GAS FROM APPLES

Otago Daily Times, Issue 22064, 21 September 1933, Page 13

GAS FROM APPLES

EFFECT ON SEEDS

(FfeoM Odb Own Correspondent.) LONDON, August 5. Some interesting observations have beea made, says the report of the Food investigation Board (His Majesty s Stationery Office, ss) bn the effects of exposing germinating seeds to a stream of air which has passed over ripe applesElmer in America has already shown that the sprouting of potatoes can he ternporarilv modified in a striking way by holding them in proximity to ripe apples Immature apples were not active m this respect, nor was any result produced by oranges or bananas. _ , fIL. The effects on germinating seeds are sufficiently parallel to justify the conclusion that they are due to the same constituent of the vapours from npe apples, as were Elmer’s effects. The active substance, whatever it is, is present in so small an amount that its chemical identification —and still more, its quantative chemical estimation—is a matter of some difficulty. As a biological indicator of its presence or absence, and very roughly of its concentration in the air stream, the germinating seeds of the common pea have proved to be convenient material. .... . ■ When the substance in. high concentration was brought into contact with germinating peas, germination was almost completely inhibited. In smaller concentrations the growth of tme seedling shoot was greatly modified. It remained short, stumpy, and swollen. The radicle crew normally in the very early stage* of germination, but later on the development of the root system of the seedling wa a also retarded. The effects were temporary, and can be produced at different stages in the early growth of the seedA good deal of time has been spent bymore than one worker in an attempt to identify the active substance. On tha whole, the evidence points to ethylene or a body of the same chemical character. One remarkable fact has emerged--namely, that the rate of respiration of seedlings is unchanged, in spite of an inhibition of growth; the dissociation of growth and rate of oxidation is a biological event well worth following up. “Apple-air” has. hoivevef, quite a diferent effect on other apples—it increase* their rate of oxidation. It is an opea question how widely spread the produo tion of poisonous substances of this chaw* acter is likely to be in the vegetable world. Direct experiment has failed t® find such active substances given’off by oranges or bananas. Pears, on the othef band, gave g positive- result.