Activity No 5Questionnaire on efficiency of

phenotypic selection

Jan Kowalczyk, IBL P19Fulvio Ducci, CRA P12

Phenotypic selection

• Method of selection, where the best individuals are selected on the basis of their appearance without any knowledge about the genetic parameters of the traits of interest.

• It includes also selecting of trees based on measurements but without calculating the genetic parameters.

Result

• We receive 25 responses 82%. • Thank you for partners:

P1 P2 P3 P4 P5 P6 P7 P8P9 P10 P11 P12 P13 P14 P15P16 P17 P18 P19 P20 P21 P22P23 P24 P25 P26 P27 P28

2. What species or group of species are involved:

20 – in total

3. What kind of strategies are used during selection?

4. What kind of methods of selection do you employ?

5. Which kind of methods are used for phenotypic selection?

6. What kind of observation and measurements are selection based on?

7. What traits are interest?

8. What are the objectives and methods of phenotypic selection ?

9. Where is phenotypic selection applied?

10. What is your raw estimation of the intensity of phenotypic selection?

11. What is the effectiveness of phenotypic selection

• Unknown - 30%• Studied in practical examples 36%• Studied in simulations using parameters 18% :

– Statistics - i, – S and Genetic gain, – Combination attitudes (GCA and/or SCA)

• Other 15% – Realized gain in field trials as mean BLUP

12. What is the scale of application of phenotypic selection?

• What is average number of plus trees selected per year? 1600 (min - 0, max - 350)

13. What are the benefits of using phenotypic selection in your

opinion?

• Quick & easy• Low cost • Simple• First step of breeding • Gain can be really high (for

heritable traits)• Conservation of genetic diversity

• High throughput• Results are valuable also at

maternal level • Can result in higher gain per time

unit• Partial avoidance of genetic bottle-

necks • Resistance against diseases and

pests

• Unexplored G x E interactions at the selection site

• Reduced genetic gains • Efficiency unknown Low

reproducibility • No a-prori knowledge of genetic

basis • Subjective evaluation of certain

traits Superficial • Small variation - low number

selected tree • Special personnel needed• Based on juvenile traits

14. What are the disadvantages of using phenotypic selection in your

opinion?

15. What is the future outlook for phenotypic selection?

• Decrease – 4 • No change - 8• Increase – 10

• 16. Practical example

• 17. Literature

Conclusions

• Phenotypic selection is frequently used • It is accepted as a method of selection• It is often breeding-efficient• It is done frequently after measurements not

only based on observations