51,815 research outputs found
Correlation of physio-chemical characteristics in the seed coat and canning quality in different dark red kidney bean (Phaseolus vulgaris l.) cultivars
No full textPlan BThe canned kidney bean (Phaseolus vulgaris L.) is one of the major consumption forms of this agricultural product. In the canning industry, seed coat splitting is considered one factor affecting the integrity of the appearance in the final product. Three different dark red kidney bean cultivars (85, 453 and Nickols) grown in the Wisconsin area were studied in this research. The physiochemical properties in this study included moisture content, the seed coat to whole seed weight ratio, the weight per seed, ash, mineral (sodium, calcium, iron, potassium and magnesium) and total crude protein content in the seed coat. The correlations of these properties with the seed coat splits were investigated. In the canned product, highly significant differences (P<0.01) in percentage of split seed coat were found among the three cultivars studied. Canned cv. 85 had significantly fewer seed coat splits than the other two cultivars. Cv. 85 was significantly higher in moisture content, as well as ash, sodium, calcium and iron content in the seed coat. The seed coat of cv. 453 was significantly higher in magnesium, and total crude protein. Cv. Nickols was found to be significantly higher in the weight per bean and seed coat splits after the canning process. Significant negative correlations were found between the percentage of seed coat splits, sodium (r = -0.89, p< 0.01), calcium (r = -0.74, P< 0.01) and iron content (r = -0.79, P< 0.05) in the seed coat. A positive correlation was found between sodium content and calcium content (r = 0.69, P< 0.05) in the seed coat. Increased calcium content in the seed coat was accompanied with increased sodium content. A significant positive relationship (r = 0.901, P< 0.01) was found between seed weight and the percentage of seed coat splits. This research suggested that several physiochemical factors of the seed coat, including weight per seed, sodium, calcium, and iron content, might play important roles in the integrity of the seed coat during the thermal processing
Life history parameters of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) at different environmental conditions on two bean cultivars
No full textLife-history parameters of the greenhouse whitefly Trialeurodes vaporariorum (Westwood), an important pest of bean crops in Colombia, were determined in environmental control chambers on two dry bean (Phaseolus vulgaris) cultivars (cv.). Trialeurodes vaporariorum longevity on cv. Chocho decreased as temperature increased from 22.6 d at 19ºC to 5.9 d at 26ºC. Fecundity was significantly lower at 19ºC (8.6 eggs/female), as compared to 22ºC (32.6 eggs/female) and 26ºC (33.3 eggs/female) on cv. Chocho. Fecundity on cv. ICA-Pijao was much higher (127.2 eggs/female) than on cv. Chocho (32.6 eggs/female) at 19ºC. The intrinsic rate of population increase (rm) was highest at 22ºC (0.061), intermediate at 19ºC (0.044) and lowest at 26ºC (0.035) on cv. Chocho, and was 0.072 on cv. ICA-Pijao at 19ºC. Life history parameters of T. vaporariorum are compared to those of one of its natural enemies, the parasitoid Amitus fuscipennis MacGown & Nebeker. Finally, data are presented on the distribution of the parasitoid related to the altitude for the Valle del Cauca, Colombi
Biochemical basis of insect resistance in winged bean (Psophocarpus tetragonolbus): characterisation of insecticidal proteins and their encoding genes
No full textMany pulses and beans grown for human comsumption are susceptible to insect attack. Winged bean, a high protein crop of the tropics, yield seeds which appear to be immune to infestation by the storage bruchid Callosobruchus maculatus. In this thesis the biochemical basis of this resisitance was investigated. Insect bio-assays were carried out in which protein fractions from seeds of winged bean were incorporated at a range of concentrations into artificial seeds, and their effects upon the development of C.maculatus determined. Both albumin and globulin fractions were toxic to the developing larvae and their toxicity correlated with their haemagglutination activity. Assay of psophocarpin fractions A, B and C found the fraction psophocarpin B to be most insecticidal. On further purification this fraction yielded two lectin fractions and a protease inhibitor fraction. Purified basic lectin was highly insecticidal to C. maculatus larvae with an LC(_50) value of 0.35%. The physiological level of this protein in winged bean seeds is sufficient to account for their resistance to attack by C maculatus. Winged bean trypsin inhibitor was also purified and tested in artificial seeds against C maculatus. However, even at concentrations in excess of twice the physiological concentration it had no deleterious effects upon development. Winged bean protein fractions, incorporated in artificial diets, proved toxic to the Lepidopteran pests Heliothis virescens and Spodoptera littoralis in bio-assays, but it appeared that the basic lectin was not responsible for toxicity towards these insects. Attempts to clone the gene encoding the winged bean basic lectin were made by constructing cDNA and genomic libraries, and heterologous lectin genes from soybean and Phaseolus were investigated as possible probes for the basic lectin gene. Purification of the basic lectin B3 and sequencing of 44% of its primary protein structure, along with comparisons with other legume lectin sequences allowed the synthesis of oligonucleotide primers for use in polymerase chain reaction experiments. However, all the PGR products obtained were shown to be the result of non-specific amplification. Further work needed to obtain the basic lectin gene is discussed
Breeding phaseolus vulgaris (common bean) for resistance to the major pest bruchids Zabrotes subfasciatus and Acanthoscelides obtectus. Biochemical bases for seed resistance in wild lines
No full textPhaseolus vulgaris (common bean) is an important source of protein for human and animal consumption. Economic losses post-harvest in storage are primarily due to the bruchid beetles Acanthoscelides obtectus (Bean Weevil) and Zabrotes subfasciatus (Mexican Bean Weevil). Wild-lines exhibiting resistance to these two species have been found and the mechanisms of resistance to each species are investigated. The mechanisms of resistance to the two species are found to be multiple, and different for each species. In the case of Z. subfasciatus, the presence of a novel storage protein and absence of the conventional storage protein constitutes the primary mechanism. The novel protein ("arcelin") is antimetabolic when included in artificial diets. In vitro digestibility studies indicate that it is indigestible to Z. subfasciatus larval gut proteases, and since arcelin constitutes the major protein of the seed the larvae starve. Arcelin has a similar amino- acid sequence to PHA. Also present is WBAI, a highly specific inhibitor of larval amylase of the two bruchid pests Z. subfasciatus and Callosobruchus maculatus, whilst having virtually no inhibitory activity on the mammalian amylase, nor on other insect, bacterial nor fungal enzymes. WBAI is similar in gross structure to the conventional amylase inhibitor obtainable from RKB (commercial P. vulgaris), and both are also immunologically similar to PHA. Both of these mechanisms are suitable for incorporation into commercial seed, and the former has already been tested, using meal from seeds, in feeding trials using rats, confirming absence of mammalian toxicity. Resistance to A. obtectus damage is accompanied by reduced starch content, and high content of an acidic polysaccharide (whose structure has not been elucidated). No protein cause for resistance was found. Inheritance of resistance to A. obtectus is recessive. Since the factor responsible for resistance is not a primary gene product and is expressed recessively, this factor is unsuitable for incorporation into breeding lines to be used for developing commercial cultivars
Biostimulants on the seed germination and seedlings vigor of snap bean cultivars
No full textThe snap bean is a legume of the same botanical species as the common bean plant (Phaseolus
vulgaris). For being a vegetable of great economic return, the use of bioregulators in its
production presents a great potential. The present work aimed to evaluate the effects of the
application of four commercial chemicals upon the germination and vigor of snap-bean
seedlings
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Complex toxic effects of Cd2+, Zn2+, and acid rain on growth of kidney bean (Phaseolus vulgaris L)
No full textComplex toxic effects of Cd2+, Zn2+, and acid rain on growth of kidney bean (Phaseolus vulgaris L) were studied in a pot experiment by measurement of fresh weights of the plants, determination of surperoxide dismutase (SOD), peroxidase (POD), and lipid peroxidation (MDA) in the plant organs, and observation of injury symptoms. The experimental results demonstrated that all treatments of Cd2+, Zn2+, and/or acid rain significantly decreased fresh weights of kidney bean and caused toxic effects on growth of the plants, especially higher amounts of Cd2+ and Zn2+ and higher acidity of acid rain. Combination of these three pollutant factors resulted in more serious toxic effects than any single pollutant and than combinations of any two pollutants. SOD, POD, and MDA in the plant organs changed with different pollution levels, but MDA content in the leaves showed the best relationship between the pollution levels and toxic effects
Construction of a comparative genetic map in faba bean (Vicia faba L.); conservation of genome structure with Lens culinaris
No full textBackground
The development of genetic markers is complex and costly in species with little pre-existing genomic information. Faba bean possesses one of the largest and least studied genomes among cultivated crop plants and no gene-based genetic maps exist. Gene-based orthologous markers allow chromosomal regions and levels of synteny to be characterised between species, reveal phylogenetic relationships and chromosomal evolution, and enable targeted identification of markers for crop breeding. In this study orthologous codominant cross-species markers have been deployed to produce the first exclusively gene-based genetic linkage map of faba bean (Vicia faba), using an F6 population developed from a cross between the lines Vf6 (equina type) and Vf27 (paucijuga type).
Results
Of 796 intron-targeted amplified polymorphic (ITAP) markers screened, 151 markers could be used to construct a comparative genetic map. Linkage analysis revealed seven major and five small linkage groups (LGs), one pair and 12 unlinked markers. Each LG was comprised of three to 30 markers and varied in length from 23.6 cM to 324.8 cM. The map spanned a total length of 1685.8 cM. A simple and direct macrosyntenic relationship between faba bean and Medicago truncatula was evident, while faba bean and lentil shared a common rearrangement relative to M. truncatula. One hundred and four of the 127 mapped markers in the 12 LGs, which were previously assigned to M. truncatula genetic and physical maps, were found in regions syntenic between the faba bean and M. truncatula genomes. However chromosomal rearrangements were observed that could explain the difference in chromosome numbers between these three legume species. These rearrangements suggested high conservation of M. truncatula chromosomes 1, 5 and 8; moderate conservation of chromosomes 2, 3, 4 and 7 and no conservation with M. truncatula chromosome 6. Multiple PCR amplicons and comparative mapping were suggestive of small-scale duplication events in faba bean. This study also provides a preliminary indication for finer scale macrosynteny between M. truncatula, lentil and faba bean. Markers originally designed from genes on the same M. truncatula BACs were found to be grouped together in corresponding syntenic areas in lentil and faba bean.
Conclusion
Despite the large size of the faba bean genome, comparative mapping did not reveal evidence for polyploidisation, segmental duplication, or significant rearrangements compared to M. truncatula, although a bias in the use of single locus markers may have limited the detection of duplications. Non-coding repetitive DNA or transposable element content provides a possible explanation for the difference in genome sizes. Similar patterns of rearrangements in faba bean and lentil compared to M. truncatula support phylogenetic studies dividing these species into the tribes Viceae and Trifoliae. However, substantial macrosynteny was apparent between faba bean and M. truncatula, with the exception of chromosome 6 where no orthologous markers were found, confirming previous investigations suggesting chromosome 6 is atypical. The composite map, anchored with orthologous markers mapped in M. truncatula, provides a central reference map for future use of genomic and genetic information in faba bean genetic analysis and breeding
Mineral Nutrition and Integration of Forage Legumes into Smallholder Farming Systems, with Emphasis on Velvet Bean [Mucuna pruriens (L) DC var. utilis].
No full textThe major objective of this work was to evaluate and compare forage supply and soil fertility effects of velvet bean (Mucuna pruriens var. utilis) integrated into smallholder cropping systems as ley, intercrop and green manure for farmers engaged in semi-commercial offtake from livestock. The results also present information about the alleviation of mineral nutrient constraints in order to raise the productivity and probability for adoption of velvet bean as a forage and green manure crop in Zimbabwe, through a series of experiments conducted on farm with farmers. Socio – economic assessments of the suitability of these interventions were also incorporated into the work. Experiments were carried out in Zana resettlement and Dendenyore communal areas of Hwedza District, Zimbabwe (18o41'S latitude; 31o42’ E longitude; 1400 m asl) to compare different systems of integrating forage legumes in terms of forage production and effect on a subsequent maize crop. The systems included velvet bean, cowpea and archer (mixed with Katambora Rhodes grass) grown as leys, intercrops or green manure, with or without SSP or lime. A weed fallow and sole maize were also included as controls. A maize cropping phase followed most of the treatments in year 2 to determine the rotational benefits of the legume systems. The trials were conducted at nine farmers’ fields and the soils were generally acidic (pH<5 – calcium chloride method), inherently infertile (low available P, Ca, Mg and mineral N and total C% < 1.5%) sands, loamy sands or light clays. The biomass production in season 1 for velvet bean with inorganic P fertilizer applied at planting (16.4 kg ha-1) ranged from 6.5 to 17 t DM ha-1 (range was 3.7 to 11.8 t DM ha-1 without P fertilizer). There was a 15% increase in velvet bean dry matter yield with lime application. Velvet bean and cowpea showed a greater response to P fertilizer application (30.9% and 29.4%, respectively), compared with Archer and Katambora Rhodes grass (14.5%). Season 2 results showed a significant (P<0.05) residual effect of velvet bean on the maize stover and grain yield. They also pointed to a positive P residual effect of velvet bean, and revealed that biomass production in perennial leys would be greater in the second season than in the first, even when the leys are grazed during the dry season. Overall, there was an increase of more than 300 kg in maize grain yield for every tonne of green manure incorporated. This was a nitrogen use efficiency of 11 kg grain/kg N applied. These results show that the application of P and lime can substantially raise productivity of velvet bean and allow it to input large amounts of N that can benefit following maize crops. A further experiment on the effect of liming on velvet bean showed that the response of velvet bean to liming in season 1 was due to a combination of increase in pH and supply of Ca and Mg. In terms of overall N and P partial nutrient balances in the systems, the green manure velvet bean (with 16.4 kg-1 P) followed by maize (with 30 kg N/ha) system proved to be the most sustainable (overall partial N balance of -88.6 kg/ha and partial P balance of 10 kg/ha), while the maize (with 30 kg N/ha) following limed velvet bean (with P) grown for hay and the maize (with 30 kg N/ha) after weed fallow systems were the least sustainable for N (-389 kg/ha) and P (-9.2 kg/ha) balances, respectively, when comparing these three systems. The results of a gross margin analysis indicated a strong residual effect of P on maize yield and that farmers growing maize after velvet bean benefit in terms of a higher maize yield and reduced inorganic fertilizer costs. A survey revealed the high potential of velvet bean to improve the existing farming systems. Velvet bean appeared particularly beneficial and attractive to commercial oriented livestock smallholder farmers. For this, it would be grown as a ley crop and hay or pods and residue fed to cattle. It appeared less attractive to non-livestock smallholder farmers, where its use would be more as a green manure to feed the soil (and then subsequently maize and humans)
A Nonparametric Efficiency Analysis of Bean Producers from North and South Kivu
No full textThe purpose of this research is to determine how technically efficient small-scale producers are in two provinces (North and South Kivu) in the Democratic of Republic (DR) of Congo at producing two different varieties of beans: bush and climbing beans. In addition to calculating the efficiency scores, this research attempts to identify what producer and field characteristics affect these scores. We hypothesize that bean producers will be more productive than producers in South Kivu and that climbing bean producers will be more productive than bush bean producers. Technical efficiency is estimated using a nonparametric approach. A tobit model is used to examine the effect of producer and field characteristic on the efficiency score. On average, farms were 66% technically efficient. North Kivu bean producers and climbing bean producers have, on average, a higher technical efficiency score than their counterparts. Implications from this research suggest that there is room for improvement in the technical efficiency scores for producers in DR of Congo. Based on the results, it may be more productive to continue focusing on improving the yield and nutritional content of climbing beans.Production Economics, Production Economics,
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