High Infestation Research Articles

Exploring Gut Microbiome Variations between Popillia japonica Populations of Azores.

Popillia japonica (Coleoptera: Scarabaeidae), is an emerging invasive pest in Europe and America. In the Azores, this pest was first found on Terceira Island during the sixties and soon spread to other islands. The rate of infestation differs between islands, and we hypothesized that microbiome composition could play a role. Therefore, we sampled 3rd instar larvae and soil from sites with high and low infestation rates to analyze the microbiome using next-generation sequencing. We analyzed twenty-four 16S DNA libraries, which resulted in 3278 operational taxonomic units. The alpha and beta diversity of the soil microbiome was similar between sites. In contrast, the larvae from high-density sites presented a higher bacterial gut diversity than larvae from low-density sites, with biomarkers linked to plant digestion, nutrient acquisition, and detoxification. Consequently, larvae from high-density sites displayed several enriched molecular functions associated with the families Ruminococcaceae, Clostridiaceae and Rikenellaceae. These bacteria revealed a supportive function by producing several CAZyme families and other proteins. These findings suggest that the microbiome must be one drive for the increase in P. japonica populations, thus providing a checkpoint in the establishment and spread of this pest.

High densities, rapid infestation and high feeding rates of corallivore gastropods on corals in Bora-Bora Island, French Polynesia

The global decline of coral reefs has prompted research into understanding the impacts of anthropogenic stressors, as well as the interactions between corals and their natural predators, especially those that proliferate into outbreaks. However, studies on gastropod corallivores are lagging behind. The present study, conducted on Bora-Bora (French Polynesia), focused on two genera of corallivore muricid gastropods: Drupella spp. living on Acropora colonies and Coralliophila violacea on Porites rus colonies. An observational experiment of Drupella spp. and C. violacea showed strong spatial variation in densities across different habitats (fringing reef, channel, barrier reef) in Bora-Bora lagoon. The highest densities found were 21 ± 6 ind.m−3 of coral for Drupella spp. on the fringing reef, and 342 ± 51 ind.m−3 for C. violacea on the barrier reef. A manipulation experiment monitored the infestation dynamics of these gastropods. For both genera, colonization of vacant coral colonies was rapid during the first 14 days and then stabilized over the next 42 days. The manipulation experiment showed that the feeding rate on live and healthy coral tissue did not change significantly with Drupella spp. density (0.6 ± 0.2 cm 2/day/ind for 1 Drupella spp., and 0.5 ± 0.1 cm 2/day/ind for 5 Drupella spp.). Overall, our study highlights the high densities of two gastropod species, their rapid movement and infestation of vacant colonies and their role in the necrosis of corals during feeding. In view of the possible outbreaks involving high densities of such predatory gastropods in a major tourist destination in the Pacific Ocean, human resources could be put in place to manually remove these gastropods in a sustainable manner, but this would require a lot of effort in terms of manpower and time. Nature-based solutions such as the conservation of natural predators should be considered to prevent large-scale destructions by these gastropod aggregations.

Infestation Status of Some Major Insect Pests of Soybean and Their Management

The study was conducted to investigate the effective management of some major insect pests of soybean in the research field of Sher-e-Bangla Agricultural University, Dhaka during the period from December, 2020 to March 2021. The experiment was designed with Randomized Complete Block Design (RCBD) with three replications. During this experiment total six insecticides were tested viz., Lambda-Cyhalothrin @1ml/L of water Neemoil @1ml/L of water with 3g of detergent; Thiamethoxam @0.5g/L of water; Spinosad @0.5ml/L of water; Chlorantraniliprole @0.3ml/L of water; Emamectin Benzoate @1ml/L of water. Data on different pests populaton number and yield were collected and recorded. The lowest population per unit of whitefly and jassid was found in Emamectin Benzoate @1ml/L of water treated plots after consecutive three times application. Similarly, lowest unit of aphid was found in Chlorantraniliprole @0.3ml/L of water; treated plots. On the other hand, Thiamethoxam @0.5gl/L of water were found effective against whitefly, aphid, pod borer per plant, while the highest infestation was observed in control plots. The maximum yield was 1.68 t/ha, observed from Emamectin Benzoate @1ml/L of water, followed by (1.61 t/ha ) Chlorantraniliprole @0.3ml/L of water Among the treatments, Emamectin Benzoate @1ml/L of water was more effective for the controlling of insect pests as well as yield of soybean.

Genomic versus phenotypic selection to improve corn borer resistance and grain yield in maize.

The study of yield and resistance/tolerance to pest are related traits fundamental for maize breeding programs. Genomic selection (GS), which uses all marker information to calculate genomic breeding values, is presented as an emerging alternative to phenotypic and marker-assisted selections for improving complex traits controlled by many genes with small effects. Therefore, although phenotypic selection (PS) has been effective for increasing resistance and yield under high infestation with maize stem borers, higher genetic gains are expected to be obtained through GS based on the complex architecture of both traits. Our objective was to test whether GS is more effective than PS for improving resistance and/or tolerance to maize stem borers and grain yield. For this, we compared different selection programs based on phenotype and genotypic value for a single trait, resistance or yield, and for both traits together. We obtained that GS achieved the highest genetic gain for yield, meanwhile phenotypic selection for yield was the program that achieved the highest reduction of tunnel length, but was ineffective for increasing yield. However, phenotypic or genomic selection for increased resistance may be more effective in improving both traits together; although the gains per cycle would be small for both traits.

Reactions of Finger Millet (Eleusine coracana (L.) Gaertn) Genotypes for Blast Resistance and Yield in Wukari and Takum Taraba State, Nigeria

Finger millet contains high level of methionine, tryptophan, vitamin B, fibre and minerals such as phosphorus, iron, calcium, which serve a good source of balance diet formulations for hypertension, obesity, diabetic patients, pregnant women, nursing mothers, children, people leaving with HIV, malnourished people, incidence of iron deficiency (anemia), and calcium deficiency causing rickets in young children. Production constraints responsible for the low yields have been identified as pests, blast and Striga, drought, low soil fertility, labor intensity, high weed infestation, low yielding varieties, lodging, and poor attitude to the crop. Finger millet blast about 50% yield losses. This disease has been identified as the highest priority constraint to finger millet production in Nigeria, since most landraces and a number of other genotypes are highly susceptible. Field trials were conducted on 22 germplasm (U 15, P224, ACC 32, ACC14, KNE814, IE 3779, KNE 628, KNE 688, KNE 1149, Etiyo Brown, Gulu E, Kala, RW 127(IE 6613), KNE 392, GBK 029681, ACC 3953, GBK 011136A, KNE 689, KNE 1034, Emiroit, Red local check and Black local check) from ICRISAT and farmers in 3 replicates at Wukari and Takum in 2019, to assess for blast disease resistance and yield. A significant negative correlation (0.52) was found between blast severity and DF (days to flowering) suggesting that late/medium flowering varieties are more resistant than the early ones as indicated by genotypes KNE814, IE 3779, KNE 628, KNE 688, KNE 1149, Gulu E,, KNE 392, GBK 029681, ACC 3953, GBK 011136A, KNE 689, KNE 1034, Emiroit and Red (local check) varieties, which were medium maturing and highly resistance to blast disease, with foliar blast severity (1.07 - 3.0), neck blast (1.5 - 2.5) and finger blast (11 - 25 %), NET (3.45 - 4.38), NFPH (5.80) and subsequently highest yield (1565 - 1887 kg/ha), compared to black local variety with the highest foliar blast severity (4.00 - 6.70), neck blast (2.7 - 4.40), finger blast (32 - 36 %), NET (2.50 - 2.70), NFPH (3.30 - 4.70) and lowest yield (688 - 989 kg/ha), respectively in Wukari and Takum locations. Hence, these varieties resistant to foliar, neck, finger blast diseases, good yield parameters are recommended as sources of germplasm for genetic improvement and further research.

Reactions of Finger Millet (Eleusine coracana (L.) Gaertn) Genotypes for Blast Resistance and Yield in Wukari and Takum Taraba State, Nigeria

Finger millet contains high level of methionine, tryptophan, vitamin B, fibre and minerals such as phosphorus, iron, calcium, which serve a good source of balance diet formulations for hypertension, obesity, diabetic patients, pregnant women, nursing mothers, children, people leaving with HIV, malnourished people, incidence of iron deficiency (anemia), and calcium deficiency causing rickets in young children. Production constraints responsible for the low yields have been identified as pests, blast and Striga, drought, low soil fertility, labor intensity, high weed infestation, low yielding varieties, lodging, and poor attitude to the crop. Finger millet blast about 50% yield losses. This disease has been identified as the highest priority constraint to finger millet production in Nigeria, since most landraces and a number of other genotypes are highly susceptible. Field trials were conducted on 22 germplasm (U 15, P224, ACC 32, ACC14, KNE814, IE 3779, KNE 628, KNE 688, KNE 1149, Etiyo Brown, Gulu E, Kala, RW 127(IE 6613), KNE 392, GBK 029681, ACC 3953, GBK 011136A, KNE 689, KNE 1034, Emiroit, Red local check and Black local check) from ICRISAT and farmers in 3 replicates at Wukari and Takum in 2019, to assess for blast disease resistance and yield. A significant negative correlation (0.52) was found between blast severity and DF (days to flowering) suggesting that late/medium flowering varieties are more resistant than the early ones as indicated by genotypes KNE814, IE 3779, KNE 628, KNE 688, KNE 1149, Gulu E,, KNE 392, GBK 029681, ACC 3953, GBK 011136A, KNE 689, KNE 1034, Emiroit and Red (local check) varieties, which were medium maturing and highly resistance to blast disease, with foliar blast severity (1.07 - 3.0), neck blast (1.5 - 2.5) and finger blast (11 - 25 %), NET (3.45 - 4.38), NFPH (5.80) and subsequently highest yield (1565 - 1887 kg/ha), compared to black local variety with the highest foliar blast severity (4.00 - 6.70), neck blast (2.7 - 4.40), finger blast (32 - 36 %), NET (2.50 - 2.70), NFPH (3.30 - 4.70) and lowest yield (688 - 989 kg/ha), respectively in Wukari and Takum locations. Hence, these varieties resistant to foliar, neck, finger blast diseases, good yield parameters are recommended as sources of germplasm for genetic improvement and further research.

Root traits explain multitrophic interactions of belowground microfauna on soil nitrogen mineralization and plant productivity

Both herbivorous and bacterivorous microfauna have been shown to influence root development, soil nitrogen (N) mineralization, and plant productivity. However, our knowledge of these effects is limited as multitrophic interactions remain largely unexplored. We investigated whether and how herbivorous nematodes (Pratylenchus zeae) and bacterivorous nematodes (Poikilolaimus oxycercus), alone and in combination, affect plant biomass (Lolium multiflorum) through root traits and/or soil N mineralization. Bacterivorous nematodes increased, whereas herbivorous nematodes decreased, plant productivity. We found that root trait coordination in response to soil microfauna was consistent with the concept of root economics space. The negative interaction between herbivorous and bacterivorous nematodes on plant productivity at high herbivorous nematode infestation could be explained by reduced N mineralization and variation in the root nitrogen concentration-root tissue density (RNC-RTD) axis aligned with increased herbivory intensity. This study revealed that herbivorous and bacterivorous nematodes moderated each other's effect on plant productivity via root trait coordination and N mineralization, and suggests, for the first time, the value of the root economics space concept for interpreting phenotypic root plasticity and functioning in response to local biotic factors.

Molecular and genetic insights into secondary metabolic regulation underlying insect-pest resistance in legumes.

Insect pests pose a major threat to agricultural production, resulting in significant economic losses for countries. A high infestation of insects in any given area can severely reduce crop yield and quality. This review examines the existing resources for managing insect pests and highlights alternative eco-friendly techniques to enhance insect pest resistance in legumes. Recently, the application of plant secondary metabolites has gained popularity in controlling insect attacks. Plant secondary metabolites encompass a wide range of compounds such as alkaloids, flavonoids, and terpenoids, which are often synthesized through intricate biosynthetic pathways. Classical methods of metabolic engineering involve manipulating key enzymes and regulatory genes to enhance or redirect the production of secondary metabolites in plants. Additionally, the role of genetic approaches, such as quantitative trait loci mapping, genome-wide association (GWAS) mapping, and metabolome-based GWAS in insect pest management is discussed, also, the role of precision breeding, such as genome editing technologies and RNA interference for identifying pest resistance and manipulating the genome to develop insect-resistant cultivars are explored, highlighting the positive contribution of plant secondary metabolites engineering-based resistance against insect pests. It is suggested that by understanding the genes responsible for beneficial metabolite compositions, future research might hold immense potential to shed more light on the molecular regulation of secondary metabolite biosynthesis, leading to advancements in insect-resistant traits in crop plants. In the future, the utilization of metabolic engineering and biotechnological methods may serve as an alternative means of producing biologically active, economically valuable, and medically significant compounds found in plant secondary metabolites, thereby addressing the challenge of limited availability.

Seasonal incidence of stem fly, Melanagromyza sojae (Zehntner) infesting black gram (Vigna mungo L.) in kharif

A field experiment on the seasonal incidence of stem fly, Melanagromyza sojae (Zehntner) infesting black gram was carried out in variety GU 1 (Gujarat Urd 1) during kharif 2017 and 2021 at Entomology farm, B. A. College of Agriculture, AAU, Anand. Infestation of M. sojaewas observed from 1st WAS i.e., 34th SMW. Later on, infestation increased gradually and its highest infestation was observed during the 39th SMW i.e., 68.33 and 73.33% of kharif, 2017 and 2021, respectively. Stem fly infestation exhibited a highly significant positive association (r = 0.519** and 0.655**, respectively) with bright sunshine hours (BSS) and maximum temperature (MaxT), respectively. Abiotic factors viz., rainfall (RF) exhibited a significant negative association (-0.458*), while evaporation (EP) showed a significant positive association (0.466*).

An economic evaluation of cattle tick acaricide-resistances and the financial losses in subtropical dairy farms of Ecuador: A farm system approach.

Estimates of economic losses in cattle due to tick infestations in subtropical areas are limited, such as in Ecuador. Ticks affect animal production and health, but those direct effects are difficult to estimate since financial exercises carried out in farms consider both costs of the inputs and revenues. This study aims to quantify the costs of inputs involved in milk production and to know the role of acaricide treatment in the production costs on dairy farms in subtropical zones using a farming system approach. Regression and classification trees were used to study the relationship between tick control, acaricide resistance and the presence of high level of tick infestation in the farm system. Even though there was no significant direct association between high levels of tick infestation and the presence of acaricide resistance in ticks, a more complex structure for resistances operates in the manifestation of high tick infestation involving levels of farm technology and no acaricide resistance. Farms with higher levels of technology allocate a lower percentage of sanitary expenses to control ticks (13.41%) in comparison to semi-technified (23.97%) and non-technified farms (32.49%). Likewise, more technified and bigger herds have a lower annual expenditure on acaricide treatment (1.30% of the production budget equivalent to 8.46 USD per animal) compared to non-technified farms where it can represent more than 2.74% of the production budget and where the absence of cypermethrin resistance increases the treatment cost to 19.50 USS per animal annually. These results can motivate the development of information campaigns and control programmes targeted to the reality of small and medium farms that are the most affected in terms of the money they invest in controlling ticks.

Infestation of white mustard agrocenosis, depending on agricultural practices in the conditions of the forest-steppe of the Middle Volga region

To obtain environmentally friendly products, in the technology of cultivating agricultural crops, the basis of modern weed control should be agricultural practices. In this regard, the purpose of the research is to select the optimal seeding rate and sowing method for white mustard, which increase the self-regulation of the number of weeds in the agrocenosis to obtain the highest seed yield. The experiment was carried out in 2020–2022 on the meadow-chernozem soil of the experimental plot of the Federal State Budgetary Educational Institution of Higher Education Penza State Agrarian University. The weather conditions during the years of research were different, but they met the requirements for the growth and development of white mustard. The growing season of mustard in the first and third years passed under conditions of sufficient moisture at the optimum temperature regime (HTC 1.3 and 1.0, respectively). In the second year of research, drier conditions developed, when the hydrothermal coefficient was 0.87. On average, the minimum infestation of mustard crops before harvesting was traced with an ordinary sowing method of 36-51 pcs/m2 with a wet weight of weeds of 75.8-106.0 g/m2, while with a wide-row method their number was 43-62 pcs/m2 with a mass of 91.0-129.2 g/m2, where the feeding area increased not only for cultivated, but also for weeds. Moreover, the agrocenosis was the cleanest with the maximum seeding rate (3 million germinating seeds/ha) and mustard sowing with a row spacing of 15 cm, where the vegetative mass actively suppressed weeds. The highest infestation in terms of quantity and weight of the weed component was established at a rate of 1.5 million and mustard sowing with a row spacing of 30 cm. Plants with row sowing with a seeding rate of 2.0-2.5 million germinating seeds/ha were more competitive, while providing a maximum oilseed yield of 2.46-2.58 t/ha.

Impact of the gall-inducing fly Polymorphomyia basilica Snow (Diptera: Tephritidae) on the growth and reproduction of Chromolaena odorata (L.) R.M.King & H.Rob (Asteraceae) in the laboratory

Gall-inducing insects are a classic example of how insects can impact the morphology and physiology of their host plants by forming galls which act as nutrient sinks. An 8-months laboratory study was conducted to determine the impact of the galls induced by Polymorphomyia basilica oviposition and or the subsequent larval feedingon the growth and reproduction of Chromolaena odorata. Three treatment levels were used, viz. control: 0% of the shoots were exposed, low infestation: 50% of shoots were exposed, and high infestation, where 100% of the shoots were exposed for P. basilica to oviposit for 48 h each month. Results showed that P. basilica oviposition and or the subsequent feeding by larvae reduced the height and flower production of C. odorata plants but promoted lateral growth by increasing the number of shoot tips. Basal stem diameter was not affected by the presence of the galls. The presence of galls also decreased the leaf and root dry biomass on the treated plants but had no significant impact on stem biomass. The difference between the low- and high-infestation treatments was only significant for root biomass, suggesting that more galls are required for the roots to be affected. Overall, the study showed that P. basilica meets the requirements of an effective biocontrol agent against C. odorata in South Africa. Its release should complement the already released agents in reducing the fitness and productivity of C. odorata.

Direct Seeded Rice as Resource Efficient Technology

In Asia, seedlings are typically transplanted into puddled soil to cultivate rice (Oryza sativa L.). Due of the manpower, water, and energy requirements of this manufacturing system, it is becoming less lucrative as these resources become more scarce. Additionally, it impairs the soil's physical qualities, negatively impacts the performance of succeeding upland crops, and increases methane emissions. Different issues, such as a declining water table, a manpower shortage during peak seasons, and worsening soil quality, need the use of alternate establishment techniques to maintain both natural resource and rice yield. Due to its low input requirement, ability to reduce greenhouse gas emissions, and ability to adjust to climatic hazards, the direct seeded rice (DSR) technique has gained a lot of attention and popularity in recent years. Dry seed must be sown into a ready seedbed, while pre-germinated seed must be sown into standing water and puddles of soil. Many farmers have switched from transplanted to DSR culture as a result of the introduction of early maturing cultivars, the application of effective fertiliser management techniques, and increased adoption of integrated weed management strategies. In certain industrialised nations, such the USA, Australia, Japan, China, and Korea, DSR technology is heavily mechanised. By switching from conventional rice to DSR, crop water requirements, soil organic matter turnover, improved nutrient management, carbon sequestration, weed management, greenhouse gas emissions, and crop intensification will all be significantly reduced. The transition from PTR to DSR is hampered by a number of factors, including a high weed infestation, the development of weedy rice, an increase in soil-borne diseases (nematodes), nutritional disorders, poor crop establishment, lodging, the prevalence of blast, brown leaf spot, etc. By addressing these limitations, DSR may show to be a very viable, economically and technically viable substitute for PTR.

Genetic Differentiation of Aedes aegypti (Diptera: Culicidae) in Areas with High Rates of Infestation in Mid-North Region of Brazil.

Aedes aegypti is the principal vector of the arboviruses-yellow fever, dengue virus, chikungunya, and zika virus. Given the epidemiological importance of this mosquito, its capacity to adapt to different habitats, and its resistance to many types of control measures, systematic research into the genetic variability of the populations of this mosquito is one of the most important steps toward a better understanding of its population structure and vector competence. In this context, the present study verified the presence of distinct genetic lineages of Ae. aegypti in areas with high infestation rates, based on the analysis of microsatellite markers. The samples were collected in nine municipalities with high building infestation rates in the Mid-North region of Brazil. Six microsatellite loci were genotyped in the 138 samples, producing a total of 32 alleles, varying from one to nine alleles per locus in each of the different populations. The AMOVA revealed greater within-population genetic differentiation with high fixation rates. The general analysis of population structure, based on a Bayesian approach, revealed K = 2, with two Ae. aegypti lineages that were highly differentiated genetically. These data on the connectivity of the populations and the genetic isolation of the lineages provide important insights for the development of innovative strategies for the control of the populations of this important disease vector.

Analysis of Rainfall and Temperature Trends and Their Implications on Green Gram Production in the Arid and Semi-Arid Lands of Kenya

Farmers have been facing numerous challenges in the production of green gram with declining yields being the main challenge. This can be attributed to the declining rainfall amounts and unreliable rainfall patterns, increased temperatures and high infestation of the crop by pests and diseases. In this study, climate data of the Makueni County on rainfall and temperature from 1991 to 2020 were obtained from the Kenya Meteorology Department. The data were analyzed in three sets; monthly, annual-monthly and seasonal time series. The analysis focuses on descriptive statistics and trend analysis. The results showed that there was no significant trend in the rainfall data at all three levels; monthly, annual-monthly and seasonal. The absence of a significant trend was associated with the high variability in the time series; hence, instability and unpredictability. The temperature time series exhibited positive linear trends where the maximum temperature increased by 0.003°C and the minimum temperature increased by 0.001°C per month. Such trends were detected in selected monthly as well as seasonal minimum and maximum temperature time series. The unpredictability of rainfall patterns and consistently but gradually rising temperature levels could be attributed to climate change. The crop optimum growing conditions are not attained, therefore, reducing production. Rapid deployment of integrated climate-smart farming techniques and adaptation strategies in the region is recommended for the green gram value chain to build resilience in the production of green gram to achieve sustainable yields.

Risk of dengue, Zika, and chikungunya transmission in the metropolitan area of Cucuta, Colombia: cross-sectional analysis, baseline for a cluster-randomised controlled trial of a novel vector tool for water containers

BackgroundArbovirus diseases such as dengue, Zika, and chikungunya are a public health threat in tropical and subtropical areas. In the absence of a vaccine or specific treatment, vector management (in this case the control of the primary vector Aedes aegypti) is the best practice to prevent the three diseases. A good understanding of vector behaviour, ecology, human mobility and water use can help design effective vector control programmes. This study collected baseline information on these factors for identifying the arbovirus transmission risk and assessed the requirements for a large intervention trial in Colombia.MethodsBaseline surveys were conducted in 5,997 households, randomly selected from 24 clusters (neighbourhoods with on average 2000 houses and 250 households inspected) in the metropolitan area of Cucuta, Colombia. The study established population characteristics including water management and mobility as well as larval-pupal indices which were estimated and compared in all clusters. Additionally, the study estimated disease incidence from two sources: self-reported dengue cases in the household survey and cases notified by the national surveillance system.ResultsIn all 24 study clusters similar social and demographic characteristics were found but the entomological indicators and estimated disease incidence rates varied. The entomological indicators showed a high vector infestation: House Index = 25.1%, Container Index = 12.3% and Breteau Index = 29.6. Pupae per person Index (PPI) as an indicator of the transmission risk showed a large range from 0.22 to 2.04 indicating a high transmission risk in most clusters. The concrete ground tanks for laundry –mostly outdoors and uncovered- were the containers with the highest production of Ae. aegypti as 86.3% of all 17,613 pupae were identified in these containers. Also, the annual incidence of dengue was high: 841.6 self-reported cases per 100,000 inhabitants and the dengue incidence notified by the National surveillance system was 1,013.4 cases per 100,000 in 2019. Only 2.2% of the households used container water for drinking. 40.3% of the study population travelled during the day (when Aedes mosquitoes bite) outside their clusters.ConclusionsThe production of Ae. aegypti mosquitoes occurred almost exclusively in concrete ground tanks for laundry (lavadero), the primary intervention target. The baseline study provides necessary evidence for the design and implementation of a cluster randomized intervention trial in Colombia.

Сравнительная эффективность действия гербицидов имидазолиноновой и сульфонилмочевинной группы на заразиху при селекции крупноплодных сортов подсолнечника

Annually, confectionary sunflower varieties occupy from 300 to 500 thousand hectares in the Russian Federation. The varieties developed last years (Karavan, Konditer, SPK Plus) are able to form high yields of seeds in the heavy agroclimatic conditions. At the same time, spreading of the new more virulent races of broomrape causes the significant decrease in yield of confectionary varieties. One of the effective methods of broomrape control is chemical one. The experiment was conducted on isolated plot in field after introducing the seeds of the virulent broomrape races in soil. Treatment with herbicides in recommended doses was conducted using backpack sprayer. The level of broomrape control with imidazolinons is significant and equitable to action of a gen of broomrape resistance Or7 by both percentage and a level of infection. Tribenuron-methyl repressed a level of infection under high infestation with broomrape in the studied confectionary sunflower varieties.

Ticks harbor and excrete chronic wasting disease prions

Chronic wasting disease (CWD) is a fatal neurodegenerative disease caused by infectious prions (PrPCWD) affecting cervids. Circulating PrPCWD in blood may pose a risk for indirect transmission by way of hematophagous ectoparasites acting as mechanical vectors. Cervids can carry high tick infestations and exhibit allogrooming, a common tick defense strategy between conspecifics. Ingestion of ticks during allogrooming may expose naïve animals to CWD, if ticks harbor PrPCWD. This study investigates whether ticks can harbor transmission-relevant quantities of PrPCWD by combining experimental tick feeding trials and evaluation of ticks from free-ranging white-tailed deer (Odocoileus virginianus). Using the real-time quaking-induced conversion (RT-QuIC) assay, we show that black-legged ticks (Ixodes scapularis) fed PrPCWD-spiked blood using artificial membranes ingest and excrete PrPCWD. Combining results of RT-QuIC and protein misfolding cyclic amplification, we detected seeding activity from 6 of 15 (40%) pooled tick samples collected from wild CWD-infected white-tailed deer. Seeding activities in ticks were analogous to 10–1000 ng of CWD-positive retropharyngeal lymph node collected from deer upon which they were feeding. Estimates revealed a median infectious dose range of 0.3–42.4 per tick, suggesting that ticks can take up transmission-relevant amounts of PrPCWD and may pose a CWD risk to cervids.

Adaptability of Genetically Engineered Bt Cotton Varieties in Different Growing Regions of Ethiopia

Cotton varieties that are high yielding and resistant to pests are required to improve production and productivity and to capitalize on the crop’s enormous potential and its critical role in Ethiopia’s expanding textile industry. Lack of improved cotton technology has forced farmers to recycle local varieties for ages which have become very susceptible to pests which are the major causes of very low productivity and quality of cotton in the country. Among major pests, bollworms (Helicoverpa armigera and Pectinophora gossypiella) account for 36–60% of yield losses. In the absence of genetically resistant or tolerant varieties, genetically engineered bollworm-resistant Bacillus thuringiensis (Bt) cotton has offered a great opportunity to reduce crop losses from bollworms. The objective of the study was to evaluate the efficacy of bollworm resistance and adaptability of Bt cotton varieties across cotton growing environments in Ethiopia and provide recommendations. Two Bt cotton hybrids (JKCH 1947 and JKCH 1050), one Bt OPV (Sudan), and three OPV conventional varieties (Weyito 07, Stam-59A, and Deltapine-90) were evaluated at seven different agro-ecologies using a randomized complete block design (RCBD) with three replications. Results showed significant differences among genotypes for yield and other traits. Hybrids JKCH 1947 and JKCH 1050 were the top high yielders under high and mild bollworm infestations, with mean seed cotton yield of 3.10 t·ha−1 each and lint yield of 1.20 and 1.19 t·ha−1, respectively, whereas the standard check Deltapine-90 (popular variety) recorded a mean seed cotton and lint yield of 2.3 t·ha−1 and 0.8 t·ha−1, respectively. Combined analysis showed that genotypes, environment, and the genotypes × environment interactions had a highly significant effect ( P < 0.05) on fiber quality. Weyito 07 and the two hybrids (JKCH 1947 and JKCH 1050) had upper half mean fiber lengths in the range of 27.78 to 32.11 mm. For fiber strength, genotypes Weyito 07, JKCH 1050, Stam-59A, and JKCH 1947 had 33.50 g/tex, 28.59 g/tex, 28.00 g/tex, and 27.75 g/tex, respectively. The fiber quality values of the hybrids were within acceptable limits, with staple lengths ranging from 27.78 to 28.44 mm and fiber strengths ranging from 27.75 to 28.59 g/tex. Results show potential adaptation of the hybrids under different cotton growing environments and their superior yield performance due also to added protection of yield losses from damage by bollworms. The contrast is bigger under high insect pressure conditions due to the genetically engineered Bt trait compared to the conventional varieties. The effective field resistance against bollworms in most locations shows that wider use of these hybrids can enhance cotton productivity and quality in Ethiopia.

Comparative transcriptome analysis of Zea mays upon mechanical wounding.

Mechanical wounding (MW) is mainly caused due to high wind, sand, heavy rains and insect infestation, leading to damage to crop plants and an increase in the incidences of pathogen infection. Plants respond to MW by altering expression of genes, proteins, and metabolites that help them to cope up with the stress. In order to characterize maize transcriptome in response to mechanical wounding, a microarray analysis was executed. The study revealed 407 differentially expressed genes (DEGs) (134 upregulated and 273 downregulated). The upregulated genes were engaged in protein synthesis, transcription regulation, phytohormone signaling-mediated by salicylic acid, auxin, jasmonates, biotic and abiotic stress including bacterial, insect, salt and endoplasmic reticulum stress, cellular transport, on the other hand downregulated genes were involved in primary metabolism, developmental processes, protein modification, catalytic activity, DNA repair pathways, and cell cycle. The transcriptome data present here can be further utilized for understanding inducible transcriptional response during mechanical injury and their purpose in biotic and abiotic stress tolerance. Furthermore, future study concentrating on the functional characterization of the selected key genes (Bowman Bird trypsin inhibitor, NBS-LRR-like protein, Receptor-like protein kinase-like, probable LRR receptor-like ser/thr-protein kinase, Cytochrome P450 84A1, leucoanthocyanidin dioxygenase, jasmonate O-methyltransferase) and utilizing them for genetic engineering for crop improvement is strongly recommended.