Thursday, August 26, 2010

Update on Phalaenopsis pollination 26 August 2010

Pollinated Phal flower front view
It has been 12 days since the pollination of 3 flowers from the large pink Phalaenopsis from Woolworths (2 x P. Golden wonder X P. no id Woolworths; 1 x P. no. id Woolworths X self). Within 48 hours the flowers wilted. You can already see the transformation beginning. The back of the flower column is beginning to swell and elongate and the front of the column has enclosed the pollinia and stigma. The petals, sepals and labellum have all become dry and papery now. The literature suggests an average time to harvest of the green pod at about 5 months after pollination for large hybrids. This will be sometime in January and I will be keeping a beady eye on any pods. By this time I would have acquired some Sigma Phytamax P6668 culture medium for seed germination. I am still working out which gelling agent I should use though, and how much will be needed. I will probably use Sigma’s Phytagel but will see if I can find any other alternatives that won’t be too expensive.

Pollinated Phal flower side view
On the same subject but a different orchid, I stumbled across an abstract for a recent South African publication on “In vitro asymbiotic seed germination and seedling growth of Ansellia africana Lindl. by Vasudevan, R. and Van Staden, J. (2010) from the University of KwaZulu-Natal’s Research Centre for Plant Growth and Development. I subsequently requested a reprint which I kindly received from the authors. The study tested whether different concentrations of sodium hypochlorite (during sterilization of seed) influenced germination and success of seedling development. Ultimately their findings suggested that the different media used were probably responsible for their different results and that keeping the seeds in darkness for a period during germination improved the quality of the protocorms. They suggested that the darkness probably promoted rhizoid development of the protocorms which once exposed to light had a better supportive mechanism already in place for the transportation of nutrients from the medium while commencing with chlorophyll development. An interesting read indeed! They recommend using Phytotechnology’s P668 orchid maintenance medium (this is nearly identical to Sigma's P6668) for seed germination in this species. I wonder if they would let me have a seedling or two from the study… mmm…I will enquire with the authors. Here is the full reference to the paper:

Vasudevan, R., & Van Staden, J. (2010) In vitro asymbiotic seed germination and seedling growth of Ansellia africana Lindl. Scientia Horticulturae 123: 496 – 504.

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