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, B1S, B2S. 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
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.
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.
12 PNL Volume 15 1983