Novel trait induction in elite wheat varieties

J Greenwood1,2, K Ramm1, S Boden3, J Evans2, B Trevaskis1 and S Swain1

  1. CSIRO Black Mountain, Canberra, ACT 2612, Australia
  2. ANU Research School of Biology, The Australian National University, Acton ACT 2601, Australia
  3. JIC Norwich Research Park, Norwich, NR4 7UH, UK

Conventional wheat genetic improvement involves the selection and combination of desirable traits from existing germplasm. This form of crop improvement can be very time consuming when combining many traits, particularly those under complex genetic control, and is limited by the genetic variation that exists in nature. At CSIRO we are exploring the potential of induced traits in wheat with a focus on changes in wheat development. The wheat inflorescence, or spike, is a specialised structure responsible for grain production, but the genetic control which underlies the size and shape of the wheat spike is poorly understood. In order to better understand the genes which control wheat spike development we have induced traits with simple (single gene) genetic control through a forward genetic mutagenesis screen. Using a combination of Sanger sequencing and RNA sequencing we have been able to identify mutations that underlie altered inflorescence development in some of our mutant lines. To confirm candidate mutations as causal, we have used co-segregation, secondary mutagenesis and transgenic approaches. By introducing novel variation in inflorescence development genes we have gained insight into regulatory networks key to inflorescence development and shown that mutagenesis is an effective means of inducing new variation in wheat.