Tissue culture lab for generating threatened Delhi trees in works

The department has identified around 10 such species – hingot, khair, bistendu, siris, palash, chamrod, doodhi, dhau, desi babool, and kulu

In a bid to generate saplings of threatened or rare native Delhi trees, the city’s forest and wildlife department is setting up a tissue culture laboratory at the Asola Bhatti Wildlife Sanctuary. The aim is to help grow endangered native Delhi trees in a controlled environment, and to regenerate saplings whose seeds are not readily available in large quantities, said an official aware of the matter.

Palash trees are among those that will benefit from the new lab. (HT Archive)

“This will especially target a majority of native Aravalli or ridge species that are facing regeneration challenges and have a poor survival rate due to the invasive vilayati kikar, which does not allow other saplings to propagate easily,” said Suneesh Buxy, Delhi’s additional principal chief conservator of forests.

So far, the department has identified around 10 such species – hingot, khair, bistendu, siris, palash, chamrod, doodhi, dhau, desi babool, and kulu.

The forest department said it has already begun the process of setting up this lab at Asola, and a tender has been floated for the project. “We are now inviting bids for the project and if no bidders are received, we will approach the irrigation and flood control department of the Delhi government to construct the lab,” said the forest official, who asked not to be named.

The official explained that though the required number of botanists and forest staff for the laboratary is yet to be finalised, the department plans to take assistance from botanists and scientists from the Indian Council of Forestry Research and Education (ICFRE) and the Forest Research Institute (FRI), both of which are in Uttarakhand’s Dehradun.

Once set up, the lab will be able to extract plant tissue from an in-vitro fully grown plant, which will generate multiple trees from the same tree, said the forest department official.

Biodiversity experts, however, argue that the exercise should only be done for “extremely rare trees” as the grown saplings will be exact clones of the parent tree. “There will be no gene-pool diversity, which leaves them vulnerable to being wiped out due to a particular viral strain or disease,” said Vijay Dhasmana, an ecologist, who is also the curator at the Aravalli Biodiversity Park in Gurugram.

A forest official told HT that the lab will ensure that the replicated saplings are free from any virus or disease at the cloning stage.

What is tissue culture?

Tissue culture, also known as micro-propogation, allows multiple plants to be produced from a parent plant using in-vitro tissue, which is incubated under a controlled environment. Through this technique, new saplings will become clones of the parent plant.

If successfully established, this will be the first plant tissue culture laboratory under the Delhi forest department, though such projects have been carried out across the country, including Delhi, in the past. In fact, the National Facility for Plant Tissue Culture Repository (NFPTCR) was established at the National Bureau of Plant Genetic Resources (NBPGR) in Delhi in 1986. They have been carrying out tissue culture experiments and research on five plant types -- tubers, bulbs, spices and plantation crops, horticultural crops and medicinal and aromatic plants.

Over 125 tissue culture labs exist, both in private institutions and as part of state of Central bodies, in the country.

Tissue culture has been particularly successful in farming, especially for tissue cultured banana, which has a higher yield than conventional banana farming. The technique has also been used for crops like apples and pomegranate, and jatropha (genus of flowering plants).

The Aravalli Plan

Buxy said that trees such as Kulu (also known as the ghost tree), palash, doodhi, and dhau – all ridge species rarely found there now – have regeneration or growth challenges. “They have a poor survival rate, largely owing to the more invasive species not allowing these native species to grow easily. Their large-scale multiplication is possible only through tissue culture, specifically shoot culture. This lab will also be useful in culturing endangered medicinal plants,” said Buxy.

Dhasmana said that while the exercise can be useful in cases of endangered or near extinct species, the list prepared by the forest department comprises species such as khair, dhak, chamrod and desi babool that are found rather commonly in the Aravallis.

“There are native species such as bakaar, elephant nettle, and the toothed leaf chilla that are hard to find and grow in the Aravallis. Tissue culturing can be useful to regenerate them but for the more common species such as desi babool or khair, this experiment will be a waste of public funds. There will also be limited genetic diversity, and the trees will be clones of a single tree or plant,” he said.

He said that other rare species which can benefit from this exercise are roundlead axlewood, moon plant, rohida, guggal, chitawal, and jaal.

A forest department official said the initial list prepared consists of species that are likely to be suitable for tissue culture practices, and that the list will be updated based on the growth shown by different plants and trees.

“This is an initial list and plan. Once the lab is ready, we will see which species are more suited to tissue culture and those not doing as well,” said the official, on condition of anonymity.

Meanwhile, Sohail Madan, who worked at the Asola Bhatti Wildlife Sanctuary till 2023, as a part of the Bombay Natural History Society (BNHS), said that cloning multiple plants from a single plant remains a problem with tissue culture as the clones are susceptible to being wiped out by a single virus or disease.

“But this can be avoided by not limiting oneself to a single seed variety. If done through different parent seeds or by using different seed varieties, one will be able to avoid having multiple trees that are clones of the same tree. Delhi’s ridge areas can particularly benefit from this, when it comes to certain species, whose seeds are hard to procure, such as peelu, jaal, and guggal,” said Madan.

Faiyaz Khudsar, scientist-in-charge of DDA’s biodiversity parks programme, said that tissue culture is one way of bringing back some native Delhi trees, which are no longer found here. “Kulu has completely vanished from Delhi’s forests, and salai is also not found at Delhi’s ridge. This experiment can revive them,” he said.

Meanwhile, Buxy said that the initial goal is to utilise the technology to regenerate species with a poor survival rate in the ridge areas. “Other than native trees, we can also try tissue culture on orchids and some shrubs,” he said.