Heat stress is a major limitation to grain yield in common bean ('Phaseolus vulgaris' L.). Tepary bean ('Phaseolus acutifolius' A. Gray) is better adapted to heat stress than common bean. Ten tepary ...bean accessions, four common bean genotypes and four interspecific lines involving 'P. vulgaris and P. acutufolius, P. coccineus and P. dumosus' were evaluated for tolerance to heat stress conditions induced under greenhouse conditions and these were compared to plants grown under ambient temperatures. The high temperature treatment was 29 +-5 degreesC during the day and was >24 degreesC (up to 27 degreesC) during the night, while the ambient temperature (AT) treatment was 25 +-5 degreesC during the day and 19+- 2 degreesC at night. The genotypic differences were evaluated for morpho-physiological characteristics of shoot and root and also yield components. The Genotype and Genotype × Temperature interactions were significant for all shoot and root morpho-physiological characteristics evaluated. Higher temperature (HT) significantly affected leaf photosynthetic efficiency, total chlorophyll content, and stomatal conductance. The effect was positive or negative, depending on the genotypes. Tepary accessions showed reduced total chlorophyll content, while common bean genotypes and the interspecific lines were less affected. Tepary accessions also showed reduced stomatal conductance, but increased leaf photosynthetic efficiency under HT. Common bean genotypes increased stomatal conductance and decreased leaf photosynthetic efficiency. High temperature decreased total root length, specific root length and pod biomass compared to ambient conditions, but there was no marked effect on pollen viability of the tested genotypes. The superior adaptation of tepary germplasm accessions to high temperature is attributed to their ability to regulate stomatal opening and photosynthetic efficiency, together with a superior ability to remobilize photosynthates from older leaves to pods during physiological maturity.
Common bean is extensively grown and consumed worldwide and it is considered a nutraceutical food and an important source of protein. Leaf spot is one of the most devastating diseases of common bean ...in tropical and subtropical production areas. In May 2021, this destructive disease was observed in the Guizhou Province of China and resulted in serious economic losses for local agricultural production. Foliar symptoms appeared as small circular tan-colored spots, which then turned dark brown and coalesced into irregular water-soaked necrotic lesions, often leading to leaf wilt or abscission. Fungal isolates were obtained from symptomatic common bean plants and a detailed morphological analysis was performed. Concatenated phylogenetic reconstruction was conducted by amplifying and sequencing the internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (gapdh) and translation elongation factor 1-alpha (tef1-α) genes. Based on morphological characters and phylogenetic analyses, the pathogen was identified as Curvularia verruculosa. In addition, the pathogenicity tests of the isolates reproduced the same symptoms as those observed in the field, and Koch's postulates were confirmed by pathogen re-isolation and identification. To our knowledge, this is the first report of C. verruculosa causing leaf spot on common bean in the world. The current study can provide a foundation for developing effective management strategies, and reducing economic losses in common bean production.
•The occurrence of leaf spot of common bean was observed in Guizhou Province, China.•Pathogen diagnosis was based on morphology and multi-locus phylogenetic analyses.•Koch's postulates proved the association of C. verruculosa with common bean leaf spot.•First report of C. verruculosa as the causal pathogen of leaf spot on common bean.•This study contributes to establish the control strategies for common bean diseases.
•Grafting success of Phaseolus vulgaris depends on the rootstock/scion combination.•Phaseolus vulgaris is compatible with P. coccineous but not with Vigna unguiculata.•Grafting P. vulgaris on P. ...coccineus increased number and total yield of fresh pods.•Grafted P. vulgaris fixed less N2 per biomass unit but produced more total biomass.
Grafting is an excellent tool to investigate shoot/root interactions involved in root nodulation by rhizobia and biological nitrogen fixation (BNF) in legumes of high economic and nutritional importance, such as common bean (Phaseolus vulgaris L.). Considering this, three landraces and one commercial cultivar of common bean were grafted onto eight different legume genotypes to identify possible rootstock × scion combinations that increase yield, and to study the impact of the root genotype on nitrogen fixation. The genotypes were three Greek landraces of Phaseolus vulgaris L. (namely ‘Chandres Therines’, ‘Pyrgetos’ and ‘Tsaoulia’), and one commercial cultivar (cv. ‘Helda’). These were grafted onto six different Greek landraces of Phaseolus vulgaris L., particularly ‘Chandres’, ‘Papouda’, ‘Pastalia’, ‘Vanilla’, ‘Zargana Chryssoupolis’ and ‘Zargana Kavalas’, one Phaseolus coccineus L. landrace originating from the Greek province Feneos, and one cowpea (Vigna unguiculata (L.) Walp) landrace originating from Arta, Greece. Grafting success was mainly determined by the rootstock genotype. The best rootstock/scion combination, attaining 100% success, was ‘Tsaoulia’ grafted onto ‘Zargana Kavalas’. Moreover, the use of P. coccineus L. as rootstock enhanced appreciably the fresh pod yield by increasing the number of fresh pods. In contrast, cowpea was an incompatible rootstock for grafting P. vulgaris, as all plants grafted on it failed to survive. Most grafting combinations reduced the% of N derived from the atmosphere (%Ndfa) through BNF. Despite the decreased%Ndfa, some rootstocks increased the biologically fixed N per cultivated area unit due to higher total biomass production, which indicates involvement of mechanisms causing rootstock/scion interactions.
The effect of hydrothermal (HT) (boiling for 15 or 120 min) and high-hydrostatic pressure (HHP) (150, 300, 450, and 600 MPa for 5, 10 or 15 min) processing on the rheological, pasting, thermal and ...functional properties of bean flours was investigated. HT and HHP treatments differently affected these properties. HT120 led to maximum values of elastic and viscous moduli (G′, G″), and gel strength of bean flours. HHP enhanced G′, G″ and gel strength as the pressure and holding time increased. The viscoelastic properties of HT120 and HHP600/5-treated bean flours correlated with the increased viscosity of these samples. The pasting profiles and thermograms indicated a full, partial, and limited starch gelatinization in HT120, HHP600/5 and HHP ≤450 MPa samples, respectively. Enthalpy values showed that HT120 caused a higher degree of protein denaturation than HHP, with protein denaturation increasing as pressurization and time increased. This had an impact on protein solubility and emulsifying activity of flours which were significantly diminished by HT15/HT120, but maintained or slightly decreased by HHP. Nevertheless, HHP-treated samples showed enhanced emulsifying stability with increased pressure and holding time. These results demonstrate that HHP has the technological potential to manufacture bean flours with a range of functionalities into diverse food products.
•HT and HHP induced varied degree of starch gelatinization and protein denaturation.•HHP improved the pasting properties and resistance to shear-thinning of bean flours.•Severe heating and the highest-pressure level increased the gel strength of flours.•The emulsifying activity of flours was reduced by HT and retained by low pressures.•HHP enhanced the emulsifying stability of flours with increasing pressure and time.
•A method for root architectural phenotyping of field-grown legumes is presented.•Genotypes can be differentiated in the field.•Heritability of scored traits ranged from very low to high.•This ...platform should be useful for legumes and possibly other dicot crops.
Low phosphorus (P) availability and drought are primary constraints to common bean and cowpea production in developing countries. Genetic variation of particular root architectural phenes of common bean is associated with improved acquisition of water and phosphorus. Quantitative evaluation of root architectural phenotypes of mature plants in the field is challenging Nonetheless, in situ phenotyping captures responses to environmental variation and is critical to improving crop performance in the target environment. The objective of this study was to develop flexible high-throughput root architectural phenotyping platforms for bean and cowpea, which have distinct but comparable root architectures. The bean phenotyping platform was specifically designed to scale from the lab to the field. Initial laboratory studies revealed cowpea does not have basal root whorls so the cowpea phenotypic platform was taken directly to field evaluation. Protocol development passed through several stages including comparisons of lab to field quantification systems and comparing manual and image-based phenotyping tools of field grown roots. Comparing lab-grown bean seedlings and field measurements at pod elongation stage resulted in a R2 of 0.66 for basal root whorl number (BRWN) and 0.92 for basal root number (BRN) between lab and field observations. Visual ratings were found to agree well with manual measurements for 12 root parameters of common bean. Heritability for 51 traits ranged from zero to eighty-three, with greatest heritability for BRWN and least for disease and secondary branching traits. Heritability for cowpea traits ranged from 0.01 to 0.80 to with number of large hypocotyl roots (1.5A) being most heritable, nodule score (NS) and tap root diameter at 5cm (TD5) being moderately heritable and tap root diameter 15cm below the soil level (TD15) being least heritable. Two minutes per root crown were required to evaluate 12 root phene descriptors manually and image analysis required 1h to analyze 5000 images for 39 phenes. Manual and image-based platforms can differentiate field-grown genotypes on the basis of these traits. We suggest an integrated protocol combining visual scoring, manual measurements, and image analysis. The integrated phenotyping platform presented here has utility for identifying and selecting useful root architectural phenotypes for bean and cowpea and potentially extends to other annual legume or dicotyledonous crops.
MicroRNAs (miRNAs) play a pivotal role in post-transcriptional regulation of gene expression in plants. Information on miRNAs in legumes is as yet scarce. This work investigates miRNAs in an ...agronomically important legume, common bean (Phaseolus vulgaris). A hybridization approach employing miRNA macroarrays - printed with oligonucleotides complementary to 68 known miRNAs - was used to detect miRNAs in the leaves, roots and nodules of control and nutrient-stressed (phosphorus, nitrogen, or iron deficiency; acidic pH; and manganese toxicity) common bean plants. Thirty-three miRNAs were expressed in control plants and another five were only expressed under stress conditions. The miRNA expression ratios (stress:control) were evaluated using principal component and hierarchical cluster analyses. A group of miRNAs responded to nearly all stresses in the three organs analyzed. Other miRNAs showed organ-specific responses. Most of the nodule-responsive miRNAs showed up-regulation. miRNA blot expression analysis confirmed the macroarray results. Novel miRNA target genes were proposed for common bean and the expression of selected targets was evaluated by quantitative reverse transcriptase-polymerase chain reaction. In addition to the detection of previously reported stress-responsive miRNAs, we discovered novel common bean stress-responsive miRNAs, for manganese toxicity. Our data provide a foundation for evaluating the individual roles of miRNAs in common bean.
Introduction Drought is one of the biggest problems for crop production and also affects the survival and persistence of soil rhizobia, which limits the establishment of efficient symbiosis and ...endangers the productivity of legumes, the main source of plant protein worldwide. Aim Since the biodiversity can be altered by several factors including abiotic stresses or cultural practices, the objective of this research was to evaluate the effect of water availability, plant genotype and agricultural management on the presence, nodulation capacity and genotypic diversity of rhizobia. Method A field experiment was conducted with twelve common bean genotypes under irrigation and rain-fed conditions, both in conventional and organic management. Estimation of the number of viable rhizobia present in soils was performed before the crop establishment, whereas the crop yield, nodule number and the strain diversity of bacteria present in nodules were determined at postharvest. Results Rainfed conditions reduced the number of nodules and of isolated bacteria and their genetic diversity, although to a lesser extent than the agrochemical inputs related to conventional management. In addition, the effect of water scarcity on the conventional management soil was greater than observed under organic conditions. Conclusions The preservation of diversity will be a key factor to maintain crop production in the future, as problems caused by drought will be exacerbated by climate change and organic management can help to maintain the biodiversity of soil microbiota, a fundamental aspect for soil health and quality.
In the present study 25 bush type common bean genotypes were evaluated for their adaptability, performance of yield, maturity and anthracnose disease. Among 25 genotypes, ten were red in colour, five ...were brown in colour, four genotypes were white, two purple and one each was black, pink, yellow and chocolate in colour. For seed shape, 16 genotypes were kidney shaped, 3 were oval, cylindrical and cuboidal. For seed coat pattern, 19 genotypes were plain and 6 were mottled. Seed size revealed that out of 25 genotypes, 6 were large, 17 were medium and two were small. Out of 25 genotypes, 14 were having green colour pods, 10 were yellow and one light green in colour. The pod curvature revealed that 15 genotypes were having medium pod curvature, 7 were curved and 3 genotypes were having straight pod curvature. WB-185 was earliest to flower, whereas WB-956 was earliest to maturity. Highest pod length was recorded in WB-185where as lowest was recorded in local Ladakh and WB-257. Maximum seeds per pod were recorded in genotype WB-185 whereas minimum seeds per pods were recorded in WB-956. Highest plant height was recorded in genotype WB-1690. Highest value for 100 seed weight was recorded in WB-966 and lowest value was recorded in WB-6. Highest yield per plant was recorded in WB-185 and lowest yield per plant was recorded in WB-1129. Analysis of variance revealed that the genotypes exhibited significant variability for all the traits. Screening of genotypes against anthracnose revealed that maximum disease incidence was shown by WB-1690 followed by WB-257, WB-1643, WB-956 and WB-1129. Maximum disease intensity was shown by WB-1690 while lowest disease intensity was recorded in WB-719.
In this study, comparative effects of foliar application of ceria nanoparticles (NPs) and Ce3+ ions on common bean plants were investigated. Soil grown bean seedlings were exposed to ceria NPs and ...Ce3+ ions at 0, 40, 80, and 160 mg Ce·L−1 every other day at the vegetative growth stage for 17 d. The plants were harvested 47 d after the last treatment. Performed analyses involved growth, physiological and biochemical parameters of the plants and nutritional quality of the pods. Ceria NPs at 40 mg Ce·L−1 increased dry weight of the plants by 51.8% over the control. Neither ceria NPs nor Ce3+ ions significantly affected other vegetative growth parameters. Pod yields and nutrient contents except for several mineral elements were also not significantly different among groups. Compared to control, pods from ceria NPs at 80 mg Ce·L−1 had significantly less S and Mn. At 40 and 80 mg Ce·L−1, ceria NPs reduced pod Mo by 27% and 21%, while Ce3+ ions elevated Mo contents by 20% and 18%, respectively, compared with control. Ce3+ ions at 80 and 160 mg Ce·L−1 significantly increased pod Zn by 25% and 120%, respectively, compared with control. At the end of the experiment, Ce3+ ions at 40, 80, and 160 mg Ce·L−1 increased contents of malondialdehyde (MDA) by 46%, 65%, and 82% respectively as compared with control. While ceria NPs led to a significant increase of MDA level only at the highest concentration. X-ray absorption near edge structure (XANES) analysis of the leaf samples revealed that both ceria NPs and Ce3+ ions kept their original chemical species after foliar applications, suggesting the observed effects of ceria NPs and Ce3+ ions on the plants were probably due to their nano-specific properties and ionic properties respectively.
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•Ceria NPs and Ce3+ ions had no adverse effect on growth and development of common bean.•The treatments had no effect on nutritional quality of the pods except changed several mineral contents.•Both treatments provoked dose-dependent oxidative damages in the leaves at the end of the experiment.•Ceria NPs and Ce3+ ions kept their original chemical species after foliar applications.
Ceria NPs and Ce3+ ions could change several mineral contents in the pods while had no significant adverse effect on the growth, development and other nutritional compositions in the pods of common bean plants after repeated foliar application.
Cold temperatures can be detrimental to crop survival and productivity. Breeding progress can be improved by understanding the molecular basis of low temperature tolerance. We investigated the key ...routes and critical metabolites related to low temperature resistance in cold-tolerant and -sensitive common bean cultivars 120 and 093, respectively. Many potential genes and metabolites implicated in major metabolic pathways during the chilling stress response were identified through transcriptomics and metabolomics research. Under chilling stress, the expression of many genes involved in lipid, amino acid, and flavonoid metabolism, as well as metabolite accumulation increased in the two bean types. Malondialdehyde (MDA) content was lower in 120 than in 093. Regarding amino acid metabolism, 120 had a higher concentration of acidic amino acids than 093, whereas 093 had a higher concentration of basic amino acids. Methionine accumulation was clearly higher in 120 than in 093. In addition, 120 had a higher concentration of many types of flavonoids than 093. Flavonoids, methionine and malondialdehyde could be used as biomarkers of plant chilling injury. Transcriptome analysis of hormone metabolism revealed considerably greater, expression of abscisic acid (ABA), gibberellin (GA), and jasmonic acid (JA) in 093 than in 120 during chilling stress, indicating that hormone regulation modes in 093 and 120 were different. Thus, chilling stress tolerance is different between 093 and 120 possibly due to transcriptional and metabolic regulation.
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