Barbarea Research Articles

Functional value of biologically active honey components

The article shows data on diastase activity and pollen analysis of honey from apiaries in the south of the Tyumen region. The research was conducted in the period 2017-2022. Honey maturation is a complex biochemical process in which biologically active substances, which include lysozyme and amylase, formed in the digestive glands of worker bees, play a significant role. They provide honey with high biological properties. Lysozyme is an antibacterial enzyme produced in the body of animals that prevents the penetration of microbes, viruses and fungi into honey. Amylase - breaks down the complex carbohydrates of nectar, converting them into glucose and fructose. These enzymes in bees are formed to a greater extent in the maxillary and pharyngeal glands. These are the high biological properties of honey. During the work on the pollen analysis of honey, it was revealed that the honey of apiaries in the south of the Tyumen region is polyphlorous, since pollen grains of various honey plants were identified in the studied honey samples, which included linden, sweet clover, rapeseed, esparcet, winter cress, dandelion, clover, sow thistle. The results of diastase activity determination showed that in experimental honey samples the diastase number was in the range from 8.0 to 23.8%, high diastase activity characterizes the quality of honey, since it, undergoing prolonged biochemical treatment, is more saturated with enzymes and biologically active substances. According to the research results, honey with high diastase activity includes samples from apiaries of Yalutorovsky and Isetsky districts.

Trait-based cropping of brassicaceous plants: Effects on ecosystem services and crop yield

Diversification of agroecosystems through mixed cropping can facilitate multiple ecosystem services that may improve yields. Intercrops may repel pests and nourish natural enemies while trap crops lure pests away from target crops. A small-scale agricultural field experiment was conducted in 2018 and 2020 in Finland to study how intercropping of brassicaceous plants and faba bean (Vicia faba) affects yield and quality of a target crop (white cabbage (Brassica oleracea var. capitata)), herbivory on the target crop, and effects of the insect communities linked to the observations. The study was conducted with five different plot arrangements in each year. Broccoli (Brassica oleracea var. italica) or turnip (Brassica rapa var. rapa) were located at the perimeters of 6 × 6 m plots as trap crops. They were planted either alone or with yellow rocket (Barbarea sp). Faba bean was planted as an intercrop in the most complex designs. Cabbage head fresh weight was greatest in the most complex plot type, which included cabbage, broccoli, yellow rocket and faba bean and the head weight was significantly greater than in the cabbage monocrop or the plots with a broccoli-only trap crop. Turnip was included in the experiment in 2020 and efficiently attracted flea beetles and pollen beetles. In 2020, the turnip trap crop alone and the most complicated designs with broccoli or turnip combined with yellow rocket and faba bean significantly reduced P. xylostella abundance in the middle of the plot. Possibilities to use trait-based cropping systems in white cabbage production are discussed.

Assemblage of Ceutorhynchinae Weevils Associated With Brassicaceae in Quebec (Canada) Agroecosystems.

Ceutorhynchinae Gistel (Coleoptera: Curculionidae) are a highly diverse phytophagous group of weevils in which the most species rich genus, Ceutorhynchus Germar (Coleoptera: Curculionidae), is mainly associated with Brassicaceae. Some Ceutorhynchinae, such as the invasive cabbage seedpod weevil (CSW), Ceutorhynchus obstrictus (Marsham), are important pests of cultivated Brassicaceae, and others are natural enemies of weeds and potential biological control agents. This study aims to characterize Ceutorhynchinae assemblages in canola growing regions of Quebec. Ceutorhynchinae were sampled in areas adjacent to canola fields or other crops in six administrative regions of Quebec during the summers of 2019 and 2020. A total of 25 Ceutorhynchinae species were collected and identified. Canonical analysis and multivariate regression tree analysis revealed that the assemblage of Ceutorhynchinae varied regionally and was either dominated by the invasive canola pest CSW or by the native weevil Ceutorhynchus neglectus Blatchley. Our results also highlighted new biological associations between weevils and Brassicaceae like the CSW with the yellow rocket, Barbarea vulgaris R. Br., native Ceutorhynchus pauxillus Dietz with common pepper grass, Lepidium densiflorum, and native Ceutorhynchus semirufus LeConte with Pennsylvania bittercress, Cardamine pensylvanica Muhl. This study also provides a useful tool to find new biological control agents against Brassicaceae weeds and to monitor the abundance and diversity of this taxon and provide baseline data to assess future impacts of exotic parasitoids of CSW on native weevils.

Prospects for habitat management to suppress vegetable pests in Australia

AbstractHabitat management is an ecologically based approach to suppress pest densities, utilising properties of non‐crop vegetation to improve the impact of natural enemies or to directly affect pest behaviour. Research in this approach has escalated dramatically this century, extending to uptake in some crops, but adoption in Australia has been lower than overseas. Here, we address the need of the Australian vegetable sector to reduce reliance on insecticides by assessing the scope for habitat management in brassica (Brassicaceae), lettuce (Lactuca sativa) (Asteraceae), capsicum (Capsicum annuum) (Solanaceae), carrot (Daucus carota) (Apiaceae), French bean (Phaseolus vulgaris) (Fabaceae) and sweetcorn (Zea mays) (Poaceae) crops. Each crop is of major economic importance, and together, they represent contrasting botanical families and production systems that are associated with different arthropod complexes. We review studies of habitat management that are based on provision of shelter, nectar, alternative prey or pollen for natural enemies (top‐down effects) or changing pest behaviour (bottom‐up effects) through intercropping or trap crops. The likely utility of these approaches under Australian conditions is assessed, and recommendations are made to promote adoption and for adaptive research. Nectar‐ and pollen‐providing plants, such as alyssum (Lobularia maritima) (Brassicaceae), offer strong potential to promote natural enemies in multiple crops whilst trap crops, especially yellow rocket (Barbarea vulgaris) (Brassicaceae), have more targeted utility against diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), the most serious pest of brassicas. Opportunities for intercrops and banker plant species are also identified. Our recommendations serve as a platform for researchers and for farmer‐led studies to help realise the full potential of habitat management approaches in Australian vegetable production systems.

Cruciferous Weeds Do Not Act as Major Reservoirs of Inoculum for Black Rot Outbreaks in New York State.

Cruciferous weeds have been shown to harbor diverse Xanthomonas campestris pathovars, including the agronomically damaging black rot of cabbage pathogen, X. campestris pv. campestris. However, the importance of weeds as inoculum sources for X. campestris pv. campestris outbreaks in New York remains unknown. To determine if cruciferous weeds act as primary reservoirs for X. campestris pv. campestris, fields that were rotating between cabbage or had severe black rot outbreaks were chosen for evaluation. Over a consecutive 3-year period, 148 cruciferous and noncruciferous weed samples were collected at 34 unique sites located across five New York counties. Of the 148 weed samples analyzed, 48 X. campestris isolates were identified, with a subset characterized using multilocus sequence analysis. All X. campestris isolates originated from weeds belonging to the Brassicaceae family, with predominant weed hosts being shepherd's purse (Capsella bursa-pastoris), wild mustard (Sinapis arvensis), yellow rocket (Barbarea vulgaris), and pennycress (Thlaspi arvense). Identifying pathogenic X. campestris weed isolates was rare, with only eight isolates causing brown necrotic leaf spots or typical V-shaped lesions on cabbage. There was no evidence of cabbage-infecting weed isolates persisting in an infected field by overwintering in weed hosts; however, similar cabbage and weed X. campestris haplotypes were identified in the same field during an active black rot outbreak. X. campestris weed isolates are genetically diverse both within and between fields, but our findings indicate that X. campestris weed isolates do not appear to act as primary sources of inoculum for B. oleracea fields in New York.

Current Knowledge and Challenges on the Development of a Dietary Glucosinolate Database in the United States.

Glucosinolates (GSLs) are a group of cancer chemopreventive sulfur-containing compounds found primarily in Brassica vegetables. The goals of this study were to summarize the current knowledge and discuss the challenges of developing a dietary GSL database for US foods. A systematic literature search was conducted for the period 1980-2020. Thirty articles were found to meet all inclusion and exclusion criteria; 27 GSLs were reported in 16 different vegetables. GSLs identified and quantified ranged from 3 for winter cress to 16 for cabbage. In general, the experimental designs of these 30 studies did not fully consider the factors related to the data quality. Enormous variations of GSLs are observed between different vegetables and in the same vegetables. In conclusion, the studies on GSLs in commonly consumed vegetables are still limited, and some data may be outdated. Currently available data are not sufficient to develop a valid GSL database in the United States.

Host plants as reservoirs of the main oil-producing cabbage crops pests in the eastern forest-steppe of Ukraine

Considering the geographical position of Ukraine, which is Such biotic factor as the vegetation distribution, which is the forage base for most insects, influences their spreading greatly. This connection is strongly expressed among the harmful herbivorous insects. The presence and distribution of the plants which are cultivated or used by humans and on which the insects are fed is certainly the first and basic condition for the emergence of a zone or a breeding ground of harmfulness. The presence of the most preferred by the insects fodder plants often leads to the formation of a zone or a center of the greatest damage (in the presence of other favorable conditions for the existence and reproduction of the pest). In the course of the researches concerning the identification of the host plants as reservoirs of the main oil producing cabbage crops pests which have been conducted in 2011–2014 in the communities (meadows, roadsides of highways and field perimeters) of the Kharkiv district of the Kharkiv region it has been found out the host plants as reservoirs for the dominant pests of the oil producing cabbage crops were dandelion, caustic buttercup, field mustard, hedge mustard, tansy mustard, yellow rocket and field shepherd’s purse. The largest number of species of the host plants as reservoirs was found on the roadsides of highways and along the field perimeters (6 species) and on the meadows (2 species).The cruciferous fleas, rape blossom beetles and cruciferous bugs visited such crops as field mustard, hedge mustard and yellow rocket most often. Field shepherd’s purse was the least significant among the identified host plants as reservoirs. Only a small amount of the cabbage fleas fed on this crop. This fact can be explained by the small white flowers that do not attract the rape blossom beetles and rose chafers as well as by a ground flat leaf rosette, which is always covered with dust and prevents the fleas and bugs from feeding.

Phytoremediation as a method for cleaning sludge beds of biological treatment plants from heavy metals

The aim of this study is to select a phytoremediation plant for cleaning sludge beds of biological treatment plants from heavy metals. The study was conducted on sludge beds of biological treatment facilities of Veliky Novgorod with a sludge retention time of 1 year and 15 years. It is established that the forms of metals in the sludges and wastewater sludge depend on the nature of the metal. Manganese (II) predominantly binds to compounds that make up sludge and wastewater sludge by the ion exchange mechanism, copper (II) – by the complex formation mechanism, zinc (II) – is codeposited with calcium and magnesium carbonates, manganese (IV) and iron hydroxides (III). Six selected plants were analyzed (bedstraw, cow vetch, field daisy, silverweed cinquefoil, base vervain, winter cress), those growing on sludge beds with a sludge retention time of 15 years, for the content of copper (II), zinc (II) and manganese (II) in different parts of plants. The phytoremediation plant was selected according to the indicators of the coefficient of biological accumulation (coefficient of biological accumulation) and translocation factor. It has been established that the bedstraw can be called a universal phytoremediation plant, in the absence of significant sludge contamination with copper (II), it is most preferable to use base vervain. Selected phytoremediation plants can be used for artificial planting on sludge beds in order to further use these beds as fertile lands.

Pests of oil producing cabbage crops in the Eastern Forest-Steppe of Ukraine

Today the major oil producing crops from the Brassicaceae family in the world and Ukraine are winter rape (Brassica napus oleifera bienis D. C.) and spring rape (Brassica napus oleifera annua Metzg.). At present the acreage of these crops in the world is over 40 million hectares, and in Ukraine there are more than 1 million hectares. Less common crops are white mustard (Sinapis alba L.) and Chinese mustard (Brassica juncea Gzem.). The world acreage under the mustard crops is about 3,0 million hectares (in Ukraine there are about 100 thousand hectares). Other oil producing crops from the cabbage family such as spring winter cress (Brassica campestris L.), winter rape (Brassica rapa oleifera DC), winter false flax (Camelina sativa subsp. pilosa N. Zinge), spring false flax (Camelina sativa var. Glabrata (DC.), oily radish (Raphanus sativus L. var. oleiformis Pers) and black mustard (Brassica nigra (L.) Koch) occupy only a small area, while the Abyssinian mustard (Crambe abyssinica Hosts. ex. RE Fr.) is not grown in our country at all. It is impossible to obtain high and stable yields of all agricultural crops without protection of plants from the harmful insects. The losses of the crops due to the pests are huge, especially during the mass reproduction of the insects. The entomocomplex of agroceonoses of oil producing cabbage crops is extremely rich and contains several hundred species. As a result of their vital functions more than 50% of the crops can be lost and as far as 25-55% growth increase in the yield can be reached due to the pollinating insects. Despite the short-term existence of agroceonoses of spring oil producing cabbage crops (90-120 days) their entomofauna is characterised by a considerable diversity of species composition. During the vegetation periods in 2007–2019 in the fields of the Educational, Research and Production Centre “Research Field” of Kharkiv National Agrarian University named after V.V. Dokuchaiev and the State Enterprise “Research Farm “Elitne” of the Institute of Plant Growing named after V.Ya. Yuriev of the National Academy of Agrarian Sciences of Ukraine we have found 54 species of specialised and multi-faceted pests of oil producing cabbage crops that belong to eight lines and 22 families. Among them 29 species are the specialised pests and 25 are multi-faceted ones. The frequency of the pest species occurrence on the crops is the following: eight species (15%) populate the crops on a mass scale, six species (11%) are moderately spread, and 40 species (74%) have a low population density. The cabbage bug, mustard bug, ground cabbage aphid, rose chafer, rape blossom beetle, mesographe flea beetle, flea beetle and diamond black moth belong to the species that populate the crops on a mass scale. Among them four species belong to the Coleoptera line, two species belong to the Hemiptera line, one species belong to the Homoptera line and one species belong to the Lepidoptera line. The representatives of the Coleoptera line dominate; their proportion in the entomological community structure is 48% (26 species). The economic importance of these pests is not the same and greatly depends on the population density and phenophase of the crop development as well as on weather conditions.

Evaluation of Trap Cropping for Control of Diamondback Moth (Lepidoptera: Plutellidae) in a Broccoli Production System.

Trap cropping, in which a trap crop is planted near a cash crop, has been used successfully for reducing pest damage in some agricultural systems. We used a meta-analysis of extensive data on two trap cropping systems, diamondback moth, Plutella xylostella (Linnaeus), exploiting cabbage and Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) exploiting maize, to show that oviposition preference for, and high larval mortality on trap crops are important indicators of effectiveness of trap cropping systems. We then evaluated Indian mustard (Brassica juncea var. juncea L. Czern.) (Capparidales: Brassicaceae) and yellow rocket (Barbarea vulgaris W. T. Aiton) (Brassicales: Brassicaceae) as trap crops for protecting broccoli (Brassica oleracea var. italica Plenck) (Capparidales: Brassicaceae) against diamondback moth in Yuma, AZ, using planting configurations compatible with current practices for commercial production and without use of insecticides. In oviposition choice tests, both yellow rocket and Indian mustard were highly preferred over broccoli in the field. Furthermore, the number of larvae and pupae was significantly lower on yellow rocket and Indian mustard compared to broccoli, indicating relatively high mortality on these trap crops. Nevertheless, during the fall and spring growing seasons, no significant differences in the number of individuals on broccoli or proportion of broccoli crowns infested at harvest occurred between plots with trap crops relative to plots exclusively planted to broccoli. Thus, with the plant density and planting patterns used and without use of insecticides, there was no evidence that trap cropping was effective for reducing diamondback moth infestation of broccoli.

Attraction of stink bugs to rocket traps with different combinations of wing and landing board color

Abstract The stink bugs, Halyomorpha halys and Riptortus pedestris, are two of the most economically important pests of leguminous crops and fruits in Korea. Here we present the results from a field monitoring test that evaluated the effect of variation in rocket trap type and color on stink bugs captures. We tested various types of rocket traps, along with wing combinations and landing boards of various colors. The test was run in soybean fields in Miryang, Korea. We developed a modified rocket trap intended to enhance the capture efficacy of stink bugs. We evaluated traps including (1) yellow rocket trap with a solar fan and blue LED lamp, (2) a yellow trap with solar fan but no light, (3) rocket traps with black, green, yellow, white, red, brown, and blue color stimuli, (4) different color combinations of trap wings, and (5) traps with a landing board were evaluated. Our results showed that yellow winged rocket traps with solar fans and blue LED lamps attracted significantly more stink bug species than other traps, in both soybean fields. Use of these improved traps such as a yellow trap with a solar fan and blue LED lamp, and a yellow trap with a solar fan would therefore enhance the monitoring and capture of stink bugs in diversified agro-ecological landscapes. The potential use of traps with a specific hue, combination of features, and modifications to monitor stink bugs accurately is discussed. Continuing improvements to traps to meet the demands of a changing pest landscape and agricultural mechanization are needed.

Trap Crops and Insectary Plants in the Order Brassicales

Abstract This paper reviews the most important cases of trap crops and insectary plants in the order Brassicales. Most trap crops in the order Brassicales target insects that are specialist in plants belonging to this order, such as the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), the pollen beetle, Meligethes aeneus Fabricius (Coleoptera: Nitidulidae), and flea beetles in the genera Phyllotreta and Psylliodes (Coleoptera: Chrysomelidae). In most cases, the mode of action of these trap crops is the preferential attraction of the insect pest for the trap crop located next to the main crop. With one exception, these trap crops in the order Brassicales have been used with brassicaceous crops. Insectary plants in the order Brassicales attract a wide variety of natural enemies, but most studies focus on their effect on aphidofagous hoverflies and parasitoids. The parasitoids benefiting from insectary plants in the order Brassicales target insects pests ranging from specialists, such as P. xylostella, to highly polyfagous, such as the stink bugs Euschistus conspersus Uhler and Thyanta pallidovirens Stål (Hemiptera: Pentatomidae). In the order Brassicales, the three most common trap crops are Indian mustard, Brassica juncea (L.) Czern, Chinese cabbage, Brassica rapa L., and yellow rocket, Barbarea vulgaris R. Br., while the three most common insectary plants are sweet alyssum, Lobularia maritima (L.) Desv., white mustard, Sinapis alba L, and B. vulgaris. Except for Tropaeolum majus L. (Tropaeolaceae) and Capparis decidua (Forssk.) Edgew. (Capparaceae), the tested trap crops and insectary plants in the order Brassicales belong to the family Brassicaceae.

Resistance and susceptibility to powdery mildew, root-knot nematode, and western flower thrips in two types of winter cress (Brassicaceae)

Two types of Barbarea vulgaris R. Br. (Brassicaceae) were tested to compare their resistance and susceptibility to powdery mildew, Erysiphe cruciferarum Opiz ex L. Junell (Erysiphales: Erysiphaceae), root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwoodi (Tylenchida: Heteroderidae), and western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae). In experiments conducted in the greenhouse, the percentage of plants showing powdery mildew symptoms ranged from 54.2 to 83.3% in P-type B. vulgaris plants and from 0 to 20.8% in G-type B. vulgaris plants. In plants infected by powdery mildew, the percentage of leaves affected was higher in P-type than in G-type plants, ranging from 11.8 to 21.1% in P-type plants, and from 0 to 0.36% in G-type plants. Infection by powdery mildew was more likely to occur on the leaves of largest diameter. Root galling showed that G- and P-type plants were equally attacked by root-knot nematode, but the multiplication rate of the nematode was 4.1–7.6 times higher in P-type than in G-type plants. Significantly more leaves per plant were damaged by western flower thrips in P-type (73.1–88.3% of leaves affected) than in G-type plants (2.1–2.9% of leaves affected). The total numbers of adult and immature thrips found per plant on P-type plants were, respectively, 29.9 and 2.5, while on G-type plants less than 0.3 adult and immature thrips were found per plant. This study indicates that G-type B. vulgaris could be a source of resistance to powdery mildew and western flower thrips.

Evaluation of an improved rocket traps, and baits combination for its attractiveness to hemipteran bugs in grass and soybean fields

Alydids and pentatomids are economic pests of leguminous crops and fruits in Korea. Direct impacts given by these phytophagous adult and nymphal by sucking on the pods, seeds and fruits can reduce germination potential of leguminous seeds, and yield poor nutritional quality. For monitoring of these bugs, various types of traps housing species-specific baiting with pheromones are widely practiced. However, a trap developed for one species has not been found to capture other species. Here, we developed a multi-species trapping device with some modification for enhancing capture efficacy of sympatric hemipteran bugs, called ‘rocket trap with solar fan’ pertaining to its shape. The trap with and without solar fan, and yellow, black, and white color stimuli were examined for the attractiveness of sympatric hemipteran bugs against conventional traps such as pyramid and fish-net traps. In addition, the attractiveness of single or mixed baits combination to sympatric hemipteran was also tested. Among the tested traps, yellow rocket trap with solar fan was found to attract significantly higher number of stink bug species. Major stink bugs, Riptortus pedestris, Halyomorpha halys, and Piezodorus hybneri were attracted to yellow rocket trap with solar fan baited with aggregation pheromone of H. halys in the fields. The yellow rocket trap baited with aggregation pheromones along with food and synergist was found more attractive to stink bugs. Results designate that yellow rocket trap with solar fan, and yellow rocket trap baited with mixed form of baits would have enhanced the monitoring and capturing sympatric hemipteran bugs in diversified agricultural landscapes.

Screening for Triterpenoid Saponins in Plants Using Hyphenated Analytical Platforms.

Recently the number of studies investigating triterpenoid saponins has drastically increased due to their diverse and potentially attractive biological activities. Currently the literature contains chemical structures of few hundreds of triterpenoid saponins of plant and animal origin. Triterpenoid saponins consist of a triterpene aglycone with one or more sugar moieties attached to it. However, due to similar physico-chemical properties, isolation and identification of a large diversity of triterpenoid saponins remain challenging. This study demonstrates a methodology to screen saponins using hyphenated analytical platforms, GC-MS, LC-MS/MS, and LC-SPE-NMR/MS, in the example of two different phenotypes of the model plant Barbarea vulgaris (winter cress), glabrous (G) and pubescent (P) type that are known to differ by their insect resistance. The proposed methodology allows for detailed comparison of saponin profiles from intact plant extracts as well as saponin aglycone profiles from hydrolysed samples. Continuously measured 1D proton NMR data during LC separation along with mass spectrometry data revealed significant differences, including contents of saponins, types of aglycones and numbers of sugar moieties attached to the aglycone. A total of 49 peaks were tentatively identified as saponins from both plants; they are derived from eight types of aglycones and with 2–5 sugar moieties. Identification of two previously known insect-deterrent saponins, hederagenin cellobioside and oleanolic acid cellobioside, demonstrated the applicability of the methodology for relatively rapid screening of bioactive compounds.

High level resistance to Pseudocercosporella capsellae offers new opportunities to deploy host resistance to effectively manage white leaf spot disease across major cruciferous crops

Field and controlled environment studies were undertaken to define the range and extent of available host resistances to Pseudocercosporella capsellae (white leaf spot) across diverse oilseed, forage and vegetable crucifers, including some wild and/or weedy species, and also within and/or derived from Brassica carinata. In each experiment, there was a wide range in host response from high resistance to high susceptibility as assessed by four disease parameters, viz. in the field for: (i) Area Under Disease Progress Curve (AUDPC) for percent leaves diseased with values ranging from 0 to 375.5; (ii) Percent Leaf Collapse Index (%LCI) for leaf collapse due to disease with values ranging from 0 to 23.0; and (iii), Percent Pod Area Disease Index (%PADI) for pod area affected with values ranging from 0 to 52.1; and (iv) under controlled environmental conditions for Percent Cotyledon Disease Index (%CDI) for cotyledon lesion size with values ranging from 0 to 27.5. At the Crawley field site, B. carinata ATC 94129 was the most resistant genotype with AUDPC = 1.2, followed by Crambe abyssinica (AUDPC 8.7), Eruca sativa Eruc-01 (AUDPC 19.3) and E. vesicaria Yellow rocket (AUDPC 19.4). B. carinata ATC 94129 and B. oleracea var. capitata had the least leaf collapse, with %LCI = 0.2. At the Shenton Park field site, 21 genotypes of B. carinata and B. oleracea var. acephala Tuscan kale showed total resistance, all with AUDPC values of 0. Of the B. napus genotypes carrying one or more B. carinata B genome introgressions, genotypes NC8 (AUDPC 23.0) and NC9-1 (AUDPC 26.2) were the most resistant. Genotypes as assessed on these disease criteria as having high level resistance generally showed no pod infection; in contrast to %PADI values up to 52 on the most susceptible genotypes. Under controlled environmental conditions, the most resistant genotype was B. carinata ATC 94129 with %CDI values of 0 and 0.2, respectively, across two experiments, along with B. napus genotypes Zhongyou 821 and Hyola 42, with a %CDI value of 0 in one of the two experiments. There was a high degree of correlation both within individual experiments across the different disease parameters and also between field and controlled environment experiments. Within both B. napus and B. juncea genotypes tested, the most resistant genotypes were from China, the most susceptible from India, with those from Australia intermediate.

Black rot-A devastating disease of crucifers: A review

Crucifers are popular temperate vegetables and occupy important place among vegetables in India as well as in the world. India is the second largest producer of crucifers in the world. These crops are affected by many diseases during the growing period which reduce the yield as well as the quality of the produce. Amongst all the diseases, black rot caused by Xanthomonas campestris pv. campestris (Pam.) Dowson is the most destructive one causing heavy losses. The disease affects primarily above ground parts of the plant at any stage of growth and causes high losses, in yield and quality especially in tropical and subtropical regions during the rainy season. All vegetables in the cruciferous family, including broccoli, brussels sprouts, cabbage, cauliflower, chinese cabbage, kale, mustard, radish, rutabaga, and turnip are susceptible to black rot. Many cruciferous weeds such as Shepherd's Purse, wild mustard, and yellow rocket are also known to be hosts of this pathogen. The pathogen is seed borne and also survives in the infected plant debris as well as cruciferous weed hosts. The disease can be managed through cultural practices, resistant hosts, seed treatment with hot water and antibiotics, fungicides, biological control as well as chemical control methods.

The interrelation between natural enemies of the invasive plant Lepidium draba L., established in a natural pasture in Eastern Romania.

Lepidium draba L. (family Brasicaceae), originally from Europe, is a problematic plant in many agricultural ecosystems in Romania. A literature survey revealed that 196 phytophagous organisms are associated with L. draba, and 80 of them were found during field surveys. In Romania Ceutorhynchus cardariae, Psylliodes wrasei, and Aceria drabae are the most promising biological agents available for controlling L. draba. Observations were made in natural pastures by the Department of Iassy in eastern Romania in 2008. The most common invasive species were Xanthium italicum, Xanthium spinosum, Elaeagnus angustifolia, L. draba, Euphorbia cyparissias, and Verbascum phlomoides, which dramatically decrease ecosystem productivity. Here we present results obtained based on field test-plant relationship phytophagy between L. draba L. and P. wrasei Leonardi and Arnold. We studied plants of the Brasicaceae family: L. draba, L. crenatum, Armoracia rusticana, and Barbarea orthoceras. Test plots comprised four L. draba planted 5 cm apart, with two test plants (L. draba, L. crenatum, B. orthoceras, or A. rusticana) planted at one of three planting distances (30 cm, 15 cm, and 5 cm) on each side of the central plants. Each planting distance variant was repeated four times, and for each variant all observations were made on 16 central L. draba plants and 8 of each test plant: L. draba, L. crenatum, B. orthoceras and A. rusticana. A total of 144 plants was studied: 48 central L. draba plants and 96 of each test species. These results do not contradict previous evidence that oligophagous species P. wrasei controls the L. draba. P. wrasei is also a potential biologic control agent for B. orthoceras (American yellowrocket), which is native to North America, including much of Canada and the western United States, as well as parts of Asia.

Barbarea vulgaris linkage map and quantitative trait loci for saponins, glucosinolates, hairiness and resistance to the herbivore Phyllotreta nemorum

Combined genomics and metabolomics approaches were used to unravel molecular mechanisms behind interactions between winter cress ( Barbarea vulgaris) and flea beetle ( Phyllotreta nemorum). B. vulgaris comprises two morphologically, biochemically and cytologically deviating types, which differ in flea beetle resistance, saponin and glucosinolate profiles, as well as leaf pubescence. An F2 population generated from a cross between the two B. vulgaris types was used to construct a B. vulgaris genetic map based on 100 AFLP and 31 microsatellite markers. The map was divided into eight linkage groups. QTL (quantitative trait loci) analysis revealed a total of 15 QTL affecting eight traits, including nine QTL for four saponins, two QTL for two glucosinolates, two QTL for hairiness, and two QTL for flea beetle resistance. The two QTL for resistance towards flea beetles in B. vulgaris co-localized with QTL for the four saponins associated with resistance. Furthermore, global QTL analysis of B. vulgaris metabolites identified QTL for a number of flavonoid glycosides and additional saponins from both resistant and susceptible types. The transcriptome of the resistant B. vulgaris type was sequenced by pyrosequencing, and sequences containing microsatellites were identified. Microsatellite types in B. vulgaris were similar to Arabidopsis thaliana but different from Oryza sativa. Comparative analysis between B. vulgaris and A. thaliana revealed a remarkable degree of synteny between a large part of linkage groups 1 and 4 of B. vulgaris harboring the two QTL for flea beetle resistance and Arabidopsis chromosomes 3 and 1. Gene candidates that may underlie QTL for resistance and saponin biosynthesis are discussed.

Can sulfur fertilisation improve the effectiveness of trap crops for diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)?

The effect of sulfur fertilisation on chemical constituents of yellow rocket, Barbarea vulgaris (R. Br.), was studied with regard to its potential use as a trap crop for the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). Two types of B. vulgaris var. arcuata were used: the G-type, resistant to P. xylostella and proposed as a 'dead-end' trap crop, and the P-type, not resistant to P. xylostella and used as a control. In G-type B. vulgaris, sulfur fertilisation increased the content of the dominant glucosinolate (S)-2-hydroxy-2-phenylethylglucosinolate by 20%. Sulfur fertilisation did not significantly change levels of the saponins 3-0-beta-cellobiosylhederagenin and 3-0-beta-cellobiosyloleanolic acid, known to act as feeding deterrents for P. xylostella larvae. In P-type B. vulgaris, the same levels of sulfur fertilisation did not change the glucosinolate content significantly. Two-choice oviposition preference tests with B. vulgaris plants showed that P. xylostella laid 144% and 45% more eggs on G- and P-type plants with sulfur fertilisation respectively. The studies suggest that sulfur fertilisation could increase the effectiveness of G-type B. vulgaris as a trap crop for P. xylostella. The effect of plant sulfur fertilisation on P. xylostella oviposition preference is associated with a quantitative glucosinolate increase, but other compounds could also be involved.