Phaseolus Research Articles

Direct defense of common bean accessions against two-spotted spider mite (Tetranychus urticae Koch.) attack

To find the direct defense of seedling resistance of common beans, by resistant mechanisms, morphological and physiological attributes of ten cultivars (Naz, Dorsa, Akhtar,KS41128, 65-062-107, 65-071-98, 65-071-306, 65-071-410, 65-071-400, and 65-071-405) were evaluated against two-spotted spider mite in 2017 at Bu-Ali Sina university, Hamedan, Iran. Among four kinds of resistant mechanisms such as antixenosis, antibiosis, tolerant tests and PRI index, both antixenosis and tolerance mechanisms determined to be the most accurate tests in the evaluating of common bean resistance against TSSM attack. Germination delay, development and fast growth, early maturity, erected posture, small cotyledon area, the more leaf thickness along with the dark-colored demonstrated were the escape mechanisms of common beans tolerant genotypes against TSSM attack. Some epidermal traits such as the first defense barrier on common bean like hook-shaped and high density of trichome especially on abaxial epidermis by having trapping behavior showed high relation with tolerant genotypes. In fact, in tolerant beans, related-traits to trichome on leaves entrapped the body parts of TSSM such as leg tarsi, mouthpart and ovipositor and prevented to move, feed and reproduction of mites and therefore, these features decreased damage to leaf area of Phaseolus vulgaris as well. The 65-071-98, 65-062-107 genotypes and NAZ, were certainly categorized as the most tolerant cultivars while Akhtar and 65-071-400 were introduced as the most susceptible accessions of common beans, respectively.

Effects of urban sewage sludge on bean (Phaseolus vulgaris L.) seedling emergence rate and development

Effects of urban sewage sludge on bean (Phaseolus vulgaris L.) seedling emergence rate and development

Estudio de dieta en poblaciones arqueológicas del centro de Argentina a través del análisis de microrrestos vegetales e isótopos estables

Se presentan los resultados obtenidos a partir del análisis de isótopos estables (δ13Ccol y δ15N) y de los microrrestos vegetales hallados en el cálculo dental de 43 individuos adultos (28 masculinos – 15 femeninos) y un individuo juvenil (masculino), datados por AMS entre 387 ± 41 y 4058 ± 89 14C años AP, con el objetivo de abordar, desde una perspectiva bioarqueológica, el estudio de la dieta de los grupos humanos que ocuparon la región central del país. Los individuos provienen de 22 sitios arqueológicos, ubicados en dos regiones geográficas diferentes de la provincia de Córdoba: Sierras y Llanuras. Las prevalencias se calcularon considerando sexo, cronología y procedencia geográfica de cada individuo. Los resultados sugieren el consumo principalmente de plantas silvestres con patrón fotosintético C3, tales como Prosopis sp., Geoffroea decorticans y Trithrinax campestris a lo largo de todo el Holoceno tardío, y la incorporación de recursos vegetales cultivados de tipo C4, como Zea mays, y C3 como Phaseolus sp. a partir de los 1192 ± 40 14C años AP en la región Llanuras, con la posterior incorporación de Cucurbita sp. y Solanum tuberosum, ambos con patrón fotosintético C3, hacia los 954 ± 85 14C años AP exclusivamente en Sierras.

Influencia de diferentes sistemas agroecológicos en los indicadores químicos de un suelo cultivado de frijol (Phaseolus vulgaris L.)

El sistema agroecológico tiene repercusión importante en el estado nutricional del suelo, que depende de su preparación y plantas que se cultivan. El presente trabajo tuvo como objetivo evaluar la influencia de diferentes sistemas agroecológicos en los indicadores químicos de un suelo cultivado de frijol (Phaseolus vulgaris L.). Se utilizó un diseño experimental de bloques al azar, ocho tratamientos y cuatro repeticiones. Los tratamientos fueron plantas de cobertura: frijol de puerco (Canavalia ensiformis, Adans.), mucuna (Mucuna pruriens), frijol gandul (Cajanus cajan (L.) Mill sp.), crotalaria (Crotalaria sp. L.) sembradas en dos sistemas de cultivos: monocultivo y asociadas con mijo (Pennisetum glaucum L.) y dos sistemas de sistema de preparación del suelo: convencional y siembra directa. Los indicadores químicos evaluados fueron: pH, materia orgánica, macro y micros nutrientes (P, K, Ca, Mg, Fe, Mn, Zn) y el rendimiento en el cultivo del frijol. El sistema de siembra directa tuvo influencia sobre los indicadores químicos del suelo, disminuyó el pH (5.26), altos contenidos de Ca y K, con valores de 1.64 y 73.21 mg kg-1 respectivamente, con respecto al sistema convencional. Los micronutrientes Cu y Zn tuvieron valores signif icativos de 0.97 y 1.38 mg kg-1 respectivamente, con respecto al sistema convencional. Los contenidos de Mg y K alcanzaron valores muy cercanos a los del suelo natural. En el rendimiento del cultivo del frijol se destacó el cultivo frijol de puerco con el mayor número de vainas por planta (14.25), granos por vainas (5.93) y granos por planta (84) y un rendimiento de 4.4 Mg ha-1.

Performance and adaptability of common bean genotypes at different agro-ecological environments in Kagera region

Sixteen common beans (Phaseolus vulgaris L.) genotypes were used to study the genotype by environment interaction and grain yield stability. The randomized complete block design was used with three replicates. Data on yield were analyzed using additive main effects and multiplicative interaction (AMMI) model, genotype plus genotype by environment interaction (GGE) biplot model was used to display graphical representation of the yield data and the yield stability index (YSi). The analysis of variance of the AMMI model indicated that environments accounted for 56.9% of the total sum of square; genotypes effect explained 9.2% and the G x E interaction effect accounted 8.9% of the total sum of squares for the 16 genotypes tested across three environments and were all significant (P < 0.01). The average grain yield were 2.7, 1.38 and 1.20 t ha-1 for Karagwe, Bukoba and Muleba respectively. According the results, the GGE biplot revealed that, the genotypes SSIN 1240, SAB 659 and DAB 219, SMR 101, SMC 162 and DAB 602 showed greater stability with the average closer to the overall average of the tested genotypes. Therefore they are recommended to be used as varieties or parents for further improvement of available cultivars. Key words: Adaptability, Phaseolus vulgaris, Kagera, genotypes, environment.

Application of Response Surface Methodology in Optimization of the Yields of Common Bean ( Phaseolus vulgaris L.) Using Animal Manures

The objective of design and analysis of experiments is to optimize a response variable which is influenced by several independent variables. In agriculture, many statistical studies have focused on investigating the effect of application of organic manure on the yield and yield components of crops. However, many of these studies do not try to optimize the application of the manures for maximum productivity, but select the best treatment among the treatment range used. This is mainly due to design and analysis of experiments applied. Therefore, there is a need to apply a statistical method that would establish the effect of the application of organic manures on crop production and in addition optimize the levels of application of these manures for maximum productivity. This study aimed at application of response surface methodology for optimization of the yields of common bean (Phaseolus vulgaris L.) using animal manure. The study was conducted at Chuka University Horticultural Demonstration Farm. The experiment was laid down in a Randomized Complete Block Design. The treatments consisted of three organic manure sources (cattle manure, poultry manure and goat manure) each at three levels (0, 3 and 6 tonnes per ha). Data was collected from six weeks after sowing to physiological maturity. Data was collected on the weight of the grain yield harvested in each experimental plot measured by use of a weighing scale. The data collected was analysis using the R-statistical software. The study findings indicated that animal manures had a significant effect (p -1, 12.7213 t ha-1 and 4.1417 t ha-1 cattle manure, poultry manure and goat manure, respectively. These were the optimum levels that would lead to maximum yield of common beans without an extra cost of input.

Bioproductos en el crecimiento y rendimiento de Phaseolus vulgaris L. var. Delicia 364

Los actuales sistemas de producción de alimentos requieren el empleo de alternativas con enfoques ecológicos y asequibles, entre los que se destaca el uso de los bioproductos generados por la acción de microorganismos que actúan en la nutrición, crecimiento y desarrollo de las plantas. El objetivo de este trabajo fue evaluar la respuesta de Phaseolus vulgaris L. var. Delicia 364 a la aplicación de bioproductos (hongos micorrícicos arbusculares y Spiruvinas) en macetas de plástico con volumen de 44 L de capacidad. En el presente experimento se utilizó el bioproducto Azofert. El experimento se realizó en el municipio El Salvador, provincia Guantánamo, Cuba. Los tratamientos se distribuyeron en un diseño completamente al azar: (T1) Azofert sin HMA (testigo); (T2) Azofert sin HMA + 2 L ha-1 de Spiruvinas; (T3) Azofert + Rhizophagus irregularis; (T4) Azofert + Glomus cubense; (T5) Azofert + Funneliformis mosseae; (T6) Azofert + Rhizophagus irregularis + 2 L ha-1 de Spiruvinas; (T7) Azofert + Glomus cubense + 2 L ha-1 de Spiruvinas; (T8) Azofert + Funneliformis mosseae + 2 L ha-1 de Spiruvinas. Se evaluó: altura de las plantas, diámetro del tallo, número de vainas, número de granos por vainas, peso de 100 granos y rendimiento. Además, se evaluó el funcionamiento micorrícico mediante la colonización micorrícica y la densidad visual. Los resultados mostraron que la aplicación de bioproductos (hongos micorrícicos arbusculares y Spiruvinas) incrementaron el crecimiento y el rendimiento del cultivo de frijol var. Delicia 364; asimismo, con la combinación Azofert + Rhizophagus irregularis + Spiruvinas se obtuvo el mayor rendimiento con 2.11 Mg ha-1, lo que representa 37.9% más que el promedio nacional.

Population Development of Bean Weevils (Coleoptera: Chrysomelidae: Bruchinae) in Landrace Varieties of Cowpeas and Common Beans

Bean weevils (Coleoptera: Chrysomelidae: Bruchinae) are responsible for large quantity losses of cowpea (Vigna unguiculata (L.) Walp.; Fabaceae) and common bean (Phaseolus vulgaris L.; Fabaceae). The magnitude of damage is related to the grains’ varietal susceptibility. The objective of this study was to determine the population development rates of Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) in 4 landrace varieties of cowpea (var. ‘UFAC-B01,’ ‘UFAC-MV01,’ ‘UFAC-MG01,’ and ‘UFAC-Q01’), as well as the population development rates of Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae) in 4 landrace varieties of common bean (var. ‘UFAC-G01,’ ‘UFAC-M01,’ ‘UFAC-P01,’ and ‘UFAC-R01’). We determined the population development rates of the weevils in each variety. The weight of 100 grains (g) and the percentage of grain weight loss were measured, and correlations between these variables were analyzed. The statistical design was completely randomized, with 4 replications. Varieties UFAC-Q01 (cowpea) and UFAC-R01 (common bean) showed lower insect population development rates than other varieties. Although variations were found in the weight of 100 grains and grain weight loss, no significant correlations with bean weevil population development were observed. The cowpea and common bean landrace varieties from the southwestern Amazon region are important sources of resistance to bean weevils. The UFAC-Q01 cowpea variety and the UFAC-R01 common bean variety showed lower susceptibility to C. maculatus and Z. subfasciatus, respectively. Resumo Os bruquideos (Coleoptera: Chrysomelidae: Bruchinae) sao responsaveis por elevadas perdas na qualidade do caupi (Vigna unguiculata (L.) Walp.; Fabaceae) e feijao comum (Phaseolus vulgaris L.; Fabaceae), sendo que a magnitude dos danos esta relacionados a susceptibilidade varietal dos graos. O objetivo desta investigacao foi determinar as taxas de desenvolvimento populacional de Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) em quarto variedades crioulas de caupi (var. ‘UFAC-B01,’ ‘UFAC-MV01,’ ‘UFAC-MG01,’ e ‘UFAC-Q01’), bem como a a taxa de desenvolvimento populacional de Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae) em quarto variedades crioulas de feijao comum (vbean weevilsar. ‘UFAC-G01,’ ‘UFAC-M01,’ ‘UFAC-P01,’ e ‘UFAC-R01’). Foram realizados bioensaios para determinar as taxas de desenvolvimento populacional dos bruquideos em cada variedade, e avaliou-se a massa de 100 graos (g), perda de massa (%) e foram realizadas analises de correlacao entre estes fatores. O delineamento estatistico foi inteiramente casualizado com quatro repeticoes. As variedades UFAC-Q01 e UFAC-R01 de caupi e feijao comum, respectivamente, apresentaram menores taxas de desenvolvimento populacional, comparando-se com as demais variedades. Embora tenha havido variacao da massa de 100 graos, perda de massa, nao foram constadas correlacoes significativamente com o desenvolvimento populacional dos bruquideos. As variedades landraces de caupi e feijao comum, oriundos da Amazonia Sul-Ocideltal, constituem importantes fontes de resistencia para bruquideos, sendo que as variedades UFAC-Q01 e UFAC-R01 de caupi e feijao comum apresentaram menor susceptibilidade ao ataque de C. maculatus e Z. subfasciatus. Key Words: Vigna unguiculata; Phaseolus vulgaris; varietal susceptibility; storage; bruchids View this article in BioOne

Effect of Sprouting on Selected Macronutrients and physical Properties of four Zambian Common Bean (Phaseolus Vulgaris) Varieties

Sprouting is one of the popular methods used to prepare legumes for human consumption. In this study, the effect of sprouting on selected macronutrients (crude protein, crude fat, crude fibre and ash) and physical properties (hydration capacity after 24 hrs and equilibrium hydration capacity) of four common bean Zambian varieties were investigated. The varieties studied were Lyambai parent, Lyambai 4-4-B, Lundazi and Carioca-38. The crude protein values ranged from 17.6-24.4% before sprouting to 28.0-30.72% at day 6 of sprouting. Crude fibre content ranged from 4.1-5.9 before sprouting to 6.0-7.8% at day 6 of sprouting. Crude fat content ranged from 1.5-3.1% before sprouting to 3.8-6.3% at day 6 of sprouting. Ash content ranged from 4.1-4.8% before sprouting to 7.2-8.1 after 6 days of sprouting. Hydration capacity ranged from 0.210 to 0.475 g/seed among the four varieties after 24 hrs of soaking. Equilibrium hydration capacity was reached at different times among the four varieties. Carioca 38 was first at 72 hrs and Lundazi was last at 120 hrs. Sprouting was found to have a positive effect on crude protein, crude fat, crude fibre and ash contents of the selected common bean varieties investigated. Further, these common bean varieties demonstrated varying hydration patterns.

Impact of drought stress on physiological characteristics and isolation of chloroplasts in common bean (Phaseolus vulgaris L.)

Chloroplasts are involved in many cellular processes and play an important role in plant stress response. In this study, the effect of drought on different physiological characteristics and the isolation of chloroplasts from leaves of drought-stressed and control plants of common bean (Phaseolus vulgaris L.) are reported. Two cultivars differing in the response to drought were analysed-Tiber and more sensitive Starozagorski eern. The results of relative water content showed that plants were under mild stress conditions after six days without watering. Negative effects of drought stress on the photosynthetic rate and chlorophyll fluorescence parameters of both cultivars were observed. The yield of isolated chloroplasts in control samples of both cultivars was at least three times higher compared to drought-stressed samples. The intactness of the isolated chloroplasts was checked and used for protein isolation. The results of the study suggested that even mild drought stress strongly affected the isolation of intact chloroplasts. Still, intact chloroplasts were enriched and were suitable for downstream proteomic analysis.

Contributions in Puerto Rico to Bean, Phaseolus spp., Research

Contributions in Puerto Rico to Bean, Phaseolus spp., Research

Contributions in Puerto Rico to Bean, Phaseolus spp., Research

Contributions in Puerto Rico to Bean, Phaseolus spp., Research

Stress induced by lead in the growth of Phaseolus vulgaris L. cnary and panamite varieties

Son pocas las especies de plantas adaptadas para sobrevivir en suelos contaminados con altas concentraciones de metales sin alterar su fisiologia y crecimiento. Para realizar los experimentos acerca de resistencia a metales pesados se selecciona especies vegetales con un ciclo biologico relativamente corto y capaz de dar a conocer los efectos del plomo que causan estres en el crecimiento de la planta. Con estos antecedentes se evaluo el estres inducido por plomo en el crecimiento de Phaseolus vulgaris var. canario y var. panamito. El diseno experimental consistio en bloques completamente al azar con tres concentraciones de 0, 25 y 50 ppm de PbSO4 con tres repeticiones cada uno. Las plantulas se adaptaron a un sistema hidroponico, el cual contenia el medio nutritivo de Hoagland modificado y las diferentes concentraciones de plomo. Los resultados muestran que la variedad del canario es la menos afectada por estres al plomo, por eso tiene un mejor crecimiento de la raiz la cual se relaciona con su peso seco y su indice de produccion relativa (RP); ademas presenta un alto indice de translocacion (48.50% a 25 ppm) con bajo coeficiente de extraccion (0.407 a 50 ppm). Se concluye que ambas variedades presentan diferentes comportamientos frente al estres por plomo.

Effect of multi-periodic and chaotic magnetic fields on plants’ growth from germination to harvest: experiment on bean (phaseolus vulgaris)

In this work, we studied the impact of electromagnetic fields of various periods on the germination, growth and production of bean (phaseolus vulgaris). The magnetization of the seeds was carried out as soon as it was placed underground in field conditions. Plant growth until pod formation was monitored under field conditions on an experimental surface of 10.0 m 2 . The electrical circuits used for magnetization made it possible to obtain electromagnetic fields of period 1, 2 and 4 as well as a non-linear or chaotic electromagnetic field. Daily 24-hour exposure with these different signals has influenced some growth parameters. The height difference was significant (at P <0.05) for the comparison between A0 and A2. We found a production time saving of approximately ten (10) days for the A4 treatment compared to the control treatment A0. Experience has shown that plants subject to the chaotic field (A5) formed the largest number of pods. The comparison between the maximum number of pods formed and the number of pods that reached maturity for each treatment showed pod losses during the last growth phase. The loss rate was 29.25%, 28.31%, 35.78%, 64.38% and 62.72% respectively for A0, A1, A2, A4 and A5 treatments.

Studies on genetic diversity of French bean (Phaseolus vulgaris L.) landraces of Himachal Pradesh based on morphological traits and molecular markers

The knowledge of the extent of underlying diversity in the germplasm can be effectively employed to breed desirable cultivars and to challenge the consequences of the unprecedented biological, physical and chemical stresses of the future growing conditions. In the present study, total 26 geographically diverse French bean genotypes collected from different agro-climatic zones of Himachal Pradesh and two check varieties viz., Baspa and Jawala were grown under randomized complete block design with three replications for deciphering the extent of genetic diversity. The extent of variability was assessed using DUS morphological traits and PCR based approach. Analysis of variance for quantitative traits showed significant differences among all the genotypes for all the characters studied. The genotypes RL-19 and RL-20 gave higher seed yield and performed better for many of the horticultural traits over all the checks. Further, 15 RAPD primers were used for scoring polymorphism at the DNA level. The French bean landraces produced 79 PCR fragments, of which 59 were polymorphic with an average of 3.93 polymorphic fragments per primer. The overall percentage of polymorphism was recorded 74.62 per cent. The average Jaccard similarity index among genotypes ranged from 0.48 to 0.98, thereby showing sufficient genetic variability. Geographical affiliations and morphological associations were observed while studying the genotypic patterns within each group i.e. A, B, C and D. Such variability is desirable in breeding programs. Which also reveal the inherent capacity of the community as a selector, conservator and improver of the potential genetic resource for sustainable future.

Response of butter beans (Phaseolus lunatus L.) for different combinations of nitrogen and phosphorus on growth, yield and quality characters

A field experiment was conducted during June-October (2017) at Horticultural Research Station, Kodaikanal to study the response of butter beans for different combinations of nitrogen and phosphorus on growth, yield and quality characters. A randomized block design was followed with 17 combinations of N (30, 40, 50 and 60 kg/ha), P (37.5, 50, 62.5 and 75 kg/ha) and K 50 kg/ha was kept constant. The experimental results revealed that all the fertilizer treatments significantly increased the plant height, number of branches per plant, days to 50 % flowering, number of pods per cluster, 100 seed weight, pod weight, pod yield per hectare, protein content and crude fibre content of butter beans. Maximum plant height (220.33 cm), number of branches per plant (4.79), minimum days to 50 % flowering (50) and 100 seed weight were recorded in the combination of 50 kg N, 37.5 kg P 2 O 5 and 50 kg K 2 O per hectare. Number of pods per cluster (6.78), pod weight (14.00 g) and pod yield per hectare (5.85 t) were maximum in the combination of 60 kg N, 75 kg P 2 O 5 and 50 kg K 2 O per hectare.

Effect of Time after Incorporation of Lablab Green Manure on Root Rot Pathogens and Establishment of Common Bean ( Phaseolus vulgaris L.)

Green manure incorporation is important for restoration of soil quality, particularly buildup of organic matter and supply of nutrients to plants. However, undecomposed plant residues reduce crop establishment and plant stand. Therefore, there is need to determine suitable time for green manure incorporation before planting. The effect of time after incorporation of lablab green manure on soilborne pathogens and bean crop establishment was evaluated by incorporating 12t/ha of lablab green manure at planting and at 7, 14, and 28 days before planting. Soil samples were collected before and after incorporation of green manure at planting, and at two, four and six weeks after planting. Data was collected on crop emergence, plant stand, yield, incidence and severity of root rot, and population of root rot pathogens. Incorporation of lablab residues 28 days before planting resulted in 21% improvement in germination, with corresponding reduction in root rot incidence and severity of 8% and 36%, respectively, compared to plots incorporated with green manure at planting. Plots incorporated with lablab green manure earlier before planting had reduced population of root rot pathogens, while those incorporation at planting excited the population of root rot pathogens and also had up to 71% reduction in grain yield compared to plots where lablab residue was incorporated 28 days before planting. The results of the study showed that a period of 28 days between Lablab green manure incorporation and planting is necessary to allow for proper decomposition, resulting in a reduction in root rot incidence and an increase in grain yield.

تهیه ایزوله پروتئین لوبیا عروس و تعیین برخی خصوصیات عملکردی آن

ترکیبات شیمیایی آرد دانه لوبیا عروس (Phaseolus Vulgaris var aroos beans) که یکی از ارقام لوبیاست اندازه‌گیری شد. ایزوله پروتئین آن با استخراج قلیایی در 5/9=pH و ترسیب اسیدی در 5/4=pH بدست آمد. برخی خصوصیات عملکردی آن شامل ظرفیت امولسیون‌کنندگی و کف‌کنندگی در pH 4، 7، 8 و 10 و تاثیر قدرت یونی نمک کلرید سدیم در غلظت‌های 0، 5/0 و 1 مولار مورد بررسی قرار گرفت. ایزوله پروتئین لوبیا عروس دارای درصد خلوص 06/89 درصد و بازده تولید 9 درصد بود. ظرفیت امولسیون‌کنندگی و کف‌کنندگی ایزوله پروتئین لوبیا عروس در 7=pH، به‌ترتیب 65 درصد و 42 درصد بود. مقدار این پارامترها با قرار گرفتن در ناحیه قلیایی و دور شدن از نقطه ایزوالکتریک افزایش یافت و بیشترین میزان در 10=pH، به‌ترتیب 23/70 درصد و 33/77 درصد بدست آمد. در طی زمان 90 دقیقه، به‌تدریج از پایداری امولسیون و کف کاسته شد. با افزایش غلظت نمک کلرید سدیم، ظرفیت امولسیون‌کنندگی و کف‌کنندگی کاهش معناداری پیدا کرد.

DNA Extraction from silica gel preserved common bean (Phaseolus vulgaris L.) leaves

Extraction of high-quality DNA from field specimen requires collection under liquid nitrogen which is not readily available in resource constrained laboratories in low- and middle-income countries (LMICs). A method of extracting DNA from silica gel preserved common bean (Phaseolus vulgaris L.) leaves is presented. Our method which does not involve the use of phenol, chloroform or isoamyl alcohol also obviates the need for low temperature incubation during the DNA extraction steps and the grinding of desiccated leaf tissue in liquid nitrogen. It relies on inactivating proteins using SDS and proteinase K and precipitation of polysaccharides using a high salt solution. DNA is further purified by exploiting its insolubility in aqueous media. We were able to extract high quality pure DNA (mean concentration 2.98 ± 0.84 μg/g of leaf tissue) with mean A260/280 of 2.1 ± 0.1 and A260/230 of 2.4 ± 0.15. The DNA was also found to be amenable to amplification using molecular marker types routinely used in molecular biology laboratories like random amplified polymorphic (RAPD) markers, inter simple sequence repeat (ISSR) markers, sequence-characterized amplified region (SCAR) markers and simple sequence repeat (SSR) markers. Our findings show that it is possible to obtain high quality DNA from leaf tissue preserved in silica gel. Our method will be invaluable to resource constrained laboratories especially in LMICs that cannot afford to buy or access liquid nitrogen in order to extract high quality DNA and to research groups undertaking field surveys that require several days or weeks off station without laboratory freezers to maintain the integrity of the tissues which is crucial for obtaining high quality DNA.

FITOTOXICIDAD DE UN SUELO CONTAMINADO CON PETRÓLEO FRESCO SOBRE Phaseolus vulgaris L. (LEGUMINOSAE)

Se evaluaron los efectos toxicos que produce un suelo contaminado con petroleo fresco sobre plantas de Phaseolus vulgaris . Para ello se genero un indice absoluto de fitotoxicidad que integra siete parametros, medidos a traves de indices relativos de fitotoxicidad para las variables: altura, longitud radical, numero de nodulos y biomasa seca (foliar, radical, del fruto y total). Asimismo, se calcularon los coeficientes de determinacion (R 2 ). El bioensayo se realizo bajo condiciones de tunel de plastico y se evaluo los efectos toxicos del petroleo en plantas de frijol negro ( P. vulgaris L.) al cabo de 100 dias. Se establecio un diseno experimental de bloques al azar en condiciones semicontroladas, con seis tratamientos con tres repeticiones por tratamiento. Las concentraciones de hidrocarburos fueron: 1500, 3000, 4500, 6000, 7500 y 9000 mg/kg de hidrocarburos totales del petroleo (HTP) y un tratamiento testigo (0 mg/kg).Al dia 100, el detrimento fisiologico [emergencia (R 2 = 0.89; b = -3.427); altura(R 2 = 0.84; b = -0.0029); longitud radical (R 2 = 0.62; b = -0.001); numero de nodulos (R 2 = 0.68; b = -0.0092) y biomasa total (R 2 = 0.77; b = -0.0014)] de las plantas mostro una correlacion negativa con la concentracion de los HTP en el suelo, con diferencias entre los tratamientos (Tukey p≤ 0.05). Al dia 68 del ensayo se observo marchitez de las plantas a concentraciones mayores de 3000 mg/kg HTP.