ANALYSIS OF CHINESE SPRING REGENERANTS OBTAINED FROM SHORT-TERM AND LONG-TERM WHEAT SOMATIC EMBRYOGENESIS

Somatic embryogenesis was initiated from 'immature embryos' on Murashi ge-Skoog (MS) medium plus 2 mg.l(-1) 2,4-dichlorophenoxyacetic acid, 2 % sucrose and 0.6% agarose. Somatic embryos were isolated and regenera ted into whole green plants on MS medium devoid of 2,4-D. These regene rants were previously demonstrated to differ in their mitochondrial DN A organization. In order to estimate their characteristics three proge nies of short-term culture regenerants and three progenies of long-ter m culture regenerants were analyzed and compared to the parental line. These somaclones obtained from the wheat variety Chinese Spring were evaluated for variation of 13 agronomic and morphological quantitative characters in comparison to the parental line. Significant variation was observed for plant height, spike length, main tiller diameter, bet ween the somaclones regenerated from long-term culture and their paren t. Differences were observed to increase with the duration of culture, leading to a significant modification of the structure of the plants. Several changes occurred during the somatic tissue cultures, but to a lesser extent than has previously been described in the literature.