a 95% selection efficiency of the zt-1 genotypes [13]. The same strategy was used to identify a cost-effective marker linked to zt-2 [14]. Five RAPD markers linked in coupling and repulsion phase to the gene were identified and further converted into SCARs, although the initial polymorphism was lost. Restriction of the SCAR SCAD16₅₈₉ with AluI (SCAD16-A), Bsp120 (SCAD16-B) and HinfI (SCAD16-H) revealed differences due to the amplification of different loci. The consensus sequence of these CAP (Cleavage Amplification Polymorphism) revealed three bands, from which two new forward SCAR primers were developed based on the specific sequences from zero tannin and high tannin genotypes. A multiplex PCR was further developed to improve the efficiency of the marker screening with the same advantages as a co-dominant marker.

The SCAR markers linked to zt-1, zt-2 and vc- will facilitate gene pyramiding in the production of faba bean cultivars with improved nutritional value for human and animal consumption. However, simple phenotypic measure of hilum and seed coat colour, possibly used with mass selection using electronic colour sorters would be a far more rapid, cheaper and easier way to select for recombinants that contain all genes of interest.

Compared with the bulked segregant analysis, the use of a candidate gene approach potentially allows the development of diagnostic or perfect markers that are completely linked to the selected trait. This approach is only possible when the target gene is well characterized in the species or in related species carrying orthologous genes. Commonly, the co-dominant nature of these markers facilitates the identification of both homozygous and heterozygous individuals. This strategy has been used to develop molecular markers linked to growth habit in faba bean.

A gene determining growth habit (CEN) was first cloned in Antirrhinum, and later several orthologous CEN/TFL1-like genes were identified in Arabidopsis, tomato, tobacco, pea, citrus, apple and other fruit species. Based on this information, an orthologue of CEN/TFL1 responsible of the growth habit in faba bean was identified and a CAPS marker based on a SNP (single nucleotide polymorphism) was developed at position 469 of the intron 2–3 [10]. This marker failed to detect some determinate genotypes since the SNP was a silent mutation. Further investigation allowed the development of a dCAPS marker based on a SNP associated with an amino acid change (Leu-9 to Arg) in the determinate growth habit genotypes. This new diagnostic marker was able to discriminate the gene of interest in a broad range of cultivars historically grown in Europe [11]. Although interesting research, these findings are unlikely to substitute for visual assessment of growth habits in early generation breeding where many other genes and combinations of gene are appraised and selected.

So far, marker research has been towards academic research rather than application and has not delivered benefits to breeding either in efficiency or effectiveness of selection. Unless research is closely linked to breeding and target traits are those where markers offer a significant advantage over existing phenotyping methods, the markers will not be implemented in commercially focused faba bean breeding programs.

Until recently, most legume crops were categorized as ‘genomic orphans’ due to the lack of enriched genetic and genomic resources [105]. Therefore, most of the genetic and genomic studies within legumes have been based on comparative genomics with Medicago truncatula. Nevertheless, significant efforts have been made recently to enrich genetic and genomic resources for lentil [106], field pea and faba bean [107]. A large number of DNA based markers have now been developed, which can be used to understand the genetics of faba bean as well as for comparative genomic studies.

Within Fabaceae family, M. truncatula and Lotus japonicus have been extensively studied at genetic and genomics level as: (i) they have small genome sizes (500 Mbp and 470 Mbp, respectively) and relatively short life cycles [108]; (ii) a large number of germplasm collections are available for them that might be useful to look for genetic polymorphisms and to study various important traits. As a result, (i) several genetic linkage maps are available for both species [109,110,111]; (ii) whole genome sequencing projects have been undertaken for these species, providing the opportunity to identify putative orthologous gene sequence resources in other crop legume species, especially those located within the Galegoid clade (Figure 1) of the Fabaceae sub-family Papilionoideae [104]; (iii) several transcriptomic and proteomic tools have been developed in both model legumes [112,113,114]. All of the genomic and genetic resources developed in these model legume species can be used across other legume species such as faba bean, lentil, field pea and chickpea for comparative analysis (Figure 1).

Comparative mapping and genome analysis can help to understand conservation and differences in gene content and order among different taxa. The development of the Legume Information System (LIS; [115]) integrates genetic and physical map data and enables macrosynteny analyses to be carried out between legume species. The initial evidence of existence of macrosynteny between legume species was provided by comparison of genetic linkage maps of lentil and chickpea to field pea that indicated the presence of eight and five large syntenic blocks, respectively [116]. Comparisons between pea and M. sativa also revealed a significant conservation of the gene order in these two species [117]. Comparisons between M. truncatula and L. japonicus indicated that both genomes share at least 10 syntenic blocks among themselves [118].

The genome of M. truncatula has been used as a reference for comparative mapping and to develop intron targeted gene based anchor markers for legume species [119]. These markers were used to study macrosyntenic relationships between lentil, chickpea, field pea, faba bean, lupins and common bean. Other comparative genomic studies also revealed that co-linearity exits between legume species to different extents depending on their phylogenetic distances. Though the genome size of faba bean is about 25-fold larger than the genome of M. truncatula, large-scale genome conservation is expected as both M. truncatula and V. faba belong to same clade. Hence, a comparative genetics approach between these two species would be useful. A composite genetic map of faba bean has been constructed [120] and intron-targeted gene-based markers have been developed and tested for faba bean. A total of 796 intron targeted amplified polymorphic markers were used to construct a comparative genetic map of faba bean and a simple and direct macrosyntenic relationship between faba bean and M. truncatula was observed [5]. This study also provided evidence for no polyploidisation, segmental duplication, or significant rearrangements in faba bean genome even though the genome size is massively large [5].

The high level of synteny that exists between most legume genomes should allow an efficient transfer of acquired knowledge in these model legumes to improve other poorly studied legume species such as faba bean. Recently, the whole genome of soybean (Glycine max) has been sequenced, which is proving to be very useful to provide further insights into legume genetics and biology [121]. Also, candidate genes identified by transcriptomic, proteomic or map-based cloning can be transferred to elite cultivars of faba bean after validation of its function through genetic transformation. Thus, comparative genomics has assisted in understanding the faba bean genome but has not delivered candidate genes from which novel genotypes or molecular markers can be developed and incorporated into breeding.

Functional genomics studies in faba bean are scarce, mostly academic and not directly related to crop improvement. Faba bean was used as a model plant to study stomatal movement [122,123,124,125]. An ABA-activated and Ca²⁺-independent protein kinase (AAPK) was identified involving in ABA action in guard cells [126]. A fia (faba bean impaired in ABA-induced stomatal closure) mutant in which the stomatal movement was disturbed was also identified in faba bean [127].

Full length cDNAs encoding three amino acid permeases were isolated from seed-specific libraries of faba bean [128]. The predicted proteins VfAAP1, VfAAP3 and VfAAP4 share up to 66% identity among themselves. Functional characterization of VfAAP1 and VfAAP3 showed that these permeases transport a broad range of amino acids [128]. However, VfAAP1 had a preference for cysteine and VfAAP3 for lysine and arginine. Cysteine repressed the expression of the GUS reporter gene under control of the VfAAP1 promoter, indicating that this transporter is modulated at the transcriptional level [128].

Legumin amounts to approximately 55% of the seed protein in faba bean and it is a representative of the 12S storage globulin family. The 12S storage globulins are hexameric holoprotein molecules composed of different types of polymorphic subunits encoded by a multigene family [129]. In faba bean, isolation of at least a vicilin gene [130] and of four legumin genes have been reported [131]. The subunits of both legumin and vicilin were found to have a wide range of heterogeneity [131]. For example, legumin was found to be composed of 29 disulphide-linked subunit pairs with different molecular weight and/or isoelectric point, while vicilin composed of as many as 59 subunits with different isoelectric points [131].

Faba bean is an excellent candidate crop to study the genetic basis for nitrogen input into temperate agricultural systems [116,132]. A cDNA library derived from root nodules was used to investigate nodule-specific clones in faba bean [133,134]. VfSUCS was found to encode a sequenced sucrose synthase and served as a source of energy in symbiotic nitrogen fixation [135]. VfNOD32 encodes a nodulin with sequence similarities to chitinases [124]. Some faba bean nodulin genes encoded glycine-rich proteins [136]. The faba bean leghemoglobin gene VfLb29 was specifically active in the infected root nodules and in arbuscule-containing cells of mycorrhizal roots. Its promoter was used to test the infected activity in root nodule cells and in the arbuscule-containing cells of mycorrhizal roots from different legume and nonlegume plants [137,138,139]. The information outlined shows that functional genomics has as yet had no impact on faba bean breeding internationally.

The investigation of in vitro regeneration of faba bean has been extensive since 1960s. The first attempts to cultivate faba bean in vitro focused on the optimal growth of callus tissue or suspension cultures rather than the induction of shoot morphogenesis and plant regeneration [143,144,145]. The influence of media composition and explant source on the initiation and maintenance of cultures were tested and the conditions optimized for maximum increase in callus fresh weight. The morphogenic potential of faba bean cells cultured in vitro was low [146]. To develop a system for plant regeneration from single cells, callus and cell suspension cultures were established over a long period of time, but all attempts to initiate shoot regeneration remained unsuccessful. A serious constraint in faba bean tissue culture is the deterioration of explant material and cultivated tissue as a result of the action of phenolic compounds. The effect of various chemical and physical parameters in axillary shoot cultures was examined and low temperatures were found to limit the formation of phenolics [147,148]. Plantlet regeneration from explants lacking pre-existing shoot meristems was first claimed by [149].

After the protoplasts were isolated from leaves and shoots [150,151] and suspension cells [152], the regeneration of faba bean plant from protoplasts was reported [153]. Somatic embryogenesis in callus and suspension cultures derived from immature cotyledons of faba bean [154], a protocol in which plantlets derived from somatic embryos could be grown to maturity [155] and an improved protocol combined with the Agrobacterium tumefaciens-mediated gene transfer [156] were subsequently been achieved.

Several investigators worked extensively on faba bean transformation and regeneration of transgenic plants [157,158,159,160,161]. The first attempts to transfer foreign genes into faba bean were attempted using Agrobacterium rhizogenes containing the binary vector pGSGluc1 carrying nptII and uidA genes under the control of the bidirectional TR1/2 promoter [160]. Beta-glucuronidase (GUS)-positive roots and subsequently transgenic calli lines were obtained. A similar study using an A. rhizogenes strain containing pBin19 for inoculation of faba bean cotyledons and stem tissue led to successful transfer of the nptII marker gene [161]. However, no transgenic faba bean plants were regenerated in any of these studies. The lack of an efficient protocol for the regeneration of transgenic plants was the main obstacle to faba bean transformation. Bacteria carrying shooty types Ti-plasmids, pGV2215 and pGV2235, were tried but neither of the two mutants appeared to improve regeneration [157]. Finally, the first transgenic faba bean plants were recovered from transformed tissues through de novo regeneration using thidiazuron (TDZ) [162]. The second successful protocol was based on direct shoot organogenesis from meristematic cells of mature or immature embryo axes [163].

The two successful studies demonstrated that transgenic approach could be used to improve protein quality in faba bean, and the bar gene (PPT acetyltransferase) could be effectively used as a selective agent of transgenic individuals, instead of the unpopular antibiotic resistance. Though the major hindrances in generating transgenic faba bean plants have been overcome, the number of transgenes that have been introduced into the faba bean genome is still limited. There are numerous traits that would be suitable for improving faba bean yield and nutritional quality. However, to complete the whole procedure of generating a commercial faba bean line, starting with the newly developed transgenic plant, then outcrossing the new trait into economically valuable genotypes, and eventually getting the approval for registration of the transgenic line, could take many years to achieve [164]. Furthermore, the acceptance of transgenic faba beans in the international marketplace, particularly Egypt, is unclear and therefore risky to pursue for large exporters such as Australia or the European Union.