Variazioni nelle caratteristiche delle cariossidi in alcune graminacee compreso il fenomeno della bianconatura inTriticum durum desf

Abstract

Abstract VARIATIONS IN THE CHARACTERISTICS OF THE SEEDS IN SOME GRAMI-NACEAE INCLUDED THE PHENOMENON OF «YELLOW BERRIES «IN» TRITICUM DURUM DESF. — An analysis of the morphological and physiological characteristics of normal seeds and yellow barries of « Cappelli » (Triticum durum) and of normal and red seeds of Haynaldia villosa has given the following results: « Cappelli » — The yellow berries, different from the normal seeds in colour, structure (which is mealy) and chemical composition (they contain less nitrogen), are also shorter and thinner. At germination, the yellow berries behave as the normal seeds. However, the shoot growth of seedlings from the yellow berries is reduced in comparison to that of normal seedlings: it is likely that this difference rests on the minor nitrogen content in yellow berries. Haynaldia villosa. — The red seeds often occur in Haynaldia spikes together with the normal ones, from which they differ in colour and size (they are shorter, narrower and thinner). Their behaviour is characterized by a gradual increase in germination percentage with increasing temperature from 15° to 25° C., in a situation of general retardation of emergence as compared with the controls. It is suggested that the red seeds may contain a substance inhibiting seed germination.