MONITORING OF CABBAGE RESPIRATION DURING FLOWERING INITIATION

Abstract

At the Physiology Laboratory of the Lithuanian Institute of Horticulture investigation is carried out on initiation of cabbage flowering. Plant analyzing system 'Ecoplant-11' was utilized to study the respiration intensity within 5 outer leaves during flowering induction, evocation and flower initiation periods of cabbage. The aim of investigation was to establish the importance of respiration over different periods of cabbage flowering initiation. The evocation processes (organogenesis stages III-IV according to F. Kuperman, 1982) within cabbage heads were established to proceed in autumn during storage, nearly at once after the heads had been placed in the storage room at low temperatures. In the course of 30 days plants overcome organogenesis stage III and after another 60 days they overcome stage IV. Formation of floral meristems, which is flower initiation (stage V) starts approximately at the beginning of February. Monitoring of leaf respiration intensity showed that respiration intensity of outer leaves does not exceed 2-mg/dm 2 h CO 2 over all periods of flowering initiation. On the whole the outer leaves of heads breathe most intensively during flowering initiation. More alternating in time intensity of cabbage respiration is observed in stage III (beginning of evocation) after the heads had been placed into storage. Intensity of leaf respiration becomes equal in stage IV (evocation). At the beginning of formation of floral meristems (end of stage IV - organogenesis stage V) the increase of respiration intensity is observed that reflects the increase of intensity within biochemical, physiological and morphogenetic processes.