Welsh Onion Plants Research Articles

Identifying and Controlling Anthracnose Caused by Colletotrichum Taxa of Welsh Onion in Sanxing, Taiwan.

Leaves of Welsh onion (Allium fistulosum) are subject to various fungal diseases such as anthracnose (Colletotrichum species) and Stemphylium leaf blight (Stemphylium vesicarium). These diseases are the main biotic limitations to Welsh onion production in northern Taiwan. From 2018 to 2020, anthracnose symptoms were observed throughout Welsh onion fields in northern Taiwan, mainly the Sanxing area. In total, 33 strains of Colletotrichum species were isolated from diseased leaves, and major causative agents were identified based on a multilocus phylogenetic analysis using four genomic regions (act, tub2, gapdh, and internal transcribed spacer). Based on this phylogeny, Colletotrichum species causing anthracnose of Welsh onion were identified as C. spaethianum (C. spaethianum species complex) and C. circinans (C. dematium species complex) in the Sanxing area, northern Taiwan. To determine and compare the pathogenicity of each species, representative fungal strains of each species were inoculated on the cultivar 'Siao-Lyu' by spraying spore suspension onto the leaf surface. Welsh onion plants were susceptible to both species, but disease incidence and severity were higher in C. spaethianum. In total, 31 fungicides were tested to determine their efficacy in reducing mycelial growth and conidial germination of representative strains of C. spaethianum and C. circinans under laboratory conditions. Five fungicides-fluazinam, metiram, mancozeb, thiram, and dithianon-effectively reduced mycelial growth and spore germination in both C. spaethianum and C. circinans. In contrast, difenoconazole and trifloxystrobin + tebuconazole, which are commonly used in Welsh onion production in northern Taiwan, mainly the Sanxing area, were ineffective. These results serve as valuable insights for growers, enabling them to identify and address the emergence of anthracnose caused by C. spaethianum and C. circinans of Welsh onion, employing fungicides with diverse modes of action. The findings of this study support sustainable management of anthracnose in Sanxing, northern Taiwan, although further field tests of the fungicides are warranted.

Solusi Recycle Sampah Organik dan Anorganik bagi Keluarga di Perumahan Taman Dramaga Permai 2 Bogor

Households are one of the contributors to organic and inorganic waste. Generally, the family needs to manage waste independently. The concept of waste recycling can be applied at the household level. The aim of waste management in the Dosen Mengabdi Reguler 2022 was to provide alternative solutions for processing organic and inorganic waste in the household based on the recycling concept. The activities were carried out from July‒November 2022 in one of the villages around the IPB campus locations, namely the Taman Darmaga Permai 2, Cihideung Ilir, Ciampea, Bogor. The core activities consist of discussions and demonstrations about compost, coenzymes, re-growing vegetable plants, and the culture of mung bean sprouts from Vima 1 and Vimil 1 varieties. About 42.9% of the 14 participants sorted household waste, and 28.6% managed waste. Compost from organic waste was harvested within one month after the process, while coenzymes were harvested after three months. Ecoenzymes were attractive to all participants as a solution for processing waste. About 50% of participants favor growing vegetables and 21.4% re-grow vegetable waste. Katuk and Welsh onion plants have 100% growth and 90% survival rates. All participants had never sprouted mung bean seeds. The sprouts can be harvested 1 to 3 days after sowing as needed. The Vima 1 mung bean variety has a sweet sprout taste and produces 657.9 g of sprouts from 100 g of seeds, while the Vimil 1 taste is slightly astringent with a lower sprout production of 543.8 g.

Diversity and Biocontrol Potential of Endophytic Fungi and Bacteria Associated with Healthy Welsh Onion Leaves in Taiwan.

Foliar diseases caused by Stemphylium and Colletotrichum species are among the major biotic factors limiting Welsh onion production in Taiwan. Owing to concerns about the environment and the development of pathogen resistance to existing fungicides, biological control using endophytes is emerging as an eco-friendly alternative to chemical control. The aim of the present study was to isolate endophytes from healthy Welsh onion leaves and investigate their antagonistic potential against the major phytopathogenic fungi associated with Welsh onion plants in Taiwan. A total of 109 bacterial and 31 fungal strains were isolated from healthy Welsh onion leaves and assigned to 16 bacterial and nine fungal genera using morphological and molecular characterization based on DNA sequence data obtained from nuclear internal transcribed spacer (nrITS) (fungi) and 16S rRNA (bacteria). Evaluation of these endophytic isolates for biocontrol activity against leaf blight pathogens Colletotrichum spaethianum strain SX15-2 and Stemphylium vesicarium strain SX20-2 by dual culture assay and greenhouse experiments resulted in the identification of two bacterial isolates (GFB08 and LFB28) and two fungal isolates (GFF06 and GFF08) as promising antagonists to leaf blight pathogens. Among the four selected isolates, Bacillus strain GFB08 exhibited the highest disease control in the greenhouse study. Therefore, Bacillus strain GFB08 was further evaluated to understand the mechanism underlying its biocontrol efficacy. A phylogenetic analysis based on six genes identified Bacillus strain GFB08 as B. velezensis. The presence of antimicrobial peptide genes (baer, bamC, bmyB, dfnA, fenD, ituC, mlna, and srfAA) and the secretion of several cell wall degrading enzymes (CWDEs), including cellulase and protease, confirmed the antifungal nature of B. velezensis strain GFB08. Leaf blight disease suppression by preventive and curative assays indicated that B. velezensis strain GFB08 has preventive efficacy on C. spaethianum strain SX15-2 and both preventive and curative efficacy on S. vesicarium strain SX20-2. Overall, the current study revealed that healthy Welsh onion leaves harbour diverse bacterial and fungal endophytes, among which the endophytic bacterial strain, B. velezensis strain GFB08, could potentially be used as a biocontrol agent to manage the leaf blight diseases of Welsh onion in Taiwan.

Geographic Distribution and Seasonal Composition of Reproductive Types of Onion Thrips, <i>Thrips tabaci</i> Lindeman in Kyoto Prefecture

The relative abundance of the reproductive types of Thrips tabaci Lindeman was occasionally surveyed by collecting female adults from the foliage of commercially grown Welsh onions, onions, and cabbages at various locations in Kyoto Prefecture between 2016 and 2018. Arrhenotokous females were found at 39 of the 46 surveyed sites and coexisted with thelytokous females at 26 sites, of which the arrhenotokous composition was higher than that of thelytokous at 19 sites. The arrhenotokous type was dominant in Kyoto City and Kumiyama Town, and thelytokous females were found to be dominant in the areas north of Fukuchiyama City. In cabbage, only arrhenotokous females were observed. The seasonal composition of T. tabaci reproductive types was additionally surveyed in Welsh onion plants grown in greenhouses in Kameoka City, Kyoto Prefecture, between November 2016 and June 2019. Thelytokous females were dominant between November 2016 and March 2017 and arrhenotokous females dominated between April 2017 and March 2018, except for January 2018. After May 2018, the thelytokous type dominated again.

High nitrogen concentration alter microbial community in Allium fistulosum rhizosphere.

Welsh onion (Allium fistulosum L.) constitutes an important plant species cultivated in China due the benefits and applications in different areas. Moreover, nitrogen is an essential nutrient during the growth and development of plant. Here, we present the effects of nitrogen on soil microbiome in welsh onion plants. We used High-throughput sequencing analysis to determine the diversity and abundances of microbes associated to soil rhizosphere in welsh onion under the influence of nitrogen application. Nitrogen application significantly influenced in the diversity of fungal community. The relative abundance of Orbiliomycetes increased with the nitrogen concentration. Nitrogen application did not affect the diversity of bacterial community, whereas the relative abundance of Acidobacteria_Gp2, Verrucomicrobiae and Sphingobacteriia decreased with the nitrogen condition. In this work, we introduced evidences of the effect of nitrogen fertilization on microbial community in welsh onion rhizosphere, and the change of microbial community may interfere the growth and development of welsh onion.

The effect of polimag S fertilizer on the macronutrient content of the edible parts of three welsh onion (Allium fistulosum L.) cultivars

Welsh onions are characterized by a relatively high storage potential, high nutritional value and mild flavor, which contribute to their growing popularity among consumers. The aim of this study was to determine the effect of Polimag S fertilizer applied at two doses on the macronutrient content of edible parts of three Welsh onion cultivars. A two-factorial field experiment was performed in a randomized block design with three replications. It was set up in the Experimental Garden of the University of Warmia and Mazury in Olsztyn, and conduccted in 2010-2011. The experimental factors were: (1) Welsh onion cultivars Long White Ishikura, Parade and Performer, grown from seedlings for bunch harvest, and (2) the application of mixed fertilizer, Polimag S, at two doses of 0.072 kg m-2 and 0.144 kg m-2. The seedlings were grown in a greenhouse, where each year seeds were sown in boxes (50 cm x 30 cm), between 14 and 20 March, to grow seedlings. At the two- or three-leaf stage, they were planted out in a field between 17 and 26 April. Forty-two seedlings were planted on a plot, at the 20 cm x 30 cm spacing. Polimag S, applied as a supplemental fertilizer at two different doses, was mixed with soil immediately before the transplanting of seedlings. A single harvest was carried out manually. Marketable yield consisted of healthy Welsh onion plants, with thickened leaf-bases of more than 1 cm in diameter, free from diseases, pests and mechanical damage. The chemical composition of Welsh onion plants was evaluated immediately after harvest. The concentrations of macronutrients (total N, P, K, Mg, Ca, S) were determined in edible parts of Welsh onion plants. Statistical analysis revealed no significant effect of a cultivar on the macronutrient content of whole Welsh onion plants, scapes and leaves. Leaves were characterized by the highest macronutrient concentrations. Polimag S at a 50% dose contributed to a significant increase in the total nitrogen and phosphorus content of whole plants. Wide Ca:Mg, Ca:P, K:Mg and K:(Mg+Ca) ratios were noted in whole Welsh onion plants.

The Yield and Winter Hardiness of Selected Welsh Onion (Allium fistolosum L.) Cultivars Grown in Soil Fertilized with Polimag® S

Welsh onion (Allium fistulosum L.) is grown in Olsztyn (NE Poland) on an area of 4.0 ha. The habitat conditions in the Warmia region are conducive to growing new Welsh onion varieties as annual crops for selective harvesting. A two-factorial field experiment was conducted in a randomized block design with there replications in the Experimental Garden of the University of Warmia and Mazury in Olsztyn in 2009 - 2012. Seeds of three Welsh onion cultivars, Long White Ishikura, Parade and Performer were used. The effects of the following experimental factors were determined: Welsh onion cultivars Long White Ishikura, Parade and Performer grown from seedlings; the application of a mixed fertilizer, Polimag® S, at two rates of 0.72 t ha-2and 1.44 t ha-2, referred to as 50% and 100% rates. The studied Welsh onion cultivars did not differ significantly with respect to yield, although an increase was noted in the total yield of Welsh onion leaves cv. Performer. Polimag® S applied at a 50% and 100% rate significantly increased the total yield of Welsh onion leaves. However, fertilization rate should not be increased above the 50% level since Welsh onion bulb yields were comparable at 50% and 100% rates of Polimag® S. During three consecutive growing seasons, Welsh onion plants cv. Long White Ishikura were characterized by the highest winter hardiness.

Kinetics of Root Ion Absorption Affected by Environmental Factors and Transpiration II. Environmental Effects and a Concentration-Dependent Model

Welsh onion plants (Allium fistulosum L.cv. Koutou) were grown under the different conditions of root zone temperature and dissolved O2 concentration. The absorptive functions in intact roots were analyzed by evaluating rates of water absorption, ion absorption, respiration and ion concentration in xylem sap simultaneously by applying the measurement system newly developed in the precedent study. The root water and ion absorption were activated with increase in root zone temperature, and the long term treatment with the high temperature and the low dissolved O2 concentration in the root zone significantly depressed water and ion absorption, while ion concentration in the xylem sap was not significantly affected by the root zone temperature. These suggest that the temperature dependence observed in root ion absorption is brought mainly through the temperature dependence of water absorption. A concentration-dependent model based on the theory of enzyme kinetics was applicable to kinetics of the root ion absorption responding to the root zone environment. The effects of root zone temperature and ion concentration on the root ion absorption were represented well by the concentration-dependent model which involves two parameters sensitive to changes in conditions of plants and the environment.

Fumonisin B1production byFusarium proliferatumstrains isolated fromAllium fistulosumplants and seeds in Japan

To test the fumonisin B(1)-producing ability of Fusarium proliferatum strains isolated from Welsh onion (Allium fistulosum) plants and seeds of commercial cultivars in Japan and to examine the applicability of PCR-based assays to discriminate between fumonisin B(1)-producing and nonproducing isolates. Fumonisin B(1) levels in 20 Fusarium isolates obtained from Welsh onion plants and seeds of seven commercial cultivars were determined by HPLC. Thirteen of the 20 isolates produced fumonisin B(1). PCR assay with FUM1 gene-specific primers amplified a DNA fragment (700 bp) only from fumonisin-producing isolates. Fusarium proliferatum isolates that can produce fumonisin B(1) were often associated with wilted Welsh onion plants and seeds of some commercial cultivars. The PCR assay with FUM1 gene-specific primers has the potential to discriminate between fumonisin B(1)-producing and nonproducing isolates. This study revealed that F. proliferatum producing fumonisin B(1) is associated with Welsh onion plants and that commercial cultivar seeds may be contaminated with the fungus. PCR amplification of FUM1 gene can be a useful tool for the rapid identification of fumonisin B(1)-producing F. proliferatum isolates.

Waterlogging tolerance of Welsh onion (Allium fistulosum L.) enhanced by exogenous spermidine and spermine

Soil flooding is a seasonal factor that negatively affects plant performance and crop yields. In order to investigate the effects of spermidine (Spd) and spermine (Spm) on the waterlogging stress, it was checked that the content of relative water content (RWC), proline, chlorophyll and malondialdehyde (MDA), net photosynthesis, the rate of hydrogen peroxide (H(2)O(2)) and superoxide radicals (O(2)(-)) generation and the antioxidant enzyme activities of superoxide dismutase (SOD) (EC 1.15.1.1), catalase (CAT) (EC 1.11.1.6), ascorbate peroxidase (APX) (EC 1.11.1.11) and glutathione reductase (GR) (EC 1.6.4.2) in Welsh onion (Allium fistulosum L) plants. Pretreatment with 2 mM of Spd and Spm effectively maintained the balance of water content in plant leaves and roots under flooding stress. In addition, the data indicate that the protective role of proline should be considered minimal, as its accumulation was found to be inversely correlated with tolerance to stress; it also significantly retarded the loss of chlorophyll, enhanced photosynthesis, decreased the rate of O(2)(-) generation and H(2)O(2) content, and prevented flooding-induced lipid peroxidation. Spd and Spm helped to maintain antioxidant enzyme activities under flooding; however, APX activity was found to increase slightly in response to Spm. The antioxidant system, an important component of the water-stress-protective mechanism, can be changed by PAs, which are able to moderate the radical scavenging system and to lessen in this way the oxidative stress. The results suggest that pretreatment with Spd and Spm prevents oxidative damage, and the protective effect of Spd was found to be greater than that of Spm.

Genetic diversity and pathogenicity of Fusarium oxysporum isolated from wilted Welsh onion in Japan

Thirty isolates of Fusarium oxysporum from wilted Welsh onion plants were examined for their diversity in nucleotide sequences of the ribosomal DNA (rDNA) intergenic spacer (IGS) region and for pathogenicity with regard to five Welsh onion cultivars. Phylogenetic analysis based on the IGS sequences revealed polyphyletic origins of the isolates and a relationship between phylogeny and pathogenicity; low virulence isolates differed genetically from those with high and moderate virulence. Mating type analysis revealed that all F. oxysporum isolates were MAT1-1 idiomorphs, suggesting that the pathogens may be clonal in the fields examined.

Exogenous putrescine reduces flooding-induced oxidative damage by increasing the antioxidant properties of Welsh onion

Soil flooding is an environmental factor of seasonal occurrence that negatively affects plant performance. Polyamines play an important role in the plant response to adverse environmental conditions including flooding stress. The objective of the present study was to assess the comparative oxidative damage to Welsh onion plants caused by flooding stress and to examine the role of putrescine (Put) in this response. Welsh onion plants were treated with Put prior to 10 d flooding. A positive effect was observed when treating with 2 mM Put. Exogenous application of Put resulted in alleviation of flooding-induced reduced relative water content, plant growth and chlorophyll fluorescence. Superoxide radical (O 2 −) and hydrogen peroxide (H 2O 2) contents were also reduced in stressed plants after Put pre-treatment and thereby the oxidative stress in plant cells was lowered. The antioxidant system, as an important component of the waterlogging-stress-protective mechanism including α,α-diphenyl-β-picrylhydrazyl (DPPH)-radical scavenging activity, superoxide anion radical scavenging, metal chelating activities and reducing power, can be upgraded by Put, which is therefore able to moderate the radical scavenging system and to lessen oxidative stress. Under non-flooding conditions, the anti-oxidative activity of Welsh onion was regulated and elevated by Put pre-treatment. These results suggest that Put confers flooding tolerance to Welsh onion, probably through inducing the activities of various anti-oxidative systems. Thus, exogenous 2 mM per plant of Put 24 h prior to flooding could alleviate flooding stress.

Changes in antioxidant properties and their relationship to paclobutrazol‐ induced flooding tolerance in Welsh onion

AbstractBACKGROUND: Flooding is an important factor affecting Welsh onion production, because under such stress the production and quenching of reactive oxygen species (ROS) in plants will fail to be kept in a balanced state. The purpose of this study was to examine the effect of paclobutrazol (PBZ) on the growth and development of Welsh onion plants (Allium fistulosum L.), particularly to evaluate changes in antioxidant properties.RESULTS: Welsh onion plants were treated with 0 and 2 ppm per plant of PBZ, subsequently subjected to non‐flooding and flooding‐stress conditions for 0, 1, 5, 9 and 13 days, followed by a 4‐day drainage period. Flooding stress was judged by any decrease in biomass production and chlorophyll content. The results indicated that PBZ applied to plants was able to protect Welsh onion from flooding stress. The increased levels of antioxidant activity in different systems, including α,α‐diphenyl‐β‐picrylhydrazyl (DPPH)‐radical scavenging activity, superoxide anion radical scavenging, metal chelating activities and reducing power observed on flooding, afforded the Welsh onion improved flooding tolerance. Under non‐flooding conditions, the antioxidative activity of Welsh onion was regulated and elevated by PBZ pretreatment.CONCLUSION: It seems that the PBZ‐induced flooding tolerance of Welsh onion is mediated through increased activities of various antioxidative systems. Thus, pre‐applying 2 ppm per plant of PBZ 24 h prior to flooding could mitigate flooding stress. Copyright © 2008 Society of Chemical Industry

Protective role of bioregulator stifun under the negative effect of cadmium

The effect of stifun on wheat, Welsh onion, and corn plants under the effect of cadmium is investigated. The protective effect of this bioregulator manifested itself in preventing inhibition of growth, stabilizing mitotic phases, and reducing the level of chromosomal aberrations. The results of histochemical investigations permit the assumption that growth regulators can reduce the uptake of cadmium ions into plant tissues.

Uptake of Exogenous L-Ascorbic Acid by Lettuce and Leaf Onion Roots through Immersion

The effects of administering a high concentration of sodium ascorbate (NaAs) and L-ascorbic acid to leaf lettuce roots for 16 hr prior to harvest on the foliar L-ascorbic acid (AsA) content were studied. Dipping roots in 2000 ppm NaAs or AsA caused the outer leaves of the plant to wilt. The foliar AsA content in the AsA treatments was remarkably greater than that in the NaAs treatments and was 4.5, 6.1 and 7.7 times greater in the 1000, 1500 and 2000 ppm treatments, respectively, in comparison with that of the control (21.5 mg/100 g FW).Immersing roots of Welsh onions and leaf lettuce for 12 hr in 1500 ppm AsA solution gradually reduced the rate of water absorption. Consequently, the fresh weight of plants treated for 12 hr decreased about 10%. However, this decrease was recovered by transferring the roots to disillued water at 15°C for 6 hr in the dark. The foliar AsA contents in the welsh onion and lettuce plants were 112.9 and 94.3 mg/100 g FW, respectively. The foliar AsA content in both plants increased linearly with time, while the increase of dehydro-ascorbic acid level was negligible. The results indicate that the AsA treatment was more effective than the NaAs treatment for AsA-rich leafy vegetables. Furthermore, we can ensure the approximate foliar AsA content after immersing the roots for a certain time period under a specific condition because the uptake rate per hr was almost constant.