Tallis, Chloe and Jess have been working hard for the past two weeks to prepare for our first trip to Sarawak in July (We fly out on July 14th). We have worked with our partners in Kuching to order everything for the new propagation lab at MRSM School and today we have been sorting out seed and seedlings in vitro to take for laboratory skills training. We want to take a good range of seed from our seed bank so that students get experience in handling seeds that sink, float or do a bit of both.

The samples show just how varied orchid seed is.

We are taking fifteen different orchid species seedlings in-vitro to include a range of South East Asian species and a range of seedling ages.

For transport the seedlings will be moved out of their sterile jars and into sterile bags (without media)

In Kuching the seedlings will be moved back into sterile jars and, of course, everything is done aseptically in a flow cabinet as shown below.

The seed and seedlings will be accompanied by an import certificates from Sarawak (The Wildlife Officer at the Nature Conservation & Constitution Division of the Forest Department Sarawak has been very helpful) along with export and phytosanitary certificates from APHA (Animal and Plant Health Authority UK). I feel that it is always a good learning experience for students to get involved with the certification for the legal export of their orchid seedlings.

This gorgeous large flowered bulbophyllum arrived in a donation collection a few years ago and has responded well to growing damp and shaded in our Warm Asia section.  Bulbophyllum sumatranum is found  from Thailand through Malaysia to Sumatra, where it grows in wet forests from 900-1500m.

The species was relatively recently separated from Bulbophyllum lobbii, which has an overlapping range and is also found further east in the Philippines.  Both species are rather variable in flower shape and colour and so I am not confident that if we come across either in the forests of Sarawak next week that I would be able to separate them.

We are planning to take Kuching school students up into nearby rainforest to identify orchids and our main target will be to help local children to identify their native orchids by genus and Sarawak bulbophyllums are a genus we are looking forward to getting to know.

Amongst the techniques we will be sharing with school students in Sarawak in our forthcoming trips (July and October) will be seed viability testing using TZ (2,3,5-Triphenyltetrazolium chloride).

Otto demonstrates the first stage – mixing orchid seed with 10% sucrose in a 1.5ml micro-tube. The tube then sits at room temperature for 24 hours. Everyone loves using a micropipette!

When the 24 hours are up it is time to remove the sucrose solution and replace it with 1% TZ solution  (centrifuges and vortex mixers are a great help with separating seeds from sucrose and then mixing with TZ) Microtubes are then put in a water bath at 40C for 24 hours for the TZ to react with respiration products and turn viable embryos red.

Great results under the dissecting microscope – red embryos = viable and so this seed that has been in our seed bank since Nov 2017 is 80-90% viable

This Brazilian Cattleya is the sister species to Cattleya purpurata featured last week (below)

Cattleya tenebrosa grows as an epiphyte in open lowland forest up to around 1000m and so enjoys warm conditions and good light. We hang our plant in the roof of the Warm Americas Zone where it gets lots of sun and we work to keep it well watered in the summer.

Its name tenebrosa means ‘dark’ referring to the flowers but it does come in a range of colours from yellow to a deep brown with a contrasting pink and purple lip. We are delighted to have many thousands of these growing in-vitro so look out for them on out sales table.

A new orchid for 365 days is this species native to warm forests from Sikkim to Thailand. It has similar growth to Micropera rostrata but smaller flowers in pink and yellow.

We grow both species in our warm asia section and find that they do well in baskets or mounted to suit the semi-pendulous growth habits and extensive arial roots.

Both species were originally included in Aerides but have been separated on the basis of the unusual flower structure.