Seedling Development in Peach, Prunus persica (L.) Batsch. I. Effects of Testas and Temperature

Abstract

Testas inhibited the germination and stem elongation of peach seeds, and the inhibition was removed by 10 weeks of stratification (i.e. exposure to cold temperatures while imbibed). Intermediate lengths of stratification (4-8 weeks) promoted the production of morphological lesions on leaves. The lack of lesion promotion after 10 weeks of stratification was due to a loss of potency by the testas, not to an inability of embryos to respond. Stratification at 25°C had no effect on the properties of the testa. The large effects of the testa on the embryo following stratification at 3°C occurred only after the seed had been shifted from 3°C to 25°C conditions, and especially during the first 3 days after the shift. The lesion-stimulating properties of the testa were reduced by leaching. The active principle was distributed throughout the testas but was transferred to the embryo by diffusion at the radicle.