lupin experiments

Experiment ideas

The following suggestions are some of the experiments which have been carried out by members of the class over the last few years. Students have had variable success with these experiments.

One factor which may lead to failure is the fact that seeds collected from the wild tend to have a large number of mould spores associated with them. It is important that the external surfaces of the seeds are cleansed by washing in 5% hypochlorite solution and then rinsing in distilled water. If germination experiments are carried out then it is essential that the germinating seeds are well ventilated. If you want to speed up germination (not in the dormancy investigation though!) then you should prick a small hole in the testa of the seeds - make sure that this is done to the opposite end of the seed from the micropyle otherwise you may damage the embryo.

What are the factors which cause changes in leaf angle folding of Lupinus arboreus leaves? There are at least two factors to which can be investigated by sampling in the field.

	The relative maturity of the leaves
	Exposure to desiccation - eg caused by heat or wind

Germination

	Which factors are responsible for maintaining dormancy?
	Are the seeds of Lupinus arboreus better able to withstand pre-exposure to high temperatures prior to germination compared with the seeds of other plants?

Leaf angle folding

	How do changes in humidity affect the degree of folding of leaf angles?
	How do changes in temperature affect the degree of folding of leaf angles?

Transpiration

	Which surfaces of the leaves have the greatest transpirational losses?
	What is the effect of temperature (or humidity) on the rate of transpiration?

Chlorophyll extracts

	Determine the absorption spectrum of the chlorophyll.
	Do plant from different populations (eg beach cf industrial wasteland) have the same absorption spectra?

Light responses

	Is germination affected by the colour of light?
	What is the effect of light colour on etiolation and chlorophyll production?

Plant hormones

	What concentration of auxin (eg indole butyric acid) has the greatest effect on germination?
	What concentration of auxin has the greatest effect on root and stem growth of Lupinus arboreus seedlings?

This page hosted by Get your own Free Home Page