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Drought resistance of tropical dry black bean lines and cultivars
López-Salinas, Ernesto;Tosquy-Valle, Oscar H.;Acosta-Gallegos, Jorge A.;Villar-Sánchez, Bernardo;Ugalde-Acosta, Francisco J;
Tropical and subtropical agroecosystems , 2011,
Abstract: the objectives of this research were to classify black seeded dry bean genotypes for their drought tolerance and to identify those with the highest seed yield efficiency under irrigated and drought stressed conditions. during the 2008 winter-spring growing season two experiments were carried out at medellín de bravo, veracruz; one was irrigated during the whole growing cycle, whereas in the other one, irrigation was withheld from the onset of flowering. nine lines, six improved cultivars and the 'arbolito' landrace (local control) were evaluated using a randomized complete block design with three replications. data recorded included days to physiological maturity, seedless aerial dry biomass production, number of pods per plant, weight of 100 seeds and seed yield. analysis of variance for the irrigated and drought stressed conditions, as well as combined analysis were performed. the drought susceptibility index (dsi) and the relative efficiency index (rei) were used as efficiency criteria. under irrigated conditions, negro inifap, 82l-17-18, negro tacaná and negro veracruz were the most productive genotypes with more than 1.0 t ha-1. under drought conditions, the last two genotypes along with line dor 448 were the most productive with a seed yield higher than 400 kg ha-1. on average, the yield obtained under drought conditions was 37.7% of that under irrigation. with dsi values of 0.71, 0.85 and 0.87, lines dor-448, ngo 17-99 and icta ju-97-1, respectively, were considered as drought tolerant. under both moisture conditions, negro tacaná and negro veracruz with rei values of 1.67 and 1.47, respectively, showed the highest seed yield efficiency.
Quantification of drought tolerance in Ethiopian common bean varieties  [PDF]
Asrat Asfaw, Matthew W. Blair
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.52016
Abstract:

Understanding the level of drought tolerance of the varieties available in each country is of paramount importance for breeding common bean for drought adaptation. The goal of this study was to evaluate 25 common bean genotypes of which 24 were released/recommended varieties for production by farmers and one was a drought tolerant check. The genotypes were planted at two sites in Ethiopia, Hawasssa and Amaro, using variable sowing dates, one that was early to avoid drought and one that was late to expose the crop to drought. The experiments were repeated over two years in Hawassa and one year in Amaro. This resulted in treatments with high and low total seasonal rainfall and six environments for analysis. The impact of drought stress on the trait expression of the varieties was not uniform across traits assessed and varieties tested. The effect of drought on photosynthate translocation and partitioning traits was much greater than on yield component traits in the varieties studied. This indicating less breeding efforts has been made in improving the varieties ability to mobilize photosynthate to the developing grain as compared to the yield component traits. Drought tolerant varieties like Hawassa Dume maintained better photosynthate translocation and partitioning than the drought sensitive varieties like Brown Speckled bean. Hawassa Dume also showed better yield stability and performed well under both drought stress and nonstress conditions. Our results indicate the relevance of high levels of photosynthate translocation and partitioning as an effective selection objective for improving drought tolerance in common bean. The information generated on the drought tolerance of the available varieties should help in the design of a breeding strategy that incorporates adaptation traits with commercial characteristics preferred by common bean farmers for varieties to be grown in diverse environments.

Susceptibility of South African dry bean cultivars to bacterial diseases
D Fourie
African Crop Science Journal , 2011,
Abstract: Dry beans are an important crop in South Africa with the annual bean consumption being approximately 120 000 t. The crop is annually subjected to a number of biotic constraints such as bacterial diseases that can cause serious yield losses especially when the climate is conducive to diseases. The use of resistant varieties is an effective way of reducing the risk of crop failure and deployment of resistance requires knowledge on the susceptibility of cultivars. Twenty-one locally grown commercial dry bean cultivars were evaluated at Potchefstroom in South Africa to evaluate the resistance to common bacterial blight, halo blight and bacterial brown spot. Results indicated that South African cultivars differed in susceptibility to bacterial diseases. Cultivars Teebus, Cerillos, PAN 146 and PAN 159 were most susceptible to common bacterial blight with Monati and OPS-RS2 having low levels of resistance. Negative correlations (r=-0.44) (P<0.001) between disease ratings and yields were obtained in the common bacterial blight trial. Levels of resistance to halo blight were observed with small seeded cultivars generally being more resistant than large seeded types. A negative correlation (r=-0.35)(P=0.001) was obtained between halo blight rating and yield. Cultivars differed regarding susceptibility to bacterial brown spot with the majority having adequate resistance. Teebus, Cerillos, Bonus and PAN 159 were most susceptible, with Mkuzi exhibiting highest levels of resistance. No correlation was obtained between disease rating and yield. Although a number of cultivars exhibited field resistance to halo blight and bacterial brown spot, all cultivars were more or less susceptible to common bacterial blight. Common bacterial blight can be considered the most important bean bacterial disease in South Africa. Improvement of common bacterial blight resistance in South African cultivars is necessary for yield stability.
Physiological performance, yield, and quality of dry bean seeds under drought stress
Casta?eda-Saucedo,Claudia; Córdova-Téllez,Leobigildo; González-Hernández,Víctor A; Delgado-Alvarado,Adriana; Santacruz-Varela,Amalio; García-de los Santos,Gabino;
Interciencia , 2009,
Abstract: net photosynthesis (a), respiration (re), stomatal conductance (gs), transpiration rate (e), yield, and its components, as well as physical and physiological quality of seeds were evaluated on dry bean (phaseolus vulgaris l.) plants cv. ?otomí?, subjected to drought stress during the stages of flowering (f), pod formation (pf) and seed filling (sf). after 3 days under drought stress, gs, e and a decreased by more than 50% at f, pf and sf, respectively; after 10 days of stress, there was total inhibition of those processes, whereas the maximum reductions showed by re were 42, 62, and 85% in f, pf and sf, respectively. drought stress induced seed yield reductions of 10, 57, and 50% at f, pf and sf, respectively. high yield losses at pf and sf were caused by reductions in the number of seeds and pods per plant and seeds per pod. at the sf stage the loss in yield was moderate, because at this stage the plants were able to form new leaves and delay pod formation until water stress was over. the physiological quality was not affected by drought stress, even though the weight of 1000 seeds was reduced by about 10%.
Evaluation of Grain Yield Potential and Dry Matter Remobilization to Seed in Commercial Bread Wheat Cultivars in Normal and Drought Conditions  [cached]
M .Tousi Mojarrad,M. R. Ghannadha
Journal of Science and Technology of Agriculture and Natural Resources , 2007,
Abstract: In order to evaluate grain yield potential and study dry matter remobilization to seed, 8 commercial bread wheat cultivars were examined in two separate experiments, using randomized complete block design with 4 replications in 2003. There were significant differences for most traits in normal and drought conditions. Sarday variety had the least grain yield in the two environments. There was considerable variation between genotypes for independent parameters of dry matter remobilization to different plant parts in the two environments. Factor analysis showed that seven factors accounted for 100 % of the data total variance in normal and drought conditions. Factor analysis also showed that the effective traits to components grain yield , height and phenological traits were important for the selection of appropriate genotypes. Calculation of drought resistance indices showed that four indices including mean productivity, geometric mean productivity, harmonic index, stress tolerance index were more effective than other indices for the selection of drought tolerant genotypes.
Evaluation of an Andean common bean reference collection under drought stress Evaluation of an Andean common bean reference collection under drought stress  [cached]
Pérez Vega Juan Carlos,Blair Matthew W.,Monserrate Fredy,Ligarreto Moreno Gustavo Adolfo
Agronomía Colombiana , 2011,
Abstract: More than 60% of common bean (Phaseolus vulgaris L.) production worldwide is impacted by the risk of drought. In this study, the goal was to evaluate 64 bush bean genotypes from the CIAT reference collection to identify possible sources of drought resistance in the Andean gene pool. Phenotypic traits such as yield, 100-seed weight (P100) and days to physiological maturity (Dpm) were evaluated on selected accessions of this collection which was grown in an 8x8 lattice with two repetitions under three environments: intermittent drought (SI) and irrigation (R) in Palmira as well as early drought (ST) in Darién, Colombia. The genotypes included 20 from the Nueva Granada 1 (NG1) sub-race, 19 from the Nueva Granada 2 (NG2) sub-race, 10 from race Peru (P), 14 Andean control genotypes and one Mesoamerican check. The variables were analyzed through a combined ANOVA across environments, while simple correlations between yield and others variables were determinate. The genotypes with better adaptation to drought showed higher yields, 100-seed weight and fewer days to physiological maturity. The coefficients of correlations among yield and 100-seed weight were significant and positive, while Dpm showed negative correlation. Fourteen genotypes were identified as drought tolerant: G4001, G5625, G6639, G16115, G17070, G18255, G21210 and G22247 from the NG1 sub-race; G5708, G14253, G18264 and LRK31 from the NG2 sub-race; and DRK47 and G22147 from race Peru. More than 60% of common bean (Phaseolus vulgaris L.) production worldwide is impacted by the risk of drought. In this study, the goal was to evaluate 64 bush bean genotypes from the CIAT reference collection to identify possible sources of drought resistance in the Andean gene pool. Phenotypic traits such as yield, 100-seed weight (P100) and days to physiological maturity (Dpm) were evaluated on selected accessions of this collection which was grown in an 8x8 lattice with two repetitions under three environments: intermittent drought (SI) and irrigation (R) in Palmira as well as early drought (ST) in Darién, Colombia. The genotypes included 20 from the Nueva Granada 1 (NG1) sub-race, 19 from the Nueva Granada 2 (NG2) sub-race, 10 from race Peru (P), 14 Andean control genotypes and one Mesoamerican check. The variables were analyzed through a combined ANOVA across environments, while simple correlations between yield and others variables were determinate. The genotypes with better adaptation to drought showed higher yields, 100-seed weight and fewer days to physiological maturity. The coefficients of correlations amon
Physiological characteristics of cassava tolerance to prolonged drought in the tropics: implications for breeding cultivars adapted to seasonally dry and semiarid environments
El-Sharkawy, Mabrouk A.;
Brazilian Journal of Plant Physiology , 2007, DOI: 10.1590/S1677-04202007000400003
Abstract: the paper summarizes research conducted at international center for tropical agriculture (ciat) on responses of cassava to extended water shortages in the field aided by modern gas-exchange and water-relation techniques as well as biochemical assays. the aim of the research was to coordinate basic and applied aspects of crop physiology into a breeding strategy with a multidisciplinary approach. several physiological characteristics/traits and mechanisms underpinning tolerance of cassava to drought were elucidated using a large number of genotypes from the ciat core germplasm collection grown in various locations representing ecozones where cassava is cultivated. most notable among these characteristics are the high photosynthetic capacity of cassava leaves in favorable environments and the maintenance of reasonable rates throughout prolonged water deficits, a crucial characteristic for high and sustainable productivity. cassava possess a tight stomatal control over leaf gas exchange that reduces water losses when plants are subjected to soil water deficits as well as to high atmospheric evaporative demands, thus protecting leaves from severe dehydration. during prolonged water deficits, cassava reduces its canopy by shedding older leaves and forming smaller new leaves leading to less light interception, another adaptive trait to drought. though root yield is reduced (but much less than the reduction in top growth) under water stress, the crop can recover when water becomes available by rapidly forming new canopy leaves with much higher photosynthetic rates compared to unstressed crops, thus compensating for yield losses with final yields approaching those in well-watered crops. cassava can extract slowly water from deep soils, a characteristic of paramount importance in seasonally dry and semiarid environments where deeply stored water needs to be tapped. screening large accessions under seasonally dry and semiarid environments showed that yield is significantly cor
Effect of management practices on mycorrhizal infection, growth and dry matter partitioning in field-grown bean
Oliveira, Antonio Alberto Rocha;Sanders, Francis Edward;
Pesquisa Agropecuária Brasileira , 1999, DOI: 10.1590/S0100-204X1999000700018
Abstract: the experiment was carried out on unsterilized field soil with low phosphorus availability with the objective of examining the effect of cultural practices on mycorrhizal colonization and growth of common bean. the treatments were: three pre-crops (maize, wheat and fallow) followed by three soil management practices ("ploughing", mulching and bare fallow without "ploughing" during the winter months). after the cultural practices, phaseolus vulgaris cv. canadian wonder was grown in this soil. fallowing and soil disturbance reduced natural soil infectivity. mycorrhizal infection of the bean roots occurred more rapidly in the recently cropped soil than in the fallow soil. prior cropping with a strongly mycorrhizal plant (maize) increased infectivity even further.
The Effect of Soaking and Cooking on the Oligosaccharide Content of Seker a Dry Bean Variety (P. vulgaris, L) Grown in Turkey
I. G. Sat,F. Keles
Pakistan Journal of Nutrition , 2002,
Abstract: In this research, the effects of cooking alone, soaking-cooking combination on the oligosaccharide contents of a registered dry bean variety, Seker grown in Turkey was studied. Saccharose, raffinose and stachyose contents of the raw material were 3.91, 1.86 and 3.84%, respectively. The highest removing, to the extent of decrease up to, approximately, 70% was achieved by soaking in 0.5 % sodium bicarbonate solution for 18 hour followed by cooking in pressured kettle. These conditions could be recommended to remove undesirable sugar contents of the Seker bean used for culinary purposes.
Nodulation and Fixed Atmospheric Nitrogen of Some Local Lima Bean (Phaseolus lunatus L.) Cultivars Grown in a Coastal Savannah Environment  [PDF]
Daniel Kwasi Asare, Christian Kofi Anthonio, Lee Kheng Heng, Emmanuel Ofori Ayeh
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.69089
Abstract: Legumes, in symbiotic association with Rhizobia, are able to fix atmospheric N. Six local lima bean (Phaseolus lunatus) cultivars were grown under rainfed conditions in a coastal savannah environment. Objectives of the study were to evaluate the nodulation and fixed atmospheric N levels of the six local lima bean cultivars using both the 15N isotope dilution method and N difference method (NDM). The linear relationship between fixed atmospheric N estimated using the 15N isotope dilution method and NDM, was also assessed. The experiment was arranged in a randomized complete block design (RCBD) in three replicates with seven treatments, comprising six lima bean cultivars (B1, B2, B3, B4, B5 and B6) and the early maturing local maize variety, “Doke”, as the reference crop. Total, effective nodules (EN) and non-effective nodules (NEN) were determined on 42 and 56 days after planting (DAP). The 15N isotopic dilution method and NDM were used to quantify the fixed atmospheric N by the lima bean cultivars on 60 DAP. Effective root nodules per plant (EN) on 56 DAP ranged from 0.71 to 1.22, with the lima bean cultivar B4 having the highest value and cultivars B2 and B5 having the lowest value of EN, respectively. Similarly on 56 DAP, the lima bean cultivar B4 had the highest NEN value while cultivars B1, B2 and B5 had the lowest NEN value of 0.71 per plant. The mean fixed atmospheric N was 8.98 kg·ha-1, based on the 15N isotope dilution method, which was lower than 10.13 kg·ha-1 of fixed atmospheric N determined using NDM. The linear relationship between fixed atmospheric N estimated using the 15N isotope dilution method and that estimated using the NDM, was positive but of average quality as the R2 value was 0.56. Consequently, the linear model obtained from this relationship is moderate as 56% of the data used for the linear regression analysis were accounted for by the linear regression model developed. However, NDM could be used for fast screening to select lima bean cultivars for a more detailed study to identify cultivars with promising fixed atmospheric N capabilities. Generally, results of the study provide opportunities for designing breeding and other agronomic programmes for enhancing the productivity and N-fixing
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