Dr. Brian Murray

Associate Professor

Ecology, Evolution and Behaviour

Phone: x88334
Rm 310

Plant Genetics and Evolution Laboratory

To help choose more suitable species for hybridization we try to understand the chromosome variation that is present.In this example from Clivia various chromosome banding techniques, which identify the sites of constitutive heterochromatin (C-banding), GC or AT rich fractions (CMA and DAPI banding), the active nucleolar organizer regions (AgNO3) and the sites of the 45S rDNA genes (FISH, fluorescent in situ hybridization), have been used to characterize chromosome variation.We then have a more rational basis for our choice of parents in a breeding programme. We also use DNA sequencing and DNA polymorphisms to gain a better understanding of the relationships between our plants.

We are also interested in evolutionary patterns and processes in wild plants and these studies also involve chromosome analysis.

In the New Zealand flora we are currently investigating the chromosomes of the native gymnosperms. This allows comparisons to be made between our ancient podocarps and the other groups of gymnosperms such as the pines.

Techniques like in situ hybridization can be used to identify the location of particular genes, as shown (right) on the prophase chromosomes of Podocarpus totara, and the positions of the same genes can be identified in other groups.

Chromosome analysis can also give interesting insights into the structure of plant populations. An example of this is our collaborative work with Dr Andrew Young at CSIRO Plant Industry in Canberra, Australia.

The button wrinklewort, Rutidosis leptorrhynchoides, is now found in only 22 populations in SE Australia but in an analysis of some 300 plants from 19 of the populations we have found 17 different cytotypes. These have different basic numbers and each of them has several polyploid races. Structural variants are also relatively common. The distribution and range of these chromosome variants is shown on the map below. This sort of information is vital when conservation strategies are to be developed as many of the populations are unique.

These populations should be preserved, and if revegetation is to be attempted then great care needs to be taken in the sourcing of plant material.

*See here for a translation into the Estonian language by Martha Ruszkowsk.

Recent Publications