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Plants & Us: A Sneak Peek at Our Seed Handling Process

Posted Date: Wednesday 10 June 2020    

On a cool, sunny day, our team ventured onto Lantau Island, the largest island of Hong Kong, to collect seeds of native plants for conservation. The route planned for the day stretched across two streams in the island. The aim was to collect seeds of plants that grow well in bright, open areas. All necessary permits had already been issued by AFCD for KFBG to collect seeds in Hong Kong’s wild areas and Country Parks. All collections sourced in this way serve as the foundation for our conservation work and facilitate deeper biological and horticultural study.

Arriving at the starting point, everybody was eager to get off the beaten track and find out what treasures lay in wait for us. Within 30 minutes, we had made our way to the beginning of the first stream. The stream started off quite narrow and was strewn with large boulders, and since it was the dry season, the water level was very low. Soon, our team spotted our first native plant in fruit: Bauhinia championii, a chaotic tangle of leafy shoots bearing dozens of dangling beans. Half the team stopped to inspect the plant and get out the tools needed to remove and pack the seeds for transportation. The other half of the team scouted out the surrounding area to see what else they could find. And so the day went on, carefully moving from one boulder to the next along the streams, we were regarded with sporadic finds. In all, we successfully collected seeds from seven native species: Phyllanthus reticulatus, Ligularia japonica, Pittosporum glabratum, Ardisia filiformis, Farfugium japonicum, Bauhinia championii and Rhapis excelsa.

Seeds collected may be of ecological and horticultural interest, but in the case of rare species, such as Ligularia japonica, they are also of conservation value. As the more common species, such as Phyllanthus reticulatus and Pittosporum glabratum, we aim to collect seeds from several different locations to enhance the overall gene pool for our conservation programmes.

We will now take you on a step-by-step journey to explain the process of how we handle the seeds once they have been brought back to our nursery. We will use Bauhinia championii as an example. This species is the nectar plant for the butterflies Graphium antiphates, Hypolimnas bolina and Graphium Agamemnon.

 

Step 1:

The seeds collected from each plant are placed in individual plastic bags in the field to keep them separate from one another. Sometimes seeds of different plants look surprisingly similar. This way of handling seeds not only reduces the chance of misidentifying them later, it also saves time.

The seeds collected from each plant are placed in individual plastic bags in the field to keep them separate from one another.

 

Step 2:

Once back in the nursery, the seeds are emptied out from the bags and placed in individual dishes. A label with a record of the plant’s Latin, English and Chinese names, date and location of collection, is given to each. In addition, a code number is assigned to aid with databasing the collections.

Once back in the nursery, the seeds are emptied out from the bags and placed in individual dishes.
 

Step 3:

Since our example species, Bauhinia championii, belongs to the bean family, Leguminosae, its seeds come packaged inside beans. When the valves of the bean turn purple, it is a sign that the seeds inside are mature and ready to be harvested. Here, we have opened the capsule and extracted the seeds.

Since our example species, Bauhinia championii, belongs to the bean family, Leguminosae, its seeds come packaged inside beans.

 

Step 4:

Next, we lay a thick layer of soil down in the bottom of a tray.

We lay a thick layer of soil down in the bottom of a tray.

 

Step 5:

The soil is moisten by spraying water.

The soil is moisten by spraying water.

 

Step 6:

One-by-one, we sow the seeds onto the surface of the soil.

One-by-one, we sow the seeds onto the surface of the soil.


 

Step 7:

We fill the tray, leaving a fair distance between each seed.

We fill the tray, leaving a fair distance between each seed.

 

Step 8:

Now we put another layer of soil over the seeds. Once again, we water it to keep it moist.

We put another layer of soil over the seeds. Once again, we water it to keep it moist.

 

Step 9:

Now we wait for germination to happen.

Now we wait for germination to happen.

 

As easy as it looks, this takes time and practice to get it right. And although we may already know how best to handle the seeds of some species, for other species we may need to do a lot of testing and experimenting to determine how to make the seeds germinate.

Coming up next! In our next report, we will describe some of the challenges and difficulties our field teams face when they collect seeds.