23 Mar 2021

How to Culture Lotus flowers in Artificial Conditions

Anjali Singh, MS

As a content and community manager, I leverage my expertise in plant biotechnology, passion for tissue culture, and writing skills to create compelling articles, simplifying intricate scientific concepts, and address your inquiries. As a dedicated science communicator, I strive to spark curiosity and foster a love for science in my audience.

Table of Contents

History of Lotus flowers

The Lotus flower, also known as the sacred flower, has a prominent place in eastern cultures; the flower's beauty makes it an excellent choice to become the national flower of India. People often associate this flower with their god or goddess. What makes this flower so unique? Why does it culturally hold a strong position in the heart of people? The answer is hidden behind its growth and survival. This article tells you conventional tissue culture techniques to grow these beautiful plants in your area or lab. Let’s begin!

Features of Lotus and its distribution worldwide

Lotus is a beautiful flower, botanically called Nelumbo nucifera. It belongs to the family of Nelumbonaceae. It’s an aquatic plant widely grown in flood plains of slow-moving rivers and delta areas. The flowers are present on a thick stem that rises over the leaves. The leaves of the plant are large, rounded, and float on the surface of the water. The petioles are 200 cm in length and 1 meter in breadth (horizontally spread). The leaves of the plant are 80 cm in diameter. The stem is lined and thick to support the big flower of the plant that is about 30 cm in diameter. The roots of the plant are attached to the mud or surface of the ponds.

The lotus plant is majorly spread in central and northern India, northern Indochina, and East Asia. Other than this, they are found in southern India, Srilanka, northern and eastern Australia, and New Guinea.

Figure: The Lotus flower and its big wide leaves are flourishing well in a pond.

The magical potential of Lotus

The lotus plant is one of two living plants of the family Nelumbonaceae. It’s also considered a living fossil as the other members of the family are extinct a long back. The existence of lotus flowers is believed to stretch 145.5 million years. The plant can thrive well in conditional extreme situations as well. In some areas, it has been observed that after being destroyed by the flood situation, these plants grow back again by themselves. They can also grow well in polluted areas and are believed to purify the water for their growth as well.

The magic of their survival is hidden behind the character of its seeds. The lotus plant drops thousand of seeds (in a year) on the surface of the pond. The seeds remain dormant under unfavorable situations when the pond dries out or gets over flooded. After the return of the growth-encouraging environment, the seeds get rehydrated and begin to flourish and spread their bloom.

Figure: A beautiful seed pot of the Lotus flower plant.

Image is taken from https://unsplash.com/photos/0-XFBJT-_B0

Techniques to culture Lotus flower

Conventional technique

1. Place lotus seeds in a warm glass of water. (if the seeds start floating on the surface it shows they are unhealthy).
2. When the roots start emerging from the seeds, transfer them to a 4-inch pot and cover roots with soil and gravel. One seed per pot.
3. Provide enough light.
4. As the plant grows, transfer the plant to bigger pots and then finally to the pond.
5. Plants may not bloom in the first year but you will see beautiful flowers in the following years.

Tissue Culture technique

The lotus plant is cultivated worldwide for its medicinal, ornamental, and edible values. Today, several explants of the lotus are used to culture these plants under in vitro conditions. It includes immature cotyledon, immature embryo, nodes, rhizome, and leaves. The success of lotus tissue culture depends on several factors like genotype of the plant, source of explants, amount of growth regulators added, external environmental factors, etc.

The following procedure of in vitro culturing of the lotus is taken from Yu, Xia & Sheng, Jiajing & Zhao et al. (2015). In vitro plant regeneration of lotus (Nelumbo nucifera).

Process

1. Collect the plant material (buds in this case) from the source plant.
2. Excise the buds from the rhizome and wash them under tap water.
3. Remove the outer sheath of buds.
4. Surface sterilize the explants with 75% ethyl alcohol for 30 s, 0.1% (w/v) mercuric chloride (HgCl2) for 7 min under sterile condition.
5. Then, rinse the materials thoroughly with sterile distilled water four times.
6. After washing, remove the inner sheath.
7. Excise the shoot apical meristem.
8. Prepare a basal Murashige and Skoog (MS) media supplemented with 2.22 µM N6-Benzylaminopurine (6-BA). Add 30 g/L sucrose, 2 g/L polyvinylpyrrolidone (PVP).
9. Adjust the pH of the media to 5.8 and then add agar to the media.
10. Autoclave the prepared media at 121°C for 15 min.
11. Culture the explants (shoot apical meristem) on the above-prepared culture media.
12. After four weeks, you can see the multiple shoots coming out.
13. Divide the shoots and subculture on the same prepared media.
14. Incubate all the cultures at 12 h of cool-white fluorescent light (40 μmolm-2s-1 of photosynthetically active radiation) at 27±2°C.
15. Prepare the rooting media with basal MS media supplemented with 0.54 µM NAA (α-Naphthalene acetic acid) and 30g/L sucrose.
16. Add 2 g/L PVP to the media and adjust the pH to 5.8. Then, add agar to the media and autoclave it at 121°C for 15 min.
17. After five continuous subcultures, transfer the cultures to the rooting media.
18. Keep plants in the above-mentioned (step 14) conditions.
19. After four weeks, the plantlets will be 8-15 cm in height.
20. Pull out the plantlet gently from the media and wash the roots under tap water.
21. Transfer the plantlets to the pots in the greenhouse with a photon fluence of 100 mmol × m-2s-1 and a 12 h photoperiod at 23±2°C.

Through tissue culture, lotus plants are being grown in three categories. First, rhizome lotus that develops enlarged edible lotus, flower lotus that fulfills the ornamental uses of consumers, and seed lotus that is solely cultured to obtain a large number of lotus seeds.

Let us know what plant you are culturing. We will be delighted to feature it on our social media platforms. For any suggestions and views, you can write to us at anjali@plantcelltechnology.com.

Happy culturing!!

References

1. Yu, Xia & Sheng, Jiajing & Zhao, Lingling & Diao, Ying & Zheng, Xingwen & Xie, Keqiang & Zhou, Mingquan & Hu, Zhongli. (2015). In vitro plant regeneration of lotus (Nelumbo nucifera). Open Life Sciences. 10. 10.1515/biol-2015-0016.
2. Xianbao Deng, Yaqian Xiong, Jing Li, Dong Yang 1,2, Juan Liu, Heng Sun, Heyun Song, Yunmeng Wang, Junyu Ma, Yanling Liu, and Mei Yang (2020). The Establishment of an Efficient Callus Induction System for Lotus (Nelumbo nucifera). Plants. ; doi:10.3390/plants9111436.
3. https://www.flowerglossary.com/lotus-flowers-meaning/
4. https://en.wikipedia.org/wiki/Nelumbo_nucifera