Rosette Stage Research Articles

First Report of Soft Rot Caused by Pectobacterium polaris on Lettuce in China.

Lettuce (Lactuca sativa) is a leafy vegetable that belongs to the family Asteraceae. It is widely cultivated and consumed around the world. In May 2022, lettuce plants (cv. 204) showing soft rot symptoms were observed in greenhouses in Fuhai District (25°18'N, 103°6'E), Kunming City, Yunnan Province, China. The disease incidence in three greenhouses (0.3 ha in size) was between 10% to 15%. The lower parts of the outer leaves showed brown and water-soaked symptoms, but at the same time the roots were asymptomatic. Sclerotinia species can cause soft decay on lettuce leaves, known as lettuce drop, which can produce symptoms partially resembling those of bacterial soft rot (Subbarao 1998). The absence of white mycelium or black sclerotia on the leaf surfaces of diseased plants indicated that Sclerotinia species were not responsible for the disease. Instead, it is more likely that bacterial pathogens were the cause. Fourteen diseased plants were sampled from three greenhouses, and potential pathogens were isolated from the leaf tissues of six plant individuals. Leaf samples were cut into pieces ca. 0.5 cm in length. The pieces were then surface-sterilized by dipping in 75% ethanol for 60 sec, followed by three successive rinses using sterile distilled water. The tissues were immersed in 250 µl of 0.9% saline in 2 mL microcentrifuge tubes and gently pressed down with grinding pestles for 10 sec. The tubes were let stand still for 20 min. Aliquots (20 μl) 100-fold dilutions of the tissue suspensions were plated onto Luria-Bertani (LB) plates and incubated at 28°C for 24 h. Three single colonies were picked from each LB plate and restreaked five times for purity. After purification, eighteen strains were obtained, and nine of these were identified by 16S rDNA sequencing using the universal primer pair 27F/1492R (Weisburg et al. 1991). Six out of nine strains (6/9) belonged to the genus Pectobacterium (OP968950-OP968952, OQ568892- OQ568894), two strains (2/9) belonged to the genus Pantoea (OQ568895 and OQ568896), and one strain (1/9) belonged to Pseudomonas sp. (OQ568897). Since the Pectobacterium strains shared identical 16S rDNA sequence, strains CM22112 (OP968950), CM22113 (OP968951) and CM22132 (OP968952) were selected as representative strains for further testing. The 16S rDNA sequences of Pectobacterium strains were 100% identical to that of the P. polaris strain NIBIO 1392 (NR_159086.1). To identify the strains to the species level, multilocus sequence analysis (MLSA) was performed using sequences of six housekeeping genes acnA, gapA, icdA, mdh, proA and rpoS (OP972517-OP972534) (Ma et al. 2007; Waleron et al. 2008). Phylogenetic analysis showed that the strains clustered with P. polaris type strain NIBIO1006T (Dees et al. 2017). They were all capable of utilizing citrate, which is an important biochemical feature in distinguishing P. polaris from its most closely related sister species P. parvum (Pasanen et al. 2020). Lettuce plants (cv. 204), at the rosette stage, were inoculated with the strains CM22112 and CM22132 by injecting 100 µl of bacterial suspensions (107 CFU·mL-1) into the lower parts of the leaf; for the controls, 100 µl of saline was used instead. Inoculated plants were incubated at room temperature (23°C) and 90% relative humidity. Five days after inoculation, only the bacteria-inoculated lettuce showed severe soft rot symptoms. Similar results were observed in two independent experiments. Bacterial colonies were obtained from the infected lettuce leaves, which showed identical sequences to P. polaris strains CM22112 and CM22132. Therefore, these strains fulfilled Koch's postulates for lettuce soft rot. P. polaris is prevalent on potato in many countries (Dees et al. 2017). To our knowledge, this is the first report of P. polaris causing soft rot on lettuce in China. This disease could seriously affect the appearance and saleability of lettuce. Further research on the epidemiology and management strategies of the disease is needed.

Evaluation of soybean selection and sowing date in a continuous cover relay-cropping system with pennycress

Pennycress (Thlaspi arvense L.) is a new winter annual oilseed crop that can be integrated as a “cash cover crop” in Midwestern USA cropping systems. Relay-cropping pennycress with soybean [Glycine max (L.) Merr.] has been shown as an effective way to produce three crops over 2 years while providing living cover on the agricultural landscape nearly year-round. However, management improvements are needed to optimize pennycress and soybean production in this new system. A 2-year field study was conducted to evaluate three soybean interseeding dates (based on pennycress growth stage) and three soybean cultivars (varied in maturity date) on the overall productivity of this relay system. Interseeding dates were SD1 (rosette stage), SD2 (bolting stage), and SD3 (initial flowering), and soybean cultivars were MG0.2 (early), MG1.1 (standard), and MG1.7 (late). In the second season, relaying soybean reduced pennycress seed yield compared with its monocrop counterpart, but the reduction was lowest (23%) at SD2. Cultivar maturity group impacted soybean seed yields in the relay system, which for MG0.2, MG1.1, and MG1.7 averaged 2,589, 3,196, and 3,445 kg ha−1, respectively. Although there was soybean yield drag associated with relay cropping, the seed yield of the MG1.7 cultivar relay interseeded at SD2 was not significantly different from a monocropped MG1.1 soybean using conventional practice (CP; winter fallow, no pennycress). The results indicate that relay interseeding of longer maturity (MG1.7) soybean for the region at the bolting stage (SD2) of pennycress optimized overall system productivity while keeping the continuous living cover on the agricultural landscape. More research will likely be needed to improve soybean selection and management regionally for this unique relay system.

Effectiveness of foliar fertilizing spring oilseed rape in the forest-steppe conditions of central black earth economic region of Russia

Trace elements are involved in almost all processes of plant life, despite the fact that they need very small amounts. The lack of trace elements in the soil does not lead to the death of plants, but is the cause of a decrease in the rate of their development. In the end, the plants do not realize their capabilities and give a low and low-quality crop. To solve this problem quickly, you can use foliar fertilizing with microfertilizers. The purpose of this study was to assess the impact of foliar fertilizing at different times with new types of complex microfertilizers on the productivity of spring rapeseed and the quality of its oilseeds.The experiments were carried out in the Lipetsk Region in Russia in 2019 and 2020 on Rif spring oilseed rape variety. Three types of fertilization during oilseed rape vegetative development were studied: a rosette stage, a bud-formation stage, and overlapping rosette + budding stage. The following agrochemical preparations were studied: Microel (0.2 L/ha), Life Force (0.4 L/ha), Boroplus (0.75 L/ha), Plantafol 20:20:20 (1 kg/ha), Plantafol 5: 15:45 (1 kg/ha) and Lignohumate (0.15 L/ha). The research results showed that processing foliar fertilization in the rosette stage with further feeding in the bud-formation phase were most effective. Because of the provision with microelements, vegetative plants were able to synthesize a full complex of enzymes. Plantafol 20:20:20 and Plantafol 5:15:45 micronutrient fertilizers provided the maximum increase in the rapeseed yield with double-spray processing, yielding 2.05 and 1.94 t/ha, respectively, and exceeding the control crops by 0.64 and 0.53 t/ha, respectively.

Оptimization of fertilizer and foliar feeding winter rape (Brassica napus L.) in the Western Polissia

Topicality. Significant changes in market conditions and disruptions in the sown area structure in Ukraine require to search for optimal and cost-effective systems of fertilisation and crop management for modern varieties and hybrids of winter rape. The application of sulphur fertilisers, ammonium nitrate in early spring fertilisation and foliar feeding with growth stimulants and microfertilisers improves winter rape growth and development, yield structure and productivity. Purpose. To develop innovative agrotechnical practices involving the compound fertilizers, microfertilizers, growth stimulants, aimed to realize the high yield potential of winter rape in the Western Polissia. Methods. The research was carried out at the Institute of Agriculture of Western Polissia on a typical low-humus light loamy chernozem. General scientific methods and analyses were used to compare the factors under study: field method was used to determine the fertiliser efficiency; visual, measuring and weighing method; laboratory method; comparative and calculation method; statistical method. The results. It was found that on winter rape crops, the best degree of overwintering was 85.5–88.8 % and 83.0–86.0 % for fertilisation with N35P90K120 + N85S40 + N30 and N35S60K90 + N85, compared to N35P60K90 + N85, where these indicators are within 77.3–77.7 %. The highest survivability of plants during the growing season was 98.4–98.6 %, when N35P90K120 + N85S40 + N30 was applied together with foliar feeding (Huliver Stymul + Avanhard Silicon Bio (1.0 + 1.0 l/ha) and Huliver Stymul + Avanhard P Phosphorus + Potassium (1.0 + 0.6 l/ha) in the rosette phase and the beginning of budding. The largest number of pods per plant is 121.5–124.0 pcs, the number of seeds per pod is 24.1–24.7 pcs, the thousand seed weight – 4.54–4.56 g was observed for fertilisation with N35P90K120 + N85S40 + N30 with two foliar feeding with Huliver Stymul + Avanhard Silicon Bio (1.0 + 1.0 l/ha) and Huliver Stymul + Avanhard P Phosphorus + Potassium (1.0 + 0.6 l/ha). The maximum yield of 4.45 t/ha was obtained with fertiliser of N35P90K120 + N85S40 + N30 and foliar feeding with Huliver Stymul + Avanhard P Phosphorus + Potassium (1.0 + 0.6 l/ha). Conclusions. It was found that early spring application of ammonium sulphate N35S40 and ammonium nitrate N50–85 kg/ha was an effective method to increase the winter rape yield to 4.45 t/ha, the increase in yield due to fertilisation varied within 5.1–15 %. When foliar feeding with a growth stimulator and microfertilisers was applied two times in the spring rosette and flower budding stage, the yield increase ranged from 2.8 to 16.5 %. Key words: winter rape, fertilization system, foliar feeding, productivity

Rhizosphere bacteria regulated arsenic bioavailability and accumulation in the soil–Chinese cabbage system

The accumulation of arsenic (As) in Chinese cabbage (Brassica rapa ssp. pekinensis) has recently been a source of concern for a potential risk to human health. It is unknown whether natural variations of As accumulation in different genotypes of Chinese cabbage are related to rhizobacterial characteristics. Experiments were conducted to investigate the mechanisms of rhizobacteria involving in As fates in a soil–Chinese cabbage system using various genotypes using high-throughput sequencing and quantitative PCR. There were significant differences in As accumulation in cabbage leaves between 32 genotypes, and genotypes of low-As-accumulation (LSA) and high-As-accumulation (HSA) were identified. The As concentrations in the shoots of LSA were 23.25 %, 24.19 %, 15.05 %, and 70.69 % lower than those of HSA in seedling stage (SS), rosette stage (RS), heading stage (HS), and mature stage (MS), respectively. Meanwhile, the relative abundances of phyla Patescibacteria (in RS), Acidobacteria and Rokubacteria (in HS) in the rhizosphere of LSA were 60.18 %, 28.19 %, and 45.38 % less than those of HSA, respectively. Additionally, both shoot-As and As translocation factor had significantly positive or negative correlations with the relative abundances of Rokubacteria or Actinobacteria. In LSA rhizosphere, the relative abundances of genera Flavobacterium (in SS), Ellin6055 and Sphingomonas (in HS) were 128.12 %, 83.69 % and 79.50 % higher than those of HSA, respectively. This demonstrated that rhizobacteria contribute to the accumulation and translocation of As in HSA and LSA. Furthermore, the gene copies of aioA and arsM in LSA rhizosphere were 25.54 % and 16.13 % higher than those of HSA, respectively, whereas the gene copies of arsC in LSA rhizosphere were 26.36 % less than those of HSA in MS, indicating that rhizobacteria are involved in As biotransformation in the soil. These results provide a comprehensive understanding of the relationship between characteristics of rhizobacterial communities and As variations in Chinese cabbage genotypes.

A new in vitro monitoring system reveals a specific influence of Arabidopsis nitrogen nutrition on its susceptibility to Alternaria brassicicola at the seedling stage.

Seedling growth is an early phase of plant development highly susceptible to environmental factors such as soil nitrogen (N) availability or presence of seed-borne pathogens. Whereas N plays a central role in plant-pathogen interactions, its role has never been studied during this early phase for the interaction between Arabidopsis thaliana and Alternaria brassicicola, a seed-transmitted necrotrophic fungus. The aim of the present work was to develop an in vitro monitoring system allowing to study the impact of the fungus on A. thaliana seedling growth, while modulating N nutrition. The developed system consists of square plates placed vertically and filled with nutrient agar medium allowing modulation of N conditions. Seeds are inoculated after sowing by depositing a droplet of conidial suspension. A specific semi-automated image analysis pipeline based on the Ilastik software was developed to quantify the impact of the fungus on seedling aerial development, calculating an index accounting for every aspect of fungal impact, namely seedling death, necrosis and developmental delay. The system also permits to monitor root elongation. The interest of the system was then confirmed by characterising how N media composition [0.1 and 5mM of nitrate (NO3-), 5mM of ammonium (NH4+)] affects the impact of the fungus on three A. thaliana ecotypes. Seedling development was strongly and negatively affected by the fungus. However, seedlings grown with 5mM NO3- were less susceptible than those grown with NH4+ or 0.1mM NO3-, which differed from what was observed with adult plants (rosette stage). The developed monitoring system allows accurate determination of seedling growth characteristics (both on aerial and root parts) and symptoms. Altogether, this system could be used to study the impact of plant nutrition on susceptibility of various genotypes to fungi at the seedling stage.

Accelerated gross nitrogen cycling following garlic mustard invasion is linked with abiotic and biotic changes to soils

IntroductionAlliaria petiolata (garlic mustard), an invasive forest herb in North America, often alters nutrient availability in its non-native ecosystems, but the mechanisms driving these changes have yet to be determined. We hypothesized three potential mechanisms through which garlic mustard could directly influence soil nitrogen (N) cycling: by increasing soil pH, by modifying soil microbial community composition, and by altering nutrient availability through litter inputs.Materials and methodsTo test these hypotheses, we evaluated garlic mustard effects on soil pH and other soil properties; fungal and prokaryotic (bacterial and archaeal) community composition; and soil N cycling rates (gross N mineralization and nitrification rates, microbial N assimilation rates, and nitrification- versus denitrification-derived nitrous oxide fluxes); and we assessed correlations among these variables. We collected soil samples from garlic mustard present, absent, and removed treatments in eight forests in central Illinois, United States, during the rosette, flowering, and senescence phenological stages of garlic mustard life cycle.ResultsWe found that garlic mustard increased soil pH, altered fungal and prokaryotic communities, and increased rates of N mineralization, nitrification, nitrification-derived net N2O emission. Significant correlations between soil pH and microbial community composition suggest that garlic mustard effects on soil pH could both directly and indirectly influence soil N cycling rates.DiscussionCorrespondence of gross rates of N mineralization and nitrification with microbial community composition suggest that garlic mustard modification of soil microbial communities could directly lead to changes in soil N cycling. We had expected that early season, nutrient-rich litter inputs from mortality of young garlic mustard could accelerate gross N mineralization and microbial N assimilation whereas late season, nutrient poorer litter inputs from senesced garlic mustard could suppress N mineralization, but we did not observe these patterns in support of the litter input mechanism. Together, our results elucidate how garlic mustard effects on soil pH and microbial community composition can accelerate soil N cycling to potentially contribute to the invasion success of garlic mustard.

The AP2 Transcription Factor BrSHINE3 Regulates Wax Accumulation in Nonheading Chinese Cabbage.

Wax is an acellular structural substance attached to the surface of plant tissues. It forms a protective barrier on the epidermis of plants and plays an important role in resisting abiotic and biotic stresses. In this paper, nonheading Chinese cabbage varieties with and without wax powder were observed using scanning electron microscopy, and the surface of waxy plants was covered with a layer of densely arranged waxy crystals, thus differentiating them from the surface of waxless plants. A genetic analysis showed that wax powder formation in nonheading Chinese cabbage was controlled by a pair of dominant genes. A preliminary bulked segregant analysis sequencing (BSA-seq) assay showed that one gene was located at the end of chromosome A09. Within this interval, we identified BraA09000626, encoding an AP2 transcription factor homologous to Arabidopsis AtSHINE3, and we named it BrSHINE3. By comparing the CDS of the gene in the two parental plants, a 35 bp deletion in the BrSHINE3 gene of waxless plants resulted in a frameshift mutation. Tissue analysis showed that BrSHINE3 was expressed at significantly higher levels in waxy plant rosette stage petioles and bolting stage stems than in the tissues of waxless plants. We speculate that this deletion in BrSHINE3 bases in the waxless material may inhibit wax synthesis. The overexpression of BrSHINE3 in Arabidopsis induced the accumulation of wax on the stem surface, indicating that BrSHINE3 is a key gene that regulates the formation of wax powder in nonheading Chinese cabbage. The analysis of the subcellular localization showed that BrSHINE3 is mainly located in the nucleus and chloroplast of tobacco leaves, suggesting that the gene may function as a transcription factor. Subsequent transcriptome analysis of the homology of BrSHINE3 downstream genes in nonheading Chinese cabbage showed that these genes were downregulated in waxless materials. These findings provide a basis for a better understanding of the nonheading Chinese cabbage epidermal wax synthesis pathway and provide important information for the molecular-assisted breeding of nonheading Chinese cabbage.

Loss of LEUCINE CARBOXYL METHYLTRANSFERASE 1 interferes with metal homeostasis in Arabidopsis and enhances susceptibility to environmental stresses

The biochemical function of LEUCINE CARBOXYL METHYLTRANSFERASE 1 (LCMT1) is to transfer a methyl group from the methyl donor S-adenosylmethionine (SAM) to the catalytic subunits of PROTEIN PHOSPHATASE 2A (PP2Ac), PP4 and PP6. This post-translational modification by LCMT1 is found throughout eukaryotes from yeast to animals and plants, indicating that its function is essential. However, Arabidopsis with knocked out LCMT1 still grows and develops almost normally, at least under optimal growth conditions. We therefore proposed that the presence of LCMT1 would be important under non-optimal growth conditions and favoured plant survival during evolution. To shed light on the physiological functions of plant LCMT1, phenotypes of the lcmt1 mutant and wild type Arabidopsis were compared under various conditions including exposure to heavy metals, variable chelator concentrations, and increased temperature. The lcmt1 mutant was found to be more susceptible to these environmental changes than wild type and resulted in poor growth of seedlings and rosette stage plants. Element analysis of rosette stage plants mainly showed a difference between the lcmt1 mutant and wild type regarding concentrations of sodium and boron, two-fold up or halved, respectively. In both lcmt1 and wild type, lack of EDTA in the growth medium resulted in enhanced concentration of copper, manganese, zinc and sulphur, and especially lcmt1 growth was hampered by these conditions. The altered phenotype in response to stress, the element and mRNA transcript analysis substantiate that LCMT1 has an important role in metal homeostasis and show that functional LCMT1 is necessary to prevent damages from heat, heavy metals or lack of chelator.

Development of a sensor-based site-specific N topdressing algorithm for a typical leafy vegetable.

Precise and site-specific nitrogen (N) fertilizer management of vegetables is essential to improve the N use efficiency considering temporal and spatial fertility variations among fields, while the current N fertilizer recommendation methods are proved to be time- and labor-consuming. To establish a site-specific N topdressing algorithm for bok choy (Brassica rapa subsp. chinensis), using a hand-held GreenSeeker canopy sensor, we conducted field experiments in the years 2014, 2017, and 2020. Two planting densities, viz, high (123,000 plants ha–1) in Year I and low (57,000 plants ha–1) in Year II, whereas, combined densities in Year III were used to evaluate the effect of five N application rates (0, 45, 109, 157, and 205 kg N ha–1). A robust relationship was observed between the sensor-based normalized difference vegetation index (NDVI), the ratio vegetation index (RVI), and the yield potential without topdressing (YP0) at the rosette stage, and 81–84% of the variability at high density and 76–79% of that at low density could be explained. By combining the densities and years, the R2 value increased to 0.90. Additionally, the rosette stage was identified as the earliest stage for reliably predicting the response index at harvest (RIHarvest), based on the response index derived from NDVI (RINDVI) and RVI (RIRVI), with R2 values of 0.59–0.67 at high density and 0.53–0.65 at low density. When using the combined results, the RIRVI performed 6.12% better than the RINDVI, and 52% of the variability could be explained. This study demonstrates the good potential of establishing a sensor-based N topdressing algorithm for bok choy, which could contribute to the sustainable development of vegetable production.

Echium vulgare and Echium plantagineum: A Comparative Study to Evaluate Their Inclusion in Mediterranean Urban Green Roofs

Green roofs (GRs) are proposed to offset against numerous environmental and socio-economic concerns associated with climate change and urban sprawl. In Mediterranean urban areas, to protect and conserve biodiversity through GRs, the use of native plant species from arid environments and with shallow roots is generally recommended. In north Europe, Echium vulgare L. is widely used on GRs for its tolerance to abiotic stresses and its attractiveness for bees; unfortunately, since this species requires cold winters to induce flowering and warm wet summers for vegetative growths, its adaptability to Mediterranean GRs has been questioned. The current study is based on the hypothesis that Echium plantagineum L. can adapt better to the Mediterranean environment than E. vulgare and offer blooms to pollinators, thus providing the important urban ecosystem service (UES) of protecting entomofauna biodiversity. To compare the adaptability of E. plantagineum vs. E. vulgare, both Echium species were grown and studied on the extensive GR installed at ENEA Casaccia Research Center, in the north of Rome, Lazio, Italy. The comparative analysis of the GR performance of the two species was based on several plant-related traits, including seed morphology, rosette stage, inflorescence, flower and root-related traits, and their biological life cycle, most of them showing significant differences (for example, rosette area was 1.42-fold major in E. plantagineum than in E. vulgare). The information provided in this manuscript will be useful to update the herbarium records for conservation biology. A dramatic water stress was purposely applied in the GR before the end of the hot summer season, and while E. plantagineum faced with success the imposed dehydration (88.4% vegetation cover), E. vulgare did not (7.5% vegetation cover), presumably because of its biennial life cycle which did not allow it to complete seed maturation (only 46.9% percentage mature seeds in E. vulgare respect to 89.5% in E. plantagineum). In summary, as the main result, this work shows that in Mediterranean areas, the inclusion of E. plantagineum in seed mixes for flower meadow GRs could represent a valuable alternative to E. vulgare in temperate areas, providing a safeguard for pollinators and allowing water and energy saving.

Genetic Variability Studies on Drought Tolerance using Agro-Morphological and Yield Contributing Traits in Rapeseed-Mustard

A study was conducted during rabi season (October-May), 2018−2019 at the Experimental Farm of Department of Genetics and Plant Breeding, CSK HPKV, Palampur (HP), India to develop reliable selection criteria for drought tolerance. 25 advanced breeding lines of different Brassica species were used to determine their mean performance, components of variability, heritability and genetic advance under moisture stress conditions created at rosette stage, flower initiation stage and siliqua formation stage using various agro-morphological and yield contributing traits. Sufficient genetic variability was found for almost all the characters except for 1000-seed weight under non-stress stage conditions. Estimates of parameters of variability revealed that phenotypic coefficients of variation were higher than their respective genotypic coefficients of variation. Under moisture stress conditions, high heritability coupled with high genetic advance was observed for number of secondary branches plant-1 in non-stress and all the moisture-stress stages. Siliqua formation stage was found most susceptible to moisture stress conditions which also led to maximum reduction in seed yield. Using drought susceptibility index, the genotypes HPBS-1 followed by HPKM-04-1 were found to be moderately drought tolerant as these exhibited the lowest drought susceptibility index value in Stage-I and Stage-III while in Stage-II, RCC-4×Varuna followed by HPBS-1 exhibited lowest drought susceptibility index value. Therefore, systematic characterization of differences in physiological responses to drought stress among elite lines is helpful in understanding mechanisms of drought resistance. Hence, traits like primary branches plant-1, secondary branches plant-1, siliquae plant-1, seeds siliqua-1, seed yield plant-1 and 1000-seed weight can be further used in selection criteria for future breeding programme aimed for enhancing drought tolerance.

The impact of foliar application of biostimulators on the morphological characteristics of the leaf rosette of winter rape plants

The field experiment was caried out in three growing seasons (2013–2016) at the Agricultural Experimental Station – Zawady (52°03'N and 22°33'E) belonging to the University of Natural Sciences and Humanities in Siedlce, Poland. The experiment was set up in a split-plot configuration with three replications. The examined factors were: I – morphotypes of winter oilseed rape: population (Poznaniak), hybrid restored with a semi-dwarf type of growth (PX104), hybrid restored with a traditional type of growth (Konkret); II – four types of biostimulators: 1. control variant, 2. biostimulator Tytanit® (titan), 3. biostimulator Asahi®SL (sodium ortho-nitrophenol, sodium para-nitrophenol, sodium 5-nitroguaiacol), 4. biostimulator Silvit® (active silicon, potassium oxide, boron – form of pure element, zinc – form of pure element). The aim of the study was to evaluate the effect of biostimulators containing various active substances on the morphological characteristics of winter oilseed rape plants in the leaf rosette stage (number of rosette leaves, tap root length, height of the growth cone) and on the fresh and dry mass of the above-ground rosette and the root system of traditional and semi-dwarf winter oilseed rape morphotypes type of growth under changing climatic conditions. The genetic factor significantly influenced the morphological features of plants, marked in autumn by inhibition of vegetation. The population variety Poznaniak developed more rosette leaves, greater length of the tap root, and fresh and dry mass of the rosette and the root system as compared to the restored hybrids. The applied biostimulators significantly influenced plant parameters determined in the fall before the vegetation inhibition. After the use of a biostimulator containing the active substance in the form of sodium o-nitrophenol, sodium para-nitrophenol and sodium 5-nitroguajakol, a significantly higher value of the tested features was obtained compared to the control variant. Regardless of the type of biostimulator used, the height of the growth cone was the same as in the control object. The most favourable parameters of the leaf rosette were obtained in the first and second periods of summer-autumn vegetation and winter dormancy, while in extreme drought conditions during sowing and a fairy dry period of emergence, its weakest features were obtained. Natural growth stimulants are becoming an increasingly common elements of agricultural plant agrotechnics. Their use has a positive effect on the growth and development of plants and increases the resistance of plants to the adverse effects of stress factors.

Effect of Irrigation Scheduling and Varieties on Yield, Yield Attribute and Profitability of Indian Mustard [Brassica juncea (L.)

An agronomic investigation to study the response of various mustard varieties to different irrigation scheduling treatments through critical growth stage approach was conducted during Rabi season of year 2019-20 at IFS research Unit farm in Banda University of Agriculture and Technology, Banda (U.P.-210001). The experiment was laid out in strip plot design with three replications. Four irrigation scheduling treatments [viz. I0: No Irrigation, I1: One Irrigation at Rosette stage, I2: One Irrigation at Pod formation and I3: Two Irrigations (1st at Rosette + 2nd at Pod Formation)] were allocated to horizontal plots; whereas two mustard varieties (viz. NRCHB-101 and PM-28) were sown in vertical plots. Higher yield attributing characters at different crop stages and at harvest viz. pod plant-1, pod length, grain pod-1 and test weight and yield (grain yield, straw yield, biological yield and harvest index) along with crop water use efficiency were recorded under treatment irrigating the crop with two times during rosette and pod formation. Similarly maximum gross return (93759 INR ha-1), net return (65238 INR ha-1) and benefit cast ratio (2.29) were recorded under two irrigations (1st at Rosette + 2nd at Pod Formation). NRCHB-101 was observed maximum yield attributing characters and yield in compared to PM-28.

Antioxidant potential and essential oil properties of Hypericumperforatum L. assessed by application of selenite and nano-selenium

It is necessary to develop a simple way to achieve food quality quantitatively. Nanotechnology is a key advanced technology enabling contribution, development, and sustainable impact on food, medicine, and agriculture. In terms of medicinal and therapeutic properties, Hypericumperforatum is an important species. For this study, a randomized complete block design with three replications was used in each experimental unit. The foliar application of selenite and nano-selenium (6, 8, 10, and 12 mg/l), control (distilled water), at the rosette stage and harvesting at 50% flowering stage has been applied as an alleviation strategy subjected to producing essential oils and antioxidant activity. Experimental results revealed that the selenite and nano selenium fertilizers had a significant effect on traits such as total weight of biomass, essential oil percentage, the content of hypericin and hyperforin, the selenium accumulation in the plant, relative leaf water content, chlorophylls, phenolic content, proline, catalase, peroxidase, malondialdehyde, and DPPH. The highest essential oil content was obtained from the control treatment when the accumulation of selenium was achieved with 12 mg/l nano-selenium. The maximum rate of hypericin was seen in the foliar application of 8 mg/l selenite whereas the maximum hyperforin was gained at 10 mg/l selenium. Conceding that the goal is to produce high hypericin/ hyperforin, and also the accumulation of selenium in the plant, treatments of 6 and 8 mg/l of selenite and nano-selenium could be applied. Consequently, an easy detection technique proposed herein can be successfully used in different ranges, including biology, medicine, and the food industry.

Effect of pyrene-induced changes in root activity on growth of Chinese cabbage (Brassica campestris L.), and the health risks caused by pyrene in Chinese cabbage at different growth stages

BackgroundPolycyclic aromatic hydrocarbons (PAHs) pose a potential risk to ecological safety and human health. They have a range of effects on plant growth and there have been few reports on the health risks associated with ingestion of vegetable crops at different growth stages.MethodologyIn this study, a pot experiment in which Chinese cabbage (Brassica campestris L.) were grown in a greenhouse for 75 days was used to investigate the dose–effect relationship of pyrene with plant growth and also the exposure risk for adults of ingestion of Chinese cabbage at different growth stages.ResultsThe results showed that low doses of pyrene (5–45 mg kg−1) promoted plant growth (20–220% and 55–97% higher than control treatment for the root biomass and shoot biomass, respectively), but significant inhibition was observed at a high dose (405 mg kg−1) (41–66% and 43–91% lower than control treatment for the root biomass and shoot biomass, respectively). High doses of pyrene reduced soil bacterial abundance and diversity during the growth of Chinese cabbage, and increased malondialdehyde (MDA) levels in the plant. The effects of pyrene on plant biomass were mainly attributed to changes in root activity induced by pyrene, as the relationship between soil pyrene concentration and biomass was similar to that between soil pyrene concentration and root activity. Furthermore, structural equation modeling analysis showed that pyrene altered growth of the vegetable by directly affecting root activity. The incremental lifetime cancer risk for adults is highest for ingestion of Chinese cabbage at the seedling stage, followed in decreasing order by the rosette stages and heading stages.ConclusionsThe health risk of consumers who have the possibility to ingest the Chinese cabbage planted in pyrene-contaminated soil would be decreased with the increasing growth periods. However, further studies are required to confirm the dose–effect relationship between pyrene concentration and Chinese cabbage growth on a field scale.Graphical

Nitrogen nutrition modifies the susceptibility of Arabidopsis thaliana to the necrotrophic fungus, Alternaria brassicicola.

The impact of the form of nitrogen (N) source (nitrate versus ammonium) on the susceptibility to Alternaria brassicicola, a necrotrophic fungus, has been examined in Arabidopsis thaliana at the rosette stage. Nitrate nutrition was found to increase fungal lesions considerably. There was a similar induction of defence gene expression following infection under both N nutritions, except for the phytoalexin deficient 3 gene, which was overexpressed with nitrate. Nitrate also led to a greater nitric oxide production occurring in planta during the saprophytic growth and lower nitrate reductase (NIA1) expression 7 days after inoculation. This suggests that nitrate reductase-dependent nitric oxide production had a dual role, whereby, despite its known role in the generic response to pathogens, it affected plant metabolism, and this facilitated fungal infection. In ammonium-grown plants, infection with A. brassicicola induced a stronger gene expression of ammonium transporters and significantly reduced the initially high ammonium content in the leaves. There was a significant interaction between N source and inoculation (presence versus absence of the fungus) on the total amino acid content, while N nutrition reconfigured the spectrum of major amino acids. Typically, a higher content of total amino acid, mainly due to a stronger increase in asparagine and glutamine, is observed under ammonium nutrition while, in nitrate-fed plants, glutamate was the only amino acid which content increased significantly after fungal inoculation. N nutrition thus appears to control fungal infection via a complex set of signalling and nutritional events, shedding light on how nitrate availability can modulate disease susceptibility.

Evaluation of temporal variability on tissue nutrient concentrations of canola

AbstractThe use of plant tissue analysis as a tool for diagnosing nutrient deficiency has steadily gained interest by producers and crop advisors in Oklahoma. A study was conducted during the 2012–2013 and 2015–2016 growing seasons at two locations near Stillwater and Perry, OK, to evaluate the variability of canola (Brassica napus L.) nutrient concentrations across various growth stages (STAGE), among several days within each growth stage (DAY), across several times during the day (TIME). Canola tissue samples were collected in the morning, noon, and evening for three consecutive days at rosette, postdormancy break, and prebolting stages. Samples were analyzed for macronutrients (N, P, K) and secondary (S, Ca, Mg) nutrient concentrations. Tissue nutrient concentrations were found to be extremely variable, as affected by main effects and interactions of sampling TIME, DAY, and STAGE. Nutrient concentration generally increased over time, for most nutrients. The analysis did not indicate any definitive pattern of tissue nutrient accumulation based on the fixed effects TIME and DAY. Although, the exact reasons for the different responses are not known, they may be related to soil physical and chemical property differences and variation in weather factors. While this work does not provide insight in the relationship between nutrient concentrations and crop yield, this does bring to light complications with using tissue analysis for management decisions. Further work must be done to investigate the relationships of tissue concentration and yield, and the viability of tissue sampling for nutrient management.

Biological Observations on the Salsola tragus L. Weed Feeder Conorhynchus kindermanni Faust, 1904 (Coleoptera: Curculionidae) in Ağrı Mountain Lowland Area

The weevil Conorhynchus kindermanni Faust, 1904 (Curculionidae: Lixinae: Cleonini) was detected in close association with Salsola tragus L. (Amaranthaceae) in Ağrı Mountain soutwestern lowland area where sandy desert. The aim of this study is to determine the life cycle of C. kindermanni feeding on S. tragus. The field research was conducted between Iğdır and Doğubayazıt district of Ağrı Province Turkey in the summer of 2020. According to the results, adults of C. kindermanni feed on S. tragus starting on the rosette stage of this weed. Mating occurs on the ground among young plants, and eggs were laid on roots attached with a glue-like secretion. The legless larvae are freely able to move in sandy soil to reach lateral branches of roots for feeding. The mature larva prepares a solitary soil-case for pupal development in the soil near the host plant root. New generation adults hibernate inside the chamber until emergence from soil in early spring. This species produces one generation in a year in the Ağrı Mountain lowland desert habitat. Key words: Conorhynchus kindermanni, Salsola tragus, weed, biological observation, Ağrı Mountain

Maturity selection but not sowing date enhances soybean productivity and land use in a winter camelina–soybean relay system

AbstractEnhancing crop diversification is needed to ensure sustainable food and energy production in the soybean [Glycine max (L.) Merr.] and maize (Zea mays L.) dominated cropping systems of the US Midwest. Relay‐cropping soybean with winter camelina [Camelina sativa (L.) Crantz] is a means to sustainably intensify food and energy production while adding cropping system diversity. However, soybean yields in relay systems tend to be less than a full‐season monocrop. We hypothesized that improved soybean selection and seeding date for relay cropping could minimize this yield gap, thus increasing agricultural land use productivity. A 2‐year field study was conducted to determine the effects of soybean maturity and seeding date (SD) on winter camelina and soybean yields and land use productivity. Three soybean genotypes differing in maturity (MG) were relayed into winter camelina at rosette (SD1), bolting (SD2), and first flowering (SD3) growth stages. The soybean MGs were MG0.2, MG1.1, and MG1.7 representing early, standard, and late maturity, respectively, for the study region. The MG1.1 sown at SD2 was grown as sole crop check using conventional practices (CP). Results demonstrated that SD3 decreased camelina seed yield compared with SD1 and SD2. Soybean yield in the relay system was greatest for the MG1.7 genotype, and averaged across SD1 and SD2, was just 11.6% less than the sole crop CP check. Relaying soybean MG1.7 at SD2 produced 43% greater total (camelina +soybean) oil yield and greatly improved land use efficiency compared with CP. Appropriate soybean genotype selection can enhance winter camelina–soybean relay system productivity and land use efficiency.