Homework No. 1

Instructions:
Read Chapters 13 and 14 of ‘Breeding for Quantitative Traits in Plants’ by Rex Bernardo.
Read the manuscript entitled ‘The power and deceit of QTL experiments: Lessons from comparative QTL studies’ by W.D. Beavis.
Discuss the assigned readings in your small groups and prepare a 20 minute presentation to be presented to the class. Group A will prepare the report for questions 1, 2, and 3. Group B will prepare the report for questions 4, 5 and 6. Be prepared to lead a discussion on the questions assigned to your group.

Group A
1) Compare the results of using 200 progenies versus 500 progenies to identify QTLs in a mapping experiment.

2) How to you explain the fact that QTL’s which were identified in one mapping population were not present in another mapping population?

3) If QTL’s are specific to each population, how would this affect the efficiency of marker assisted selection (MAS)?

Group B
4) How did the size of the mapping population affect the estimate of the magnitude of the QTL?

5) Marker assisted selection is predicted to be most effective for traits of low heritability. Why would QTL’s of small effect be difficult to map?

6) Why is it necessary to confirm the presence of a QTL?