QCM Genosensor for Detection of Golden Mosaic-Resistant Transgenic Common Beans in Non-Amplified Samples

In Menoua Division, common bean (Phaseolus vulgaris L.) is amongst the legumes which are greatly cultivated with farmers growing different cultivar types. Upon harvest, these cultivars are stored to be used as food over the storage period or for sale. Unfortunately appropriate facilities for storing the cultivars after harvest are not available hence predisposing the grains to fungi infection. The knowledge of cultivar resistant to damage by storage fungi would therefore have a considerable value in the absence of appropriate storage structures. This research aimed at determining whether differences might exist among common bean cultivars in susceptibility to damage by fungi under storage environment by farmers in Menoua Division and also identifying the less susceptible cultivar type to fungi infection. Six different common bean cultivars were evaluated for fungi contamination upon storage using PDA media. The large seeded bean cultivar was designated the most susceptible to fungi infection on storage having the significantly highest (P ˂ 0.05) fungi population. The least susceptible were the into bean cultivar, navy bean cultivar and Pea bean cultivar. Four storage fungi genera were isolated from the different bean cultivars. These included: Aspergillus, Fusarium, Penicillium, Morphospeciesor 'Mycelia sterilia'. Inherent differences exist among cultivars of common bean in susceptibility to infection and damage by storage fungi.

The objective of this study was to determine the genetic diversity among Brazilian carioca common bean (Phaseolus vulgaris L.) cultivars for traits related to nitrogen use efficiency (NUsE). An additional objective was to identify potential parents and promising parental combinations to assist common bean breeding programs in the development of cultivars with improved NUsE. The experiments were carried out at the Experimental Stations of the Instituto de Desenvolvimento Rural do Paraná (IDR–Paraná) in Londrina and Ponta Grossa, Brazil, during the rainy season in 2017. Thirty‐nine common bean cultivars were evaluated under high (40 kg N ha−1) and low N (0 kg N ha−1) applied as top‐dressing. The cultivars were genotyped using the genotyping‐by‐sequencing (GBS) approach with restriction enzyme CviAII. A total of 23,823 single nucleotide polymorphism (SNP) markers were identified throughout the common bean genome. A wide genetic variability was observed for NUsE‐related traits under high and low N conditions. In addition, correlations were found between shoot dry biomass and NUsE, N uptake efficiency (NUpE), and N utilization efficiency (NUtE) under low N, indicating the possibility of indirect selection of these traits by the plant shoot dry biomass. Interestingly, the most low‐N‐tolerant cultivars were not necessarily the most responsive and/or NUsE, suggesting that different morphophysiological mechanisms control these traits. The cultivars that stood out positively in this study can be used as parents in breeding programs aimed at developing cultivars that are adapted to N limitation.

Common bean (Phaseolus vulgaris L.) can be affected by several viral diseases, including golden mosaic caused by the Bean golden mosaic virus (BGMV). When infected by BGMV, bean plants undergo major physiological changes, leading to a reduction or complete loss of productivity. This study aimed to evaluate and compare seven bean cultivars and lineages, as well as the legume calopo (Calopogonium mucunoides Desv.), for the severity of golden mosaic symptoms and BGMV titre following inoculation. The study was conducted in the greenhouse under controlled environmental conditions. Plants were inoculated with viruliferous whiteflies [Bemisia tabaci (Gennadius)], and evaluated for severity of disease symptoms at 7, 10, 15, 20, and 25 days after inoculation (DAI). The virus titre was measured by quantitative PCR (qPCR) analysis with primers specific for the virus coat protein gene. All bean genotypes were symptomatic for BGMV infection, but calopo was not. There were differences among the tested cultivars and lineages for the expression of symptoms. Differences in BGMV titre also were observed among the cultivars at 10 and 25 DAI. The bean cultivar ‘Tangará’ had a greater viral titre but exhibited lower symptom severity than the other cultivars. Calapo was tolerant to BGMV.

Shoot biomass is considered a relevant component for crop yield, but relationships between biological productivity and grain yield in legume crops are usually difficult to establish. Two field experiments were carried out to investigate the relationships between grain yield, biomass production and N and P accumulation at reproductive stages of common bean (Phaseolus vulgaris) cultivars. Nine and 18 cultivars were grown on 16 m² plots in 1998 and 1999, respectively, with four replications. Crop biomass was sampled at four growth stages (flowering R6, pod setting R7, beginning of pod filling R8, and mid-pod filling R8.5), grain yield was measured at maturity, and N and P concentrations were determined in plant tissues. In both years, bean cultivars differed in grain yield, in root mass at R6 and R7 stages, and in shoot mass at R6 and R8.5, whereas at R7 and R8 differences in shoot mass were significant in 1998 only. In both years, grain yield did not correlate with shoot mass at R6 and R7 and with root mass at R6. Grain yield correlated with shoot mass at R8 in 1999 but not in 1998, with shoot mass at R8.5 and with root mass at R7 in both years. Path coefficient analysis indicated that shoot mass at R8.5 had a direct effect on grain yield in both years, that root mass at R7 had a direct effect on grain yield in 1998, and that in 1999 the amounts of N and P in shoots at R8.5 had indirect effects on grain yield via shoot mass at R8.5. A combined analysis of both experiments revealed that biomass accumulation, N and P in shoots at R6 and R7 as well as root mass at R6 were similar in both years. In 1998 however bean accumulated more root mass at R7 and more biomass and N and P in shoots at R8 and R8.5, resulting in a 57 % higher grain yield in 1998. This indicates that grain yield of different common bean cultivars is not intrinsically associated with vegetative vigor at flowering and that mechanisms during pod filling can strongly influence the final crop yield. The establishment of a profuse root system during pod setting, associated with the continuous N and P acquisition during early pod filling, seems to be relevant for higher grain yields of common bean.

One of the many aspects related to intercropping and practically not studied is the fertilization of the crops involved. The nutritional requirement of the species can be modified as a result of the interaction. The objective of this work was to evaluate the nutrition of common bean and castor bean subjected to different forms of the split of nitrogen (N) rate in coverage. Two experiments were carried out in the summer harvests of 2009/2010 and 2010/2011, using a randomized block design, in a 2 × 2 × 6 + 4 factorial scheme, with three replications. The treatments were composed of two common bean cultivars and two castor bean cultivars in intercropping system, combined with six forms of split of nitrogen fertilization coverage. The four additional treatments were composed of the two common bean and castor bean cultivars in monoculture, using the 40 kg ha−1 of N in coverage. For common beans, the split of 30:70 kg ha−1 of N increased the concentration of P (32.3%), K (6.0%), Ca (12.1%), Mg (78.5%), S (180.0%), B (17.9%), Cu (35.5%), Fe (3.1%), Mn (9.2%) and Zn (47.9%) in relation to control treatment. For castor beans, the same split increased the concentration of P (43.5%), K (9.4%), Mg (130.7%), S (3.2%), B (15.8%), Cu (28.4%), Fe (37.6%), Mn (40.5%) and Zn (70.2%). Pérola and Energia cultivars obtained higher values of leaf nutrients for common bean and castor bean, respectively. Leaf nutrient concentrations were higher in the monoculture when compared to intercropping for both crops.

This study is aimed to evaluate the adaptive mechanism in two common bean ( Phaseolus vulgaris L.) cultivars, cv. Bronco and cv. Paulista subjected to different concentrations of NaCl (0, 25, 50 and 75 mM). Salt treatments resulted in a significant decrease in the fresh and dry biomasses of shoots and roots as well as leaf relative water content (RWC) in both bean cultivars. Salt stress determines a diversion of plant metabolism towards the synthesis of phenolics, proline and trigonelline (TRG) components together with an increase in the NADP + /NADPH ratio. This increase was accompanied with a significant increase in glucose-6-phosphate dehydrogenase (G-6-PDH) and L-phenylalanine ammonia-lyase (PAL) activities in both bean cultivars. Furthermore, increasing NaCl levels induced oxidative stress measured in terms of malondialdehyde and H 2 O 2 contents. Salt stress triggered an increase in guaiacol peroxidae (GPX) activity in both bean cultivars, whereas polyphenol oxidase (PPO) activity increased only in Bronco plants. The results are discussed in the light of possible roles and regulation of cellular redox potential (NADP + /NADPH) in the maintenance of acclimative mechanism in the two common bean cultivars grown under NaCl stress.

Bean anthracnose caused by Colletotrichum lindemuthianum is one of the most destructive diseases in all bean growing areas. AFLP analysis was used to assess genetic variability and relationships among C. lindemuthianum isolates from Slovenia. Isolates were obtained from different common bean growing regions in Slovenia and have previously been characterized as races 23, 55, 103 and 131. AFLP clustering revealed two main groups that did not clearly correspond to race classification based on pathogenicity towards differential common bean cultivars. Local common bean germplasm as well as the set of 12 international differential bean cultivars were evaluated for resistance against the four C. lindemuth-ianum races that occur in Slovenia. None of the 26 local common bean landraces and cultivars was resistant to all four races; however, six genotypes reacted as moderately resistant. Considerably higher level of resistance was recorded among differential common bean cultivars, particularly those derived from the Mesoamerican germplasm. Introgression of some major anthracnose resistance genes from the Mesoamerican germplasm is therefore recommended to develop resistant common bean cultivars for our production system.

Interspecific breeding lines (IBL) VCW 54 (Reg. No. GP‐276, PI 655531) and VCW 55 (Reg. No. GP‐277, PI 655532) of common bean (Phaseolus vulgaris L.) resistant to white mold [WM; caused by Sclerotinia sclerotiorum (Lib.) de Bary] were jointly developed at the University of Idaho‐Kimberly Research and Extension Center and Colorado State University, Fort Collins, CO. The Agricultural Experiment Stations of Idaho and Colorado released VCW 54 and VCW 55 on 10 Dec. 2008. Both IBL were derived from congruity backcrossing between small‐seeded tropical black bean cultivar ICA Pijao and P. coccineus L. accession G 35172. ICA Pijao has an indeterminate upright growth habit Type II and resistance to bean common mosaic virus and some races of rust pathogen, and tolerance to bean golden mosaic virus (BGMV). G 35172 has large purple‐mottled seeds, an indeterminate climbing growth habit Type IV, and resistance to BGMV. G 35172 also is variable for WM reaction. VCW 54 has scarlet flowers, purplish black seed, and the highest WM resistance. VCW 55 has white with pink‐striped flower, black seed, and an intermediate level of WM resistance. Both IBL also have growth habit Type II, small seeds, and are late maturing, requiring ≥100 d from planting to maturity in southern Idaho. White mold resistance from VCW 54 and VCW 55 should be pyramided with WM resistance from across Phaseolus species and introgressed into common bean cultivars using appropriate crosses, population sizes, and disease screening and selection methods.

IPR Celeiro is a common bean (Phaseolus vulgaris L.) cultivar with a carioca-type seed and moderate resistance to Bean Golden Mosaic Virus (BGMV). IPR Celeiro has a normal life cycle and an upright architecture. This cultivar was released for the purpose of integrating its use with disease management systems in the cultivation areas affected by this virus.

SummarySixteen common bean (Phaseolus vulgaris L.) cultivars with different life cycles and growth habits were intercropped with four maize cultivars, to evaluate the competitive ability of each yield component, following a methodology similar to that used for diallel crosses. The experiments were done in 1991 at two sites in Brazil. The intercropping combinations were evaluated using an 8 × 8 quadratic lattice design with three replications. Two other experiments were done on monocultures, using a randomized complete block design with three replications. The variable considered was ‘maize equivalent yield’, obtained by adjusting for the price difference between the species. The method used showed that the differences in performance of the many intercropped combinations can be explained by ‘general complementing ability’ (gĉa) of each cultivar, since there was no significant effect of ‘specific complementing ability’ (sĉa). The best maize cultivars to be intercropped with common bean (indicated by high gĉa values) were BR–201 and C–525, which produced high grain yields when intercropped without detrimental effects on legume yields. FT–84–292, Carioca 300V and ESAL506 were the common bean cultivars with the highest yields when intercropped, which was also reflected in their good performance in monoculture. Significant cultivar × location interactions occurred only in monocultures, supporting the belief that intercropping is a more stable cropping system.

O objetivo deste trabalho foi identificar progênies de feijoeiro (Phaseolus vulgaris) na geração F4 provenientes do cruzamento entre cultivares resistentes ao Bean golden mosaic virus (BGMV). Os parentais foram as cultivares Carioca-MG (suscetível) e IAPAR-57, IAPAR-72 e IAPAR-65 (resistentes). A população de 480 progênies foi obtida pelo modelo dialélico completo. Estas foram semeadas em campo sob inoculação natural e estudada ao nível de plantas individuais para cálculo do índice de doença de BGMV (I.D.) Em relação ao I.D. médio, as progênies foram mais resistentes do que seus parentais (2,62 e 2,87), respectivamente. O processo de seleção foi realizado pelo I.D. (sigmag² = 0,2729 e h a² = 0,3953), onde foram obtidas famílias com grãos do tipo carioca e com I.D. inferior aos parentais resistentes. Segundo o GS% estimado, não serão necessárias muitas progênies ou famílias para se obter progresso com seleção para BGMV. O genótipo IAPAR-72 foi o parental superior na obtenção de progênies de maior resistência (menores I.D.). Possivelmente o mecanismo de resistência é do tipo resistência parcial.

Bean Golden Mosaic Virus and Bean Golden Yellow Mosaic Virus (Geminiviridae)

An experiment was conducted in the greenhouse to evaluate the effects of seed phosphorus (P) concentration on growth, nodulation, and nitrogen (N) and P accumulation of three common bean (Phaseolus vulgaris L.) cultivars. Seeds were produced under low or high soil P levels, and soaked, or not, in 200 mM KH2PO4 solution. The experiment had a 3×3×2×2 factorial block design: three cultivars (ICA Col 10103, Carioca and Honduras 35), three levels of applied P (15, 30 and 45 mg P kg−1 soil), two native seed P concentrations, and two seed soaking treatments. Plants were harvested at flowering. Soaked seeds increased the number, dry mass and P content of nodules, but did not affect plant growth. Plants originated from seeds with high native P concentration presented higher shoot dry mass and nodule number and mass at every soil P level, and were less responsive to increased soil P supply, than plants from low seed P. In plants from seeds with high P, soil P levels did not alter significantly root dry mass, while in plants from seeds with low P bean cultivars expressed wider differences in root dry mass. The genotypic variability of nodulation was influenced by soil P levels and seed P concentration. Both higher soil or seed P supply enhanced N and P accumulation in shoots. These results indicate that a high seed P concentration produces plants less dependent on soil P supply, and can enhance nodulation and N2 fixation of common bean. Seed P supply affected the cultivar performance, and should be considered in evaluation of bean genotypes.

A study was undertaken comparing the water requirements of two common bean ( Phaseolus vulgaris L.) cultivars to generate specific recommendations aimed at optimizing water use. To accomplish this work, the agronomic performance, responsiveness to water and water productivity of these two common bean cultivars of determinate and indeterminate growth habits were identified. The 2-year experiment was carried out during the winter growing season in the southeast of Brazil. Cultivars IAC Imperador, with an early season of determinate growth habit, and IPR Campos Gerais, having a mid-season of indeterminate growth habit, were subjected to five irrigation levels (54, 70, 77, 100, and 132 % of the crop evapotranspiration). Water deficit affected agronomic performance, reducing plant height (by up to 29 %), leaf area index (by up to 40 %), soil cover fraction (by up to 28 %), and grain yield (GY - by up to 31 %), in both cultivars. In contrast, excess water was more detrimental to cultivar IAC Imperador. Cultivar IPR Campos Gerais produced 18 % more than GY, showing superior water productivity and response to irrigation depth than IAC Imperador. Out of all the variables evaluated, the soil cover fraction correlated the most with grain yield in both common bean cultivars during the 2-year study. In other words, cover fraction evaluation in common bean allows for estimating crop production potential, which helps producers and technicians in their decision making regarding management practices. Thus, a cultivar directly affects water use in common bean production, thereby suggesting the need for a or water conservation strategy and sustainability of irrigated common bean production.

Molecular characterization of the first commercial transgenic common bean immune to the Bean golden mosaic virus