Plant Growth Chamber Research Articles

Evaluation of Foxtail Millet Varieties for Thermotolerance at Seedling Stage using Temperature Induction Response Technique (TIR)

In the present scenario of climate change, Foxtail millet is the best crop of choice and an indispensable component of dryland farming due to its C4 plant type and tolerance against the abiotic stresses. However, all the foxtail millet varieties may not sustain under severe temperature stress particularly at germination and seedling growth stages. Therefore, screening of varieties is required to identify the stress tolerant varieties in foxtail millet which can combat temperature stress at seed germination and early seedling growth stages which is the need of the hour under ever changing climatic conditions. Hence, A lab experiment was conducted to standardize the temperature induction response (TIR) protocol for foxtail millet seedlings using WGC-450 programmable plant growth chamber. Temperatures were standardized as sub lethal i.e. challenging temperatures as 38°C – 54°C for 5 hours and lethal temperatures as 56°C for 3 hours. Seven foxtail millet varieties (Suryanandi, SiA 3156, Srilakshmi, SiA 3085, Narasimharaya, Krishnadevaraya and Prasad) were screened for intrinsic tolerance using the standardized Thermo Induced Response (TIR) protocol. Out of the seven varieties evaluated, SiA 3085, Prasad, Suryanandi, Srilakshmi were identified to possess high level of thermo tolerance in terms of higher seedling survival with less reduction in root and shoot growth. The varieties with intrinsic heat tolerance can be explored for the development of heat stress tolerant varieties.

Structural changes in Nelumbo flower petals during opening and closing.

Nelumbo nucifera is one of several plant species with flowers that typically open in the early morning and close by noon. This movement normally repeats for 3 days, with all petals falling off on day 4. However, detailed observations of flower movement in Nelumbo species are limited. Movement of flowers on plants in growth chambers were observed using time-lapse photography. Petals were examined with scanning electron microscopy or fixed and sectioned for light microscopy to determine whether changes in cell size contribute to petal elongation during flowering. This study is the first to microscopically observe petal cells of a Nelumbo species during flowering in controlled conditions. Petals elongated during the 4-day flowering period. Inner petals were more elongated than the outer petals. Among the basal, central, and tip regions of a single petal, the cells in the basal region enlarged the most. Outer and inner epidermal cells in the basal region of the inner petals, on both adaxial and abaxial sides, gradually enlarged during the flowering period through cycles of repeated increases as the petals opened and decreases as they closed. Petals opened and closed repeatedly as they elongated, primarily in their basal region. Cells in the basal region of the petal on the adaxial and abaxial sides periodically fluctuated in size, increased during flower opening and decreased during closing, but differences in these patterns were observed between the two sides, suggesting that one of the driving forces behind the opening and closing of flowers of Nelumbo species is the increase and decrease in the size of the petal cells.

Image Processing and Support Vector Machine (SVM) for Classifying Environmental Stress Symptoms of Pepper Seedlings Grown in a Plant Factory

Environmental factors such as temperature, humidity, light, and CO2 influence plant growth, and unfavorable environmental conditions cause stress in plants, producing symptoms in their early growth stages. The increasing importance of optimizing crop management strategies has led to a rising demand for the precise evaluation of stress symptoms during early plant growth. Advanced technologies are transforming plant health monitoring through enabling image-based stress analysis. Machine learning (ML) models can effectively identify the important features and morphological changes connected with various stress conditions through the use of large datasets acquired from high-resolution plant images. Therefore, the objective of this study was to develop a method for classifying the early-stage stress symptoms of pepper seedlings and enabling their identification and quantification using image processing and a support vector machine (SVM). Two-week-old pepper seedlings were grown under different temperatures (20, 25, and 30 °C), light intensity levels (50, 250, and 450 µmol m−2s−1), and day–night hours (8/16, 10/14, and 16/8) in five controlled plant growth chambers. Images of the seedling canopies were captured daily using a low-cost red, green, and blue (RGB) camera over a two-week period. Eighteen color features, nine texture features using the gray-level co-occurrence matrix (GLCM), and one morphological feature were extracted from each image. A two-way ANOVA and multiple mean comparison (Duncan) analysis were used to determine the statistical significance of the treatment effects. To reduce feature overlap, sequential feature selection (SFS) was applied, and a support vector machine (SVM) was used for stress classification. The SFS method was used to identify the optimal features for the classification model, leading to substantial increases in stress classification accuracy. The SVM model, using these selected features, achieved a classification accuracy of 82% without the SFS and 86% with the SFS. To address overfitting, 5- and 10-fold cross-validation were used, resulting in MAEs of 0.138 and 0.163 for the polynomial kernel, respectively. The SVM model, evaluated with the ROC curve and confusion matrix, achieved a classification accuracy of 85%. This classification approach enables real-time stress monitoring, allowing growers to optimize environmental conditions and enhance seedling growth. Future directions include integrating this system into automated cultivation environments to enable continuous, efficient stress monitoring and response, further improving crop management and productivity.

Root Infection and Minituber Yield Response to Powdery Scab in Plant Growth Chamber Conditions

Powdery scab, caused by the soil borne Plasmodiophorid Spongospora subterranea f. sp. subterranea (Sss), is an increasing concern. Developing resistant varieties with enduring resistance is crucial for sustainable disease management. However, the lack of a consistent infection assay for Sss hindered effective evaluation of disease symptoms, including root gall formation and tuber lesions. This study introduces a reliable method for assessing Sss pathogenicity using a sand/potting mixture in a controlled-environment plant growth chamber. Potato plants were inoculated with three types of inocula sourced from root galls, infested soil, and scab-like tube lesions. All inocula successfully induced root galls and tuber lesions, with the tuber lesion-derived inoculum producing the highest number of root galls. Additionally, the method demonstrated a marked impact on tuber yield, weight, and size in both highly susceptible and moderately susceptible cultivars. These findings underscore the efficacy of this infection assay as a robust tool for evaluating Sss pathogenicity. This method holds promise for screening potato germplasm to develop resistant varieties against powdery scab.

Effect of fluoride toxicity on morphological, biochemical and physiological parameters in different oat cultivars

Fluoride is one of the most highly toxic soil and air pollutant prevalent in aquatic as well as terrestrial ecosystems. It seriously affects crop plant quality and productivity worldwide. Although a crop with great nutritional value; oats are susceptible to a variety of abiotic stresses. In the current study, the responses of six oat cultivars (JHO-99-1, JHO-2009, BJ-2012, KANT, JHO-822, and JHO-2000) to fluoride stress on growth measurements, photosynthetic pigments, and photosynthetic parameters have been studied. The fluoride (200 and 400 mg/kg) was added to the soil artificially, seeds were sown and the pots were kept under controlled conditions. Another set of plants without the fluoride treatment (0 mg/kg) were labeled as control. The experiment was conducted in a plant growth chamber and fluoride was artificially added to the soil prior to seeding. All six oat cultivars subjected to fluoride stress exhibited an overall decrease in plant growth when compared to the control. Further under fluoride stress, while the oat cultivars also showed a decrease in chlorophyll content and different photosynthetic parameters but on the contrary the antioxidant activities were increased. While the cultivar JHO-822 was most affected under fluoride stress, JHO-99-1 showed tolerance toward fluoride toxicity in comparison to other cultivars JHO-2009, BJ-2012, KANT, JHO-822, and JHO-2000. It is concluded that the tolerance or susceptibility of a cultivar to fluoride can be well correlated with various parameters studied in the present study.

An arrow in the quiver: evaluating the performance of Hyptis suaveolens (L.) Poit. in different light levels

BackgroundHyptis suaveolens (L.) Poit., native to the American tropics, is a pantropical annual plant and a major invasive species throughout India. It was anticipated that the availability of sunlight, coupled with its superior reproductive potential, persistent propagule bank, and dispersal ability, could lead to an increase in the growth and spread of this invader, thus potentially impeding herbaceous growth and diversity in non-native areas. Clarifying its ecological fitness and competitive performance will be useful to manage the spread of H. suaveolens in natural ecosystems that are facing a wide range of anthropogenic pressures.MethodsThe present study is a three-tier experiment. In the first tier, a field study was conducted to assess the patterns of H. suaveolens abundance and herbaceous species diversity in response to light availability (sun, 842–1072 µmol m–2 s−1 and shade 253–341 µmol m–2 s−1) in the tropical dry deciduous ecosystems in the Vindhyan highlands, India. Furthermore, the impact of H. suaveolens abundance on the resident native and non-native species abundance and diversity was also studied. In the second tier, a randomized common garden experiment was conducted to understand the trait fitness of H. suaveolens in sun (940 µmol m–2 s−1) and shade (300 µmol m–2 s−1) conditions. In the third tier, a plant growth chamber experiment with high-light (940 µmol m–2 s−1) and low-light (300 µmol m–2 s−1) treatments was done to learn how H. suaveolens partitions its biomass between aboveground and belowground plant parts.ResultsThe field study indicated that the sunlit areas had a higher abundance of H. suaveolens and a lower diversity of resident herbaceous species than the shaded areas. The common garden experiment showed that sun-dwelling H. suaveolens individuals performed better in germinative, vegetative, eco-physiological, and reproductive traits than the shade-dwelling individuals. The growth chamber experiment exhibited that plants grown in high-light environment had greater seed germination, seedling recruitment, and aboveground biomass than those grown in low-light environment, whereas plants grown in low-light environment exhibited a higher root mass ratio than the high-light individuals. These results suggest that H. suaveolens individuals mask the understory vegetation owing to higher seedling recruitment, relative growth rate, photosynthetic performance, resource acquisition-allocation, and reproductive output in response to high-light conditions.ConclusionsThe study concludes that light significantly controls the invasive population dynamics of H. suaveolens in dry deciduous forests. In high-light areas, H. suaveolens populations dominate the forest understory with suboptimal shade tolerance. In shade environment, H. suaveolens maintains a persistent soil seed bank along with ‘Oskar individuals’ that become active in response to high-light availability. The modus operandi is a ‘sit and wait’ strategy. The current study provides insights on prioritizing areas for H. suaveolens management that will potentially reduce the risk of biological invasions on the native species diversity of tropical regions.

First Report of Charcoal Rot on Soybean Caused by Macrophomina phaseolina in Manitoba, Canada.

First Report of Charcoal Rot on Soybean Caused by Macrophomina phaseolina in Manitoba, Canada.

Circadian-based approach for improving physiological, phytochemical and chloroplast proteome in Spinacia oleracea under salinity stress and light emitting diodes

Salt stress is a recognized annihilating abiotic stress that has a significant impact on agricultural and horticulture crop productivity. Plant development faces three distinct dangers as a result of salt stress: oxidative stress, osmotic stress, and ionic toxicity. It has been shown that plants can forecast diurnal patterns using the circadian clock; moreover, they can manage their defensive mechanism for the detoxification of reactive oxygen species (ROS). Circadian rhythmicity in gene expression assembles transcription and translation feedback networks to govern plant shape, physiology, cellular and molecular activities. Both external and internal variables influence the systemic rhythm via input routes. The Malav Jyoti (MJ) and Delhi Green (DG) genotypes of spinach (Spinacia oleracea) were grown in the plant growth chamber. The chamber had an optimized temperature of 25 °C and humidity of 65% containing light emitting diode (LED) having Red: Blue: white (one side) and White fluorescent (other side) under salinity stress. The samples were collected on the basis of 4 h intervals of circadian hours (0 h, 4 h, 8 h and 12 h) during Day-10 and Day-20 of salt treatments. Under salt stress, the circadian and light-emitting diode-based strategy had a substantial influence on spinach's anti-oxidative responses, stomatal movement, CO2 assimilation, PS-I and II efficiency, phytochrome pigment efficiency, and photosynthesis. Based on the findings of the free radical scavenging enzyme tests, the photoperiodic hours for the proteome analysis were set to 11 am and 3 pm on Day-20. When compared to white fluorescent, this study found that LED has the capacity to influence the entrainment cues of the circadian clock in the cultivation of salt-sensitive spinach genotypes. According to our findings, changing the cellular scavenging mechanism and chloroplast proteome has increased the survival rate of spinach genotypes under LED when compared to white fluorescent.

Alpha-amylase Inhibition of Carpobrotus edulis (L.) Bolus Exposed to Low and High-Temperature Conditions

Carpobrotus edulis is an edible medicinal plant from South Africa and is used for the treatment of different ailments and disorders, including diabetes mellitus. Diabetes is a persistent metabolic condition distinguished by high levels of glucose concentrations in the bloodstream. Due to climate change-related conditions, plants may be subjected to extreme temperature events such as cold fronts and heat waves. Hence the aim of the study was to expose Carpobrotus edulis leaves to temperature conditions and then assesses their antidiabetic activity against alpha-amylase in different solvents. The objective was to keep plants in growth chambers set at either 15/10oC and 45/35oC (day and night), respectively, and harvested at 48-hour intervals (48, 96, and 144). These were compared to plant samples in control conditions (25/15oC). Under control (25/15°C) conditions, the aqueous extract displayed effective inhibition of alpha-amylase (IC50 = 195mg/ml). In contrast to the control extracts, the hexane solvent consistently exhibited the highest inhibitory activity against alpha-amylase under both low (15/10°C) and high (45/35°C) temperature conditions. This trend was observed across all three harvest durations. After 48 hours of high-temperature conditions, the IC50 value was 131mg/ml. While after 96 and 144 hours of low-temperature conditions, the IC50 values were 214mg/ml and 131mg/ml, respectively. The results suggest that Carpobrotus edulis, exposed to low and high temperature conditions, has potential antidiabetic properties against alpha-amylase. This is an interesting aspect of how environmental conditions can impact medicinal properties. The outcome may have significant implications for the use of the plant by indigenous people, who depend on it for the treatment of various ailments, including diabetes. It will also have implications for the antidiabetic research of the plant as well as climate change research.

Physiological processes in Phalaenopsis pulcherrima cultivated in hermetically sealed vessels

The hermetic condition is the least studied factor associated with the spaceflights. Phalaenopsis pulcherrima is promising for space farming as it can be cultivated in small substrate blocks, and its photosynthetic apparatus is well adapted to elevated CO2 concentrations and temperatures.Three-year-old meristematic P. pulcherrima plants were planted into plastic (acrylic) vessels filled with fibrous substrate. In control, vessels had an open top. The hermetic conditions were reached by sealing the vessels’ covers with a parafilm. Both control and hermetic vessels were placed in a plant growth chamber where test plants were cultivated under controlled conditions of air temperature, illumination, air humidity, and soil moisture. After 6 and 24 months of cultivation, the CO2 concentration in the hermetic and control vessels was measured, and the physiological characteristics of each test plant, such as the content of macro- and micronutrients, photosynthetic pigments, free amino acids, and content of labile carbohydrates (%) in the leaves of the test-plants were determined.It was revealed that cultivation of P. pulcherrima in hermetic conditions affected its basic physiological processes such as photosynthesis, mineral nutrition, carbohydrates, and amino acid metabolisms. The effect size of this stress factor depended on the duration of exposition period. Long-term cultivation of P. pulcherrima under hermetic conditions promoted the accumulation of nonenzymatic antioxidants (viz. chlorophyll b, carotenoids, and amino acids), which contributed to the adaptation of this orchid species to oxidative stress caused by hermetic environment.

Replacing Mancozeb with Alternative Fungicides for the Control of Late Blight in Potato.

Mancozeb (MZ) is a broadly used fungicide for the control of plant diseases, including late blight in potatoes caused by the oomycete Phytophthora infestans (Mont.) De Bary. MZ has been banned for agricultural use by the European Union as of January 2022 due to its hazards to humans and the environment. In a search for replacement fungicides, twenty-seven registered anti-oomycete fungicidal preparations were evaluated for their ability to mitigate the threat of this disease. Fourteen fungicides provided good control (≥75%) of late blight in potted potato and tomato plants in growth chambers. However, in Tunnel Experiment 1, only three fungicides provided effective control of P. infestans in potatoes: Cyazofamid (Ranman, a QiI inhibitor), Mandipropamid (Revus, a CAA inhibitor), and Oxathiapiprolin + Benthiavalicarb (Zorvek Endavia, an OSBP inhibitor + CAA inhibitor). In Tunnel Experiment 2, these three fungicides were applied at the recommended doses at 7-, 9-, and 21-day intervals, respectively, totaling 6, 4, and 2 sprays during the season. At 39 days post-inoculation (dpi), control efficacy increased in the following order: Zorvec Endavia > Ranman > Revus > Mancozeb. Two sprays of Zorvec Endavia were significantly more effective in controlling the blight than six sprays of Ranman or four sprays of Revus. We, therefore, recommend using these three fungicides as replacements for mancozeb for the control of late blight in potatoes. A spray program that alternates between these three fungicides may be effective in controlling the disease and also in avoiding the build-up of resistance in P. infestans to mandipropamid and oxathiapiprolin.

Differential transcriptome and metabolite profile with variable fluoride tolerance and altered genomic template stability in the identification of four fluoride-tolerant or fluoride-sensitive rice cultivars

Fluoride toxicity is the most commonly experienced challenge to rice plants due to irrigation with fluoride-polluted groundwater. In the present study, four hydroponically grown rice cultivars (Badshahbhog, Swarna, Sukumar and Shatabdi) were screened for fluoride tolerance on the basis of physiological and molecular parameters. Rice cultivars were maintained at 37 °C under 16/8 h light/dark photoperiodic cycle with 700 μmol photons m−2 s−1 intensity and relative humidity (50 %) in a plant growth chamber for 20 days. Treatment with NaF (50 mg L−1) caused considerable fluoride accumulation in Shatabdi which hindered its growth and triggered the formation of H2O2 and enhanced lipoxygenase and protease activity that eventually led to higher malondialdehyde formation and electrolyte leakage from the cells. This was accompanied with degradation of photosynthetic pigments (chlorophyll a, b, total chlorophyll, xanthophyll and carotenes) and inhibition in Hill activity. Higher formation of osmolytes (proline, amino acids and glycine betaine) and activity of enzymatic antioxidants (SOD, CAT, APX and GPX) reversed the effect of fluoride toxicity in Badshahbhog, concomitant with proper maintenance of the expression of gene concerned with photosynthetic mechanism (PsbA, PsbY, PsaH, PetC, PetH, Rbcs, Rca and rsp9) which preserved the photosynthetic machinery, providing sufficient energy to the seedlings to overcome the stressed conditions. RAPD profiling and GTS also established the superiority of Badshahbhog over the three cultivars, making it an efficient fluoride-tolerant variety.

First Report of Fusarium oxysporum Causing Leaf Wilt on Dinteranthus vanzylii (Green Stone Plant) in China.

Dinteranthus vanzylii is a low-growing species in the family Aizoaceae, native to southern Africa, with a pair of thick grey leaves covered with dark red spots and stripes. This stone-like succulent grows near the ground, which may protect it from water evaporation and herbivores. Dinteranthus vanzylii has become popular in China due to its attractive appearance and easy indoor cultivation. In September 2021, 7% of D. vanzylii (approximately 140 pots) showed leaf wilt symptoms in a commercial greenhouse located in Ningde (119°35'39.696″E, 27°23'30.556″N), Fujian Province, China. The diseased plants were shrivelling and eventually underwent necrosis. Their leaf tissues were rotting and carpeted with white mycelium. The leaf tissues of 10 symptomatic plants were cut into 0.5 cm2 pieces, surface-sterilized and placed on PDA medium. According to the colony morphology after 7 days of culture, 20 fungal isolates with abundant whitish aerial mycelium were divided into two types: 8 isolates produced lilac pigment whereas 12 did not. Both produced unicellular ovoid microconidia, sickled-shaped macroconidia with 3 - 4 septa and single or paired smooth, thick-walled chlamydospores on carnation leaf agar (CLA). Molecular identification based on DNA sequences from EF1-α (O'Donnell et al. 1998), RPB1 and RPB2 (O'Donnell et al. 2010) revealed 100% identity among isolates within each group; however, there were several base differences between two types. Sequences of representative isolates KMDV1 and KMDV2 were deposited in GenBank (acc. nos.: OP910243, OP910244, OR030448, OR030449, OR030450 and OR030451), which showed 99.10% - 99.74% identity with different F. oxysporum strains (GenBank acc. nos.: KU738441, LN828039, MN457050, MN457049, ON316742 and ON316741). Phylogenetic tree inferred from the concatenated EF1-α, RPB1 and RPB2 revealed that these isolates clustered with F. oxysporum. Thus, these isolates were identified as F. oxysporum. Using a root-drenching method, 10 one-year-old healthy D. vanzylii were inoculated in conidial suspensions (1*106 conidia/mL) of isolates KMDV1 and KMDV2 for 60 min, respectively. They were transplanted into pots with sterilized soil and incubated in a plant-growth chamber at 25°C and 60% relative humidity. Control plants were treated with sterilized water. The pathogenicity test was repeated three times. All plants inoculated with each isolate developed leaf wilt symptoms after 15 days and were dead after 20 - 30 days. However, no symptoms were observed in the control plants. Fusarium oxysporum was reisolated and confirmed based on morphology and EF1-α sequence analysis. No pathogens were isolated from the control plants. This is the first report of F. oxysporum causing leaf wilt disease on D. vanzylii in China. To date, several diseases have been reported on members of the Aizoaceae. For instance, collar and stem rot on Lampranthus sp. caused by Pythium aphanidermatum (Garibaldi et al. 2009), wilt on Lampranthus sp. and Tetragonia tetragonioides caused by Verticillium dahliae (Garibaldi et al. 2010; Garibaldi et al. 2013), and leaf spot on Sesuvium portulacastrum caused by Gibbago trianthemae (Chen et al., 2022). Our research could provide insight into fungal diseases on members of the Aizoaceae and contribute to their cultivation and management.

Response of Shoot and Root Growth, Yield, and Chemical Composition to Nutrient Concentrations in Soybean Varieties Grown under Soilless and Controlled Environment Conditions

The practice of cultivating crops in a controlled environment using a soilless culture method is seeing an increasing level of popularity. The aforementioned challenges include addressing climate change, combating pests and diseases, mitigating falling soil fertility, and ensuring constant production and quality. One of the potential crops that could be grown with such a method is soybean. Soybean cultivation in a controlled environment using soilless culture still needs more information, especially regarding nutrient solution management of certain soybean varieties. Thus, this study investigated the impact of nutrient concentrations and variety on soybean growth, yield, and chemical composition. This research was carried out in a plant growth chamber using expanded clay aggregate as a soilless substrate. The treatments were four nutrient concentrations: 0% (control), 50%, 100%, and 150%, and two different varieties: Martina and Johanna. The findings of this research revealed that there were significant differences in nutrient treatments on all parameters measured. Application of nutrient concentration at 50% resulted in the most profound root size for both varieties. Applying 100% nutrient concentration produced a higher 100-grain weight for the Johanna variety. Application of nutrient concentration at 150% resulted in the highest shoot weight and shoot:root ratio for both varieties, with varietal differences. Furthermore, applying nutrient concentration at 150% also produced the highest grain yield/pot, protein yield, and lipid yield for both varieties. Thus, the nutrient concentration between 100% and 150% gave a positive effect and can be applied for planting Martina and Johanna using this system.

Development of a Low-Cost Plant Growth Chamber for Improved Phenotyping Research

Development of a Low-Cost Plant Growth Chamber for Improved Phenotyping Research

First report of peanut root rot caused by Fusarium acuminatum in Shandong Province, China.

Peanut (Arachis hypogaea L.) is one of the most economically important crops as a major source of edible oil and protein. In July 2021, a root rot disease was observed on peanut in Laiwu (36º22' N, 117º67' E), Shandong Province, China. Disease incidence was approximately 35%. Disease symptoms included root rot, vessels with a brown to dark brown discoloration, plus progressive yellowing and wilting of leaves from the base leading to whole plant death. To determine the causal agent, symptomatic roots with typical lesions were cut into small pieces, surface sterilized in 75% ethanol for 30 s, and 2% NaClO for 5 min, rinsed three times in sterile water and placed on potato dextrose agar (PDA) at 25℃ (Leslie and Summerell 2006). After 3 days of incubation, whitish-pink to red colonies growing from the roots were observed. Eight single-spore isolates had identical morphological traits that were similar to those of Fusarium spp. A representative isolate (LW-5) was used for morphological characterization, molecular analysis, and pathogenicity test. On PDA, the isolate formed dense aerial mycelia, which were initially white, then became deep pink with age and formed red pigments in the medium. On carnation leaf agar (CLA), macroconidia with 3 to 5 septa were abundant, relatively slender, curved to lunate, that measured 23.7 to 52.2 × 3.6 to 5.4 μm (n=50). Microconidia were oval, 0 to 1 septa. Chlamydospores were globose with a smooth outer wall in chains or single. Following DNA extraction of isolate LW-5, primers EF1-728F/EF1-986R (Carbone et al., 1999), RPB1U/RPB1R, and RPB2U/RPB2R (Ponts et al., 2020) were used to amplify the partial translation elongation factor 1 alpha (TEF1-α), RNA polymerase II largest subunit (RPB1), and RNA polymerase II second largest subunit (RPB2) regions for DNA sequencing, respectively. BLASTn analysis of TEF1-α (GenBank accession No. OP838084), RPB1 (OP838085), and RPB2 (OP838086) sequences, revealed 99.66, 99.87, and 99.09% identity with those of F. acuminatum (OL772800, OL772952 and OL773104), respectively. Isolate LW-5 was identified as F. acuminatum based on morphology and molecular analysis. Twenty Huayu36 peanut seeds were each planted in a 500-ml sterile pot containing 300 g of autoclaved potting medium (nutritive soil: vermiculite=2:1 in volume). Two weeks after seedling emergence, 1 cm depth of the potting medium was dug around the plants to expose the taproot. Two 5-mm wounds per taproot were scratched with a sterile syringe needle. Potting medium in each pot of 10 inoculated plants was mixed with 5 ml of conidial suspension (106 conidia per ml). The other 10 plants were used as non-inoculated controls and treated with sterile water in the same manner. The seedlings were placed in a plant growth chamber maintained at 25°C, RH >70%, 16-h light per day, and irrigated with sterile water. After 4 weeks, inoculated plants exhibited yellowing and wilting symptoms that were similar to those observed in the field, while non-inoculated control plants had no symptoms. F. acuminatum was re-isolated from diseased roots and confirmed using morphological features and DNA sequence analysis of TEF1-α, RPB1 and RPB2. F. acuminatum was reported to cause root rot on Ophiopogon japonicus (Linn. f.) (Tang et al., 2020), Polygonatum odoratum (Li et al., 2021), and Schisandra chinensis (Shen et al., 2022) in China. To our knowledge, this is the first report of root rot on peanut caused by F. acuminatum in Shandong Province, China. Our report will provide crucial information for studying the epidemiology and management of this disease.

A hyperspectral plant health monitoring system for space crop production.

Compact and automated sensing systems are needed to monitor plant health for NASA's controlled-environment space crop production. A new hyperspectral system was designed for early detection of plant stresses using both reflectance and fluorescence imaging in visible and near-infrared (VNIR) wavelength range (400-1000 nm). The prototype system mainly includes two LED line lights providing VNIR broadband and UV-A (365 nm) light for reflectance and fluorescence measurement, respectively, a line-scan hyperspectral camera, and a linear motorized stage with a travel range of 80cm. In an overhead sensor-to-sample arrangement, the stage translates the lights and camera over the plants to acquire reflectance and fluorescence images in sequence during one cycle of line-scan imaging. System software was developed using LabVIEW to realize hardware parameterization, data transfer, and automated imaging functions. The imaging unit was installed in a plant growth chamber at NASA Kennedy Space Center for health monitoring studies for pick-and-eat salad crops. A preliminary experiment was conducted to detect plant drought stress for twelve Dragoon lettuce samples, of which half were well-watered and half were under-watered while growing. A machine learning method using an optimized discriminant classifier based on VNIR reflectance spectra generated classification accuracies over 90% for the first four days of the stress treatment, showing great potential for early detection of the drought stress on lettuce leaves before any visible symptoms and size differences were evident. The system is promising to provide useful information for optimization of growth environment and early mitigation of stresses in space crop production.

Advance an Automated Indoor Hydroponic Unit for Plant Growth Detection with Compatible for Two Different Plant Varieties

The study aimed to design and fabricate an automated indoor hydroponic plant growth chamber, by comparing the manual system to determine plant growth and development and the sub-objective was to send data to the IoT platform. The sensor-based automated system incorporated pH, TDS, temperature, and humidity sensors, controlled by solenoid valves using Arduino. Tomato and lettuce plants were grown in both systems and growth parameters were measured. The results showed that the automated system maintained consistent temperature, humidity, pH, and EC levels similar to the outdoor system (vary in 30-32, 52-79, 5.5-6.5, and 1.5-2.5 dS/m ranges respectively). Furthermore, the automated indoor system significantly enhanced the plant growth of tomato and lettuce plants compared to the manual system. Significantly higher plant heights of 27.9±1.9 cm and 27.4±4.9 cm, the leaf lengths of 3.2±0.1 cm and 3.9±0.1 cm were observed for the tomatoes and the lettuces respectively in the automated indoor system. A significant difference was observed between the SPAD reading of the automated indoor tomato of 30±0.9 and the outdoor tomato of 26±0.4. Similarly, SPAD readings for the automated indoor lettuce of 23±0.3 and outdoor lettuce of 17±0.5 were significantly different (Pr=<0.0001, Pr≤0.05). These findings highlight the effectiveness of the automated hydroponic system in accommodating plant preferences and its potential for improving agricultural practices. By integrating IoT platforms for data analysis, this technology can optimize plant growth, enhance yields, and facilitate informed decision-making in hydroponic farming.

The antifungal effect of propolis extract against cotton wild disease (Verticillium dahliae Kleb.)

The aim of this study is to investigate the antifungal activity of propolis against V. dahliae Kleb. under both in vitro and in vivo conditions. Firstly, the inhibitory effect of the propolis on mycelial growth in Potato Dextrose Agar (PDA) media containing its ethanol extract (PE) at various concentrations (0.003, 0.06, 0.125, 0.25, 0.5, and 1 ppm/mL) was investigated under in vitro conditions. Then to assess the effect of PE on non-defoliating (PHCVd3 isolate) and defoliating (PHCVd47 isolate) pathotypes of V. dahliae, the varieties Giza 45 (resistant), Carmen (tolerant), and Acala SJ2 (susceptible) treated with PEE (1 ppm/mL) were observed in the plant growth chamber up to the 4-6 leaf stage. The whole in vitro experiments were carried out with three replicates, and the studies in vivo experiment were with five replicates depending on a completely randomized parcels design. The most effective dose of PEE with1 ppm/mL dose resulted in 75.2% suppression against the PHCVd3 isolate, while the effect of the same dose against the PHCVd47 isolate was 74.4%. The lowest disease severity index (DSI) values against PHCVd3 and PHCVd47 isolates in cotton cultivars treated with PE were 1.34 and 1.64 in the Giza 45, respectively, and the highest DSI values were 3.80 and 3.90 in the Acala SJ2 cultivar in vivo experiment, respectively. The findings indicate that PE treatment has a promising effect against cotton wilt disease that could be combined with known plant protection strategies.

English

Arvi (Colocasia esculenta) is widely cultivated sweet and starchy corms as a staple food in most of the African and Asian countries. Black rot caused by Ceratocystis fimbriata is the most damaging post-harvest disease of Arvi in many countries. In June, 2019, the black rot disease symptoms were noticed on edible corms of Arvi for sale in different vegetable shops in Faisalabad, Pakistan. These symptoms were comprised of small, brown to greenish, slightly sunken spots or lesions which later on enlarged as black rot on the harvested corms. A comprehensive study was initiated to explore the pathogen associated with symptomatic corms. White to grey mycelia and black perithecia with long necks were observed within the lesions. The isolated pathogen was identified as Ceratocystis fimbriata based on morpho-physiological characteristics. Pathogenicity was proved on inoculated corms at 26±2°C and 70% relative humidity (RH) in plant growth chamber. The fungus was further tested for growth and reproduction physiology under different growth media and environmental parameters. A significant interaction between mycelial growth and culture media was observed. Highest mycelial growth (9 cm) of C. fimbriata was showed by Potato Carrot Agar (PCA) and lowest growth (0%) was observed on Water Agar (WA). There was a significant correlation between Temperature, RH, and hydrogen ion (pH) concentration responsible for the growth of C. fimbriata at (P < 0.01). The optimum fungal growth (8.75, 8.96, and 8.95 cm) was measured at 25°C, 70% RH, and pH 8 respectively. The paper may act as basic resource for future research on the epidemiology of this disease.