Effect of Nano-multi Micronutrients on Agronomic Traits, Nutrient Uptake and Soil Fertility in Pot Trial of Maize (Zea mays L.)
Vipul Bundake, Veena Khilnani, Archana Kale
et al.
A pot experiment of maize was carried during summer seasons of March–July, 2023 and 2024 at the experimental field of Rashtriya Chemicals and Fertilizers, Mumbai, India, to assess the impact of multi nano micronutrients formulation (NM) on maize growth. The experiment was structured using a Completely Randomized Block Design with 12 treatments, including control with only water, Recommended Dose of Fertilizer (RDF), and different concentrations of NM having zinc (Zn), copper (Cu), iron (Fe), manganese (Mn) and boron (B) ranging from 20 mg to 0.15 mg 15 kg-1 of soil, as well as commercial micronutrients and micronutrient salts. Results revealed that application of 100% RDF+0.312 mg (T9) and 0.156 mg (T10) of nano micronutrients with drenching recorded better results of nutrient uptake (NU), apparent recovery (ANR) and agronomic efficiency (ARE). The NU (kg ha-1) of nitrogen (120.368), potassium (101.422), Cu (0.114), Fe (1.235), Mn (0.107) and Zn (6.069) was higher in T9 when compared to 100% RDF. The ANR was 9154.19% higher in T10 and 158.28% higher for Nitrogen(N), Phosphorus (P), and Potassium compared to 100% RDF. The protein and chlorophyll content were better in T9 and T10 of nano micronutrients respectively. The applications of T9 and T10 was found to be most effective in NU, ARE, ANR, protein content and chlorophyll content. Higher nutrient content in soil was found in treatment with lower concentrations. Overall, lower concentration of nano micronutrients appeared to be more effective for all traits.
Agriculture, Plant ecology
Updated Taxonomy of Chinese <i>Craterellus</i> (Hydnaceae, Cantharellales) with Three New Species Described
Tian Jiang, Lei Zhao, Xu Zhang
et al.
Species of <i>Craterellus</i> are interesting and important due to their mycorrhizal properties, medicinal value, and edibility. Despite extensive research on <i>Craterellus</i> in China, its taxonomy remains inadequately understood. This study presents three newly described species of <i>Craterellus</i>, namely <i>C. albimarginatus</i>, <i>C. involutus</i>, and <i>C. longitipes</i>, identified through morphological and phylogenetic analyses, with the goal of refining the taxonomy of Chinese <i>Craterellus</i>.
OsAAI1 is dependent on the nitrate pathway toregulate rice root development in response to high salt stress
Jinli Liu, Haimin Liao, Shasha Chen
et al.
Salt stress limits plant growth and yield. Though nitrogen fertilizer can alleviate salt damage, the effects of salt and nitrate on the stress resistance gene OsAAI1 are unclear. This study examined the Salt stress sensitivity of OsAAI1 transgenic lines and nitrate's role. Results showed OsAAI1 expression decreased with Salt and increased with nitrate. Under salt stress, the mutant OsAAI1 (osaai1) had significantly higher plant height, root length and number, and lower ROS accumulation than ZH 11, while OsAAI1 overexpression (OE 19) showed opposite trends. OE 19 also had lower antioxidant enzyme activities and higher MDA content. Analyses of topology, biomass distribution and connectivity of root scans after 30 and 50 days of salt stress treatment showed that osaai1 was able to sustain root growth and development under salt stress conditions, whereas OE 19 was more damaged. Exogenous salt stress tests confirmed these findings. Notably, nitrate application enhanced OsAAI1 is salt tolerance, improving root growth and increasing ROS scavenging enzyme activities. Under KNO₃ induction, high-concentration KNO₃ restores the root phenotype in OE 19. In conclusion, overexpression of OsAAI1 was more sensitive to salt, and OsAAI1 regulated ROS homeostasis through the nitrate pathway to enhance its tolerance to salt stress.
Integrating pollinators’ movements into pollination models
Juliane Mailly, Louise Riotte-Lambert, Mathieu Lihoreau
Accurate prediction of pollination processes is a key challenge for sustainable food production and the conservation of natural ecosystems. For many plants, pollen dispersal is mediated by the foraging movements of nectarivore animals. While most current models of pollination ecology assume random pollen movements, studies in animal behaviour show how pollinating insects, birds and bats rely on sensory cues, learning and memory to visit flowers, thereby producing complex movement patterns. Building upon a brief review of pollination and movement models, we argue that we need to better consider pollinators’ cognition to improve predictions of animal-mediated pollination across all spatial scales, from individual flowers, to plants, habitat patches and landscapes. We propose a practical roadmap for the integration of behavioural models into pollination models and discuss how this synthesis can refine predictions regarding plant mating patterns and fitness. Such crosstalk between animal behaviour and plant ecology research will provide powerful mechanistic tools to predict and act on pollination services in the context of a looming crisis.
Establishment of Biocontrol Agents and Their Impact on Rhizosphere Microbiome and Induced Grapevine Defenses Are Highly Soil-Dependent
Catarina Leal, Ales Eichmeier, Kateřina Štůsková
et al.
With a reduction in available chemical treatments, there is an increased interest in biological control of grapevine trunk diseases. Few studies have investigated the impact of introducing beneficial microorganisms in the rhizosphere on the existing indigenous soil microbiome. In this study, we explored the effect of two biocontrol agents (BCAs), Trichoderma atroviride SC1 (Ta SC1) (Vintec; Certis Belchim) and Bacillus subtilis PTA-271 (Bs PTA-271), on the grapevine rhizosphere bacterial and fungal microbiome as well as plant defense expression using high-throughput amplicon sequencing and quantitative real-time polymerase chain reaction (PCR), respectively. Additionally, we quantified both Ta SC1 and Bs PTA-271 in the rhizosphere over time using droplet digital PCR. The fungal microbiome was more affected by factors such as soil type, BCA treatment, and sampling time compared with the bacterial microbiome. Specifically, Ta SC1 application produced negative impacts on fungal diversity, whereas application of BCAs did not affect bacterial diversity. Interestingly, the survival and establishment of both BCAs showed opposite trends depending on the soil type, indicating that the physicochemical properties of soils have a role in BCA establishment. Fungal co-occurrence networks were less complex than bacterial networks but highly impacted by Ta SC1 application. Soils treated with Ta SC1 presented more complex and stable co-occurrence networks, with a higher number of positive correlations. Induced grapevine defenses also differed according to the soil, being more affected by BCA inoculation on sandy soil. The findings of this research emphasize the complex relationships among microorganisms in the rhizosphere and highlight the significance of taking into account various factors, such as soil type, sampling time, and BCA treatment, and their influence on the structure and dynamics of microbial communities.
Plant culture, Microbial ecology
Association Mapping of Seed Coat Color Characteristics for Near-Isogenic Lines of Colored Waxy Maize Using Simple Sequence Repeat Markers
Tae Hyeon Heo, Hyeon Park, Nam-Wook Kim
et al.
Waxy maize is mainly cultivated in South Korea for the production of food and snacks, and colored maize with increased anthocyanin content is used in the production of functional foods and medicinal products. Association mapping analysis (AMA) is supported as the preferred method for identifying genetic markers associated with complex traits. Our study aimed to identify molecular markers associated with two anthocyanin content and six seed coat color traits in near-isogenic lines (NILs) of colored waxy maize assessed through AMA. We performed AMA for 285 SSR loci and two anthocyanin content and six seed coat color traits in 10 NILs of colored waxy maize. In the analysis of population structure and cluster formation, the two parental lines (HW3, HW9) of “Mibaek 2ho” variety waxy maize and the 10 NILs were clearly divided into two groups, with each group containing one of the two parental inbred lines. In the AMA, 62 SSR markers were associated with two seed anthocyanin content and six seed coat color traits in the 10 NILs. All the anthocyanin content and seed coat color traits were associated with SSR markers, ranging from 2 to 12 SSR markers per characteristic. The 12 SSR markers were together associated with both of the two anthocyanin content (kuromanin and peonidin) traits. Our current results demonstrate the effectiveness of SSR analysis for the examination of genetic diversity, relationships, and population structure and AMA in 10 NILs of colored waxy maize and the two parental lines of the “Mibaek 2ho” variety waxy maize.
Effectiveness, efficiency, and equity in jurisdictional REDD+ benefit distribution mechanisms: Insights from Jambi province, Indonesia
Riko Wahyudi, Wahyu Marjaka, Christian Silangen
et al.
The jurisdictional REDD+ (JREDD+) mechanism, aimed at reducing emissions from deforestation and forest degradation, has been crucial in global climate change mitigation efforts. However, designing effective, efficient, and equitable benefit-distribution policy at the site level remains a challenge. This research assesses three benefit distribution mechanisms in Indonesia for JREDD+ initiatives, facilitated by the Indonesian Environment Fund (IEF). They include: (1) distribution through the provincial revenue and expenditure budget (APBD), (2) distribution through intermediary institutions (LEMTARA), and (3) direct distribution or transfer to beneficiaries. Each mechanism is evaluated on effectiveness, efficiency, and equity, considering bureaucratic processes and stakeholder capacities. The study utilizes public deliberation by involving relevant stakeholders at the national and Jambi province levels and expert judgment by purposively selecting based on certain criteria to help determine the optimal mechanism as the reference for achieving Indonesia's climate mitigation goals and the administrative intricacies involved. The findings suggest that direct distribution to beneficiaries is the most efficient and equitable, although using LEMTARA is deemed slightly more effective for targeted fund allocation. The study provides recommendations for policy makers on enhancing institutional capacities and integrating flexible inclusive mechanisms to optimize JREDD+ benefit distribution at the sub-national level.
Distribution of zooplankton biomass in the Shatt Al-Arab River and Shatt Al-Basra Canal, Southern Iraq
Afaq Jebir, Shaker Ajeel, Talib Khalaf
Zooplankton is the important component of aquatic ecosystems. These organisms are important biological indicator of water quality of aquatic ecosystem due to their response to the environmental changes. In this study, we investigated distribution of zooplankton biomass in the Shatt Al-Basra Canal and Shatt Al-Arab River. Zooplankton samples were collected from two stations in the Shatt Al-Basra Canal, before (S1) and after (S2) the dam, and two stations in the Shatt Al-Arab River, Al-Siba (S3) and Al-Faw (S4). The biomass of zooplankton in the Shatt Al-Basra Canal varied between 23.102 - 520.875 mg/m3 in terms of wet weight and 3.787 - 102.132 mg/m3 in terms of dry weight at two stations (before the dam and after the dam) during the period of January and May, respectively. The displacement volume and standing crops also showed variations of the biomass of zooplankton. In the Shatt Al-Basra Canal, the range was from 0.06 ml/m3 and 3.9 mgC/m3 during January at S1 to 1.083 ml/m3 and 70.395 mgC/m3 during May at S2. While in the Shatt Al-Arab River, the biomass of zooplankton in terms of wet weight ranged from 10.671 - 655.78 mg/m3 during December at S3 (Al-Siba) and may at S4 (Al-Faw) respectively. In terms of dry weight, the biomass ranged from 1.423 to 168.149 mg/m3 in S3 during the December and in S4 during May respectively. In terms of displacement volume and standing crops, they ranged from 0.03 ml/m3 to 1.95 mgC/m3 during December at S3 to 1.819 ml/m3 and 118.235 mgC/m3 during February at S4.
Fungicide-Mediated Shifts in the Foliar Fungal Community of an Invasive Grass
Brett R. Lane, Amy E. Kendig, Christopher M. Wojan
et al.
Invasive plants, which cause substantial economic and ecological impacts, acquire both pathogens and beneficial microbes in their introduced ranges. Communities of fungal endophytes are known to mediate impacts of pathogens on plant fitness but few studies have examined the temporal dynamics of fungal communities on invasive plants. The annual grass Microstegium vimineum, an invader of forests and riparian areas throughout the eastern United States, experiences annual epidemics of disease caused by Bipolaris pathogens. Our objective was to characterize the dynamics of foliar fungal communities on M. vimineum over a growing season during a foliar disease epidemic. First, we asked how the fungal community in the phyllosphere changed over 2 months that corresponded with increasing disease severity. Second, we experimentally suppressed disease with fungicide in half of the plots and asked how the treatment affected fungal community diversity and composition. We found increasingly diverse foliar fungal communities and substantial changes in community composition between timepoints using high-throughput amplicon sequencing of the internal transcribed spacer 2 region. Monthly fungicide application caused shifts in fungal community composition relative to control samples. Fungicide application increased diversity at the late-season timepoint, suggesting that it suppressed dominant fungicide sensitive taxa and allowed other fungal taxa to flourish. These results raise new questions regarding the roles of putative endophytes found in the phyllosphere given the limited number of pathogens known to cause disease on M. vimineum in its invasive range.
Plant culture, Microbial ecology
Development of Rice Variety With Durable and Broad-Spectrum Resistance to Blast Disease Through Marker-Assisted Introduction of Pigm Gene
Zhiming Feng, Zhiming Feng, Mingyou Li
et al.
Rice blast, caused by Magnaporthe oryzae (M. oryzae), is one of the most destructive diseases threatening rice production worldwide. Development of resistant cultivars using broad-spectrum resistance (R) genes with high breeding value is the most effective and economical approach to control this disease. In this study, the breeding potential of Pigm gene in geng/japonica rice breeding practice in Jiangsu province was comprehensively evaluated. Through backcross and marker-assisted selection (MAS), Pigm was introduced into two geng rice cultivars (Wuyungeng 32/WYG32 and Huageng 8/HG8). In each genetic background, five advanced backcross lines with Pigm (ABLs) and the same genotypes as the respective recurrent parent in the other 13 known R gene loci were developed. Compared with the corresponding recurrent parent, all these ABLs exhibited stronger resistance in seedling inoculation assay using 184 isolates collected from rice growing regions of the lower region of the Yangtze River. With respect to panicle blast resistance, all ABLs reached a high resistance level to blast disease in tests conducted in three consecutive years with the inoculation of seven mixed conidial suspensions collected from different regions of Jiangsu province. In natural field nursery assays, the ABLs showed significantly higher resistance than the recurrent parents. No common change on importantly morphological traits and yield-associated components was found among the ABLs, demonstrating the introduction of Pigm had no tightly linked undesirable effect on rice economically important traits and its associated grain weight reduction effect could be probably offset by others grain weight genes or at least in the background of the aforementioned two varieties. Notably, one rice line with Pigm, designated as Yangnonggeng 3091, had been authorized as a new variety in Jiangsu province in 2021, showing excellent performance on both grain yield and quality, as well as the blast resistance. Together, these results suggest that the Pigm gene has a high breeding value in developing rice varieties with durable and broad-spectrum resistance to blast disease.
Enhanced Degradation of Juvenile Hormone Promotes Reproductive Diapause in the Predatory Ladybeetle Coccinella Septempunctata
Yu-Yan Li, Jun-Jie Chen, Meng-Yao Liu
et al.
Improved knowledge on the regulation of reproductive diapause in Coccinella septempunctata, an important predator of aphids, is crucial for improving shelf-life and mass production of the ladybeetles. In many insects, the absence of juvenile hormone (JH) is a central regulator of reproductive diapause. JH is principally degraded by JH esterase (JHE) and JH epoxide hydrolase (JHEH). Previous studies have shown that genes encoding these enzymes were upregulated in early diapause of C. septempunctata, but whether increased JH degradation contributes to the reduction of JH levels and facilitates reproductive diapause remains unknown. Here, we investigate the role of JH and JH degradation genes during reproductive diapause in C. septempunctata females. Applying methoprene, a JH analogue, to the diapause preparation females clearly elevated JH signaling and reversed diapause program, suggesting that a lower level of JH is critical for the induction of reproductive diapause in the ladybeetle. Full-length cDNA sequences of JHE and JHEH were cloned and characterized, and their deduced proteins contain all the conserved active domains and typical motifs as identified in other insects. The expressions of JHE and JHEH were both significantly increased in diapause preparation and remained at a high level for a period throughout diapause, and then decreased after the termination of diapause. Knocking down these JH degradation genes clearly increased the expression levels of JH-inducible genes Krüppel-homolog 1 (Kr-h1) and vitellogenin (Vg), indicating an elevated JH level. Simultaneously, silencing JH degradation genes distinctly reduced diapause-related features and promotes reproduction, indicated by accelerated ovary growth, yolk deposition, and suppressed lipid accumulation. These results indicate that the enhanced JH degradation plays a critical role in regulating reproductive diapause of C. septempunctata.
Induced Local and Systemic Defense Responses in Tomato Underlying Interactions Between the Root-Knot Nematode Meloidogyne incognita and the Potato Aphid Macrosiphum euphorbiae
Crispus M. Mbaluto, Crispus M. Mbaluto, Esraa M. Ahmad
et al.
Plants mediate interactions between different herbivores that attack simultaneously or sequentially aboveground (AG) and belowground (BG) organs. The local and systemic activation of hormonal signaling pathways and the concomitant accumulation of defense metabolites underlie such AG-BG interactions. The main plant-mediated mechanisms regulating these reciprocal interactions via local and systemic induced responses remain poorly understood. We investigated the impact of root infection by the root-knot nematode (RKN) Meloidogyne incognita at different stages of its infection cycle, on tomato leaf defense responses triggered by the potato aphid Macrosiphum euphorbiae. In addition, we analyzed the reverse impact of aphid leaf feeding on the root responses triggered by the RKN. We focused specifically on the signaling pathways regulated by the phytohormones jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), and indole-3-acetic acid (IAA) as well as steroidal glycoalkaloids as induced defense compounds. We found that aphid feeding did not induce AG hormonal signaling, but it repressed steroidal glycoalkaloids related responses in leaves, specifically when feeding on plants in the vegetative stage. Root infection by the RKN impeded the aphid-triggered repression of the steroidal glycoalkaloids-related response AG. In roots, the RKN triggered the SA pathway during the entire infection cycle and the ABA pathway specifically during its reproduction stage. RKN infection also elicited the steroidal glycoalkaloids related gene expression, specifically when it was in the galling stage. Aphid feeding did not systemically alter the RKN-induced defense responses in roots. Our results point to an asymmetrical interaction between M. incognita and Ma. euphorbiae when co-occurring in tomato plants. Moreover, the RKN seems to determine the root defense response regardless of a later occurring attack by the potato aphid AG.
HSP70 plays an ambiguous role during viral infections in plants
V. HÝSKOVÁ, K. BĚLONOŽNÍKOVÁ, N. ČEŘOVSKÁ
et al.
Heat shock and almost all types of stresses associated with oxidative stress are accompanied by heat shock protein (HSP) expression. HSPs are involved in refolding denatured proteins and directing unrepairable proteins for degradation. Thus, under stress conditions, HSPs help to restore cellular balance. However, in virus-infected plants, HSP70 can have both positive and negative effects because viruses usually recruit HSP70. HSP70 can promote the replication and translation of the viral genome, the formation of viral replication complexes, and the propagation of viral particles from cell to cell and throughout the plant. HSP gene silencing in various virus-host plants systems and the comparison of susceptible and resistant species have shown that HSPs70 accelerate the development of infection. Conversely, during the process known as thermotherapy, the temperature increase inhibits viral replication in some host and virus systems. The success of thermotherapy depends not only on the temperature and treatment period or duration but also on the plant species and viral strain. In this review, we discuss the ambiguous role that HSPs70 play during viral infections in plants towards weighing the balance between their positive and negative functions.
Biology (General), Plant ecology
Integrated Farming System (IFS): A Review
Shweta Khobragade, Sanghamitra Mohapatra, M. Mahananda
et al.
Adoption of Integrated Farming System (IFS) leads to sustainability and stability in farm income through multiple enterprises that aim at maximum utilization of available natural resources to meet the family needs. It aims at generating a threshold level of farm income required for the farm family to maintain sustained interest in farming thus preventing migration of people from the farming sector. Integrated Farming System which combines activities of food-crop farming with horticulture, animal husbandry, fisheries, forestry and other science related to farming on the same field at the same or almost the same time needs to be developed as a solution to food security problem resulting from decreasing food productivity and climate change. IFS itself is important for sustainable development of farmer by improving yield, economic return, employment generation, nutritional security and livelihood.
Agriculture, Plant ecology
Study on Three Sarcocapnos Species as Potential Sources of Bioactive Compounds: Relation between Phenolic Content and Bioactivity by Multivariate Analysis
María del Pilar Fernández-Poyatos, Gökhan Zengin, Carlos Salazar-Mendías
et al.
In this work, we report the phenolic composition and bioactivity of the aerial parts of three species of Sarcocapnos (S. enneaphylla, S. pulcherrima, and S. saetabensis) to study their potential as sources of bioactive compounds to revalorize them and contribute to the conservation of these plant species. Samples were collected in different locations in the province of Jaén (southeast of Spain), and qualitative and quantitative analyses of phenolic compounds were performed by high-performance liquid chromatography with diode array and mass spectrometry detection. S. enneaphylla presented the highest concentration of phenolic compounds (58 mg/g DE). The most abundant compound in S. enneaphylla and S. saetabensis was rutin (35 mg/g DE and 11.7 mg/g DE, respectively), whereas isorhamnetin-O-rutinoside was dominant in S. pulcherrima (11.5 mg/g DE). Several assays were performed to evaluate the potential bioactivity of the three species of Sarcocapnos. These assays included antioxidant and radical scavenging (ABTS and DPPH), reducing power (CUPRAC and FRAP), phosphomolybdenum and metal chelating, and enzyme inhibitory activity (acetylcholinesterase, amylase, butyrylcholinesterase, glucosidase, and tyrosinase). In general, all methanolic extracts presented the highest phenolic and flavonoid contents, as well as the highest radical scavenging, antioxidant, and enzyme inhibitory properties. This relationship between phenolics and bioactivity was confirmed by multivariate analysis.
A native parasitic plant and soil microorganisms facilitate a native plant co‐occurrence with an invasive plant
Junmin Li, Ayub M. O. Oduor, Feihai Yu
et al.
Abstract Invasive plants often interact with antagonists that include native parasitic plants and pathogenic soil microbes, which may reduce fitness of the invaders. However, to date, most of the studies on the ecological consequences of antagonistic interactions between invasive plants and the resident biota focused only on pairwise interactions. A full understanding of invasion dynamics requires studies that test the effects of multiple antagonists on fitness of invasive plants and co‐occurring native plants. Here, we used an invasive plant Mikania micrantha, a co‐occurring native plant Coix lacryma‐jobi, and a native holoparasitic plant Cuscuta campestris to test whether parasitism on M. micrantha interacts with soil fungi and bacteria to reduce fitness of the invader and promote growth of the co‐occurring native plant. In a factorial setup, M. micrantha and C. lacryma‐jobi were grown together in pots in the presence versus absence of parasitism on M. micrantha by C. campestris and in the presence versus absence of full complements of soil bacteria and fungi. Fungicide and bactericide were used to suppress soil fungi and bacteria, respectively. Findings show that heavy parasitism by C. campestris caused the greatest reduction in M. micrantha biomass when soil fungi and bacteria were suppressed. In contrast, the co‐occurring native plant C. lacryma‐jobi experienced the greatest increase in biomass when grown with heavily parasitized M. micrantha and in the presence of a full complement of soil fungi and bacteria. Taken together, our results suggest that selective parasitism on susceptible invasive plants by native parasitic plants and soil microorganisms may diminish competitive ability of invasive plants and facilitate native plant coexistence with invasive plants.
Brood sex ratio in the Yellow-bellied Prinia (Prinia flaviventris)
Zhifeng Ding, Fang Ji, Qiuli Huang
et al.
Abstract Background The adjustment of sex ratios in birds can occur at the egg and nestling stages. Previous studies showed that the sex ratio was affected by environmental factors and parental condition; it may result in seasonal and ecosystem differences. Methods In this study, the brood sex ratio of the Yellow-bellied Prinia (Prinia flaviventris) in the Nonggang area, Guangxi, southwestern China, was investigated during the breeding season from May to June in 2013 using PCR amplification from whole-genome DNA extracted from blood samples. A total of 31 nests of Yellow-bellied Prinia, including 132 brood fledglings and 31 pairs, were sampled. Results The results showed that the brood sex ratio of the Yellow-bellied Prinia was 1:1, and sex ratios of different nests were evenly distributed within the study area. No significant relationship was found between parental quality and nest characteristics with the brood sex ratio. Conclusions The present study indicated that no brood sex ratio bias in the Yellow-bellied Prinia highlighted the complexity of sex ratio adjustment in birds. In spite of our negative results, the lack of an association between brood sex ratio and parental quality and environmental factors in the Yellow-bellied Prinia provides valuable information on the adjustment of sex ratios in birds.
Análisis económico de la disposición a pagar por un seguro como medida de adaptación al cambio climático, en los agricultores del valle Tumbes
Javier Mijahuanca, Federico Guerrero
La agricultura es una de las actividades más importantes de Tumbes, tanto por su aporte a la producción regional como por la fuente de trabajo que genera; sin embargo, la dinámica de su proceso en algunas oportunidades se ve interrumpida por un evento de importancia mundial como es el fenómeno “El Niño” que causa pérdidas económicas para el productor que no puede cancelar sus préstamos, tiene dificultades para iniciar la siguiente campaña agrícola y recurre a solicitar apoyo al estado. Los seguros permiten al productor adaptarse a los efectos del cambio climático y proteger sus producciones ante un peligro recurrente; sin embargo, en nuestra región no existen antecedentes del uso de seguros agrícolas; tema que ha sido inquietante para el autor que planteó la presente investigación con el objetivo de analizar el beneficio económico de la disposición a pagar por un seguro como medida de adaptación al cambio climático, en los agricultores del valle Tumbes. La principal técnica utilizada fue la encuesta, el cuestionario ha sido aplicado a los agricultores de los tres cultivos importantes del valle Tumbes que son el arroz, banano convencional y banano orgánico. Los resultados obtenidos indican que el 70,3% de los agricultores están dispuestos a adquirir un seguro como medida de adaptación al cambio climático, obteniéndose beneficio económico aún en sus cultivos.
Ecology, Agriculture (General)
High-throughput analysis of ammonia oxidiser community composition via a novel, amoA-based functional gene array.
Guy C J Abell, Stan S Robert, Dion M F Frampton
et al.
Advances in microbial ecology research are more often than not limited by the capabilities of available methodologies. Aerobic autotrophic nitrification is one of the most important and well studied microbiological processes in terrestrial and aquatic ecosystems. We have developed and validated a microbial diagnostic microarray based on the ammonia-monooxygenase subunit A (amoA) gene, enabling the in-depth analysis of the community structure of bacterial and archaeal ammonia oxidisers. The amoA microarray has been successfully applied to analyse nitrifier diversity in marine, estuarine, soil and wastewater treatment plant environments. The microarray has moderate costs for labour and consumables and enables the analysis of hundreds of environmental DNA or RNA samples per week per person. The array has been thoroughly validated with a range of individual and complex targets (amoA clones and environmental samples, respectively), combined with parallel analysis using traditional sequencing methods. The moderate cost and high throughput of the microarray makes it possible to adequately address broader questions of the ecology of microbial ammonia oxidation requiring high sample numbers and high resolution of the community composition.
Environmental effect of conventional and GM crops of cotton (Gossipium hirsitum L.) and corn (Zea mays L.)
Kelly Ávila, Alejandro Chaparro-Giraldo, Giovanni Reyes
In the corn belt of Valle de San Juan and in the cotton zone of El Espinal, municipalities in the department of Tolima (Colombia), 10 conventional corn producers, 10 producers of genetically modified corn, five producers of conventional cotton and 15 producers of transgenic cotton were surveyed in the first half of 2009 to contrast the differences in the environmental impact associated with use of insecticides and herbicides, which were evaluated by estimating the environmental index quotient-EIQ. In the case of maize, an EIQ of 42 was found in the conventional type, while transgenic technology had an EIQ of 3.03. In the cultivation of cotton, an EIQ of 263.59 was found for the conventional type while for transgenic technology this value varied between 335.75 (Nuopal BG/RR) and 324.79 (DP 455 BG/RR). These data showed a lower environmental impact using GM technology in the cultivation of maize when compared to the conventional counterpart, in connection with the use of insecticides and herbicides, in the context of time, space and genotypic analysis. This effect was not observed in the case of cotton, where environmental impacts were similar