ISSN e: 2007-4018 / ISSN print: 2007-3828

English | Español

     

 
 
 
 
 
 
 
 

     Articles in press, 2021   Creative Commons License

      
 

     Vol. -, issue - publicación en avanzada - 2021  

 
  

Isolated rhizobacteria of Jatropha curcas L.: antagonistic activity of phytopathogens and plant growth promoter

Rizobacterias aisladas de Jatropha curcas L.: actividad antagonista de fitopatógenos y promotora del crecimiento de plantas

Erubiel Toledo-Hernández; Guadalupe Peña-Chora; Jeiry Toribio-Jiménez; Yanet Romero-Ramírez; Alejandro Bolaños-Dircio; Miguel G. Velázquez-del Valle; Ana N. Hernández-Lauzardo; Renato León-Rodriguez; Silvana Vero

Keywords: Bacillus mojavensis; Bacillus subtilis; Bacillus thuringiensis; Pseudomonas aeruginosa; Curvularia lunata; Fusarium equiseti

10.5154/r.rchscfa.2020.04.029

Received: 2020/03/14
Accepted: 2021/01/15
Available online: 2021-01-15
Pages:-

Introduction: Jatropha curcas L. is a species native to Mexico that has recently been considered an important crop to produce biofuel. Objective: To isolate and identify rhizobacteria from J. curcas with antagonistic activity against phytopathogenic fungi (Curvularia lunata and Fusarium equiseti) of this crop and evaluate their capacity to promote tomato plant growth. Materials and methods: The isolates were obtained by serial dilution and antagonistic activity was assessed by volatile and diffusible compounds on PDA medium. In addition, the production of antifungal compounds and metabolites that promote the plant growth were determined. The isolates were identified by amplifying the 16S RNA and sodA genes. Finally, the isolates were inoculated on tomato seeds to evaluated plant growth promotion and germination. Results and discussion: The antagonistic bacteria were identified as Bacillus mojavensis, Bacillus subtilis, Bacillus thuringiensis, and Pseudomonas aeruginosa. The antifungal effect on the mycelial growth of C. lunata and F. equiseti was due to the presence of volatile and diffusible compounds with between 30 % and 79 % inhibition. Pseudomonas aeruginosa showed the strongest inhibitory effect (48.7 to 79.8 %). Bacillus subtilis (A1), B. mojavensis (A4) and B. thuringiensis (A6, A8) showed the highest germination (70 % to 88 %). The vegetative growth of tomato plants treated with the isolates was significantly higher than the controls (P < 0.05). Conclusion: Eight rhizobacteria isolated from J. curcas showed antagonistic activity against C. lunata and F. equiseti and demonstrated their capacity to improve the germination and promote growth in tomato plants.

....

Introduction: Jatropha curcas L. is a species native to Mexico that has recently been considered an important crop to produce biofuel. Objective: To isolate and identify rhizobacteria from J. curcas with antagonistic activity against phytopathogenic fungi (Curvularia lunata and Fusarium equiseti) of this crop and evaluate their capacity to promote tomato plant growth. Materials and methods: The isolates were obtained by serial dilution and antagonistic activity was assessed by volatile and diffusible compounds on PDA medium. In addition, the production of antifungal compounds and metabolites that promote the plant growth were determined. The isolates were identified by amplifying the 16S RNA and sodA genes. Finally, the isolates were inoculated on tomato seeds to evaluated plant growth promotion and germination. Results and discussion: The antagonistic bacteria were identified as Bacillus mojavensis, Bacillus subtilis, Bacillus thuringiensis, and Pseudomonas aeruginosa. The antifungal effect on the mycelial growth of C. lunata and F. equiseti was due to the presence of volatile and diffusible compounds with between 30 % and 79 % inhibition. Pseudomonas aeruginosa showed the strongest inhibitory effect (48.7 to 79.8 %). Bacillus subtilis (A1), B. mojavensis (A4) and B. thuringiensis (A6, A8) showed the highest germination (70 % to 88 %). The vegetative growth of tomato plants treated with the isolates was significantly higher than the controls (P < 0.05). Conclusion: Eight rhizobacteria isolated from J. curcas showed antagonistic activity against C. lunata and F. equiseti and demonstrated their capacity to improve the germination and promote growth in tomato plants.

....
 

Chemical-mechanical damage caused by the brown-rot fungus Gloeophyllum trabeum (Pers.) Murrill on Pinus pseudostrobus Lindl. wood

Chemical-mechanical damage caused by the brown-rot fungus Gloeophyllum trabeum (Pers.) Murrill on Pinus pseudostrobus Lindl. wood

Eduardo Días-Rivera; Wilber Montejo-Mayo; Mauro Martínez-Pacheco; Abril Munro-Rojas; Enrique Ambriz-Parra; Crisanto Velázquez-Becerra

Keywords: Wood damage; mechanical properties; sawn timber; xylophagous fungi; holocellulose

10.5154/r.rchscfa.2020.05.033

Received: 2020-05-06
Accepted: 2021-02-04
Available online: 2021-02-04
Pages:-

Introduction: Wood is susceptible to be used as a carbon source by various fungal species damaging the wood, by exposing the wood to different environmental conditions. Its durability has been categorized according to its weight loss, without considering the decrease of the physicochemical and mechanical properties inherent to the weight loss. Objective: To evaluate how the weight loss in Pinus pseudostrobus Lindl. wood exposed to brown-rot fungi Gloeophyllum trabeum (Pers.) Murrill affects the physicochemical and mechanical properties. Materials and methods: Sawn timber pieces of P. pseudostrobus were inoculated with G. trabeum. Periodically (zero, three, six and nine months) and with the help of a universal testing machine, parallel compression (PC), static bending (SB) and perpendicular compression to the grain (CPG) were evaluated, and holocellulose, cellulose and lignin were quantified. Results and discussion: After nine months of interaction with G. trabeum, the pieces of wood were resistant to degradation, considering only weight loss. However, the chemical-mechanical properties evaluated showed that the fungus made a thinning and breakdown of the tissue cells in the wood that induced a significant decrease in the values of SB (100 to 56 N∙mm -2 ) and CPG (42.2 to 20.2 N∙mm -2 ), which reduced its resistance to mechanical stress. Such damage is not reflected in the material’s aesthetic, which is alarming, since the common user of the pinewood could not notice the problem. Conclusions: The wood that has been exposed to fungal degradation is significantly compromised in its mechanical properties, disabling it for construction, because the chemical properties show us that the fungus causes low resistance to mechanical stress by diminishing SB and CPG.

....

Introduction: Wood is susceptible to be used as a carbon source by various fungal species damaging the wood, by exposing the wood to different environmental conditions. Its durability has been categorized according to its weight loss, without considering the decrease of the physicochemical and mechanical properties inherent to the weight loss. Objective: To evaluate how the weight loss in Pinus pseudostrobus Lindl. wood exposed to brown-rot fungi Gloeophyllum trabeum (Pers.) Murrill affects the physicochemical and mechanical properties. Materials and methods: Sawn timber pieces of P. pseudostrobus were inoculated with G. trabeum. Periodically (zero, three, six and nine months) and with the help of a universal testing machine, parallel compression (PC), static bending (SB) and perpendicular compression to the grain (CPG) were evaluated, and holocellulose, cellulose and lignin were quantified. Results and discussion: After nine months of interaction with G. trabeum, the pieces of wood were resistant to degradation, considering only weight loss. However, the chemical-mechanical properties evaluated showed that the fungus made a thinning and breakdown of the tissue cells in the wood that induced a significant decrease in the values of SB (100 to 56 N∙mm -2 ) and CPG (42.2 to 20.2 N∙mm -2 ), which reduced its resistance to mechanical stress. Such damage is not reflected in the material’s aesthetic, which is alarming, since the common user of the pinewood could not notice the problem. Conclusions: The wood that has been exposed to fungal degradation is significantly compromised in its mechanical properties, disabling it for construction, because the chemical properties show us that the fungus causes low resistance to mechanical stress by diminishing SB and CPG.

....
 

Effect of livestock on regeneration of queñoa (Polylepis australis Bitt.) forest in the Southern Andean Yungas of northwestern Argentina

Efecto del ganado sobre la regeneración del bosque de queñoa (Polylepis australis Bitt.) en las Yungas Australes del noroeste argentino

Griet An Erica Cuyckens; Flavia Mazzini; Rocío F. Julián; David E. Medina; Gustavo F. Guzmán

Keywords: restoration; seedling emergence; saplings; anthropic effect; extensive livestock

10.5154/r.rchscfa.2020.05.035

Received: 2020-05-20
Accepted: 2021-01-22
Available online: 2021-02-05
Pages:-

Introduction: Polylepis forest is an ecosystem stated with conservation priority and threatened by anthropogenic effects; extensive livestock is one of the most frequent disturbances in this forest. Objective: To study the effect of livestock on the early stages of regeneration of a queñoa (Polylepis australis Bitt.) forest. Materials and methods: Within a pure forest of P. australis at Parque Provincial Potrero de Yala, Jujuy, Argentina, densities of seedlings (˂1 year) and saplings (˃1 year and ˂30 cm) were measured in the presence (0.23 heads∙ha -1 ) and absence of livestock, for a year. Linear mixed models (normal distribution) were adjusted for density of seedlings and saplings. Data was analyzed with a Chi-square test (χ 2 ). Results and discussion: Presence of livestock had no impact on seedling density, but significantly decreased density of saplings (P < 0.001); in areas without livestock (10.58 ± 6.64 individuals∙m -2 ) was three times higher than with presence of livestock (3.17 ± 3.86 individuals∙m -2 ). Difference in density of seedlings and saplings was significantly (P < 0.001) over the years. This indicates that there is potential for natural regeneration, but livestock would affect stages after seedling emergence, representing a threat to the forest. Conclusion: This study provides important information for livestock management in mountain forests of P. australis. A long-term study of the effect of livestock on seedling and sapling density, and over the entire distribution range, is needed.

....

Introduction: Polylepis forest is an ecosystem stated with conservation priority and threatened by anthropogenic effects; extensive livestock is one of the most frequent disturbances in this forest. Objective: To study the effect of livestock on the early stages of regeneration of a queñoa (Polylepis australis Bitt.) forest. Materials and methods: Within a pure forest of P. australis at Parque Provincial Potrero de Yala, Jujuy, Argentina, densities of seedlings (˂1 year) and saplings (˃1 year and ˂30 cm) were measured in the presence (0.23 heads∙ha -1 ) and absence of livestock, for a year. Linear mixed models (normal distribution) were adjusted for density of seedlings and saplings. Data was analyzed with a Chi-square test (χ 2 ). Results and discussion: Presence of livestock had no impact on seedling density, but significantly decreased density of saplings (P < 0.001); in areas without livestock (10.58 ± 6.64 individuals∙m -2 ) was three times higher than with presence of livestock (3.17 ± 3.86 individuals∙m -2 ). Difference in density of seedlings and saplings was significantly (P < 0.001) over the years. This indicates that there is potential for natural regeneration, but livestock would affect stages after seedling emergence, representing a threat to the forest. Conclusion: This study provides important information for livestock management in mountain forests of P. australis. A long-term study of the effect of livestock on seedling and sapling density, and over the entire distribution range, is needed.

....
 

Seed production, dispersal and seed bank in Lupinus montanus Kunth at the upper limit of its altitudinal distribution in the Nevado de Toluca.

Producción, dispersión y banco de semillas en Lupinus montanus Kunth en el límite superior de su distribución altitudinal en el Nevado de Toluca

Diana Córdoba-Rodríguez; J. Jesús Vargas-Hernández; Francisca O. Plascencia-Escalante; Javier López-Upton; Marlín Pérez-Suárez; Carlos Trejo-López

Keywords: Fabaceae; lupine; altitudinal migration; alpine zone; soil slope

10.5154/r.rchscfa.2020.06.045

Received: 2020-06-17
Accepted: 2021-02-10
Available online: 2021-02-13
Pages:-

Introduction: In response to climate change, plants can adapt, migrate or die; however, migration by natural dispersion of seed can be very slow. Objective: To determine productive potential, dispersal distance and seed bank of Lupinus montanus Kunth (lupine) at the upper limit (4 200 m) of its natural distribution at the “Nevado de Toluca” mountain. Materials and methods: The seed bank was estimated in an area of 1.88 m2. Three sampling sites were established with plants in reproductive stage (15 plants) isolated from other adult plants. Seed production was determined in traps placed at the four orientations of each plant and spatial pattern of dispersal was also determined. Results and discussion: Seedbank density was 4.26 seeds∙m-2 of soil. Lupinus montanus produced over 5 500 seeds per plant in one reproductive cycle; its seed potential was associated with plant height and number of stems. The number of seeds collected varied significantly (P < 0.0001) with respect to distance from the mother plant. The dispersion curve was adjusted (P < 0.01) to a negative exponential model (R2 = 0.849). Dispersal in the four orientations was symmetrical; 97 % of the seeds fell at a distance ≤2 m from the mother plant. Conclusions: Only 3.2 % of the seeds of L. montanus reached a distance greater than 2 m from the mother plant; however, dispersal is uniform in all orientations, therefore soil slope does not represent a limiting factor for the altitudinal migration of species.

....

Introduction: In response to climate change, plants can adapt, migrate or die; however, migration by natural dispersion of seed can be very slow. Objective: To determine productive potential, dispersal distance and seed bank of Lupinus montanus Kunth (lupine) at the upper limit (4 200 m) of its natural distribution at the “Nevado de Toluca” mountain. Materials and methods: The seed bank was estimated in an area of 1.88 m2. Three sampling sites were established with plants in reproductive stage (15 plants) isolated from other adult plants. Seed production was determined in traps placed at the four orientations of each plant and spatial pattern of dispersal was also determined. Results and discussion: Seedbank density was 4.26 seeds∙m-2 of soil. Lupinus montanus produced over 5 500 seeds per plant in one reproductive cycle; its seed potential was associated with plant height and number of stems. The number of seeds collected varied significantly (P < 0.0001) with respect to distance from the mother plant. The dispersion curve was adjusted (P < 0.01) to a negative exponential model (R2 = 0.849). Dispersal in the four orientations was symmetrical; 97 % of the seeds fell at a distance ≤2 m from the mother plant. Conclusions: Only 3.2 % of the seeds of L. montanus reached a distance greater than 2 m from the mother plant; however, dispersal is uniform in all orientations, therefore soil slope does not represent a limiting factor for the altitudinal migration of species.

....
 

Influencia de factores externos e internos en el prendimiento inicial de injertos de Pinus pseudostrobus var. oaxacana (Mirov) Harrison

Influencia de factores externos e internos en el prendimiento inicial de injertos de Pinus pseudostrobus var. oaxacana (Mirov) Harrison

Rubén Barrera-Ramírez; J. Jesús Vargas-Hernández; Ricardo López-Aguillón; Hipólito Jesús Muñoz-Flores; Eduardo J. Treviño-Garza; Oscar A. Aguirre-Calderón

Keywords: -

10.5154/r.rchscfa.2020.05.037

Received: 2020-05-20
Accepted: 2021-03-09
Available online: 2021-03-11
Pages:-

 

Application of a multigranular approach based on the 2-tuple fuzzy linguistic model for the evaluation of forestry policy indicators

Aplicación de un enfoque multigranular basado en el modelo lingüístico difuso 2-tupla para la evaluación de indicadores de política forestal

José Luis Romo-Lozano; Rosa M. Rodríguez; Roberto Rendón-Medel; Álvaro Labella

Keywords: National Forest Program; qualitative assessment; fuzzy sets; linguistic hierarchies; expert panels

10.5154/r.rchscfa.2020.06.043

Received: 2020-06-17
Accepted: 2021-03-11
Available online: 2021-03-26
Pages:-

Introduction: The need for quality indicators is well recognized by users and proponents of public policy evaluation. Indicators recurrently include qualitative attributes for which there are few studies assessing the level of compliance. Objective: To apply a multigranular approach, based on the 2-tuple fuzzy linguistic model, to evaluate 13 indicators of the National Forestry Program, established in the system of social policy indicators derived from the National Development Plan 2012-2018 of Mexico. Materials and methods: The method uses the 2-tuple fuzzy linguistic representation model and an extension called extended linguistic hierarchies,designed to solve problems with multigranular linguistic information. The indicators'level of compliance was evaluated based on four criteria: clarity, relevance, monitoring, and adequacy. Results and discussion: The structure defined in evaluating social policy indicators corresponds appropriately to that used with the 2-tuple fuzzy linguistic model. The evaluation resulted in a sorted list in which the indicator “Rate of change of timber forest production” had the best rating with a “very high” level of compliance; 10 other indicators had the “high” level of compliance, and the remaining two indicators were rated with “moderate” compliance. Conclusions: The 2-tuple fuzzy linguistic model allowed the appropriate evaluation of the level of compliance with the desirable attributes of indicators.

....

Introduction: The need for quality indicators is well recognized by users and proponents of public policy evaluation. Indicators recurrently include qualitative attributes for which there are few studies assessing the level of compliance. Objective: To apply a multigranular approach, based on the 2-tuple fuzzy linguistic model, to evaluate 13 indicators of the National Forestry Program, established in the system of social policy indicators derived from the National Development Plan 2012-2018 of Mexico. Materials and methods: The method uses the 2-tuple fuzzy linguistic representation model and an extension called extended linguistic hierarchies,designed to solve problems with multigranular linguistic information. The indicators'level of compliance was evaluated based on four criteria: clarity, relevance, monitoring, and adequacy. Results and discussion: The structure defined in evaluating social policy indicators corresponds appropriately to that used with the 2-tuple fuzzy linguistic model. The evaluation resulted in a sorted list in which the indicator “Rate of change of timber forest production” had the best rating with a “very high” level of compliance; 10 other indicators had the “high” level of compliance, and the remaining two indicators were rated with “moderate” compliance. Conclusions: The 2-tuple fuzzy linguistic model allowed the appropriate evaluation of the level of compliance with the desirable attributes of indicators.

....
 

Interspecific grafting as an alternative for asexual propagation of Pinus rzedowskii Madrigal & Caball. Del. in danger extinction

Injerto interespecífico como alternativa para la propagación asexual de Pinus rzedowskii Madrigal & Caball. Del. en riesgo de extinción

Edgar R. Solorio-Barragán; Patricia Delgado-Valerio; Agustín Molina-Sánchez; Virginia Rebolledo-Camacho; Miguel Á. Tafolla-Martínez

Keywords: survival; phylogenetic relationships; side-veneer grafting; grafting; Pinus pinceana

10.5154/r.rchscfa.2020.06.046

Received: 2020-06-17
Accepted: 2021-03-22
Available online: 2021-04-01
Pages:-

Introduction: Pinus rzedowskii Madrigal & Caball. Del. is endemic to Mexico, in danger of extinction and low natural reproduction. An alternative for propagation is interspecific grafting, under the assumption that the phylogenetically more related species positively influence survival. Objectives: To evaluate grafting survival of P. rzedowskii with rootstocks of five Pinus species. Materials and methods: Interspecific grafting of P. rzedowskii with P. pinceana Gordon & Glend, P. maximartinezii Rzed, P. ayacahuite var. veitchii (Roezl) Shaw, P. pseudostrobus Lindl. and P. rzedowskii (control treatment) was carried out. The grafting method was side-veneer graft; grafting was quantified for six months and survival was evaluated using the nonparametric Kaplan-Meier method. Results and discussion: The highest final grafting survival and expected survival function were obtained with rootstocks of P. rzedowskii (85.7 ± 0.21 %; m = 0.97), followed by P. pinceana (80 ± 0.31 %; m = 0.95); P. pseudostrobus had the lowest values (20 ± 0.89 %; m = 0.66). Significant differences (P < 0.0001) were observed between P. pseudostrobus and P. maximartinezii regarding P. rzedowskii a P. pinceana. Conclusion: P. pinceana, a species phylogenetically closer to P. rzedowskii and P. maximartinezii, was the one with the highest survival rate, which may be an alternative for the rescue and ex situ conservation of P. rzedowskii.

....

Introduction: Pinus rzedowskii Madrigal & Caball. Del. is endemic to Mexico, in danger of extinction and low natural reproduction. An alternative for propagation is interspecific grafting, under the assumption that the phylogenetically more related species positively influence survival. Objectives: To evaluate grafting survival of P. rzedowskii with rootstocks of five Pinus species. Materials and methods: Interspecific grafting of P. rzedowskii with P. pinceana Gordon & Glend, P. maximartinezii Rzed, P. ayacahuite var. veitchii (Roezl) Shaw, P. pseudostrobus Lindl. and P. rzedowskii (control treatment) was carried out. The grafting method was side-veneer graft; grafting was quantified for six months and survival was evaluated using the nonparametric Kaplan-Meier method. Results and discussion: The highest final grafting survival and expected survival function were obtained with rootstocks of P. rzedowskii (85.7 ± 0.21 %; m = 0.97), followed by P. pinceana (80 ± 0.31 %; m = 0.95); P. pseudostrobus had the lowest values (20 ± 0.89 %; m = 0.66). Significant differences (P < 0.0001) were observed between P. pseudostrobus and P. maximartinezii regarding P. rzedowskii a P. pinceana. Conclusion: P. pinceana, a species phylogenetically closer to P. rzedowskii and P. maximartinezii, was the one with the highest survival rate, which may be an alternative for the rescue and ex situ conservation of P. rzedowskii.

....