Application of Synthetic Low Molecular Weight Heterocyclic Compounds Derivatives of Pyrimidine, Pyrazole and Oxazole in Agricultural Biotechnology as a New Plant Growth Regulating Substances

Study of plant growth regulating activity of synthetic low molecular weight heterocyclic compounds derivatives of pyrimidine, pyrazole, and oxazole was conducted. It was found that all tested synthetic heterocyclic compounds used at concentration 10-9M/l of distilled water revealed high stimulating auxin-like activity on vegetative growth of two cultivars of pea and maize, and stimulating cytokinin-like activity on growth of the isolated cotyledons of pumpkin. The obtained biometric indexes of 21st-day-old seedlings of pea (Pisum sativum L.) of cultivar L35/11 middle stalwart bewhiskered grown on the water solution of heterocyclic compounds used at concentration 10-9M/l of distilled water were higher of the biometric indexes of 21st-day-old seedlings of pea grown either on the distilled water (control) or on the water solution of auxins IAA and NAA used at the same concentration 10-9M/l of distilled water in average: at the 7-8% - by total length of seedlings, at the 6-46% - by total length of roots, and at the 15-70% - by total number of roots. The obtained biometric indexes of 21st-day-old seedlings of pea (Pisum sativum L.) of cultivar L303/04 semi-dwarf bewhiskered grown on the water solution of heterocyclic compounds used at concentration 10-9M/l of distilled water were higher of the biometric indexes of 21st-day-old seedlings of pea grown either on the distilled water (control) or on the water solution of auxins IAA and NAA used at the same concentration 10-9M/l of distilled water in average: at the 18-23% - by total length of seedlings, at the 15-76% - by total length of roots, and at the 16-116% - by total number of roots. The obtained biometric indexes of 14th-day-old seedlings of maize (Zea mays L.) hybrid Palmyra FAO 190 grown on the water solution of heterocyclic compounds used at concentration 10-9M/l of distilled water were higher of the biometric indexes of 21st-day-old seedlings of maize grown either on the distilled water (control) or on the water solution of auxins IAA and NAA used at the same concentration 10-9M/l of distilled water in average: at the 23 % - by total length of seedlings, 5-37% - by total length of roots, and at the 7-87% - by total number of roots. The specific bioassay on cytokinin-like activity conducted on the 16th-day-old cotyledons isolated from seeds of muscat pumpkin (Cucurbita moschata Duch. et Poir.) of cultivar Gilea, showed that all heterocyclic compounds derivatives of pyrimidine, pyrazole, and oxazole used at concentration 10-9M/l of distilled water demonstrated high stimulating cytokinin-like activity. The indexes of biomass growth of isolated cotyledons of pumpkin grown on the water solution of heterocyclic compounds used at concentration 10-9M/l of distilled water were higher of the indexes of biomass growth of isolated cotyledons of pumpkin grown either on the distilled water (control) or on the water solution of phytohormone cytokinin Kinetin used at the same concentration 10-9M/l of distilled water in average at the 6-30%. It was shown also the positive effect of some from tested synthetic heterocyclic compounds derivatives of pyrimidine, pyrazole, and oxazole on activation of photosynthetic processes in the leaves of 21st-day-old pea seedlings and 14th-day-old maize seedlings due to increase of synthesis of photosynthetic pigments in the plant cells; the content of chlorophyll a was increased in average at the 4-36%; the content of chlorophyll b was increased in average at the 3-74%; the content of chlorophylls a+b was increased in average at the 5-36%; the chlorophylls a/b ratio was increased in average at the 3-44%; the content of carotenoids was increased in average at the 3-37% as compared with control, IAA and NAA, respectively; the carotenoid/chlorophyll ratio was increased in average at the 7-17% as compared with control.