Laceleaf Plant: Classification, Characteristics, Micropropagation, and Economic importance
Introduction
The Araceae family member Anthurium andraeanum has thousands of varieties that are very well-liked by gardeners and florists, greatly enhancing the floricultural industry. Anthurium flowers have a higher production cost than other planting materials.
Tropical plants called Anthuriums are cultivated for their lavish cut blooms and appealing foliage. Today’s globe has begun to recognize anthurium as a popular cut flower. Growing anthuriums have the potential to be a profitable commercial farming venture since it makes the most of the ready market for cut flowers and generates significant profits for both the cut flower and the entire plant. The cut flower market for anthuriums is only getting started in India. At this time, most nurseries and small gardens are where anthuriums are grown. Around Bangalore, Belgaum, Goa, Sirsi, and other modern cities, some innovative farmers began producing anthurium in protected conditions. Assam, Kerala, Tamil Nadu (Salem), and Karnataka (Coorg) are significant anthurium-growing states because of their favourable climates.
Classification
Kingdom: Plantae
Order: Alismatales
Family: Araceae
Genus: Anthurium
Species: andraeanum
Scientific name: Anthurium andraeanum
Common name: Laceleaf, Flamingo flower, Tailflower, Painter’s palette
Characteristics
1. Anthurium belongs to the Araceae family, which has 108 genera and about 3750 monocotyledonous species.
2. Araceae is a family of flowering plants that includes the species Anthurium andraeanum.
3. It is a perennial herbaceous plant that is grown for its showy, heart-shaped inflorescence, which lasts for a very long time.
4. The species is indigenous to Ecuador and Colombia. Several uses for Anthurium andraeanum species are landscaping plants, flowering potted plants, and cut flowers.
5. Slow-growing perennial Anthurium andraeanum needs damp, shaded environments like those found in tropical rainforests.
6. The vase life of an anthurium is between 14 and 28 days. It is a modified leaf (spathe) with several little botanical flowers on a pencil-like protrusion (spadix).
7. The cultivars of Anthurium andraeanum have long held a prestigious place in the world’s floriculture trade.
8. Both sexual and asexual methods can be used to spread Anthurium andraeanum. However, vegetative propagation strategies tried on these plants have not yielded positive results, and tissue culture techniques now appear to be an alternative to boost the output of anthurium, which is typically propagated by seeds.
9. Because of cross-pollination and heterozygous progeny, seed propagation is not preferred. Additionally, it is hindered by the seeds’ poor viability and low germination rate.
10. Anthurium has been successfully micropropagated using a variety of explants. Pierik et al. published the first report on the tissue culture of Anthurium (1974). Both direct shoot regeneration from lamina explants and adventitious shoot production from callus were successful in regenerating Anthurium andraeanum. Nowadays, there are many people doing floriculture all over the world.
11. Both potted plants and cut flowers made from anthurium are offered, but the cut flower market is substantially larger. Among tropical flowers, the trade value of anthurium is second only to that of spray tropical orchids, and the size of the global anthurium import market is believed to be greater than US$ 20 million yearly.
12. Micropropagation is a factor in the trade-in anthuriums’ consistent growth. Due to the relatively costly cost of micropropagation, anthurium flowers are out of the reach of the average person.
Micropropagation
Anthurium is typically propagated using the following techniques:
(1) By seeds: Seeds are strewn on a finely shredded medium and maintained in a shaded area of seventy-five percent. After germination, transplantation can be completed in 4 to 6 months. A plant grows from seed to bloom in three years. Achieving homogeneity is impossible.
(2) Vegetative: Allowing a plant to sprout side branches or suckers, which are subsequently rooted and cultivated as individual plants, is a frequent technique for growing a well-liked cultivar. The mother plant is let to expand and produce additional suckers.
(3) Tissue culture is a method for quick, widespread clonal replication that is gaining popularity.
Selecting the plant material to be propagated is the first step in micropropagation. In a sterile environment, plant tissues are taken from an intact plant. The growth of the healthiest plants depends on the use of clean, virus- and fungus-free stock materials. Following the selection of the plant material for culture, the collection of explants, which may include stem ends, anthers, petals, pollen, and other plant parts, commences. Following a series of typically repeated bleach and alcohol washes, the explant material is then surface sterilized before being washed in sterile water. This small fragment of plant tissue, occasionally only one cell, is placed on a growth medium that frequently contains sucrose as an energy source and one or more plant growth regulators (plant hormones). Agar is typically used to thicken the media and generate a gel that supports the explant during growth. Some plants can be grown successfully on straightforward media, while others need more challenging media. Depending on the medium, plant tissue develops and differentiates into new tissues. For instance, plant buds are grown into branched shoots using media containing cytokines.
Explant selection
An explant is a tissue taken from a plant that will be cultivated. It is sometimes asserted that any piece of a plant, including single, undifferentiated cells and sections of shoots, leaves, stems, flowers, and roots, can yield a totipotent explant. However, not all plants exhibit this trait.
Factors influencing the Selection of explant
Explant’s Age
Because physiologically younger tissue is typically significantly more sensitive in vitro, the age of the explant can be quite significant. Older tissue frequently won’t develop a callus that can regenerate. Additionally, because it is typically the most recently generated tissue, younger tissue makes it simpler to surface cleanse and create clean cultures.
Size of Explants
The reaction of the tissue is influenced by the explant size. The harder it is to culture an explant, in general, the smaller it gets. Usually, the culture medium needs to include extra parts. To support the culture, the larger explants likely include greater nutrient stores and plant growth, and regulators. Every part of a plant has a variable hormonal balance, and depending on where an explant is placed, it may or may not have a different endogenous amount of plant growth regulators. Variable in vitro responses can be brought on by internal variations in hormone balance in the tissue. Explants from healthy plants are preferable to those from plants that are under nutritional or water stress or that are showing signs of illness.
Sterilization
Modern plant tissue culture is carried out in an aseptic environment with air that has been HEPA-filtered by a lamina flow cabinet. Surface disinfection of explants in chemical solutions is required because living plant materials from the natural environment are inherently polluted on their surfaces (and occasionally interiors) with germs (usually alcohol and sodium or sodium hypochlorite). The widely used method entails surface disinfection of initial explants with 70 percent (v/v) ethanol for 1 minute, followed by 0.01 percent HgCl2 alone for 7–12 minutes, and rinsing in sterile distilled water or treating with 1-3 percent sodium hypochlorite for 15-20 minutes. This method is favourable to the majority of the explants. But Gantait et al. sterilized the shoot ends of Anthurium andraeanum types by first immersing them in cetrimide, an antifungal solution, for five minutes, then rinsing them with NaOCl and 0.1 percent HgCl2. Later, Jahan et al. successfully incorporated 0.01 percent Tween-20 as a surfactant and utilized 70 percent (v/v) ethanol for 1 minute, and 1.5 percent NaOCl for 8 minutes as a disinfectant. The explants were most recently surface sterilized for 1 min in 70% (v/v) ethanol, steeped in gentamicin solution for 30 min, and then again bathed in 20% (v/v) commercial bleach [containing 5% (v/v) NaOCl] for 12 min to lessen contamination caused by fungal, endogenous and exogenous bacteria.
Media
Explants are often placed on the surface of a solid culture medium after sterilization, while this practice is occasionally used, especially when cell suspension cultures are needed. Inorganic salts, a few organic minerals, vitamins, and plant hormones are typically found in both solid and liquid media. A gelling agent, typically pure agar, is added to liquid media to create solid media. The morphology of the tissues that develop from the initial explant is greatly influenced by the medium’s makeup, particularly the plant hormones and the nitrogen supply (nitrate as opposed to ammonium salts or amino acids). A surplus of auxin, for instance, frequently leads to the multiplication of roots, whereas a surplus of cytokines may result in shoots. The form of the callus will vary on the plant species and the makeup of the media, but a balance of auxin and cytokine will frequently result in an unorganized proliferation of cells. To allow for growth or to change the shape of the culture, parts are often cut off and moved to fresh media (sub-cultured).
Organogenesis
A stage of micropropagation called organogenesis involves the direct or indirect regeneration of axillary buds or adventitious organs from the explants. An important aspect of organogenesis is the growth hormone standardization ratio.
Economic importance
The field of floriculture is rapidly developing. Compared to most crops and other horticulture crops, floriculture is currently a lucrative vocation with the potential for greater profits. Due to the liberalization of the economy and the globalization of trade, demand for flowers is growing more quickly in both the Indian and international markets. The most popular and in-demand flowers are the rose, chrysanthemum, carnation, gladiolus, and anthurium. Because of their higher returns per unit area and gorgeous, eye-catching, long-lasting flowers, anthuriums are becoming more and more popular. Anthurium, initially discovered in South America, has been hybridized by researchers in the Netherlands and Hawaii. Today, hundreds of species flourish in greenhouses, both at sea level and at heights of up to 1,200 meters. Anthuriums are bred for their colour, longevity, and resistance to disease.
Since 1986, world production has decreased by 25% due to high expenses for land, money, start-up fees, and propagation materials in several producer nations as well as ongoing productivity decreases in Hawaii. However, there has been a recent increase in demand for these blooms in the Asian market, specifically, as a result of geographic diversity.
The estimated global floriculture product consumption is 50 billion US dollars, with just trade accounting for 5.2 billion US dollars. The global inputs of floriculture products, comprising cut flowers, cut foliage, and live plants, have reached 3,000 million US dollars, reflecting the growth in the flower trade worldwide. Over half of this amount comes from cut flowers. With India contributing only 2 billion rupees, the global floriculture trade is now projected to be worth 750 billion rupees. Netherlands and Colombia are two of the biggest exporters of cut flowers. Kenya, Sri Lanka, Thailand, Italy, and Israel. Taiwan, Singapore, Peru, Mexico, Costa Rica, Brazil, Ethiopia, Zimbabwe, Mauritius, and Malaysia are among the developing nations that provide flowers. In addition to these, there is a rise in the import of cut flowers from throughout the world, such as orchids, anthuriums, foliage, and living plants. India’s contribution to the cut flower market, however, is insignificant. The value of Malaysia’s exports of floriculture goods climbed from 2.39 US dollars in 1984 to 4.87 US dollars in 1987. The current estimate for the global floriculture market is 750 billion rupees, which includes India’s paltry 2 billion rupee contribution.
Indian Contribution
The andreanum cultivar is mostly cultivated for cut flowers. Anthuriums were first grown on a small scale for cut flowers in India in the 1980s, and since then, they have been grown commercially in many different parts of the nation. In Kerala, anthurium cultivation started to pick up steam in the 1990s, and in more recent years, it has become just as popular as orchids there. Anthuriums are currently mostly grown in a few small gardens and nurseries. But some forward-thinking farmers began cultivating anthurium in protected areas near Bangalore, Belgaum, Goa, Sirsi, etc. Assam, Kerala, Tamilnadu (Salem), and Karnataka (Coorg) are significant states for anthurium cultivation due to their favourable climates.