Induction of adventitious buds on roots of the potato

Auxin treatment of de-eyed potato slices induced root formation. When the roots were exposed to light, adventitious buds were formed.This method for bud formation may be used to produce non-chimerical potato mutants, when the buds can be obtained from mutagenically treated tissue. An additional purpose is the investigation of the L₃ of existing mutants.This investigation was supported by the EURATOM-ITAL Association, Wageningen, The Netherlands.     

Das forstliche Verzinsungsprozent

Ohne Zusammenfassung     

Ripening of Tomatoes

Experiments were carried out with aldrin, dieldrin, isodrin, endrin and DDT to ascertain whether, employed as insecticides, these compounds had any effect on cell division in onion root-tips. The doses used were equal to, or greatly in excess of, the recommended rates of application. By germinating onion seeds in direct contact with the insecticide under investigation, it has been shown that none of the compounds had any effects on germination or growth rate. High doses of aldrin, dieldrin or isodrin had a slight toxic effect on the resting cell, which, with aldrin, was also caused by the recrystallized compound. Aldrin and dieldrin had no effect on the dividing cell. Isodrin and endrin caused slight stickiness between chromatids in anaphase, which was insufficient to prevent the completion of division in the cell, and DDT caused a delay in the early stages of prophase and a shortening of chromosomes in metaphase.

Pot experiments, with high doses of each compound, showed that germination and growth rate were unaffected by any of the compounds. Resting cells were not affected and dividing cells were affected only by slight stickiness in anaphase, except with DDT, which also caused a slight delay in metaphase.

Attention has been drawn to the advantages of these compounds over gamma-BHC, chlordane and toxaphene as insecticides, from the point of view of causing less damage to the plant.