Comprehensive profiling of Phaseolus species revealed key biochemical differences relevant to nutrition and crop improvement. Genotyping confirmed species-level separation and two gene pools in P. vulgaris, with evidence of introgression. Proteomic analysis identified over 11100 proteins, with P. vulgaris showing the highest diversity. Functional proteins, storage proteins, digestive enzymes, and protease inhibitors were linked to amino acid composition and digestibility. All 20 standard and nine essential amino acids were detected, with P. lunatus displaying a distinct essentials profile. Metabolomics identified 6717 compounds, 57% shared across species, dominated by flavonoids, polyphenols, and terpenoids. P. lunatus had 592 unique metabolites, while P. acutifolius had 98, suggesting a conserved, drought-adapted metabolome. Although the total fat was low, P. vulgaris accessions had higher omega-3 content and favorable omega-6/omega-3. Ionomic profiling revealed a variation in Ca, Fe, and Zn, with one P. vulgaris line accumulating unsafe Pb and Cd. Multiomics enables identification of nutrient-rich, climate-resilient, food-safe accessions.

One of the strategies to combat micronutrient malnutrition is by developing biofortified common bean lines (Phaseolus vulgaris L.) capable of tolerating different stress conditions. In this study, the adaptive responses of different biofortified bean lines grown under combined stress of acidic soil and high-temperatures were evaluated in the Colombian Amazon. A total of 247 common bean lines from the Mesoamerican gene pool were used to determine the adaptive response in terms of phenological, physiological, and agronomic behavior under combined stress conditions. The lines tested were obtained from different single crosses, double crosses, and backcrosses between different bean materials, of which 146 were obtained from F4 families with high iron (Fe) content in seed and 99 common bean lines from F5 families. Different bean lines had grain yields (GY) higher than 1400 kg ha−1 from the F5 (lines: 859, 805, 865, and 657) and F4 (lines: 2853 and 2796) families. The superior performance of these lines was related to a higher photosynthate partitioning that has allowed an increase in pod formation (pod partitioning index, PPI) from the canopy biomass (CB) and grain filling (pod harvest index, PHI; harvest index, HI), resulting in higher values of GY. Values of GY were correlated with CB (r = 0.36), PPI (r = 0.6), PHI (r = 0.68), and HI (r = 0.8, p < 0.001). This increase in agronomic performance is due to a greater allocation of energy to the photosynthetic machinery (ΦII) and its dissipation in the form of heat (ΦNPQ), with increases in the leaf temperature difference (LTD). Based on the results obtained, six biofortified lines of common bean (lines F5: 859, 805, 865, and 657; lines F4: 2853 and 2796) showed traits of tolerance to combined stress and can serve as progenitors to increase Fe and Zn concentration in the seeds of lines that tolerate the combined stress from acidic soil and high temperature in the Colombian Amazon region.

Knowledge is limited about the level of bioactive compounds and antioxidant activity of seeds from bred lines of common beans developed from interspecific crosses using four different Phaseolus species (P. vulgaris L., P. coccineus L., P. acutifolius A. Gray. Gray., and P. dumosus). In this study, differences in the nutritional quality of seeds among 112 bean genotypes were evaluated by measuring the levels of phenolic compounds, pigments, antioxidant activity, and sugars. The bean genotypes were grown under high temperatures and acid soil conditions in the Amazon region of Colombia. Five typology groups of bean genotypes were identified based on the level of bioactive compounds and their functional capacity: (1) highly bioactive and functional (HBF); (2) moderately bioactive and functional (MBF); (3) moderate antioxidant content with pigment influence (MACP); (4) moderately antinutritional with limited antioxidant potential (MALAP); and (5) antinutritional, low bioactive, and functional (ALBF). We developed a nutritional quality index (NQI) with values ranging from 0 to 1 based on the nutritional and anti-nutritional balance of each genotype and the higher values of the NQI of a genotype indicating greater nutritional quality. We found three interspecific bred lines (SER 212, SER 213, and RRA 81), with NQI values higher than 0.8. These three lines belong to the typology group of HBF. The superior nutritional quality of these three interspecific bred lines is attributed to a greater level of bioactive compounds and antioxidant capacity. These three bred lines may serve as useful parents to develop nutritionally superior and stress-resilient beans from bean breeding programs. Further research is needed to explore the role of testa color in improving the nutritional quality of seeds of common bean genotypes grown under different climatic conditions.

Cancer is a public health crisis affecting approximately 19.3 million globally, annually. Lung cancer has the highest percentage of incidence and is responsible for 27% of cancer-related deaths. The prevalence of lung cancer worldwide led us to investigate differential gene expression in lung adenocarcinoma and small cell lung cancer cell lines in comparison to a healthy lung cell line. We also investigated the effect of lung tumor microenvironment to bone marrow derived pluripotent mesenchymal stem cells (PMSC) and tumor associated macrophages. This research involved cancer and healthy cell line culture with appropriate medium. Whole transcriptomic and small non-coding RNA sequencing and analysis by Ingenuity Pathway Analysis (Qiagen, USA), Quantitative RT-PCR and ELISA assays. We further studied morphological changes and differential gene expression in extracellular vesicles(exosomes) isolated from the TAM and TME exposed PMCs by atomic force microscopy and RNA sequencing techniques. The results of our investigation showed differential gene expression and novel core canonical pathways in the lung cancer cells, TME exposed TAM, and PMSC. We also observed morphological changes in TME derived exosomes from TAM and PMSC. RNA sequencing results showed differential gene expression of both coding and non-coding RNAs including tRNA fragments. Thus, our findings of this investigation led to identification of multiple cancer related genes and small non-coding microRNA, long non-coding RNA, and tRNA fragments which will have potential diagnostic and therapeutic target value that demands further future research. Acknowledgement: This research is supported by a grant from US NIH-NIGMS- 5T34GM100831-08 and US-NIH Grant# U 54 MD007597-31-5959. Citation Format: Hirendra N. Banerjee, Joseph Hedley, Cheslsey Aurelus, Narendra Banerjee, Kuldeep Rawat, Quentin Reaves, Shennel Brown, Darla Gilmartin, Makieyah Liverman, Jazmine Cuffee, Elizabeth Cagle, Erik Armstrong, Brent Lake, Santosh Mandal, Somiranjan Ghosh, Stephen Beebe, Kamal Asadipour, Christopher Krauss, Santanu Bhattacharya, Tanmay Kulkarni, Zahidur Abedin. An investigation to study differential gene expression of lung cancer cells, tumor associated macrophages, and bone marrow derived mesenchymal stems cells in the tumor microenvironment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5477.

Cancer immunotherapy has had a significant impact on the management of many types of solid tumors. While some patients respond favorably to it, a significant number of patients do not respond or initially respond but develop resistance later, highlighting an unmet need to improve the effectiveness of this treatment. Cancers with intrinsic resistance include breast cancer, not only respond poorly to single agent immunotherapy, but also often show no durable response. Tumor microenvironment (TME) plays a critical role in both pre-existing and acquired immune resistance which is responsible for the low immunogenicity of cancers. We previously reported that an electrical engineering technology generating nanosecond length electric pulses (nsEP) can greatly enhance the immunogenicity of poorly immunogenic cancers including 4T1 breast and Pan02 pancreatic in animal models. To understand how nsEPs overcome predominant immunosuppression in the TME to induce a strong immune response, we further investigated the effects of nsEPs on the breast TME by performing transcriptomic and immune profiling of 4T1 breast cancer cells treated with nsEP. RNAseq data and cell death signaling results demonstrated that nsEPs induced regulated necrotic cell death rather than apoptosis. NsEPs-treated cancer cells greatly decreased angiogenic factors and multiple chemoattracts for myeloid-derived suppressor cells (MDSCs) and macrophages. On the other hand, nsEP-treated cancer cells significantly upregulated chemoattracts for T lymphocytes and a number of proinflammatory/immunostimulatory cytokines. Flow cytometry analysis showed that the dynamic changes of TME following nsEP treatment included: (1) the significant reduction of immunosuppressive cells (MDSCs, Tregs and TAMs); (2) the preservation of cytotoxic CD8+ T cells and conventional CD4+ T cells; and (3) a persistent elevation in cytotoxic cells vs Treg ratio and tissue resident memory CD8+ T cells. Taken together, our results suggest nsEP is a TME modifier that can potentially overturn the immunosuppressive hurdle in the TME to promote antitumor immunity. Citation Format: Lifang Yang, Anthony Nanajian, Stephen Beebe, Siqi Guo. Nanosecond Electric Pulses Modify Breast Tumor Microenvironment to Promote Antitumor Immunity [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-07-17.

The development of biofortified and stress tolerant common bean lines contribute to counteract micronutrient malnutrition in the current condition of climate variability. Our objective was to evaluate the adaptive responses of biofortified common bean (Phaseolus vulgaris L.) lines under acidic soils and high temperature stress conditions in the Amazon region of Colombia. Adaptive responses were evaluated based on phenological, physiological and agronomic differences under combined stress conditions. A total of 247 common bean lines from the Mesoamerican gene pool were evaluated under field conditions at Florencia, Caquetá, Colombia. The common bean lines evaluated included 146 from F4 families with high iron (Fe) content and 99 common bean lines from F5 families that were obtained from simple crosses, double crosses and backcrosses among different bean lines. Lines with tolerance to combined stress conditions of acidic soil and high temperature were found with grain yields greater than 1,400 kg ha-1 from the F5 (lines: 859, 805, 865, 657) and F4 (lines: 2853, 2796) families. This improved agronomic response is likely due to the greater partitioning of photosynthates from canopy biomass (CB) toward pod formation (pod partitioning index, PPI) and grain filling (pod harvest index, PHI; harvest index, HI), which translated into higher grain yields (GY). GY was correlated with CB (r = 0.36), PPI (r = 0.6), PHI (r = 0.68), and HI (r = 0.8, P<0.001). The physiological responses that contributed toward superior agronomic performance of biofortified common bean lines include greater allocation of energy to the photosynthetic machinery (ΦII) and its dissipation in the form of heat (ΦNPQ) as the leaf temperature differential (LTD) increased under combined stress conditions. Six biofortified common bean lines (F5 lines: 859, 805, 865, 657; F4 lines: 2853, 2796) were identified with multiple stress resistance traits and these lines can serve as parents for further genetic improvement of common bean for multiple stress tolerance in the Amazon region of Colombia.

Many common bean (Phaseolus vulgaris L.) plants cultivated in areas of the world with acidic soils exhibit difficulties adapting to low phosphorus (P) availability, along with aluminum (Al) toxicity, causing yield loss. The objective of this study was to evaluate the influence of an increase in P supply level on the agronomic, phenological, and physiological performance of two common bean breeding lines grown in acidic soil, with low fertility and under high temperature conditions, in a screenhouse. A randomized complete block (RCB) design was used under a factorial arrangement (five levels of P × 2 genotypes) for a total of 10 treatments with four replications. The factors considered in the experiment were: (i) five P supply levels (kg ha−1): four levels of P0, P15, P30, and P45 through the application of rock phosphate (RP), and one P level supplied through the application of organic matter (PSOM) corresponding to 25 kg P ha−1 (P25); and (ii) two advanced bean lines (BFS 10 and SEF10). Both bean lines were grown under the combined stress conditions of high temperatures (day and night maximum temperatures of 42.5 °C/31.1 °C, respectively) and acidic soil. By increasing the supply of P, a significant effect was found, indicating an increase in the growth and development of different vegetative organs, as well as physiological efficiency in photosynthesis and photosynthate remobilization, which resulted in higher grain yield in both bean lines evaluated (BFS 10 and SEF10). The adaptive responses of the two bean lines were found to be related to phenological adjustments (days to flowering and physiological maturity; stomatal development), as well as to heat dissipation strategies in the form of heat (NPQ) or unregulated energy (qN) that contributed to greater agronomic performance. We found that, to some extent, increased P supply alleviated the negative effects of high temperature on the growth and development of the reproductive organs of bean lines. Both bean lines (BFS 10 and SEF 10) showed adaptive attributes suited to the combined stress conditions of high temperature and acidic soil, and these two lines can serve as useful parents in a bean breeding program to develop multiple stress tolerant cultivars.

Common bean (Phaseolus vulgaris L.) is an important legume crop worldwide and is a major nutrient source in the tropics. Common bean reproductive development is strongly affected by heat stress, particularly overnight temperatures above 20°C. The desert Tepary bean (Phaseolus acutifolius A. Gray) offers a promising source of adaptative genes due to its natural acclimation to arid conditions. Hybridization between both species is challenging, requiring in vitro embryo rescue and multiple backcrossing cycles to restore fertility. This labor-intensive process constrains developing mapping populations necessary for studying heat tolerance. Here we show the development of an interspecific mapping population using a novel technique based on a bridging genotype derived from P. vulgaris, P. Acutifolius and P. parvifolius named VAP1 and is compatible with both common and tepary bean. The population was based on two wild P. acutifolius accessions, repeatedly crossed with Mesoamerican elite common bush bean breeding lines. The population was genotyped through genotyping-by-sequencing and evaluated for heat tolerance by genome-wide association studies. We found that the population harbored 59.8% introgressions from wild tepary, but also genetic regions from Phaseolus parvifolius, a relative represented in some early bridging crosses. We found 27 significative quantitative trait loci, nine located inside tepary introgressed segments exhibiting allelic effects that reduced seed weight, and increased the number of empty pods, seeds per pod, stem production and yield under high temperature conditions. Our results demonstrate that the bridging genotype VAP1 can intercross common bean with tepary bean and positively influence the physiology of derived interspecific lines, which displayed useful variance for heat tolerance.

Increasing seed yield in common bean could help to improve food security and reduce malnutrition globally due to the high nutritional quality of this crop. However, the complex genetic architecture and prevalent genotype by environment interactions for seed yield makes increasing genetic gains challenging. The aim of this study was to identify the most consistent genomic regions related with seed yield components and phenology reported in the last 20 years in common bean. A meta-analysis of quantitative trait locus (QTL) for seed yield components and phenology (MQTL-YC) was performed for 394 QTL reported in 21 independent studies under sufficient water and drought conditions. In total, 58 MQTL-YC over different genetic backgrounds and environments were identified, reducing threefold on average the confidence interval (CI) compared with the CI for the initial QTL. Furthermore, 40 MQTL-YC identified were co-located with 210 SNP peak positions reported via genome-wide association (GWAS), guiding the identification of candidate genes. Comparative genomics among these MQTL-YC with MQTL-YC reported in soybean and pea allowed the identification of 14 orthologous MQTL-YC shared across species. The integration of MQTL-YC, GWAS, and comparative genomics used in this study is useful to uncover and refine the most consistent genomic regions related with seed yield components for their use in plant breeding.

Intercropping is a common practice among smallholder farmers cultivating common bean (Phaseolus vulgaris L.) and maize (Zea mays L.). It affects agronomic performance, dry matter partitioning, and grain yield. Simultaneous intercropping of common bean with maize can influence growth, development, and dry matter partitioning of grain of common bean. The main objectives of this study are to: (i) evaluate the dynamics of growth and development of the different vegetative organs, and (ii) determine the efficiency in dry matter partitioning to yield components of two common bean lines grown under monoculture compared with two simultaneous intercropping patterns (pattern 1, pattern 2) with maize and managed with two types of fertilizer application. A randomized complete block design (RCBD) with 3 replications was used in a nested trifactorial arrangement in split-plot scheme. The field experiment was conducted in two seasons under conditions of acid soils and high temperatures in the western Amazon region of Colombia. Simultaneous intercropping patterns 1 and 2 had a negative effect on growth dynamics of maize compared to maize monoculture. But the two bean lines when associated with maize showed no significant differences on growth dynamics under both types of fertilizer application. Under both intercropping patterns, the maize cobs were larger, a condition that increased the number of grains, but with smaller size of grains compared to monoculture. In the case of two bean lines, the growth and development responses were different: under monoculture the number of pods and seeds per plant was higher while the number of grains per pod increased under intercropping patterns. Among the two bean lines, 100-seed weight was significantly higher in BFS 10 compared to ALB 121. At the grain yield level of common bean, the simultaneous intercropping pattern increased 516 kg ha−1 and 993 kg ha−1 more than that obtained in monoculture (4936 kg ha−1) with inorganic and organic fertilizer, respectively. Results from this study indicated that smallholders in the Amazon region of Colombia can achieve higher grain yield through the implementation of simultaneous intercropping of maize with common bean line (BFS 10) under organic fertilizer application.

The evaluation of disease resistance is considered an important aspect of phenotyping for crop improvement. Identification of advanced lines of the common bean with disease resistance contributes to improved grain yields. This study aimed to determine the response of the photosynthetic apparatus to natural pathogen infection by using chlorophyll (Chla) fluorescence parameters and their relationship to the agronomic performance of 59 common bean lines and comparing the photosynthetic responses of naturally infected vs. healthy leaves. The study was conducted over two seasons under acid soil and high temperature conditions in the western Amazon region of Colombia. A disease susceptibility index (DSI) was developed and validated using chlorophyll a (Chla) fluorescence as a tool to identify Mesoamerican and Andean lines of common bean (Phaseolus vulgaris L.) that are resistant to pathogens. A negative effect on the functional status of the photosynthetic apparatus was found with the presence of pathogen infection, a situation that allowed the identification of four typologies based on the DSI values ((i) moderately resistant; (ii) moderately susceptible; (iii) susceptible; and (iv) highly susceptible). Moderately resistant lines, five of them from the Mesoamerican gene pool (ALB 350, SMC 200, BFS 10, SER 16, SMN 27) and one from the Andean gene pool (DAB 295), allocated a higher proportion of energy to photochemical processes, which increased the rate of electron transfer resulting in a lower sensitivity to disease stress. This photosynthetic response was associated with lower values of DSI, which translated into an increase in the accumulation of dry matter accumulation in different plant organs (leaves, stem, pods and roots). Thus, DSI values based on chlorophyll fluorescence response to pathogen infection could serve as a phenotyping tool for evaluating advanced common bean lines. Six common bean lines (ALB 350, BFS 10, DAB 295, SER 16, SMC 200 and SMN 27) were identified as less sensitive to disease stress under field conditions in the western Amazon region of Colombia, and these could serve as useful parents for improving the common bean for multiple stress resistance.

Common bean (Phaseolus vulgaris L.) is the most important legume for direct human consumption worldwide. It is a rich and relatively inexpensive source of proteins and micronutrients, especially iron and zinc. Bean is a target for biofortification to develop new cultivars with high Fe/Zn levels that help to ameliorate malnutrition mainly in developing countries. A strong negative phenotypic correlation between Fe/Zn concentration and yield is usually reported, posing a significant challenge for breeders. The objective of this study was to investigate the genetic relationship between Fe/Zn. We used Quantitative Trait Loci (QTLs) mapping and Genome-Wide Association Studies (GWAS) analysis in three bi-parental populations that included biofortified parents, identifying genomic regions associated with yield and micromineral accumulation. Significant negative correlations were observed between agronomic traits (pod harvest index, PHI; pod number, PdN; seed number, SdN; 100 seed weight, 100SdW; and seed per pod, Sd/Pd) and micronutrient concentration traits (SdFe and SdZn), especially between pod harvest index (PHI) and SdFe and SdZn. PHI presented a higher correlation with SdN than PdN. Seventy-nine QTLs were identified for the three populations: 14 for SdFe, 12 for SdZn, 13 for PHI, 11 for SdN, 14 for PdN, 6 for 100SdW, and 9 for Sd/Pd. Twenty-three hotspot regions were identified in which several QTLs were co-located, of which 13 hotpots displayed QTL of opposite effect for yield components and Fe/Zn accumulation. In contrast, eight QTLs for SdFe and six QTLs for SdZn were observed that segregated independently of QTL of yield components. The selection of these QTLs will enable enhanced levels of Fe/Zn and will not affect the yield performance of new cultivars focused on biofortification.

Abstract Background: Nanodiamonds (ND) have attracted significant interest for use in several biomedical applications. These applications can be very useful if safety and compatibility of ND have been proved. Results: We assessed the effects of ND (100 nm, Carboxylated) on primary macrophages and a macrophage-like cell line and found that these particles are not toxic to these cells at the lower concentrations, but they may interfere with cell’s functions and differentiation. Internalization of ND by these cells in a time- and dose-dependent manner were mostly via phagocytosis and clathrin-dependent endocytosis and localized to the cytoplasm but not into the nucleus. No significant induction of inflammatory cytokines and no reduction in the ability of these cells to respond to lipopolysaccharides (LPS) were noted. However, the endocytic activity of these cells was significantly reduced. In addition, ND exposure reduced the ability of differentiating bone marrow cells to express macrophage surface markers. Conclusions: Our findings suggest that ND are not cytotoxic to macrophages at the tested concentrations, but they can interfere with macrophage functions and differentiation.

Disease stress caused by plant pathogens impacts the functioning of the photosynthetic apparatus, and the symptoms caused by the degree of severity of the disease can generally be observed in different plant parts. The accurate assessment of plant symptoms can be used as a proxy indicator for managing disease incidence, estimating yield loss, and developing genotypes with disease resistance. The objective of this work was to determine the response of the photosynthetic apparatus to the increased disease severity caused by web blight Thanatephorus cucumeris (Frank) Donk on the common bean (Phaseolus vulgaris L.) leaves under acidic soil and the humid tropical conditions of the Colombian Amazon. Differences in chlorophyll fluorescence parameters, including Fv/Fm, Y(II), Y(NPQ), Y(NO), ETR, qP, and qN in leaves with different levels of severity of web blight in an elite line (BFS 10) of common bean were evaluated under field conditions. A significant effect of web blight on the photosynthetic apparatus was found. A reduction of up to 50% of energy use dedicated to the photosynthetic machinery was observed, even at the severity scale score of 2 (5% surface incidence). The results from this study indicate that the use of fluorescence imaging not only allows for the quantifying of the impact of web blight on photosynthetic performance, but also for detecting the incidence of disease earlier, before severe symptoms occur on the leaves.

Acid soils in the Amazon region are characterized by low fertility and high aluminum saturation causing reduced crop yields. Improving genetic adaptation of crop genotypes together with suitable agronomic management practices can mitigate the impact on crop production in acid soils. The objective of the present study was to determine the photosynthetic and grain yield responses of two common bean lines to intercropping with maize under two types of fertilizer applications in the Colombian Amazon region. A randomized complete block design (RCBD) with 3 replications in a nested trifactorial arrangement was used consisting of two advanced bean lines of BFS 10 and ALB 121 (main plots); three cropping system patterns of monoculture, intercropping pattern 1, intercropping pattern 2 (subplots); and two types of fertilizer applications, chemical and organic (sub-subplots) for a total of 12 treatments. The experiment was conducted in two growing seasons and the effects of the treatments were evaluated during two growth stages within a cropping season. Measurements included photosynthetic gas exchange characteristics, chlorophyll fluorescence, specific leaf area, viability of pollen and grain yield. Mean values from two growing seasons were presented. Photosynthetic response of BFS 10 was superior to ALB 121 under both monoculture and intercropping patterns with either chemical or organic fertilizer application. Both bean lines showed an increase in apparent quantum efficiency and maximum rate of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO) carboxylation (Vcmax) during pod filling growth stage when grown in association with maize, particularly with organic fertilizer application. Small farmers in the Amazon region can benefit from either one of the two bean lines by growing them as intercrops with maize, using organic fertilizer application.

Intercropping the common bean (Phaseolus vulgaris L.) with maize (Zea mays L.) is a widely used agronomic practice in smallholder farms in different regions of the world. Although it is a common practice in the Colombian Amazon region, crop yields are low due to the degradation of low fertility, acidic soil and high-temperature stress. Studies are needed on how the integration of genetically adapted common bean breeding lines into an intercropping system can benefit smallholders. The objective of this study was to: (i) evaluate differences in agronomic performance of two common bean lines when intercropped with maize in two different patterns under two types of fertilizer applications; and (ii) identify which intercropping pattern is better to maximize productivity and land use in the Colombian Amazon region. To achieve these aims, 2 field experiments (October 2018 to January 2019, season 1; April to June 2019, season 2) were conducted in the Colombian Amazon region. A randomized complete block design (RCBD) with three replications in a nested trifactorial arrangement in a split-plot scheme was used. The experimental design consisted of 2 advanced bean breeding lines of BFS 10 and ALB 121 (main plots); 3 cropping system patterns, including a monoculture, intercropping pattern 1, and intercropping pattern 2 (subplots); and 2 types of fertilizer, inorganic and organic (sub-subplots), for a total of 12 treatments. The experiment was conducted in two growing seasons in low fertility, acidic soil. Different competition indices and monetary advantage index values were estimated depending on the yield and cost of production from maize and bean intercropping patterns (land equivalent ratio, LER; relative crowding coefficient, RCC; aggressiveness index, AI; competitive ratio, CR). A significant effect on grain yield was observed with both intercropping patterns compared to monocropping of beans and maize. Grain yields obtained for maize were similar under monoculture with both types of fertilizer application, while both bean lines yielded better in monoculture under the application of inorganic fertilizer. Under intercropping patterns, the yield reductions were from 8 to 30% for maize and from 43 to 72% for the 2 bean lines. LER values increased with intercropping patterns under both types of fertilization, which was supported by positive values in the actual yield loss index. The interaction indices between the two crop components showed a greater dominance of maize over beans (RCC, AI, CR). However, the intercropping systems increased the economic advantage (the monetary advantage index) over monocropping. Smallholders in the Amazon region can profit through increased grain yield as well as land-use efficiency by integrating a genetically adapted bean breeding line, BFS 10, as an intercrop with maize under the application of organic fertilizer.

Common bean (Phaseolus vulgaris L.) production in the tropics typically occurs in rainfed systems on marginal lands where yields are low, primarily as a consequence of drought and low phosphorus (P) availability in soil. This study aimed to investigate the physiological and chemical responses of 12 bush bean genotypes for adaptation to individual and combined stress factors of drought and low P availability. Water stress and P deficiency, both individually and combined, decreased seed weight and aboveground biomass by ∼80%. Water deficit and P deficiency decreased photosynthesis and stomatal conductance during plant development. Maximum rates of carboxylation, electron transport, and triose phosphate utilization were superior for two common bean genotypes (SEF60 and NCB226) that are better adapted to combined stress conditions of water deficit and low P compared to the commercial check (DOR390). In response to water deficit treatment, carbon isotope fractionation in the leaf tissue decreased at all developmental stages. Within the soluble leaf fraction, combined water deficit and low P, led to significant changes in the concentration of key nutrients and amino acids, whereas no impact was detected in the seed. Our results suggest that common bean genotypes have a degree of resilience in yield development, expressed in traits such as pod harvest index, and conservation of nutritional content in the seed. Further exploration of the chemical and physiological traits identified here will enhance the resilience of common bean production systems in the tropics.

Root rot in common bean is a disease that causes serious damage to grain production, particularly in the upland areas of Eastern and Central Africa where significant losses occur in susceptible bean varieties. Pythium spp. and Fusarium spp. are among the soil pathogens causing the disease. In this study, a panel of 228 lines, named RR for root rot disease, was developed and evaluated in the greenhouse for Pythium myriotylum and in a root rot naturally infected field trial for plant vigor, number of plants germinated, and seed weight. The results showed positive and significant correlations between greenhouse and field evaluations, as well as high heritability (0.71–0.94) of evaluated traits. In GWAS analysis no consistent significant marker trait associations for root rot disease traits were observed, indicating the absence of major resistance genes. However, genomic prediction accuracy was found to be high for Pythium, plant vigor and related traits. In addition, good predictions of field phenotypes were obtained using the greenhouse derived data as a training population and vice versa. Genomic predictions were evaluated across and within further published data sets on root rots in other panels. Pythium and Fusarium evaluations carried out in Uganda on the Andean Diversity Panel showed good predictive ability for the root rot response in the RR panel. Genomic prediction is shown to be a promising method to estimate tolerance to Pythium, Fusarium and root rot related traits, indicating a quantitative resistance mechanism. Quantitative analyses could be applied to other disease-related traits to capture more genetic diversity with genetic models.

In our study, we analyzed 30years of climatological data revealing the bean production risks for Western Amazonia. Climatological profiling showed high daytime and nighttime temperatures combined with high relative humidity and low vapor pressure deficit. Our understanding of the target environment allows us to select trait combinations for reaching higher yields in Amazonian acid soils. Our research was conducted using 64 bean lines with different genetic backgrounds. In high temperatures, we identified three water use efficiency typologies in beans based on detailed data analysis on gasometric exchange. Profligate water spenders and not water conservative accessions showed leaf cooling, and effective photosynthate partitioning to seeds, and these attributes were found to be related to higher photosynthetic efficiency. Thus, water spenders and not savers were recognized as heat resistant in acid soil conditions in Western Amazonia. Genotypes such as BFS 10, SEN 52, SER 323, different SEFs (SEF 73, SEF 10, SEF 40, SEF 70), SCR 56, SMR 173, and SMN 99 presented less negative effects of heat stress on yield. These genotypes could be suitable as parental lines for improving dry seed production. The improved knowledge on water-use efficiency typologies can be used for bean crop improvement efforts as well as further studies aimed at a better understanding of the intrinsic mechanisms of heat resistance in legumes.

Knowledge of the physiological basis for improved genetic adaptation of common bean (Phaseolus vulgaris L.) lines to acid soils and high temperature conditions in the Amazon region of Colombia is limited. In this study, we evaluated the differences among 41 common bean lines in energy use, leaf cooling, photosynthate partitioning to pod formation and grain filling, and grain yield over two seasons under acid soil and high temperature stress in the Amazon region of Colombia. Common bean lines evaluated included medium and large seeded interspecific lines of Mesoamerican and Andean gene pools with different levels of adaptation to abiotic stress conditions and some lines are improved for iron and zinc (biofortified) concentration in seeds. We found three bean lines (GGR 147, SMG 21 and SMG 12) that were superior in their photosynthetic response, leaf cooling, photosynthate partitioning ability to pod formation and grain filling, resulting in grain yields exceeding 1900 kg ha−1 under acid soil and high temperature stress conditions. The superior photosynthetic performance was attributed to the efficient use of absorbed energy on the electron level in thylakoids, which is mainly oriented to a higher quantum yield of PSII (ΦII), lower energy dissipation in the form of heat (ΦNPQ), high linear electron flow (LEF) and high fraction of PSI centers in open state (PSIopen). We speculate that these photosynthetic and photosynthate partitioning responses of superior bean lines are part of the genetic adaptation to acidic soils and high temperature stress conditions. Among the evaluated bean lines, three lines (GGR 147, SMG 21 and SMG 12) combined the desirable attributes for genetic improvement of stress tolerance and biofortification. These lines can serve as parents to further improve traits (energy use efficiency and multiple stress resistance) that are important for bean production in the Amazon region.