The inheritance of restriction fragment length polymorphisms in the flax rust Melampsora lini

P A Anderson1, G J Lawrence, A Pryor

  • 1CSIRO Division of Plant Industry, GPO Box 1600, 2601, Canberra, ACT, Australia.

Insights

This study used random cDNA probes to identify genetic variations, called restriction fragment length polymorphisms (RFLPs), in flax rust fungus (Melampsora lini) populations. These genetic markers help understand flax rust diversity and inheritance patterns.

Area of Science:

  • Plant Pathology
  • Molecular Genetics
  • Mycology

Background:

  • Flax rust fungus (Melampsora lini) poses a significant threat to flax cultivation (Linum usitatissimum).
  • Understanding genetic diversity within M. lini is crucial for developing effective disease management strategies.

Purpose of the Study:

  • To identify and characterize genetic polymorphisms in Melampsora lini using random cDNA probes.
  • To investigate the inheritance patterns of detected restriction fragment length polymorphisms (RFLPs).
  • To assess the genetic relationship between M. lini races from cultivated and native flax species.

Main Methods:

  • Synthesis of random complementary DNA (cDNA) probes from polyadenylated RNA of germinated urediospores.
  • Detection of restriction fragment length polymorphisms (RFLPs) in different races of M. lini.
  • Segregation analysis of RFLPs in an F2 progeny population derived from a cross between two rust races.

Main Results:

  • Twenty-two cDNA probes were used, with 14 detecting RFLPs in cultivated flax races and 19 detecting polymorphisms between cultivated and native flax races.
  • Segregation analysis of seven RFLPs revealed single-locus inheritance for six, with an unusual two-locus model proposed for the seventh.
  • No linkage was observed between RFLP loci and nine avirulence loci.

Conclusions:

  • Random cDNA probes are effective in detecting RFLPs and revealing genetic diversity in Melampsora lini.
  • The study provides insights into the inheritance of RFLPs, contributing to the genetic mapping of flax rust.
  • The genetic markers identified can aid in understanding the evolution and population structure of M. lini.