Faba Bean Genotypes Research Articles

Assessment of Eight Faba Bean (Vicia faba L.) Cultivars for Drought Stress Tolerance through Molecular, Morphological, and Physiochemical Parameters

Determining and improving drought-tolerant cultivars is a major goal of plant breeding to face climate change. The productivity of faba bean in Egypt is affected by abiotic stresses, especially drought stress. This study evaluated eight Egyptian faba bean cultivars for drought tolerance under three soil water regimes consisting of well-watered (100% field capacity), moderate drought stress (50% field capacity), and severe drought stress (25% field capacity) regimes in pots under greenhouse conditions using biochemical, physiochemical, and molecular parameters. The cultivars Nubariya 1, Nubariya 3, and Giza 716 showed the highest proline content values under 50% field capacity conditions, with 4.94, 4.39, and 4.26 mmol/g fresh weights, respectively. On the other hand, the cultivars Sakha 1, Sakha 4, Nubariya 1, and Nubariya 3 exhibited the highest proline contents (7.8, 7.53, 6.17, and 6.25, respectively) under 25% field capacity treatment. The molecular profiling was conducted using SCoT and SRAP approaches. Fresh leaves were utilized to extract the DNA, and ten primers for SRAP and six for SCoT were used in the PCR procedures. SCoT and SRAP-PCR generated 72 loci, of which, 55 were polymorphic, and 17 were monomorphic. SCoT and SRAP each had 48 and 24 total loci, respectively. The average polymorphism (%) values achieved via SCoT and SRAP were 70.93% and 80%, respectively. Based on the molecular profiles, the cluster analysis identified three clusters. The first cluster comprised Giza 716 cultivars; the second cluster included Sakha 1, Sakha 3, Sakha 4, and Akba 3300 cultivars; the third cluster comprised two cultivars Nubariya 1 and Nubariya3. According to the study’s findings, Sakha 1, Sakha 4, Nubariya 1, and Nubariya 3 are remarkable parents for developing drought-tolerant faba bean genotypes. Additionally, this study concluded that SRAP and SCoT markers recreated trustworthy banding profiles to evaluate the genetic polymorphism among faba bean cultivars, which are regarded as the cornerstone for genetic improvements in crops.

Accumulation of Minerals in Faba Bean Seeds and Straw in Relation to Sowing Density

Faba beans (Vicia faba L.) are a high-protein legume crop that can be widely cultivated in most climates in Europe. The amino acid composition of the faba bean protein is also beneficial for monogastric animals since it contains a great deal of lysine, an amino acid that is deficient in cereals. Two genotypes of faba beans were cultivated at three sowing densities (45, 60 and 75 seeds per m2) during three growing seasons (years 2013–2015). The aim of the research was to assess accumulation of nutrients (N, P, K, Ca and Mg) of two faba beans in seeds and straw under different sowing densities. A field experiment was conducted in 2013–2015 at fields of Wroclaw University of Environmental and Life Sciences in southwestern Poland from which plant material was used for chemical analysis in terms of determining the accumulation of the following elements—N, P, Mg, K and Ca—in the seeds and straw. The results showed that the genotypes of the faba bean varied greatly in accumulation of nutrients in various sowing densities and in following years of research. However, the average accumulation of nitrogen, calcium and magnesium in seeds for three years (2013–2015) was significantly higher in the Bobas cultivar under 60 seeds per m2 as well as in both tested cultivars using 75 seeds per m2. Accumulation of potassium and phosphorus in seeds was highest in both analyzed cultivars using 60 and 75 seeds per m2 (average for 2013–2015). Considering accumulation of elements in the straw of faba bean, it is shown that the concentration of potassium and calcium was the highest in both tested cultivars under the effect of sowing density at 60 and 75 seeds per m2 while the concentration of nitrogen, phosphorus and magnesium did not differ significantly as an effect of the interaction of cultivar and sowing date (average for 2013–2015). Weather conditions played an important role in accumulation of nutrients of both faba bean genotypes in the years of research (2013–2015).

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.

Evaluation of Resistance to Leaf Spot Diseases and Yield Characteristics in Faba Bean Genotypes through Cluster Analysis and Genotype by Trait Biplot

Evaluation of Resistance to Leaf Spot Diseases and Yield Characteristics in Faba Bean Genotypes through Cluster Analysis and Genotype by Trait Biplot

Performance of Some Faba bean Genotypes for Tolerance to the Infestation of Broomrape (Orobanche crenata) Weed

Performance of Some Faba bean Genotypes for Tolerance to the Infestation of Broomrape (Orobanche crenata) Weed

Intercrops as foraging habitats for bees: Bees do not prefer sole legume crops over legume-cereal mixtures

Enhancing crop diversity is an option to make agriculture more sustainable and biodiversity friendly. Intercropping grain legumes together with cereals leads to higher crop diversity and has a broad range of agronomic and ecological benefits. However, sole crop stands of grain legumes might be richer in floral resources than grain legume-cereal intercrops and thus are probably more useful to mitigate the lack of flower resources in agricultural landscapes, which is a main driver of pollinator decline. Yet, little is known about differences between both cropping systems and different legume genotypes in terms of attractiveness for pollinators and how these differences moderate the pollinators’ foraging behavior and consequences for grain legume yields. In a field trial, we analyzed the abundance of flower visiting insects, the foraging behavior of pollinators and related effects on grain yield per plant across six different faba bean genotypes (Vicia faba L.) grown as sole crops or as intercrops with wheat. As foraging behaviors, we considered legal flower visits (i.e. frontal visits) and illegal flower visits (i.e. nectar robbing through bite holes). We recorded characteristics of V. faba genotypes on crop stand level (V. faba plant height, number of V. faba inflorescences and leaf area index (LAI)). V. faba-wheat intercrops and sole crop stands of V. faba were equally attractive foraging habitats for pollinators, implying that intercrops are as suitable as sole crops to mitigate the lack of floral resources. Yield per V. faba plant was positively affected by bee pollination, with this effect being determined by the number of illegal flower visits, suggesting that this foraging strategy does not adversely affect V. faba yields and even has a positive effect. Intercrops had higher yields per V. faba plant than sole crop stands of V. faba, indicating agronomic advantages of this farming practice. Although V. faba genotypes differed in their plant traits, these differences could not explain shifts in the number of flower visiting insects. However, illegal flower visits increased with a higher number of inflorescences whereas the number of legal flower visits declined. Based on our small-scale experiment, we conclude that the use of V. faba-wheat intercrops brings agronomic benefits while serving as a foraging habitat for pollinators that proved to be as attractive as sole crop stands of V. faba.

Assessment of drought tolerance indices in faba bean genotypes under different irrigation regimes.

Drought stress has devastating impacts on faba bean production, particularly with the current abrupt climate changes in arid environments. Hence, it is essential to identify drought-tolerant genotypes. The present study aimed at assessing six faba bean genotypes under three irrigation levels during two winter successive growing seasons (2018/2019 and 2019/2020). The applied irrigation levels were well-watered (every 4 days (D1), moderate drought every 8 days (D2), and severe drought 12 days (D3)) regimes. The analysis of variance exhibited highly significant differences among genotypes, irrigation treatments, and their interactions for all studied traits, except the number of pods plant-1 in the first season. Yield traits of all assessed genotypes decreased significantly with increasing drought stress. Otherwise, proline content (Pro) increased significantly with increasing drought stress. The genotypes Giza.843, Nubaria.2, and Nubaria.3 recorded the highest values of plant height, number of branches/plant, pods/plant, pods weight/plant, 100 seed weight, seed yield/plant, and seed yield/kg under drought stress. Similarly, the highest Pro was displayed by Giza.843 and Nubaria.3 under drought stress in both seasons. Furthermore, Giza.843, Nubaria.2, and Nubaria.3 genotypes had the highest values for most tolerant indices. Accordingly, these genotypes could be exploited in developing drought-tolerant and high-yielding faba bean genotypes in arid environments through breeding programs.

Salinity Stress and the Influence of Bioinoculants on the Morphological and Biochemical Characteristics of Faba Bean (Vicia faba L.)

Faba bean (Vicia faba L.) is an economically important crop cultivated globally for fulfilling human requirements. However, the productivity of the faba bean has declined due to poor management of soil, particularly under salt stress. Salt stress is a major constraint to crop productivity worldwide. Therefore, the objective of the present investigation is to check the behavior of faba bean genotypes on the basis of morphological and biochemical traits in response to salinity. In this study, we studied seven different treatments (including control) applied to faba bean under salt stress. Bioinoculants such as Trichoderma viride, Pseudomonas flourescens, Glomus mosseae, and Gigaspora gigantean, each separately and in combination, were tested for their efficacy under salinity stress. Data recorded on days to flowering (48.92 ± 1.15), days to maturity (144.56 ± 1.95), plant height (141.93 ± 4.81 cm), number of branches per plant (4.87 ± 0.09), number of clusters per plant (18.88 ± 0.24), number of pods per plant (48.33 ± 1.06), pod length (5.31 ± 0.02 cm), catalase (222.10 ± 2.76 mg), hydrogen peroxide (24 ± 4.58 mol/g), malondialdehyde (45 ± 1.00 mol/g), electrolyte leakage (54.67 ± 5.03), chlorophyll (51.67 ± 3.06 mg/g), proline content (2.96 ± 0.12 mg/g), and on other parameters indicated the combined inoculation of all the species (consortium) was taken to be highly effective even under salt stress. Overall, the consortium treatment comprising all of the bioinoculants was observed to be the most efficient treatment in improving all the morphological and biochemical traits of faba bean under salt stress. Although, other treatments also demonstrated considerable effects on faba bean as compared to one without bioinoculants under salt stress.

Acid Soil Resistance of Faba Bean (Vicia faba L.) Genotypes in the Highlands of Dawro Zone, Southwest Ethiopia

Soil acidity and its driven soil fertility problems are causing wide gap between actual farmers yield and research yield in faba bean in the highlands of Dawro zone and Ethiopia

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.

Radiosensitivity of seedling traits to varying gamma doses, optimum dose determination and variation in determined doses due to different time of sowings after irradiation and methods of irradiation in faba bean genotypes

Purpose Three experiments were conducted to assess the effect of different doses of gamma radiation on various seedling traits; determine the optimum doses of gamma radiation for different faba bean genotypes; find out the variation in optimum doses with respect to the different times of sowings after irradiation and methods of irradiation. Materials and methods Five faba bean genotypes viz., L-2013-060, L-2013-092, Anandnagar Local, Gazipur Local and Bangla Gangachar were used in these experiments. In Experiment I, seeds of five experimental genotypes were exposed to different doses (100 Gy 200 Gy, 300 Gy, 400 Gy, 500 Gy, 600 Gy, 700 Gy and 800 Gy) of gamma radiation and were sown immediately after irradiation. In Experiment II, seeds of Bangla Gangachar and L-2013-060 were exposed to varying doses (100–800 Gy) of gamma radiation and were sown at seven sowings starting from 0 h to 24 h at 4-h intervals after irradiation. In Experiment III, L-2013-092 genotypes was exposed to different doses (100 –800 Gy) of gamma radiation with two different methods of irradiation. Results In Experiment I, the lethal dose 50 (LD50) values have arrived at 140 Gy, 669 Gy, 575 Gy, 386 Gy and 158 Gy for L-2013-060, L-2013-092, Anandnagar Local, Gazipur Local and Bangla Gangachar, respectively. The growth reduction 50 (GR50) doses for different seedling traits ranged from 130 Gy to 320 Gy for L-2013-060, 250 Gy to 480 Gy for L-2013-092, 130 Gy to 370 Gy for Anandnagar Local, 200 Gy to 350 Gy for Gazipur Local and 250 Gy to 400 Gy for Bangla Gangachar. In Experiment II, the values for LD50 of the genotypes Bangla Gangachar and L-2013-060 were significantly singular for different time intervals of sowing. The values of GR50 for most of the seedling traits were found to increase with the delay in sowing after irradiation from 4 to 24 h when compared with the immediately sown seed lots. In Experiment III, LD50 for L-2013-092 was 337 Gy with Method 1 and 669 Gy with Method 2. In Method 1, most of the growth parameters attained GR50 doses lower than Method 2. The first method was found to increase the radiosensitivity of L-2013-092. Conclusion Every experimental genotype used in these three experiments showed dose-dependent retardation of different seedling traits. These optimized doses may be employed to establish mutant populations for exploiting the novel traits of faba bean. The time of sowing after irradiation and method of irradiation was found to be essential for confirming optimum doses.

Genetic Variability and Character Associations of Faba Bean (Vicia faba L.) Genotypes, Southeastern Ethiopia

Faba bean is an important legume crop because of its high‐yield potential and nutrition-dense grains. This study was conducted to determine variability, heritability, and correlation between yield and yield components in 22 faba bean germplasm accession. The trial was conducted with RCBD design across two locations in the 2015/16 main cropping season. The ANOVA result showed significant variation among genotypes with p&lt;0.05. The genotype by environmental interaction result showed significant difference p&lt;0.05 on chocolate spot among genotypes in the trial. The minimum grain yield was recorded at 2380.8kgha-1 from genotype 17 and the maximum grain yield was recorded from genotype 5(5598.1kgha-1). The genotypic and phenotypic coefficient of variation ranged from 2.91 to 15.64 and 3.23 to 23.42 respectively. Moderate phenotypic and genotypic coefficients of variation were recorded from grain yield and thousand seed weight, while days to maturity, plant height, and the number of seeds per pod recorded lower phenotypic and genotypic coefficients of variation. Days to 50% flowering, days to maturity, and thousand seed weights were recorded as higher estimates of heritability. Thousand seed weights showed higher estimate of heritability along with high genetic advance. For the future breeding strategies, this information helps the researcher to improve faba bean genotypes.

Effect of Phosphate Fertilization on the Growth and Yield of Three Genotypes of Faba Bean( Vicia faba L.)

A field experiment was carried out in the winter season 2020-2021 in Al- Bualwan area of Fallujah District - Anbar Governorate to study the effect of phosphate fertilization on the growth and yield traits of the faba bean crop. The experiment was applied using a randomized complete block design (RCBD) according to the split-plot arrangement with three replications. The main plots included three levels of phosphate fertilization (0, 60, 120) kg P2O5 h-1, while the sub plots included three faba bean genotypes (American, Italian, and Dutch). According to the study levels, phosphate fertilizer was added in one batch before planting. The most important results were the following: The American genotype superiority in growth and yield traits, giving the highest average for each plant height( 95.63) cm, number of branches (10.11 ) branch plan-1 , leaf area per plant( 1053) cm2 plant-1, number of pods( 17.50 )pod plant-1, number of seeds per pod (6.11) seed pod-1, the weight of 100 seed (96.06) g and the total seed yield is( 4.168) tons ha-1. The effect of phosphate fertilizer was significantly in most of the studied traits. The level 120 kg P2O5 ha-1 gave the highest average for each of the plant height( 94.00) cm, number of branches( 9.83) branch plant-1, leaf area of the plant (2342) cm 2 plant-1, number of pods (17.83) pod plant-1, weight of 100 seed( 95.44) g and total seeds yield( 4.078) tons ha-1. There was a significant interaction between the American genotype and the level of 120 kg P2O5 ha-1 of phosphate fertilizer in plant height, number of branches per plant, leaf area, number of pods per plant and weight of 100 seeds.

Agronomic Performance of Broomrape Resistant and Susceptible Faba Bean Accession

The faba bean (Vicia faba) is a temperate grain legume, that is regaining interest due to the high demand for food and feed uses and the environmental services provided. The parasitic weed broomrape (Orobanche crenata) appears as the major constraint to agricultural production in the Mediterranean Basin. The yield stability can be managed by adjusting agronomic practices and breeding for adaptation. In this study, we compared the performance of three susceptible faba bean accessions with that of eight lines previously selected for their broomrape resistance, in multi-environment field trials. Results confirmed that the grain yield in the region was negatively affected, mainly by broomrape infection, followed at a distance by ascochyta blight (Ascochyta fabae), whereas the grain yield was little affected by the low occurring levels of chocolate spot infection (Botrytis fabae). The yield was favored by rain at flowering and was reduced by low temperatures at pre-flowering and flowering, and by high temperatures at flowering and grain-filling. The combined ANOVA showed significant effects of the genotype, environment, and genotypex environment interaction. The weighted average of the absolute scores biplot (WAASB), a heat map with 21 scenarios based on the WAASB ratio and the multi-trait stability index (MTSI) were utilized to determine the mean performance and stability of the faba bean genotypes. Quijote, Navio6, Baraca and FaraonSC are proposed as ideal lines for cultivation in the region and to be further used in future breeding programs.

Biplot analysis of non parametric measures of stability for long term evaluation of fababean genotypes

Non parametric measures of stability were compared based on ranks of faba bean genotypes evaluated for the period of long term in the country. High yielding genotypes were HB13-48, HB13-10 and HB13-46 also selected by the Geometric Adaptability Index (GAI) along with larger values of Harmonic means (Har). Measure Si1 selected HB13-11, Vikrant and HB13-48 as opposed to HB13-15, HB13-6 and HB13-9 by Si2 values. Vikrant, HB13-9 and HB13-6 genotypes considered by Si3 and Si4 measure selected HB13-15, Vikrant and&nbsp; HB13-9 faba bean genotypes. The next two Si5andSi6 pointed towards HB13-15, Vikrant and HB13-49 genotypes, while Si7pointed for HB13-15, Vikrant and HB13-9 genotypes.&nbsp; Measure based on ranks as per corrected yield of genotypes CSi1 selected HB13-15, HB13-9 and HB13-38, while CSi2&nbsp; found HB13-15, HB13-9 and HB13-6 as suitable candidates, while values of&nbsp; CSi3&nbsp; settled for HB13-15 HB13-9 and HB13-6 genotypes. Measure CSi4 identified HB13-15, HB13-9, HB13-6 &nbsp;and CSi5 pointed towardsHB13-15, HB13-38 and HB13-43, while CSi6 observed suitability of HB13-15,&nbsp; HB13-9 and HB13-26 and lastly CSi7 values identified HB13-15, HB13-9 &nbsp;and HB13-38 genotypes. Composite measures consider the ranks of genotypes as per yield and corrected yield simultaneously, values of NPi(1) measure the observed suitability of HB13-11, HB13-38 and HB13-43.Whereas, as per NPi(2) valuesHB13-15, HB13-9 and&nbsp; HB13-18&nbsp; would be genotypes of choice, while NPi(3)&nbsp; identifiedHB13-15, HB13-9 and HB13-6. NPi (4) found HB13-9, HB13-6 and Vikrant&nbsp; as suitable genotypes, while values of Z1 favoured HB13-16, HB13-2 and Vikrant&nbsp; and Z2 settled for HB13-2, Vikrant, HB13-18. Biplot graphical analysis observed NPi(1) had maintained a close relationship with CSi3, CSi6, CCVR, CSDR, CSi5, CSi2. SDR showed a strong association with Si5, Si2, Si1, NP(2), NPi(3) , NPi (4) , CVR, Si3, Si6 &nbsp;and AvgR measures. Spearman rank correlation showed a highly significant positive correlation with GAI, Har, Si3, Si6, Coefficient of variation based on ranks (CVR), Median value based on ranks of genotypes (MedR), Average of ranks (AvgR) measures and significant positive correlation with NPi(2), NPi(3) and NPi,(4) while very weak relationships expressed with Geometric Adaptability Index based on corrected yield values (CGAI), Harmonic mean as per corrected yield values (Char), CSdr, Z1, Z2, CSi1,CSi2,CSi3,CSi4,CSi5,CSi6,CSi7, NPi(1),CSdr measures. Highly significant positive correlation expressed by GAI with Har, MedR AvgR and CAvgR only and weak with Si3, Si6, more over weak negative correlations with remaining measures. Nonparametric measures would be quite useful to the breeders to put forward stable high yielder genotypes in changing climatic fluctuations. &nbsp;Keywords: Faba bean, Rank based measures, Si(s), CSi(s), NPi(s),&nbsp;&nbsp; Biplot analysis

Genetic improvement of faba bean (Vicia faba L.) genotypes selected for resistance to chocolate spot disease

Inter-varietal hybridization is a powerful tool for genetic improvement and production of new genotypes for a trait of interest. Four parents of faba beans (Vicia faba L.) were hybridized using agromorphological and molecular characterization to obtain genotypes resistant to the chocolate spot disease. The study was done at the Nubaria Research Station, Giza, Egypt. Eight traits including resistance to chocolate spot, days to flowering, plant height (cm), number of branches/plant, number of pods/plant, number of seeds/plant, 100-seed weight (g), and seed yield/plant were estimated during the three growth seasons of 2016/2017, 2017/2018, and 2018/2019. Genetic parameters revealed by RAPD and ISSR markers assessed the genetic variation of genotypes with their generations. Crosses 1 (P1 “Nubaria-1” x P2 “Sakha-1”), 2 (P1 “Nubaria-1” x P3 “T.W”), and 3 (P1 “Nubaria-1” x P4 “Camolina”) revealed high resistance to disease with high yield. Markers patterned specific loci of resistant parents at a length of 360, 470, 450, 660, and 140 bp in RAPD and 1100, 810, 650, 700, 480 bp in ISSR. Inter-varietal hybridization between the resistant and susceptible genotypes is considered one of the most promising methods to obtain germplasm with resistance and high yield.

Long-term evaluation of new elite genotypes of Faba bean (Vicia faba L.) by Superiority Index and AMMI analysis

Highly significant effects of genotypes yield had been observed during field evaluation. A total variation of 51% accounted by the environments, 32.9% by genotype x environment interaction, and only 10.7% due to the genotypes in AMMI analysis. Adaptability measure harmonic means of relative performance of genotypes ranked HB13-48, HB13-10 and HB13-11 as per their performance. The relative performances of genetic values were settled for HB13-48, HB13-10, HB13-26 genotypes. ASV1 and ASV measures pointed HB13-26, HB13-15 and HB13-40 as of stable performance. Biplot analysis observed the strong bondage of arithmetic, geometric and harmonic means along with relative performance of genetic values and measure of the relative performance of the genotypic values. The information accrued from the study may be useful in cultivating stable genotype(s).

Using δ15N to screen for nitrogen fixation: Reference plant position and species

AbstractThe δ15N natural abundance technique is frequently used to quantify the proportion of legume nitrogen derived from atmospheric fixation (%Ndfa). This method compares the δ15N of a legume with a nonlegume reference plant to estimate the %Ndfa. For accurate estimations, it is recommended to pair each legume plot with a nonlegume reference plant to account for spatial variation. However, this pairing scheme is not feasible in large screening trials. Here, we tested the feasibility of eliminating reference plants to screen a faba bean (Vicia faba L.) population for %Ndfa. The first experiment screened 63 faba bean genotypes for %Ndfa by comparing estimates derived from an adjacent wheat (Triticum aestivum L.) reference plant in a nearest neighbor scheme (NN) with an arbitrary δ15N reference value (AR) of 7‰. Average and standard deviation of the genotypes’ %Ndfa were 58 ± 13% in 2019 and 72 ± 8% in 2020 using the NN model and 61 ± 11% in 2019 and 75 ± 7% in 2020 using the AR model. The AR model was able to identify a majority of the high and low %Ndfa genotypes in both years. In a second study, wheat and a dicot weed within the field were used as reference plants to estimate the %Ndfa. The weed reference plant resulted in 3 to 13% higher %Ndfa values compared with the wheat in three out of four testing environments, but the variation did not alter ranking of the genotypes for %Ndfa.

Genotypic variability for tolerance to low soil phosphorus availability in faba bean (Vicia faba L.)

The capacity of legumes to fix atmospheric dinitrogen in partnership with rhizobia provides an input-saving and resource-conserving alternative, thereby reducing the need for chemical fertilizers while enhancing overall crop productivity. However, low soil nutrient availability, notably phosphorus (P), is among the most nutrient limitations for legumes, since legume nodules responsible for N2 fixation have a high P requirement. In order to explore the genetic variability for P uptake and use efficiency in low-P availability in soils, three faba bean genotypes namely Sidi Aich, Castel and Diva were studied in two field sites (S1 and S2) over two growing seasons 2018 and 2019. At flowering stage, plants were harvested and analyzed for their nodulation, growth, P content and yield. Results indicate that low-P availability in the soil of S1 significantly limited plant growth, nodulation, and grain yield for all genotypes though with highest extent for Diva and Castel. We found a significant correlation between nodule growth of all genotypes and Olsen-P content in the rhizosphere soil during two growing seasons. It is concluded that the genotypes selected for their P uptake and use efficiency had a higher yield and could best adapt to low-P availability under field conditions.

Effect of sowing dates on Orobanche crenata infection and yield and its components of some faba bean genotypes.

Effect of sowing dates on Orobanche crenata infection and yield and its components of some faba bean genotypes.