Carrot Plants Research Articles

Selectivity of the herbicide linuron sprayed in pre-emergence and post-early in carrot

Herbicide application is a method for weed control in carrot crops. However, the choice of the chemical treatment (herbicide, association of products, dose, and time of application) should consider its selectivity to the crop. It is desired to analyze the selectivity of linuron for carrot plants, when sprayed on pre-emergence and post-early cultivated plants. Two experiments were carried out in the field in an area of the commercial production of carrots, one with the Verano cultivar and the other with BRS Planalto. Both experiments included an experimental design with randomized blocks in a factorial 2 x 4 + 1 with six and four replications for the experiments with Verano and BRS Planalto, respectively. The herbicide linuron (675 and 990 g a.i. ha-1) was sprayed at four times, counting from the carrot sowing day: in the pre-emergence of the crop at 0, 3, and 6 days after sowing (DAS) and in the post-early emergence at 9 DAS, when the plants had 1 or 2 cotyledons. An untreated control was maintained as an additional treatment. Linuron was selective for the carrot plant cultivars Verano and BRS Planalto, in both doses tested, when sprayed in the pre-emergence, up to six days after sowing, and in the post-early (plants with 1 or 2 cotyledon leaves) at nine days after sowing.

Foliar-applied ethephon enhances the content of anthocyanin of black carrot roots (Daucus carota ssp. sativus var. atrorubens Alef.)

BackgroundBlack carrots (Daucus carota ssp. sativus var. atrorubens Alef.) constitute a valuable source of anthocyanins, which are used as natural red, blue and purple food colourants. Anthocyanins and phenolic compounds are specialised metabolites, accumulation of which often requires elicitors, which act as molecular signals in plant stress responses. In the present study, ethephon, an ethylene-generating compound was explored as enhancer of anthocyanin and phenolic contents during growth of ‘Deep Purple’ black carrots. The effects of ethephon on several parameters were investigated, and the expression of biosynthetic anthocyanin genes was studied during growth and anthocyanin accumulation.ResultsRoots of ethephon-treated carrot plants exhibited an increase in anthocyanin content of approximately 25%, with values ranging from 2.25 to 3.10 mg g−1 fresh weight, compared with values ranging from 1.50 to 1.90 mg g−1 fresh weight in untreated roots. The most rapid accumulation rate for anthocyanins, phenolic compounds, soluble solids and dry matter was observed between 10 and 13 weeks after sowing in both untreated and ethephon-treated carrots. The differences in anthocyanin contents between untreated and treated carrots increased for several weeks after the ethephon treatment was terminated. Five cyanidin-based anthocyanin forms were identified, with variable relative abundance values detected during root growth. Overall, the expression of the anthocyanin biosynthetic genes analysed (PAL1, PAL3, F3H1, DFR1, LDOX2) increased in response to ethephon treatment, as did the expression of the MYB1 transcription factor, which is associated with activation of the phenylpropanoid pathway under stress conditions. In addition, a correlation was proposed between ethylene and sugar contents and the induction of anthocyanin synthesis.ConclusionsThis study presents a novel method for enhancing anthocyanin content in black carrots. This finding is of economic importance as increased pigment concentration per unit of biomass implies improved profitability parameters in food colour production. We provide new insight into the accumulation patterns of the different cyanidin-based anthocyanins and phenolic compounds during root growth. Moreover, we show that enhanced anthocyanin content in ethephon-treated carrots is accompanied by increased expression of anthocyanin biosynthetic genes.

Produção de etanol a partir dos subprodutos de cenoura

Carrot (Daucus carota L.) plant of the family umbelliferae, is characterized as one of the most important olericulture. The by-products of scrubbers and processing industries carrot can be valued by food purposes or for obtaining extracts for later use. Carotene extract carrot it is a precursor of vitamin A, especially s-carotene, as well as having antioxidant function. The by-products generated after the carotenoid extraction at high lignocellulosic biomass content, likely to produce second-generation ethanol. The development of this technology allows full use of the carrot products, increasing the production of ethanol. The present review is to discuss the use of carrot for carotenoid extraction and the use of the waste generated from this extraction for second-generation ethanol production.

Simultaneous detection of mixed 'Candidatus Phytoplasma asteris' and 'Ca. Liberibacter solanacearum' infection in carrot

Symptoms of shoot and root malformation were observed in carrot plants in fields located in the North of Gran Canaria Island (Spain), during surveys carried out in spring 2015 and 2016. Total DNA extraction from the leaves of symptomatic plants was performed and PCR assays were carried out to detect the agents possibly associated to the observed symptoms. While ‘ Candidatus Liberibacter solanacearum’ was detected in the majority of tested symptomatic samples, phytoplasmas belonging to the ribosomal group 16SrI were detected only in two samples. Phylogenetic analyses and sequencing, together with virtual RFLP, confirmed that ‘ Ca . L. solanacearum’ strains detected in carrot samples belong to haplotype D.

EVALUATION OF VARIOUS GENOTYPES OF CARROTS IN THE NURSERY OF INITIAL BREEDING FORMS

The investigations were conducted on the fields of the Kazakh Research Institute of Potato and Vegetable Growing located on the northern slope of the Zailiysky Alatau, 40 km to the west of Almaty city, under irrigation conditions. The soil of the experimental site is dark chestnut with medium-loamy structure. 37 carrot accessions with different geographic origins were the object of the study in the nursery of the initial breeding forms to evaluate their productivity and field resistance to foliar diseases such as Alternaria, Powdery Mildew. When symptoms expressed maximally 1.5 months before the harvest of carrot, visual assessment of leaf surface damaged by foliar infections was carried out according to the scale of infection, where 0 meant no damaged leaves; 1 meant very light damage (1-10% of leaves); 2 meant light damage (11-25% of leaves); 3 meant medium damage (26-50% of leaves); 4 meant severe damage (over 51% of leaves). The visual observation showed that two breeding accessions CR00655 and CR01253 had immunity to powdery mildew that maximally spread out over other carrot accessions approaching of 100% of damage of leaf surface with the score from 1.8 to 3.8 points, when disease developing from 45.0 to 93.8%. Alternaria spread on carrot plants not very intensively, only 17% of plants in the nursery were hardly attacked at 0.1-0.4 points as scored. The correlation analysis showed the absence of any link between characteristics of productivity and damage parameters caused by foliar diseases at r=0,005-0,225.

CARROT SEED GROWING THROUGH WINTERING SEEDLINGS

The results of research work on carrot seed growing through wintering seedlings carried out at laboratory of seed studies and seed production of Transnistrian Research Institute of Agriculture, on the soil of the first terrace at the rive Dniester were presented in the article. Seed bearing plants of garden carrot ‘Krasavka’ were the object of the study. The seeds were sown to produce the seedlings on 15-16 August. In the first decade of December the plants were covered with white agrotextile with density 23g/m2 that was removed at the beginning of April. The proportion of plant that passed the winter depending on a year of cultivation was 95-100% under argotextile, and 50-80% in open plot. The plants under agrotextile reached 28 cm a high and had 5-7 well-developed leaves, while those on the open plot were at phase of active foliage growing about 10-13 cm. long. Thus, for early mechanized planting in optimal terms the wintering seedlings grown under agrotextile had the best biometrical characteristics. Moreover the outcome of carrot seedlings was 1.2-1.25 million per hectare. Such quantity of seedlings was sufficient to plant 9-10 ha of carrot plants, where the coefficient of multiplication reached 9-10, and only 3 when growing seeds through mother plant as biennial culture. Viability of seed plants grown through seedlings was 100%. Losses of plant with weight 120-150 grams from damage caused by diseases was 23%. The seed yield, when growing seedlings was 639 kg/ha, but growing through plants was 332 kg/ha. The seed outcome suitable for precise mechanized sowing through seedling growing was 77%, where seed germination was 90%, with seed fraction 1.51 and >2.0 mm. It was essentially improved their yielding characteristics. Seed outcome from this fraction obtained through planting method was 32%. The proportion of seeds in fraction 1-1.5 mm was 68%. For mechanized single-seed sowing, the seeds can be used only after mini-coating. The seed growing from wintering seedlings fully excluded the application of fungicides for plant protection and seedlings from diseases; there are no expenses for building the expensive storage facilities needed for mother plant storing.

Detection and molecular characterization of phytoplasmas associated with vegetable and alfalfa crops in Qassim region

ABSTRACTDuring a survey conducted in Qassim province, Saudi Arabia, in the year in 2015, 120 samples of carrot (Daucus carota subsp. sativus), onion (Allium cepa), faba bean (Vicia faba), green mustard (Brassica juncea) and alfalfa (Medicago sativa) plants displaying symptoms reminiscent of phytoplasma diseases were collected and tested for phytoplasma infection. Phytoplasma-specific PCR products were only amplified from symptomatic plants by nested-PCR. Disease incidence ranged from 3.14% in alfalfa crop fields 1 year after cultivation to 77.48% in 3-year-old fields. In the five carrot fields sampled in this study, the incidence changed from 3.2% to 100% after 7 months of cultivation. Phylogenetic analysis revealed that all Qassim phytoplasma isolates belong to the 16SrII group. Most of them shared 100% identity with papaya yellow crinkle (16SrII-D Y10097). The results from phylogenetic and virtual restriction fragment length polymorphism analyses of the 16S rRNA gene sequence confirmed that the phytoplasma of Qassim isolates under study is a member of 16SrII-D subgroup. To the best of my knowledge, the onion and green mustard are considered new hosts for the 16SrII group; therefore, this is the first report on the association of phytoplasma with diseases of faba bean, onion, carrot, mustard and alfalfa in Qassim province, Saudi Arabia.

Ionizing radiation from Chernobyl affects development of wild carrot plants.

Radioactivity released from disasters like Chernobyl and Fukushima is a global hazard and a threat to exposed biota. To minimize the deleterious effects of stressors organisms adopt various strategies. Plants, for example, may delay germination or stay dormant during stressful periods. However, an intense stress may halt germination or heavily affect various developmental stages and select for life history changes. Here, we test for the consequence of exposure to ionizing radiation on plant development. We conducted a common garden experiment in an uncontaminated greenhouse using 660 seeds originating from 33 wild carrots (Daucus carota) collected near the Chernobyl nuclear power plant. These maternal plants had been exposed to radiation levels that varied by three orders of magnitude. We found strong negative effects of elevated radiation on the timing and rates of seed germination. In addition, later stages of development and the timing of emergence of consecutive leaves were delayed by exposure to radiation. We hypothesize that low quality of resources stored in seeds, damaged DNA, or both, delayed development and halted germination of seeds from plants exposed to elevated levels of ionizing radiation. We propose that high levels of spatial heterogeneity in background radiation may hamper adaptive life history responses.

First report of leafminer Lyriomyza spp. in Daucus carota in Brazil.

spp. in leaves of D. carota (Apiaceae) in Brazil.The study was conducted in commercial carrot plantations (cv ‘Juliana’) in the municipality of Rio Paranaiba and Sao Gotardo, Minas Gerais, Brazil (19° 12’ 57.91” S, 46° 13’ 41.08” W), with an average temperature of 26.32 °C, 45-98% RH, and 1,321 mm annual rainfall and an average altitude of 1,250 m. Sixty carrot plants were selected in three plantations. Sampling was conducted during the drier months (July to September) and raining months (January to March). The evaluated characteristics were the numbers of mined leaflets per plant and mines per plant. The number of mined leaflets and mines per plant were evaluated by performing a direct counting of these features throughout the plant.During the sampling period,

Transgenic approaches to enhance disease resistance in carrot plants to fungal pathogens

Transgenic approaches to enhance disease resistance in carrot plants to fungal pathogens

Growth and root yield of carrot as affected by magnetic water and sowing times

This study examines effects of two sowing times (28/10 and 14/11 of 2014) and differentlevels of magnetic treatment of irrigation (0, 2500, 5000gauss) on productivity and yieldof carrot plants. A pot experiment was conducted at the Agriculture Research Center,Ministry of Agriculture in Kurdistan region-Iraq. This study was carried out during 28-10-2014 and 14-5-2015 the two factor experiment was laid out in complete randomizeddesign with four replicates, each replicate contain three plants. Data were collected fromall plants at harvest time and statistically analyzed. Comparisons between means weremade by using least significant differences test (LSD) at 5% probability. Magnetizedwater at the level of 2500gause caused the most significant effects on plant length(55.58cm), root length (30.19cm), (root diameter (35.14mm) and root dry weight(128.19gm). However, the sowing time 14/11 was more effective on plant length(54.64cm) and vegetative growth fresh weight (17.64gm). While the longest root obtainedwhen the seeds sown in 28/10. On the other hand the interaction of 2500gauss and4/11/2014 sowing time gave the maximum plant length, shoot fresh weight and rootdiameter (59.67cm, 20.63 gm and 43.75mm respectively), but the longest root and highestroot fresh weight were found in the interaction of the same level of magnetic water with28/10/2014 sowing time. The highest amount of the chlorophyll in the leaves (52.815%)was measured from the interaction of 2500gauss magnetic water and 14/11/2014 sowingtime, and the best carotene content in the roots (3.427mg/ml) was obtained from5000gauss magnetic water in the same sowing time.

Carrot Plant-A Potential Source of High Value Compounds and Biological Activities: A Review

Essential oil of carrot is produced and accumulated in the secretary ducts known as vittae. Phytochemical studies have shown that the major chemical components of carrot plant are polyphenols, flavonols, glycosides, alkaloids, saponins, sesquiterpenoids and essential oil. Chemical constituents of carrot seed essential oil obtainedby hydrodistillation have been the subject of frequent researches. The composition of essential oil varies with plant parts. The carrot essential oil possesses biological activities like antimicrobial, antibacterial, antifungal, herbicidal, antioxidant, anticancer etc. The health benefits of carrot essential oil can be attributed to its antiseptic, disinfectant, detoxifying, antioxidant, anticarcinogenic, tonic, carminative, depurative, diuretic and stomachic properties.Major components present in different parts of carrot plant are listed along with their chemical composition. The morphological details of plant, its essential oil, chemicalconstituents and biological activities have been discussed in this review.

Expression profiles of genes involved in jasmonic acid biosynthesis and signaling during growth and development of carrot.

Jasmonates (JAs) are recognized as essential regulators in response to environmental stimuli and plant development. Carrot is an Apiaceae vegetable with great value and undergoes significant size changes over the course of plant growth. However, JA accumulation and its potential roles in carrot growth remain unclear. Here, methyl JA (MeJA) levels and expression profiles of JA-related genes were analyzed in carrot roots and leaves at five developmental stages. MeJA levels in the roots and leaves were the highest at the first stage and decreased as carrot growth proceeded. Transcript levels of several JA-related genes (Dc13-LOX1, Dc13-LOX2, DcAOS, DcAOC, DcOPR2, DcOPR3, DcOPCL1, DcJAR1, DcJMT, DcCOI1, DcJAZ1, DcJAZ2, DcMYC2, DcCHIB/PR3, DcLEC, and DcVSP2) were not well correlated with MeJA accumulation during carrot root and leaf development. In addition, some JA-related genes (DcJAR1, DcJMT, DcCOI1, DcMYC2, and DcVSP2) showed differential expression between roots and leaves. These results suggest that JAs may regulate carrot plant growth in stage-dependent and organ-specific manners. Our work provides novel insights into JA accumulation and its potential roles during carrot growth and development.

Differential Contribution of the First Two Enzymes of the MEP Pathway to the Supply of Metabolic Precursors for Carotenoid and Chlorophyll Biosynthesis in Carrot (Daucus carota).

Carotenoids and chlorophylls are photosynthetic pigments synthesized in plastids from metabolic precursors provided by the methylerythritol 4-phosphate (MEP) pathway. The first two steps in the MEP pathway are catalyzed by the deoxyxylulose 5-phosphate synthase (DXS) and reductoisomerase (DXR) enzymes. While DXS has been recently shown to be the main flux-controlling step of the MEP pathway, both DXS and DXR enzymes have been proven to be able to promote an increase in MEP-derived products when overproduced in diverse plant systems. Carrot (Daucus carota) produces photosynthetic pigments (carotenoids and chlorophylls) in leaves and in light-exposed roots, whereas only carotenoids (mainly α- and β-carotene) accumulate in the storage root in darkness. To evaluate whether DXS and DXR activities influence the production of carotenoids and chlorophylls in carrot leaves and roots, the corresponding Arabidopsis thaliana genes were constitutively expressed in transgenic carrot plants. Our results suggest that DXS is limiting for the production of both carotenoids and chlorophylls in roots and leaves, whereas the regulatory role of DXR appeared to be minor. Interestingly, increased levels of DXS (but not of DXR) resulted in higher transcript abundance of endogenous carrot genes encoding phytoene synthase, the main rate-determining enzyme of the carotenoid pathway. These results support a central role for DXS on modulating the production of MEP-derived precursors to synthesize carotenoids and chlorophylls in carrot, confirming the pivotal relevance of this enzyme to engineer healthier, carotenoid-enriched products.

Influence of Cultivars and Seed Thermal Treatment on the Development of Fungal Pathogens in Carrot and Onion Plants

Carrot and onion are vegetables representing an important segment of fresh market. They suffer from serious fungal diseases that can inflict great damage on crops, i.e. alternaria leaf blight, peronospora downy mildew, and botrytis neck rot. The resistance of selected carrot and onion cultivars important for the production of vegetables in the Czech Republic was tested by exposure to targeted infection by the above fungal pathogens. The exposure of eleven carrot cultivars to spores of Alternaria dauci showed that the most resistant and sensitive cultivars were Katrin, Cortina F1, Afalon F1 and Favorit, Tinga, Berlika F1, respectively. A targeted infection of onion cultivars with Botrytis aclada clustered them into three groups: Amfora F1, Bolero, Tosca, Triumf F1 (strong resistance), Avalon, Grenada (medium resistance), Alice, Karmen, Všetana (low resistance). Similar groups were distinguished also after the infection with Peronospora destructor: Avalon, Bolero, Tosca (strong resistance), Alice, Amfora F1, Grenada, Karmen, Triumf F1 (medium resistance),Všetana (low resistance). Hot water treatment of carrot seeds applied after the inoculation with A. dauci decreased the development of the infection 1.3-2.3-fold, whereas the protective effect observed with onion seeds against the infection by P. destructor and B. aclada was lower.

Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata.

Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0–30 cm) were 1.65 mg kg-1 and 88 μg L-1, and 0.92 mg kg-1 and 48.6 μg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0–5 and 0–30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions.

Peruvian carrot (Arracacia xanthorrhiza Bancroft) as raw material for producing special native starches

The use of natural starches in food or non-food industries is difficult, as there are no starches with essential properties for a particular application. Thus, it is important to identify different alternative starch sources with wide variability in starch properties. The aim of this study was to evaluate roots production and starch properties of Peruvian carrot genotypes [BGH clones (4560, 5741, 5744, 5746, 5747, 6414, 6513, 6525, 7609) and “Amarela de Senador Amaral” cultivar] growing in Brazil. The experimental design was randomized complete block design with four replications. After eight-month growing of Peruvian carrot plants, roots were collected and the total production of roots, and their dry matter and starches contents were analyzed. The roots were processed for starch extraction. Starches were evaluated for phosphorus and amylose contents as well as for thermal and pasting properties. Results showed differences for all parameters analyzed for roots and starches between materials. Peruvian carrot starches presented varied chemical, thermal and pasting properties which can be exploited by food industry as native starches.

Assessing the Likelihood of Transmission of Candidatus Liberibacter solanacearum to Carrot by Potato Psyllid, Bactericera cockerelli (Hemiptera: Triozidae).

‘Candidatus Liberibacter solanacearum’ (Lso) is a phloem-limited bacterium that severely affects important Solanaceae and Apiaceae crops, including potato, tomato, pepper, tobacco, carrot and celery. This bacterium is transmitted to solanaceous species by potato psyllid, Bactericera cockerelli, and to Apiaceae by carrot psyllids, including Trioza apicalis and Bactericera trigonica. Five haplotypes of Lso have so far been described, two are associated with solanaceous species and potato psyllids, whereas the other three are associated with carrot and celery crops and carrot psyllids. Little is known about cross-transmission of Lso to carrot by potato psyllids or to potato by carrot psyllids. Thus, the present study assessed whether potato psyllid can transmit Lso to carrot and whether Lso haplotypes infecting solanaceous species can also infect carrot and lead to disease symptom development. In addition, the stylet probing behavior of potato psyllid on carrot was assessed using electropenetrography (EPG) technology to further elucidate potential Lso transmission to Apiaceae by this potato insect pest. Results showed that, while potato psyllids survived on carrot for several weeks when confined on the plants under controlled laboratory and field conditions, the insects generally failed to infect carrot plants with Lso. Only three of the 200 carrot plants assayed became infected with Lso and developed characteristic disease symptoms. Lso infection in the symptomatic carrot plants was confirmed by polymerase chain reaction assay and Lso in the carrots was determined to be of the haplotype B, which is associated with solanaceous species. EPG results further revealed that potato psyllids readily feed on carrot xylem but rarely probe into the phloem tissue, explaining why little to no Lso infection occurred during the controlled laboratory and field cage transmission trials. Results of our laboratory and field transmission studies, combined with our EPG results, suggest that the risk of Lso infection and spread between psyllid-infested solanaceous and Apiaceae crops is likely to be negligible under normal field conditions.

The Increased Content of Micronutrients in Celery, Carrot, Parsnip and Parsley Plants after Treatment with Sodium Naphthenate

Summary Young plants of celery, parsley, parsnip and carrot, grown in nutrient solution, were treated with sodium naphthenate (10−7 mol dm−3), applying foliar and root treatments. Both treatments affected the root content of all investigated elements present in the nutrient solution, but in a different way, depending on the plant species. An average change (increase/decrease) in the contents of investigated essential elements was about 35%. Our experiments with naphthenate showed that this treatment may enhance the efficiency of essential elements uptake and increase its content in plants without changing concentration of these elements in the nutrient solution. Especially interesting results were obtained in the case of carrot, as increased contents were observed in the elements that are usually deficient in nutrition (Fe, Zn, Mn), whereas the other remained unchanged.

OCCURRENCE AND MOLECULAR DETECTION OF SPIROPLASMA CITRI IN CARROTS AND ITS INSECT VECTOR, CIRCULIFER TENELLUS, IN MEXICO

In 2014, carrot plants in Zacatecas, Mexico, were found with yellow, brown, or purple-colored leaves, which were occasionally smaller and rolled. Roots of these affected plants were hairy, deformed, and small. Molecular diagnostics failed to detect phytoplasmas in these samples, but identified Spiroplasma citri in 58 and 94% of the samples using PCR targeting the spiralin and adhesion-related protein 1 (arp1) genes, respectively. Sequence analysis confirmed the presence of S. citri, and identified a novel, putative arp gene in one carrot sample. S. citri is a phytopathogenic mollicute transmitted by leafhopper species. Beet leafhoppers (Circulifer tenellus Baker) collected in the same state of Zacatecas, Mexico, were subsequently tested for S. citri infection, and 36.5% were positive using PCR targeting the arp1 gene. Sequencing analysis confirmed the presence of S. citri in the leafhoppers. This is the first report of S. citri in carrot and C. tenellus in Mexico. Previously in the Americas, S. citri in carrot was only reported in Washington and California in the United States. The presence of S. citri in carrots and the beet leafhopper in Mexico, suggests that this pathogen could become a threat to vegetable industries in this region of Mexico, including the carrot industry.