Important ARS Questions on Diallele Mating Designs

1. (a) What is diallel cross?
(b) What genetic information is obtained from its analysis which has relevance to plant breeding?
(c) Discuss the advantages and limitations of graphic and combining ability analyses. (ARSE, 1986

2. (a) Distinguish between general and specific combining ability.
(b) Griffing has proposed models I and II for combining ability analysis. What do these models signify?
(c) Give the situation under which these models can be used. How does a plant breeder use this information. (ARSE, 1991)

3. What is a diallel cross? Describe briefly the two approaches of diallel cross analysis.

4. Describe briefly different types of diallel cross and give their merits and demerits.

5. What is Vr-Wr graph? Describe its significance in diallel cross analysis?

6. Differentiate between the following :
   (i) Hayman’s and Griffing’s approach
   (ii) Half diallel and full diallel
   (iii) Fixed effect model and random effect model
   (iv) Half-sib and Full-sib

7. Write short notes on the following :
   (i) Vr-Wr Graph
   (ii) Hayman’s Approach
   (iii) Griffing’s approach
   (iv) Degree of Dominance
   (v) Half Sibs
   (vi) Full Sibs

8. Explain Haymen’s approach of diallel analysis.

9. Discussed Griffing’s approach of diallel analysis.

10. Give brief comparison of Hayman’s and Griffing’s approach of diallel cross analysis.