Studies on the growth and fruiting in the tomato. VII

Abstract

The present studies were carried out to ascertain the influence of the application of nucleic acid and antimetabolites of nucleic acid on the growth and the flower formation of tomato plants.Spraying with nucleic acid and antimetabolites of nucleic acid was begun when the cotyledon expanded fully and repeated 10 times at 3-day-intervals.1. Effect of application of DNA and RNA on the vegetative and reproductive processes.Plants were sprayed with 200, 1, 000 and 3, 000 ppm solution of DNA and RNA decomposed by autoclaving.All concentrations of DNA and the lower concentrations of RNA sprays failed to induce any effect on the plant growth and the flower formation. High concentration of RNA spray increased the number of flowers.2. Effect of application of guanine, uracil, uridine and uridylic acid on the vegetative and reproductive processes.Plants were sprayed with solution of guanine, uracil, uridine and uridylic acid at 200, 1, 000 and 3, 000ppm.All concentrations of guanine, uridine and uridylic acid sprays failed to induce any effect on the plant growth and the flower formation. High concentration of uracil spray increased the number of flowers.3. Effect of application of 8-azaguanine and thiouracil on the vegetative and reproductive processes.Plants were sprayed with solution of 8-azaguanine at 5×10-4 and 2×10-3M and thiouracil at 5×10-5, 2×10-4, 4×10-4 and 6×10-4M.High concentration of 8-azaguanine and thiouracil spray restricted the plant growth, being follwed by the retardation of the flower bud differentiation, the increase in the number of leaves to the first inflorescence and the decrease in the number of flowers with the retardation of their development.4. Effect of application of 5-bromouracil and ethionine on the vegetative and reproductive processes.Seedlings were sprayed with solution of 5-bromouracil at 5×10-4 and 2×10-3M and ethionine at 5×10-4 and 10-3M.High concentration of 5-bromouracil and ethionine spray restricted the plant growth, but failed to induce any effect on the flower formation.5. Effect of application of acriflavin, mitomycine and chloramphenicol on the vegetative and reproductive processes.Plants were sprayed with solution of acriflavin, mitomycine and chloramphenicol at 1, 10 and 50ppm.The higher the concentration of acriflavin, mitomycine and chloramphenicol solution, the weaker the plant growth, the later the flower bud differentiation, resulting in the increase in the number of leaves to the first inflorescence, and in the less number of flowers.6. Role of nucleic acid on the flower formation.Applications of nucleic acid increased the number of flowers, and applications of antimetabolites of nucleic acid retarded the flower formation.From the present results it may be suggested that the increase of nucleic acid in the apical part was an important factor for the induction of flower bud in the tomato plant.