Correlation-Based Network Analysis of the Influence of Bemisia tabaci Feeding on Photosynthesis and Foliar Sugar and Starch Composition in Soybean

Bemisia tabaci (MEAM1) represents a species of economic importance in soybean. One of the obstacles to the management of B. tabaci is the quantification of damage by the pest because damage is indirectly inferred through losses in productivity. The objective of this study was to characterize the influence of B. tabaci feeding on soybean by assessing effects on photosynthetic parameters and the sugar and starch content of soybean leaves. The goal was to identify the optimal parameter to directly quantify pest damage on crop yield. Correlation networks were created among data on sugar content (fructose, glucose, and sucrose), starch and photosynthetic parameters (initial fluorescence, performance index on absorption basis, and turn-over number), and the number of nymphs at each of three infestations level (low, medium, and high) during both the vegetative and reproductive stage of the crop. In general, nymphs were more abundant during the vegetative stage. Starch content was strongly correlated with nymph density. A strong positive correlation was observed between fructose and nymph density during the vegetative stage. Among the photosynthetic parameters, the turn-over number N was positively correlated with nymph density at a low-infestation level and negatively correlated with nymphs when they occurred at a high-infestation level. B. tabaci feeding affected the plant’s physiology and its interaction is reflected in part by the relationships among photosynthetic parameters as well as the levels of sugars and starch. This understanding might be useful in developing better monitoring tools for pest management.

Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents

The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

Evaluation of traits related to bread wheat (Triticum aestivum L.) root in drought tolerance applied at the beginning of vegetative and reproductive stages

<p class="042abstractstekst">Roots play an important role in wheat grain yield, especially under drought stress conditions. To investigate root characteristics under drought stress conditions in bread wheat, 90 lines F10 obtained from the crossing (‘Yecora Rojo’ × ‘Chinese Spring’) randomly with the parents of the population were examined. The study was conducted in the form of a split-plot design with a randomized complete block base in three conditions including: 1. no stress, 2. application of drought stress at the beginning of the vegetative stage, and 3. application of drought stress at the beginning of the reproductive stage. The results showed, interaction between genotype and condition of drought was significant for all root-related traits, except shallow root dry mass, at the level of 1 % probability. The response of root-related traits to different types of drought stress was very complex. The longest root length, decrease for 13.3 % was during stress at the beginning of the vegetative stage in comparison to non-stress conditions, while the same trait increased for 4.9 % during stress at the beginning of the reproductive stage, comparison to non-stress conditions. The results of principal component analysis under non-stress conditions showed that by considering the distribution of genotypes compared to the first two components, genotypes can be identified that have more yield with the proper root condition and vice versa.</p>

Interactive Effects of Organic Fertilizers and Drought Stress on Growth and Nutrient Content of Brassica juncea at Vegetative Stage

With the ongoing climate change scenario and alarmingly increased land degradation, understanding complex interactions of drought stress and organic fertilizers on morpho-physiological traits and dynamics of nutrient concentration is pivotal for sustainable production leafy vegetables such as mustard (Brassica juncea). Thus, this study evaluated the effect of drought stress and organic fertilizers on B. juncea growth, physiology, and dynamics of nutrient concentration at the vegetative stage. The plants were exposed to three water stress levels (well-watered (100% field capacity, FC), mild (50% FC), and severe (25% FC) supplemented with three organic fertilizers (chitosan, ultra green, and home-grown natural vegetable foods) either individually or in combination during the vegetative growth stage. Water stress had a negative effect on growth and physiological traits, and macro- and micronutrients of mustard. However, the ameliorative effects of fertilizer application were revealed by improved plant height, leaf area, relative water content, membrane stability index, and chlorophyll content from 9.7% to 26.9%, 28% to 32.72%, 7.97% to 39.51%, 7.93% to 39.66%, and 29.68% to 56.53%, respectively. Analysis of variance revealed a significant effect of soil moisture level, fertilizer type and their interaction on content of macronutrients (Ca, K, P, N, C, S, Na, Mg) and micronutrients (Fe, Zn) in mustard leaves. However, there was no significant effect detected for Cu across all factors as well the interaction effect on Mn. Overall, our results indicated that application of organic fertilizers enables mustard plant to withstand the deleterious effect of drought stress, resulting in improved growth and physiological traits as well as leaf nutrient content.

The Effect of Drying Processes on the Nutritional and Phytochemical Levels of Chia Leaves (Salvia hispanica L.) at Different Stages of Growth

Chia leaf (Salvia hispanica L.) is an underutilized low-cost source of nutrients. The leaf is currently not widely utilized as compared to the chia seeds which have wide use in the food industry. The present study investigated the effect of solar-drying and oven-drying chia leaves harvested at different stages of growth on their nutritional and phytochemical composition. The chia leaves were harvested at four stages of early vegetative stage, late vegetative stage, budding stage and flowering stage. Oven drying was done at45 ºC for 24hours, and solar dried in a solar drier until a constant weight was achieved. The results indicated significant differences (p<0.05) between treatments and stages of maturity. Results also showed that solar dried had better nutritional and phytochemical retention over oven dried chia leaves. Crude protein was highest in solar dried leaves at early vegetative stage (FS1) 4.48%, compared to 4.44% for oven dried chia leaves. The fiber content increased from the fresh leaf at 12.4% to high content in solar dried leaf at the early vegetative stage at 23.33%, while oven dried leaves had high content at the flowering stage at 22.09%. There were minimal changes in fat content of the dried chia leaves compared to fresh sample at 5.908%, with high fat levels noted for oven dried leaf at the early vegetative stage (FS3) at 5.68% and solar dried leaves at 4.71% at the budding stage. The difference in fat content could be attributed to degradation during the drying processes. Ash content on the other hand showed difference at different stages of growth from raw samples for both solar- and oven dried leaves. Highest retention of phenolic content was recorded at 147.62 mg/GAE for solar dried leaves at the budding stage (FS3). However, oven dried leaf samples recorded high phenolic content at 124.06 mg/GAE at the late vegetative stage. The flavonoid levels were recorded highest for solar dried leaves at the budding stage at 299.8 mg/CE, compared to high content for oven dried leaves at the budding stage recorded at 270.4 mg/CE. Scavenging activity was highest recorded for solar dried samples at the budding and flowering stages at 100 µg/100g compared to oven dried leaves at 80.85 µg/100g at the late vegetative stage. Solar drying is the simplest and convenient low-cost technology for preserving the nutritional quality and retention of phytochemical ranges of chia leaves which will enhance their utilization when abundantly available.

Effect of Organic Manures and Inorganic Fertilizer on the Leaf Characters of Banana

A field experiment was carried out at Instructional cum Research Farm, Department of Horticulture, Biswanath College of Agriculture, AAU, Biswanath Chariali to study the effects of organic manures and inorganic fertilizer on leaf characters of banana cv. Amritsagar (AAA) during 2016-2017. The research work was carried out with the treatments as follows T1: FYM (Farm Yard Manure) + Microbial Consortia, T2: Enriched Compost, T3: Vermicompost, T4: Microbial Consortia, T0: RDF (FYM + NPK). Healthy suckers were planted in each plot with spacing of 2.1m x 2.1m on 27th May 2016. The treatments T1, T2, T3 and T4 were laid out in certified organic block in RBD with 5 replications while the treatment T0 was laid out outside the organic block with five replications. In the organics, T1 recorded the highest number of functional leaves (7.97, 12.46 and 5.37) in vegetative stage, shooting stage and harvesting stage respectively. Highest leaf area of 2.69 m2 at vegetative stage and 11.17 m2 at shooting stage were recorded in T1 while lowest leaf area of 2.41 m2 at vegetative stage and 8.89 m2 at shooting stage were recorded in T4. Leaf area index was highest in T1. Chlorophyll content index in both vegetative stage (45.29) and shooting stage (65.56) was also highest in T1. Comparing the leaf characters (number of functional leaves, leaf area, leaf area index and chlorophyll content index) under organic treatments with that of T0 treated plants, it was found that plants treated with inorganic fertilizer had more number of functional leaves and better leaf character than that of the plants treated with organics.

Unveiling Endophytic Bacterial Community Structures of Different Rice Cultivars Grown in a Cadmium-Contaminated Paddy Field

Endophytic bacteria play potentially important roles in the processes of plant adaptation to the environment. Understanding the composition and dynamics of endophytic bacterial communities under heavy metal (HM) stress can reveal their impacts on host development and stress tolerance. In this study, we investigated root endophytic bacterial communities of different rice cultivars grown in a cadmium (Cd)-contaminated paddy field. These rice cultivars are classified into low (RBQ, 728B, and NX1B) and high (BB and S95B) levels of Cd-accumulating capacity. Our metagenomic analysis targeting 16S rRNA gene sequence data reveals that Proteobacteria, Firmicutes, Actinobacteria, Acidobacteria, Bacteroidetes, and Spirochaetes are predominant root endophytic bacterial phyla of the five rice cultivars that we studied. Principal coordinate analysis shows that the developmental stage of rice governs a larger source of variation in the bacterial communities compared to that of any specific rice cultivar or of the root Cd content. Endophytic bacterial communities during the reproductive stage of rice form a more highly interconnected network and exhibit higher operational taxonomic unit numbers, diversities, and abundance than those during the vegetative stage. Forty-five genera are significantly correlated with Cd content in rice root, notably including positive-correlating Geobacter and Haliangium; and negative-correlating Pseudomonas and Streptacidiphilus. Furthermore, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States analysis shows that functional pathways, such as biosynthesis of siderophore and type II polyketide products, are significantly enhanced during the reproductive stage compared to those during the vegetative stage under Cd stress. The isolated endophytic bacteria from the Cd-contaminated rice roots display high Cd resistance and multiple traits that may promote plant growth, suggesting their potential application in alleviating HM stress on plants. This study describes in detail for the first time the assemblage of the bacterial endophytomes of rice roots under Cd stress and may provide insights into the interactions among endophytes, plants, and HM contamination.

Effect of different pasture legumes on growth profile and forage production of the selected native pasture grasses mix at different growth stages

The present experiment aimed to investigate the effect of introducing different pasture legumes on the growth profile and forage production of the selected native pasture grass species at different stages of growth. In a completely randomized design with 5 treatments and 5 replications, the mixture of Sorghum plumosum (SP) and Bothriochloa pertusa (BP) was introduced respectively with one of the forage legumes ie. Alysicarpus vaginalis (AV), Pueraria phasoloides (PP), Desmodium incanum (DI), and Clitoria ternatea (CT). Growth profile and forage production were measured at 40, 60, and 80 days after planting. Results showed that CT and PP significantly improved the growth and DM production of SP and suppressed (P<0.05) the growth of BP during the early vegetative stage but did not during the late vegetative stage. Introduction of legumes reduced (P<0.05) DM production of SP and the total forage production but improved (P<0.001) the DM production of B. pertusa as well as a leaf:stem ratio of both types of grass at the generative stage. PP had the highest (P<0.05) contribution of legumes to the total DM forage production during early and vegetative stages, meanwhile AV and DI during the generative stage. In conclusion, the introduction of forage legumes did not improve the DM production of both grass species but modify their growth profile toward a better quality as shown by increased leaf:stem ratio. P. phasoloides provide the highest foliage during the vegetative stage and A. vaginalis and D. incanum during the generative stage.