OSMOSIS 11, AUTUMN 1996
Contents
Director's Letter
Workshop Calendar
Plant Tissue Culture 2: The effect of sugar on root explants
Post Bag
Stabilising film can plant pots
Letter from the Director
Dear Colleague
Demand for our workshops is as buoyant as ever and the feedback from those who attend indicates that we seem to be getting it right for most people. Comments include: 'Enthusiasm makes the day! Science is fun', 'Feel inspired to pass this knowledge onto colleagues as well as improving my own classroom practice'. Philip Harris has now sold well over 1000 brassica kits and NCBE has sold 253 Plant DNA kits since November 1995 when the kit was launched. This figure includes 122 kits for which SAPS has given a grant of £85.
We are gradually expanding our Internet presence and have material now on two web servers. The URLs for these sites are given above. A generous grant from the Gatsby Foundation is enabling us to set up our own web server in the Department of Plant Sciences here in Cambridge. This will allow us to develop an interactive forum on the World Wide Web which we shall launch at the ASE Annual Meeting. Dr Mary MacDonald has been appointed to develop and manage this site and to carry out further development work on our DNA and tissue culture protocols. Mary has over 20 years experience in plant science research and a network of useful contacts in the plant science community.
Finally, apologies to all who found it hard to get through on the telephone in September. The College installed a new telephone system which created a few problems. All is well now but please note our new telephone number - 01223 507168.
Richard Price
Programme Director
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Post Bag
We are still getting questions about the best temperatures for the growth of the rapid cycling brassicas under lights.
· Our colleagues in Wisconsin, USA have pointed out that the plants grow best at about 20-22 C, when most plants will develop normally and flower on time. At 17 C plants develop more slowly, whereas at 24 C fertility may be reduced, and by 28 C male sterility may be a problem. It should be remembered that under lights, the temperature can be 1 - 2 C warmer than the room temperature. Plenty of ideas for investigations here!
We are interested to hear about your plants, - What temperatures do yours grow at? How long do they take until the first flower opens? Our instructions recommend that you limit your plants to eight pods. How many seeds do you get per pod? We could collate data nationally to generate larger data sets, and test the suitability of these temperatures based on your results.
Q. We have used thin layer chromatography (TLC) idea from Osmosis 8, but find that the colours fade. Is there any way to make a permanent record of the colours?
· John Hobden (Primary Teacher as Scientist Project, Homerton College) found that a colour photocopier gives an excellent permanent colour picture of the thin layer plate. However, a standard copier will also give an indication of where the spots are. Draw round the spots in pencil and then use a felt pen or crayon to colour code the spots. Several plates can be put on a single sheet for photocopying. You could also investigate whether chlorophyll is still present in autumn leaves.
Q. Where can we get Venus Fly Trap (Dionaea muscipula) plants?
· Good garden centres have these for sale in micro propagation tubes, with instructions for transferring them to compost and growing them. As many as 5 - 6 plants can be obtained from each tube which costs about £2.50, so this offers a cheap sustainable source of the plants. They grow best in a 1:1 mixture of lime-free sharp sand and moss peat.
Q. I am looking at rates of photosynthesis and need an accurate way of recording leaf area. I have tried drawing round the leaves, but they often slip and wilt.
· Stick leaves to graph paper and photocopy them. Count the number of squares which are completely covered and then add an estimate for the area of those partly covered. This method can also be used to estimate the amount of variegation on variegated leaves.
· John Hewitson (Oundle School) adds.. Alternatively the photocopied leaves can be cut out and weighed. A figure for the weight of paper per sq. cm is easy to determine, so the mass can be converted to area. For simple leaves, e.g. privet or potato, it is possible to produce a relationship between length x breadth and the leaf area. It is then possible to measure leaves whilst on the plant and to calculate their area from the relationship you have found.