Enhancing growth,yield, biochemical,and hormonal contents of snap bean (Phaseolus vulgaris L.) sprayed with moringa leaf extract

Increasing growth and productivity of food crops via safe biostimulants is a very important issue in the current years. This study aimed to investigate the potential of moringa leaf extract (MLE) in improving the performance of snap bean (Phaseolus vulgaris L.) cv. ‘Paulista’ under field conditions. Hormonal analysis of MLE revealed its richness of various classes of phytohormones particularly salicylates. The results revealed that all MLE concentrations had a positive effect on growth, biochemical, yield, and yield related traits as well as yield quality of snap bean compared to control, and the effect was dose-dependent. Moreover, increasing pods yield of snap bean may be related to gibberellins (GA₇) content than other plant hormones. In conclusion, the leaf extract of moringa provides a good source of phytohormones that have a positive role to stimulate growth and productivity of snap bean plants.     

普通菜豆种质资源苗期抗旱性综合评价

我国普通菜豆的主产区主要分布在干旱、半干旱地区。干旱是影响其生长的主要因素之一。为了筛选抗旱种质资源以及建立抗旱性评价方法,以50份来源不同的普通菜豆品种为材料,采用盆栽法,设正常供水和干旱胁迫2种处理,在干旱胁迫12 d和复水3 d后分别取样测定各项形态和生理指标;采用干旱胁迫和复水后两者的抗旱度量值(D值)、聚类分析和逐步回归方程以及通径分析相结合的方法,对普通菜豆进行苗期的抗旱鉴定及抗旱指标的筛选。结果表明,干旱12 d后超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性,复水3 d后相对叶绿素含量、相对含水量与各自D值显著相关,两处理的丙二醛(MDA)含量与各自D值极显著相关。根据各自D值进行聚类分析,将50份供试材料进行抗旱级别分类,两处理分类结果的一致率达到40%,邻级率为60%,未出现跨级材料;综合两处理的分类结果进一步细分,可分为高抗、中高抗、中抗、中低抗和低抗5个抗旱级别,其中高抗材料10份、中高抗材料25份、中抗材料7份、中低抗材料6份、低抗材料2份。综上所述,普通菜豆苗期干旱胁迫和复水后的D值相互判定的方法可提高鉴定结果的可靠性;干旱胁迫下的SOD活性、POD活性、MDA含量和复水后的相对叶绿素含量、相对含水量、MDA含量可作为普通菜豆苗期抗旱性鉴定的指标,尤其是两者的MDA含量可直接用于普通菜豆资源的抗旱性鉴定。本研究为简化鉴定筛选工作提供了方法和理论依据。     

Growth traits,physiological parameters and hormonal status of snap bean (Phaseolus vulgaris L.) sprayed with garlic cloves extract

Garlic extract has been established to enhance the growth and yield of some plant crops, but little is known about its content of phytohormones. A field study was carried out, in two growing seasons, to evaluate the performance of snap bean (Phaseolus vulgaris L.) cv. ‘Paulista’ in terms of growth traits, biochemical parameters, hormonal status and yield characteristics in response to two-time foliar spray at 30 and 45 days after sowing with three concentrations (1:40, 1:20 and 1:10) of garlic cloves extract (GCE). The experiment was designed in completely randomized blocks in a factorial arrangement with three replicates. The hormonal analysis indicated that GCE contains high levels of various phytohormones particularly salicylates, auxins, and gibberellins. Plant height, leaf area, leaves number, plant weight, flowers number and leaf and pod chemical compositions were significantly enhanced in response to GCE. The high dose of GCE caused the maximum increase in number of pods, pod fresh weight as well as the total pod yield. This stimulating effect of GCE may be due not only to its nutritional factors but also to its richness of phytohormones and phenolic compounds, and it can be further used as a plant growth promoter (PGP).     

Modifications to physicochemical and nutritional properties of hard-To-cook beans (Phaseolus vulgaris L.) by extrusion cooking.

The objective of this work was to evaluate extrusion cooking as a means to improve the nutritional properties of Phaseolus vulgaris L. that had been stored either at 42 degrees C and 80% relative humidity for 6 weeks or for periods >1 year in cereal stores in tropical conditions. Storage under these conditions resulted in an increase in cooking time increased (7.7- and 12-fold, respectively) as a result of development of the hard-to-cook (HTC) defect. Single-screw extrusion of the milled beans was carried out at four barrel temperatures and two moisture contents. The extrudate bulk density and water solubility index decreased with increasing temperature, whereas the water absorption index increased due to the higher proportion of gelatinized starch in the extruded samples. Both fresh and HTC beans contained nutritionally significant amounts of lectins, trypsin, and alpha-amylase inhibitors, which were mostly inactivated by extrusion. Extrusion also caused a considerable redistribution of insoluble dietary fiber to soluble, although the total dietary fiber content was not affected. Changes in solubility involved pectic polysaccharides, arabinose and uronic acids being the main sugars involved. Stored beans subjected to extrusion cooking showed physical and chemical characteristics similar to those of extrudates from fresh beans.     

Polyphenols in wild and weedy Mexican common beans (Phaseolus vulgaris L.)

The polyphenolic composition of 62 wild and weedy Mexican bean collections from diverse origins, grouped by their seed coat color, was assessed. According to spectrophotometric analysis, the range of total phenols, condensed tannins, and total anthocyanins presented wide differences. Furthermore, the phenolic acid, flavonoid, and anthocyanin profiles were analyzed using HPLC. Ferulic was the main phenolic acid. Kaempferol and quercetin were the main flavonoids, and the isoflavones daidzein and coumestrol were found in only low levels in few collections. Delphinidin was the main anthocyanidin found, followed by petunidin, cyanidin, malvidin, pelargonidin, and peonidin. The wide variation observed in polyphenolic contents was more related to their genotype than to the color factor. These results show that some wild and weedy beans are good sources of phenolic compounds for use in breeding programs focused on nutrition and health.     

Physicochemical, nutritional, and microstructural characteristics of chickpeas (Cicer arietinum L.) and common beans (Phaseolus vulgaris L.) following microwave cooking

Microwave cooking of legumes such as chickpeas and common beans was evaluated by assessing the cooking quality (cooking time, firmness, cooking losses, and water uptake) and the physicochemical, nutritional, and microstructural modifications in starch and nonstarch polysaccharides. Compared to conventional cooking, microwave cooking with sealed vessels enabled a drastic reduction in cooking time, from 110 to 11 min for chickpeas and from 55 to 9 min for common beans. The solid losses, released in the cooking water, were significantly less after microwave cooking than after conventional cooking (6.5 vs 10.6 g/100 g of dry seed in chickpeas and 4.5 vs 7.5 g/100 g of dry seed in common beans). Both cooking procedures produced a redistribution of the insoluble nonstarch polysaccharides to soluble fraction, although the total nonstarch polysaccharides were not affected. Increases in in vitro starch digestibility were similar after both cooking processes, since the level of resistant starch decreased from 27.2 and 32.5% of total starch in raw chickpeas and beans, respectively, to about 10% in cooked samples and the level of rapidly digestible starch increased from 35.6 and 27.5% to about 80%. SEM studies showed that the cotyledons maintained a regular structure although most of the cell wall was broken down and shattered by both cooking procedures. In addition, the ultrastructural modifications in the cotyledon's parenchima and cells are consistent with the chemical modifications in NSP and the increase in starch digestibility after cooking.     

Yield and yield components of white bean (Phaseolus vulgaris L.) cultivars affected by boric acid rates and methods of application

To investigate the effect of boric acid on yield and yield components of three white bean cultivars consisted of Jules, G11867, and Shekoofa, a 2-year field split-plot experiment was carried out based on a randomized complete block design with three replications during 2013 and 2014. Boron treatments consisted of 1 – control (no boric acid), 2 and 3 – application of 2 and 4?kg ha^?1 of boric acid by irrigation water, respectively, 4 and 5 – foliar spray of 0.025% and 0.05% of boric acid solutions, respectively, and 6 – combination of 2?kg ha^?1 of boric acid in irrigation water?+?foliar spray by 0.025% boric acid solution. Boron application significantly increased yield and its components in respect to control. The highest grain yields of all cultivars were obtained from application of 2?kg ha^?1 boric acid mixed in irrigation water?+?foliar spray by 0.025% of boric acid solution.     

Inoculation response in kidney beans (Phaseolus vulgaris,L.) to vesicular-arbuscular mycorrhizal fungi and rhizobia in non-sterilized soil

The effect of dual inoculation on three local cultivars (Miss Kelly, Portland Red, Round Red) of red kidney beans (Phaseolus vulgaris, L.) with four strains of Rhizobium leguminosarum bv. phaseoli and three species of vesicular-arbuscular mycorrhizal (VAM) fungi was examined in a clay loam soil. Rhizobial strains B 17 and B 36, each paired with Glomus pallidum or G. aggregatum, were the most effective pairings for cv. Miss Kelly. Inoculation of Miss Kelly with any of these pairings significantly (P=0.05) increased growth, number of nodules, nodule dry weight, mycorrhizal colonization, and shoot N and P content than other pairings. The growth response by cv. Portland Red was significantly improved by pairings of B 36 or B 17 with any of the three VAM fungi. For both cultivars (Miss Kelly and Portland Red), CIAT 652 or T 2 paired with VAM fungi did not give a positive growth response. In contrast, for cv Round Red the T 2 rhizobial strain in combination with any of the three VAM fungi showed a significant (P=0.05) growth improvement in all parameters. Our results suggest that while dual inoculation of VAM fungi and rhizobia significantly improves the growth response by red kidney beans, the best pairings of VAM fungus and rhizobia for each cultivar need to be carefully selected.     

Rhizobium Proliferation-Supporting Substances in Seed Exudates of Common Bean (Phaseolus vulgaris L.)

Seed exudates collected from three cultivars (cv. Hokkaikintoki, Himetebou, and Kurodane-kinugasa) of common bean ( Phaseolus vulgaris L.) were fractionated based on several physicochemical properties, and the nutrient substances in the fractions effective for Rhizobium proliferation were determined. Regardless of the common bean cultivars, the low molecular weight and high polarity fraction showed the most beneficial effect on Rhizobium proliferation. After further separation of the low molecular weight and high polarity fraction, the promoting effect was detected in the non-ionic and the cationic plus ampho-teric subtractions. Although the amount of sugars or amino acids exuded from a seed was, respectively, similar in all the cultivars except for the sugars in Kurodanekinugasa, the content of these compounds per seed-weight was inversely proportional to the seed size. Ten sugars and twenty-one amino acids were, respectively, identified in the non-ionic and cat-ionic plus amphoteric subtractions, and there were some differences in the composition of these substances between common bean cultivars.     

Competitive interaction among strains of Rhizobium leguminosarum bv. phaseoli in the nodulation of kidney beans (Phaseolus vulgaris L.)

We examined the competitiveness of five effective Rhizobium leguminosarum biovar phaseoli strains in the nodulation of kidney beans (Phaseolus vulgaris L.), either alone or in pairwise combination, against the indigenous strains. The results showed that the introduced Rhizobium sp. strains (B2, B17, B36, T2, or CIAT 652) occupying 64–79% of the total nodules (as single inocula) were more competitive in nodulation than the native rhizobia. However, the competitiveness of the individual Rhizobium sp. strain either increased or decreased when used in a pairwise combination of double-strain inocula. For example, strain B17, although quite competitive against the indigenous population (68% nodule occupancy), became poorly competitive in the presence of strain B2 (reduced from 68 to 2.5%). A similar reduction in nodule occupancy by strain B17 was observed in the presence of B36 or CIAT 652, indicating that two competitive strains may not always be compatible. These results suggest that it is important to co-select competitive as well as compatible rhizobia for multistrain inoculant formulation.     

Antioxidant activity of processed table beets (Beta vulgaris var, conditiva) and green beans (Phaseolus vulgaris L.)

It has been shown that thermal processing of tomatoes and sweet corn results in increased antioxidant activities despite the loss of vitamin C. Until now, it is unclear whether this positive effect of thermal processing occurs with all crop produce. Therefore, analysis of a root vegetable (beets) and of a legume (green beans) was undertaken to address this question. Antioxidant activity of beets processed under typical commercial processing conditions remained constant despite an 8% loss of vitamin C, a 60% loss of color, and 30% loss of dietary folate. There was a slight but significant 5% increase in phenolic content of processed beets. In contrast, vitamin C and dietary folate content of green beans remained constant, whereas a 32% reduction in phenolic compounds occurred after typical commercial processing conditions. The antioxidant activity of green beans was reduced by 20%. These findings along with previous works suggest that the effects of thermal processing vary with the respective produce crop type. It also reinforces the concept that optimal health benefits may be achieved when a wide variety of plant foods (fruits, vegetables and whole grains) and preparation methods are incorporated into the diet.     

The inorganic N requirement,nodulation and yield of common bean (Phaseolus vulgaris L.) as influenced by inherent soil fertility of eastern Ethiopia

Though mineral N application impaired nodulation initiation and function, it improves the productivity of common bean. The effect of inorganic application on common bean productivity, however, is dependent on the availability of plant nutrients including nitrogen (N) in the soils. Therefore, multilocation field experiments were conducted at Babillae, Fedis, Haramaya, and Hirna to evaluate the effect of inherent soil fertility status on responsiveness of common bean to different rates of N fertilizer application and its effect on nodulation, yield, and yield components of common bean. The treatments were six levels of N fertilizer (0, 20, 40, 60, 80, and 100 kg N ha^?1) laid out in randomized completed block design with three replications. The result revealed that 20 kg N ha^?1 application significantly improved the nodule number (NN) and nodule dry weight (NDW) except Hirna site, in which reduction of NN and NDW was observed. Although the remaining investigated yield and yield components were significantly improved due to N fertilizer in all study sites, 40 kg N ha^?1 application resulted in significantly increased GY of common bean at Fedis, Haramaya, and Hirna site, while 60 kg N ha^?1 at Babillae site. The highest total biomass yield (7011.6 kg ha^?1) and GY (2475.28 kg ha^?1) of common bean were recorded at Hirna and Haramaya sites, respectively, indicating the importance of better fertile soil for good common bean production. Hence, it can be concluded that the effect of inorganic N on common bean was irrespective of soil fertility rather the total amount of N in soil would affect the need of different rate of inorganic N.     

Breeding for bean fly resistance in common bean (Phaseolus vulgaris L.): a review

The bean fly (Ophiomya spp) is the most important yield limiting insect pest of common bean in Africa. The insect pest can cause complete crop loss affecting bean production and productivity under epidemic conditions. Effective control of bean fly is essential for sustainable bean production Africa. The overall progress, opportunities and challenges of the bean fly control strategies. The biology and ecology of bean fly and the economic importance of the insect pest is presented as well as the existing controlling strategies, with an emphasis on the breeding on breeding strategies used, research progress achieved challenges and opportunities. In conclusion, significant research progress have been made in breeding for bean fly resistance evident by identification of breeding lines, understanding resistance mechanism and development of breeding strategies. However, there is a need for further research to validate the available information and also explore new breeding methods such molecular breeding which has not been explored at present. Such studies will accelerate breeding for bean fly resistance.     

Effect of fermentation and autoclaving on dietary fiber fractions and antinutritional factors of beans (Phaseolus vulgaris L.)

The effect of fermentation on antinutritional factors and also on total dietary fiber (TDF), insoluble (IDF) and soluble (SDF) dietary fiber fractions was studied in beans (Phaseolus vulgaris L.). The processes studied were two types of fermentation (lactic acid and natural), and a portion of the obtained flours were processed by autoclaving. The dietary fiber (DF) content and its components were determined using the enzymatic-gravimetric and enzymatic-chemical methods. The TDF content ranged from 24.5% dry matter (DM) in the raw to 25.2% DM in the processed beans. All the processing treatments significantly decreased the SDF content, and irrelevant changes were noticed in the IDF content of processed beans. Cellulose content of all samples was reduced by the processing treatments. Correspondingly, higher amounts of resistant starch was observed in the processed beans, except in the lactic acid fermented ones. However, the levels of pectic polysaccharides and Klason lignin were higher in the samples fermented by Lactobacillus plantarum. The action of microorganisms was determinant for the different degradation of the bean cell wall, disrupting the protein-carbohydrate integration, thus reducing the solubility of DF.     

Near-infrared spectroscopy analysis of seed coats of common beans ( Phaseolus vulgaris L.): a potential tool for breeding and quality evaluation

Near-infrared spectroscopy (NIRS) is a well-established technique for determining the components of foods. Sample preparation for NIRS is easy, making it suitable for breeding and/or quality evaluation, for which a large number of samples should be analyzed. We aimed to assess the feasibility of NIRS to estimate parameters that seem to influence consumers' perception of the seed coat of common beans: dietary fiber (DF), uronic acids (UA), ashes, calcium, and magnesium. We used reference methods to analyze ground seed coats of 90 common bean samples with a wide range of genetic variability and cultivated at many locations. We registered the NIR spectra on intact beans and ground seed coat samples. We derived partial least-squares (PLS) regression equations from a set of calibration samples and tested their predictive power in an external validation set. For intact beans, only RER values for ashes and calcium are good enough for very rough screening. For ground seed coat samples, the RPD and RER values for ashes (3.49 and 14.09, respectively) and calcium (3.57 and 12.70, respectively) are good enough for screening. RPD and RER values for DF (2.60 and 9.15, respectively) and RER values for magnesium (6.57) also enable rough screening. A poorer correlation was achieved for UA. We conclude that NIRS can help in common bean breeding research and quality evaluation.     

Effect of natural and controlled fermentation on chemical composition and nutrient dialyzability from beans (Phaseolus vulgaris L.)

The effect of natural and controlled fermentation with an inoculum of Lactobacillus plantarum and additional thermal treatment (dry heat at 120 degrees C for 20 min) on the availability of N, P, Fe, Cu, Zn, Ca, and Mg from Phaseolus vulgaris L. var. carrilla was estimated using an in vitro method based on equilibrium dialysis. Natural and controlled fermentations caused significant reductions in the pH and phytate content (36%) of the bean flours, with a concomitant increase in the titratable acidity and free phosphorus content, and had no effect on the other nutrients studied. The percentage of dialyzable N, P, Cu, and Mg was significantly improved by both types of fermentation, whereas Zn dialyzability was significantly reduced. The greatest reduction was observed for the bean flour fermented with an inoculum of L. plantarum. The percentage of dialyzable Fe improved significantly as a result of natural fermentation but was not affected by controlled fermentation. The application of dry heat at 120 degrees C for 20 min caused a significant increase in Fe dialyzability and a further reduction in the percentage of dialyzable Zn in fermented bean flours but did not affect the dialyzability of the other nutrients studied.     

Changes in polyphenols of the seed coat during the after-darkening process in pinto beans (Phaseolus vulgaris L.)

Proanthocyanidins and flavonoids were isolated and identified from seed coats of two aged and nonaged pinto bean lines: 1533-15 and CDC Pintium. The seed coat of 1533-15 darkens slowly and never darkens to the same extent as CDC Pintium. Analysis of the overall level of proanthocyanidins using a vanillin assay demonstrated that aged and nonaged seed coats of CDC Pintium had significantly higher levels of proanthocyanidins than aged and nonaged 1533-15 seed coats. Aged and nonaged seed coats of both lines were found to contain one main flavonol monomer, kaempferol, and three minor flavonols, kaempferol 3-O-glucoside, kaempferol 3-O-glucosylxylose, and kaempferol 3-O-acetylglucoside. These compounds were identified by NMR and ESI-MS analysis (except for kaempferol 3-O-acetylglucoside, which was tentatively identified only by ESI-MS analysis) and quantified using HPLC-DAD. The combined concentrations of all the kaempferol compounds in seed coats of CDC Pintium were significantly higher than in seed coats of 1533-15, and the combined contents did not change after aging. The content of kaempferol decreased nearly by half in the seed coats of CDC Pintium after aging, whereas no significant change was observed in the seed coats of 1533-15. Proanthocyanidin fractions from both lines, aged and nonaged, were subjected to LC-MS/MS analysis and found to be composed primarily of procyanidins. Procyanidins in the seed coats were predominantly polymers with the degree of polymers higher than 10. The proportion of these polymers decreased after aging, while that of the low-molecular-weight procyanidins increased. A catechin-kaempferol adduct was tentatively identified in both lines by LC-MS/MS, and the concentration increased in the seed coats after aging.     

Effect of exudate released from seeds and seedling roots of common bean (Phaseolus vulgaris L.) on proliferation of Rhizobium sp. (Phaseolus)

Effects of seed and root exudates obtained from common bean on the proliferation of Rhizobium sp. (Phaseolus) were examined in a combination of three plant cultivars with three Rhizobium strains. In the first experiment, seed or root exudate was mixed with an Andosol soil extract, and bacterial proliferation in the mixture was traced. Seed exudate was prepared from hydroponic solution used in seed imbibition for 24 h, and a series of root exudates was prepared from a hydroponic solution collected every 24 h from the initiation of rooting up to 96 h after rooting. Regardless of the common bean cultivars and Rhizobium strains used, Rhizobium population markedly increased of the 24 h of culture in the mixture containing seed exudates, whereas a negligible increase was detected in the mixture with root exudates. The mixture containing root exudates collected within a period of 72–96 h after initial rooting (96–120 h after seed imbibition) exerted an inhibitory effect on Rhizobium proliferation. The seed exudates contained large amounts of sugars, amino acids, nitrogen, phosphorus, potassium, and magnesium compared to any root exudates. In the second experiment, Rhizobium was inoculated directly to common bean seeds sowed in a vermiculite bed which was sterilized and moistened with a plant nutrient solution. Compared with the control (without seed), a remarkable increase in the number of bacterial cells was observed in all the combinations of plant cultivars and Rhizobium strains 24 h after sowing. These results reveal that seed exudates of common bean have a substantial potential to promote Rhizobium proliferation, and that root exudates in a particular period of culture contain some inhibitory factors.     

Bioaccessibility of phenols in common beans ( Phaseolus vulgaris L.) and iron (Fe) availability to Caco-2 cells

Samples of common and biofortified beans ( Phaseolus vulgaris ), both raw and cooked (autoclaved at 120 degrees C for 20 min) were analyzed for their polyphenol composition. Polyphenols were identified via HPLC-UV/diode array detection. Cooking favored the extraction of polyphenols without the need of a hydrolysis step, a fact that is of interest because this is the usual form in which beans are consumed. The main differences between white and colored beans were the presence of free kaempferol (13.5-29.9 microg g(-1)) and derivatives (kaempferol-3-O-glucoside) (12.5-167.5 microg g(-1)), only in red and black beans. An in vitro digestion (pepsin, pH2; pancreatin-bile extract, pH 7) was applied to beans to estimate bioaccessibility of individual polyphenols. Kaempferol from seed coats exhibited high bioaccessibility (45.4-62.1%) and a potent inhibitor effect on Fe uptake at concentrations ranging from 0.37 to 1.30 microM. Caco-2 cell ferritin formation was used to evaluate Fe uptake. Cell Fe uptake was significant only from white beans.