USE OF IN-VITRO TISSUE-CULTURE TO STUDY H ETEROSIS IN THE PEA

Correlations between growth of callus on culture media and growth of w hole plants in the field were studied in different pea cultivars, muta nts, and hybrids. Expression of quantitative traits in whole plants wa s shown to correlate with callus growth in vitro. The highest correlat ion was found between explant growth in tissue culture and field viabi lity of plants: r = 0.845, P < 0.001. Correlation coefficientin in the reciprocal recessive model calculated for these parameters was 0.910 (P < 0.001). Mutants and hybrids that had a complex of compensator gen es were characterized by high heterosis both under field conditions an d in vitro. Thus, in vitro callus culture can be used to model breedin g for heterosis and to predict productivity and heterosis in pea plant s.