Brassica napus L. Origin and diffusion Source: gardeningsolutions.ifas.ufl. edu/ Origin: it is thought to have originated in either the Mediterranean area or Northern Europe, from a cross between two diploid species, B. oleracea and B. rapa. Distribution: naturalized in temperate regions throughout the world Invasive potential: low Photo: P.Hillman Photo: nordgen.org Source: knowyourvegetables.co.uk Introduction Bright yellow flowering herb, widely grown for the production of animal feed, vegetable oil for human consumption (it is the third largest source of vegetable oil in the world), and biodiesel; it is also exploited for honey production. Its seed contains 35-45% of oil, 25-35% of protein, 5-7% fiber, 4-8% of glucosinolates. Several varieties of B. napus have been selected and certified for better product quality and improved processing techniques. Common names: Rape, oilseed rape, rapeseeds, canola (English), Colza (Italian) Description Life-form and periodicity: annual or perennial herb Height: 30 cm 1 m Roots habit: the tap-root is large and thickened, the root system is deep in relation to the aerial parts of the plant, mainly concentrated within the first 35-40 cm of soil. Culm/Stem/Trunk: the stem is herbaceous, branching, erect, reddish-purple below, greenish-red above, glabrous, Crown: -
Fam. Brassicaceae Description Leaf: the leaves are simple, alternate, glaucous, divided transversely into lobes with an enlarged terminal lobe and smaller lateral lobes. The middle and upper leaves are oblong-lanceolate, thicker and sessile. Rate of transpiration: 4,9 7,8 mm/day Reproductive structure: the flowers are united in terminal racemes. They have 4 sepals and 4 yellow petals. Propagative structure: the fruit is 2-celled, elongated capsule called a silique, containing 20-30 seeds. The seeds are curved, red-brown to black colour. Development Sexual propagation: flowers are capable of self-pollination or outcrossing; pollen grains have the ability to cross-pollinate through physical contact between neighbouring plants and/or be pollinated by insects; pollen can also become airborne and potentially travel at least several kilometres downwind. Moderate seed spread rate; the greatest potential for the movement of canola seeds is from postharvest spillage by agricultural machinery or during transportation away from the production areas. Asexual propagation: there are no reports of vegetative reproduction under field conditions Growth rate: rapid Habitat characteristics Light and water requirement: it needs full sun and moist soil for maximum performance Soil requirements: it is adapted to medium and fine textured soils. It has a higher requirement for nitrogen, phosphorus and sulphur than cereals and other crops and will not produce high yields unless all three elements are adequately supplied. It prefers moist and deep soils, with a good water retention and ph 6,5. Tolerance/sensitivity: low drought tolerance and intolerance to shade. Some varieties can be reasonably frost tolerant.
Phytotechnologies applications Brassica spp. is well known as hyperaccumulator of heavy metals; due to its fast growth it can be exploited for phytoextraction (Bañuelos et al, 2005; Turan & Esringü, 2007). It has been also used to enhance the biodegradation of organic contaminants in soil as chlorophenols, hydrocarbons and polychlorinated biphenyls (Adam & Duncan, 1999; Agostini et al., 2003; Reed & Glick, 2005; Javorská et al., 2009). Experimental studies -Experiment 1- Reference Contaminants of concern Mechanism involved in phytoremediation: Phytostabilisation/rhizodegradation/phyt oaccumulation/phytodegradation/phytov olatilization/ hydraulic control/ tolerant Types of microorganisms associated with the plant Requirements for phytoremediation (specific nutrients, addition of oxygen) Substrate characteristics Laboratory/field experiment Age of plant at 1st exposure (seed, post-germination, mature) Length of experiment Initial contaminant concentration of the substrate Post-experiment contaminant concentration of the substrate G. Adam and H.J. Duncan, 1999. Effect of diesel fuel on growth of selected plant species. Env. Geochemistry and Health 21: 353 357 Diesel oil, a complex mixture of hydrocarbons Rhizodegradation Laboratory experiment Seed 14 days Plant were exposed to different concentrations of diesel oil: 0 g/kg, 25 g/kg, 50 g/kg
Phytotechnologies applications Post-experiment plant condition Contaminant storage sites in the plant and contaminant concentrations in tissues (root, shoot, leaves, no storage) Germination rates of plants exposed to 0, 25 and 50 g/kg of diesel oil were 100%, 100%, 95% respectively The oil seed rape cultivar Martina germinated well in the presence of diesel but the production of top growth was noticeably reduced to 17.8% and 16.6% of the control top growth in 25 g diesel/kg soil and 50 g diesel/kg soil treatments, respectively. The same pattern was observed for root biomass with reductions falling to 21% and 20% of the control biomass for the two treatments Plants grown in diesel oil contaminated soil exhibit formation of adventitious roots (root structures which arise in unusual positions) Plant roots avoid diesel oil contaminated areas if they have uncontaminated soil to grow into. If there is no available uncontaminated soil, roots grow through contaminated regions until they find an area of uncontaminated soil. No storage Experiment 2- Reference Contaminants of concern Mechanism involved in phytoremediation: Phytostabilisation/rhizodegradation/phyt oaccumulation/phytodegradation/phytov olatilization/ hydraulic control/ tolerant Types of microorganisms associated with the plant Turan, M., & Esringu, A. (2007). Phytoremediation based on canola (Brassica napus L.) and Indian mustard (Brassica juncea L.) planted on spiked soil by aliquot amount of Cd, Cu, Pb, and Zn. Plant Soil and Environment, 53(1), 7. Cu, Cd, Pb and Zn Phytoaccumulation
Phytotechnologies application Requirements for phytoremediation (specific nutrients, addition of oxygen) Substrate characteristics Laboratory/field experiment Age of plant at 1st exposure (seed, post-germination, mature) Length of experiment Initial contaminant concentration of the substrate Post-experiment contaminant concentration of the substrate Post-experiment plant condition Contaminant storage sites in the plant and contaminant concentrations in tissues (root, shoot, leaves, no storage). Soil contaminated with heavy metals was treated with EDTA at the rates of 0 (control), 3, 6 and 12 mmol/kg. (EDTA was sprayed on the soils surface; concentrations are based on the upper soil layer). After plant sowing, each pot was fertilised with N, P and K using urea (120 mg N/kg), calcium phosphate (100 mg P/kg) and potassium sulphate (50 mg K/kg) as a basal fertilising. The soil was sampled in a depth of 0-15 cm from agricultural fields in Turkey. Particle size distribution: 30.7% sand,35.9 silt, 33.4 clay;ph 7.31. The soil was spiked with specific amounts of heavy metals. Plants were grown in a growth chamber. Seed 96 days 50 mg/kg Cd (CdCl2), 50 mg/kg Cu (CuSO4), 50 mg/kg Pb [Pb(NO3)2] and 50 mg/kg Zn (ZnSO4). Application of EDTA significantly decreased root and shoot dry matter yields. The total dry weight of biomass was also affected by the contamination; on average, the metals caused a reduction of about 75% in root and shoot dry matter. Application of EDTA at the rates of 3, 6 and 12 mmol per kg significantly increased Cu, Cd, Pb and Zn concentration in shoots and roots. The increase rate was often 10-fold or more. Application of EDTA at rates over 6.0 mmol/kg decreased total heavy metal uptake significantly due to decreasing total dry matter weight. In all EDTA application rates, heavy metal concentrations in roots were about 4 6 times higher than in shoots.