INTERACTION AND LINKAGE OF YIELD COMPONENTS IN PEA

PNL Volume-15 1983 RESEARCH REPORTS u

Csizmadia, L. Research Station of Vegetable Crops Research Institute

Ujmajor, Hungary-

There are few reports indicating that non-allelic interactions and

linkage might play an important role in the inheritance of pea seed

yield and its components (3,4,5). This question was investigated in two

of our crosses. In cross A, between Ujmajori Arany x Grune Perle, we

studied the following populations: P1, P2, F1, F2, F3, B_1S, B_2S. In

cross B, between Wav.01 x Triton, the populations were: P1, P2, F1, F2,

F3, B1, B2. Information on the nature of the genetic effects and the

partitioning of the variation were obtained by weighted least square

analysis (1,2). In cross B the number of statistics was insufficient

for the test of linkage.

Table 1 gives the estimates of the parameters of the digenic inter-

action model for seed yield components in the two crosses. The simple

additive-dominance model is adequate only for seeds/5 pods in Cross B;

hence in all other cases some form of epistasis is present. The highly

significant Chi-square for 100 seed weight in Cross A indicates the

operation of higher order interaction, but the number of families does

not allow fitting the required model. In other cases the 6 parameter

model fits well, indicating digenic epistasis, either duplicate or

complementary.

The standard test for linkage based on second degree statistics was

performed for Cross A (Table 2). There is good evidence of linkage in

the characters pods/plant and seeds/5 pods. In the case of 100 seed

weight, the failure of detecting linkage could be due to the strong

epistasis. This complex case would require a more sophisticated joint

analysis or non-allelic interaction and linkage.

1. Cooke, P., R. M. Jones, K. Mather, G. W. Bonsall, and J. A. Nelder.

1962. Heredity 17:115-133.

2. Hayman, B. I. 1958. Heredity 12:371-390.

3. Krarup, A. and D. W. Davis. 1970. J. Amer. Soc. Hort. Sci.

95:795-797.

4. Sharma, R. P., K. S. Nadpuri, and J. C. Kumar. 1977. Indian J.

Hort. 34:157-162.

5. Singh, S. P. and H. N. Singh. 1 979. Indian J. Agric. Sci.

49: 401-403.