Allium Cepa, which is commonly known as onion, is a culinary ingredient that is used in almost all cuisines around the world. It is an essential ingredient in sauces, curries, and other dishes. Allium Cepa is a source of various compounds, many of which are biologically active. These include thiosulfinates, flavonoids, and phenolic acids. Allium Cepa can also be used for medical purposes due to its characteristics. These characteristics include being antimicrobial, antidiabetic, anticancer, and containing antioxidant effects (Kuete et al., 2017). Lemna Minor, also known as surface-floating duckweed, is a commonly used ingredient in the field of aquafeeds. Lemna Minor can be cultivated in standard outdoor tanks and has a wide range of applications. It is considered to be a rich source of essential and non-essential amino acids. Lemna Minor is also considered to have a rich nutritional value (Chakrabarti et al., 2018). This essay focuses on the key biological characteristics of Allium Cepa. In addition to this, it also discusses the biological composition of Lemna Minor.
Allium Cepa has been cultivated by humans for centuries. They have been commonly used in regions like China, India, and the Middle East (Saxena et al., 2010). The first step in the cultivation of Allium Cepa is to ensure that the pollination process takes place. Allium Cepa is a liliaceous crop and is considered to be protandrous. Allium Cep’s biological characteristics are influenced by the fact that the crop relies on insect pollination rather than being a self-pollination plant. Another key biological aspect of Allium Cepa is that its height may vary due to the genotype. Commonly-grown Allium Cepa plant can have a height between 0.9 metres and 1.2 metres. The flowers of the plant are covered in white sheath known as a spathe. Since the plant is grown inside an umbel, the sheath tends to split. The colour of Allium Cepa may change with the age of the flower. This colour could either be white or bluish (Devi et al., 2015).
Another key aspect of the Allium Cepa plant is that it is visited by a range of insects and organisms (Balemi et al., 2007). An onion umbel may be visited by small flies, honey bees, bumblebees, butterflies, and other small insects. The blossoms of Allium Cepa are such that they attract both pollen-collecting and nectar-collecting insects. It is estimated that nearly 267 different types of insects could visit onion flowers, resulting in a direct influence on the biology of the crop. For instance, the visit of honey bees can enrich Allium Cepa with potassium and sugar content. Similarly, the insects visiting Allium Cepa can have a major influence on the sucrose content (Devi et al., 2015).
The key biological components of Allium Cepa are sulphur amino acids, vitamins, and minerals. It is a biennial plant which includes fibrous roots and fleshy leaf bases. Two of the most discussed biological properties of Allium Cepa are that it is antimicrobial in nature and that it has a strong oxygen absorbance capacity. The skin extract obtained from Allium Cepa can also be used as a skin-whitening agent. This is because of the presence of melanin within the compound. The skin extract of the plant is also useful in terms of the treatment of obesity. This is because Allium Cepa includes quercetin, and it has strong antioxidant characteristics (Marrelli et al., 2019).
These antioxidant characteristics are extremely useful in terms of treating common diseases such as obesity and diabetes. These characteristics are evident in the skin and edible part of Allium Cepa. The antioxidant characteristics have been tested and proved for a range of Allium Cepa variants such as Jaune d’Espagne, Fuentes de Ebro, Calçot de Valls, and Grano de Oro. Similarly, oxygen absorbance capacity is also highly useful. An experiment was conducted on Allium Cepa variants from Brazil. The experiment indicated that Allium Cepa was able to decrease superoxide dismutase activity in diabetic rats. These properties can also be used in terms of treating higher than usual enzyme levels and pancreatic complications in diabetic rats. Lemna Minor also finds application in the field of fertilizers due to its ability to absorb nutrients. It can be added to traditional fertilizers to improve their efficiency (Marrelli et al., 2019; Fredotović et al., 2017).
Lemna Minor is one of the most commonly-found free-floating plants. These plants typically flourish in eutrophic and mesotrophic lakes. This is because such water bodies have ample nutrient content that is needed to foster the growth of Lemna Minor (Ireland et al., 2004). The biology of these plants is highly influenced by physiological changes in uptake kinetics. Lemna Minor has the ability to intake significant quantities of inorganic nitrogen. This implies that the plant has the ability to assimilate nutrients, and this characteristic can have multiple biological uses for humans. Although the absence of large roots in Lemna Minor has a negative impact on its ability to absorb a wide range of nutrients, the plant still has the ability to absorb nitrogen and minimise its harmful effects (Cedergreen and Madsen, 2002).
Lemna Minor is categorised under Lemneceae. Their length can vary from under 1 millimetre to several millimetres. These plants tend to multiply by vegetative means. The mother frond leads to the generation of daughter fronds, and these daughter fronds are gradually abscised. In some cases, Lemna Minor may have roots. The primary use of these roots is only to provide a base to the plant. These roots do not have the capacity in intake nutrients, and this process is only undertaken in the actual plant. Lemna Minor can also grow by means of sexual reproduction, and instances of this process have been recorded in nature. Such instances have also been fostered in the laboratory with controlled conditions (Juhel et al., 2011). Lemna Minor can be extremely high in protein content, with recorded instances as high as 38% of the dry weight. The primary colour of Lemna Minor is bright green, although the plant can also be pale in its appearance. During its growth, Lemna Minor can undergo various stages of transformation. The first stage includes the cultivation of the plant by means of agrobacterium. Further, the transgenic fonds of the plant can be cultivated as part of a sequential transformation. Additionally, the regeneration and fostering of Lemna Minor can also be achieved in controlled conditions (Yamamoto et al., 2001).
One of the primary uses of Lemna Minor is that it is considered to be a feedstuff in practical diets of animals. This is because of the absorption and intake properties of the plant. Dried Lemna Minor can be used to feed fish, as it helps the fish in retaining vital nutrients (Cheng et al., 2002). Lemna Minor is also a good source of amino acids and vitamins, thereby making it a suitable component of animal diet. Further, the leaves of duckweed are low in fibre content. The fibre content in them is limited to under 5% of the total weight. This implies that there is very little indigestible material in Lemna Minor, making it a suitable choice for animal feed. In addition to the above, Lemna Minor can also include minerals such as Phosphorus and Potassium. Further, Lemna Minor’s biological properties allow it to be converted into live weight by fish. This quick absorption makes it a useful component of fish feed (Yılmaz et al., 2004).
Lemna Minor also has the ability to absorb metals like copper. This means that the plant can be used in the field of biomonitoring. Biomonitoring can be a useful way of tracking and controlling aquatic pollution. Lemna Minor is suitable for the biomonitoring process because it quicky absorbs metals. This could help scientists in monitoring the cleanliness of water bodies such as lakes. A wider application for Lemna Minor could be to ensure the preservation of large-scale water bodies and natural ecosystems. These applications make Lemna Minor important plants for the environment, especially to track and monitor the growth of aquatic organisms (Kellaf and Zardoui, 2010; Gubbins et al., 2011).
This essay focused on analysing the biological characteristics of Allium Cepa and Lemna Minor. From the review, it is evident that Allium Cepa, also known as onion, is cultivated by making use of a range of factors, and this provides it with a unique antioxidant and oxygen absorbance capacity. Allium Cepa is also rich in amino acids, and this property can be used for various human treatment mechanisms. Allium Cepa also has a very high nutritional value, thereby becoming a key component of the human diet. It is also used in the preparation of various sauces and curries. Further, Lemna minor, also called duckweed, is one of the most commonly found species of aquatic freshwater plants. It is primarily used as animal fodder, but can also be deployed in order to recover nutrients from wastewater. These plants tend to grow by means of vegetative reproduction. Lemna minor also has pharmaceutical applications, due to the presence of proteins.
Balemi, T., Pal, N. and Saxena, A. (2007) Response of onion (Allium cepa L.) to combined application of biological and chemical nitrogenous fertilizers, Acta Agriculturae Slovenica, 89(1), pp.107-111.
Cedergreen, N. and Madsen, T.V. (2002) Nitrogen uptake by the floating macrophyte Lemna minor, New phytologist, 155(2), pp.285-292.
Chakrabarti, R., Clark, W.D., Sharma, J.G., Goswami, R.K., Shrivastav, A.K. and Tocher, D.R. (2018) Mass production of Lemna minor and its amino acid and fatty acid profiles, Frontiers in Chemistry, 6, pp.479-482.
Cheng, J., Landesman, L., Bergmann, B.A., Classen, J.J., Howard, J.W. and Yamamoto, Y.T., (2002) Nutrient removal from swine lagoon liquid by Lemna minor 8627, Transactions of the ASAE, 45(4), pp.1003-1010.
Devi, S., Gulati, R., Tehri, K. and Poonia, A. (2015) The pollination biology of onion (Allium cepa L.) - A Review, Agricultural Reviews, 36(1), pp.1-13.
Fredotović, Ž., Šprung, M., Soldo, B., Ljubenkov, I., Budić-Leto, I., Bilušić, T., Čikeš-Čulić, V. and Puizina, J. (2017) Chemical composition and biological activity of Allium cepa L. and Allium× cornutum (Clementi ex Visiani 1842) methanolic extracts, Molecules, 22(3), pp.448-450.
Gubbins, E.J., Batty, L.C. and Lead, J.R. (2011) Phytotoxicity of silver nanoparticles to Lemna minor L., Environmental Pollution, 159(6), pp.1551-1559.
Ireland, H.E., Harding, S.J., Bonwick, G.A., Jones, M., Smith, C.J. and Williams, J.H. (2004) Evaluation of heat shock protein 70 as a biomarker of environmental stress in Fucus serratus and Lemna minor, Biomarkers, 9(2), pp.139-155.
Juhel, G., Batisse, E., Hugues, Q., Daly, D., van Pelt, F.N., O’Halloran, J. and Jansen, M.A. (2011) Alumina nanoparticles enhance growth of Lemna minor, Aquatic toxicology, 105(3-4), pp.328-336.
Kellaf, N. and Zardoui, M. (2010) Growth, photosynthesis and respiratory response to copper in Lemna minor: a potential use of duckweed in biomonitoring, Journal of Environmental Health Science & Engineering, 7(4), pp.299-306.
Kuete, V., Karaosmanoğlu, O. and Sivas, H. (2017) Anticancer activities of African medicinal spices and vegetables, Available at https://www.sciencedirect.com/science/article/pii/B9780128092866000145 [Accessed on 21 January 2019].
Marrelli, M., Amodeo, V., Statti, G. and Conforti, F. (2019) Biological properties and bioactive components of Allium cepa L.: Focus on potential benefits in the treatment of obesity and related comorbidities, Molecules, 24(1), pp.119-129.
Saxena, A., Tripathi, R.M. and Singh, R.P. (2010) Biological synthesis of silver nanoparticles by using onion (Allium cepa) extract and their antibacterial activity, Dig J Nanomater Bios, 5(2), pp.427-432.
Yamamoto, Y.T., Rajbhandari, N., Lin, X., Bergmann, B.A., Nishimura, Y. and Stomp, A.M. (2001) Genetic transformation of duckweed Lemna gibba and Lemna minor, Vitro Cellular & Developmental Biology-Plant, 37(3), pp.349-353.
Yılmaz, E., Akyurt, İ. and Günal, G. (2004) Use of duckweed, Lemna minor, as a protein feedstuff in practical diets for common carp, Cyprinus carpio, fry, Turkish journal of fisheries and aquatic sciences, 4(2), pp.105-109.