Studies of the "tree factor" that inhibits the ripening of attached apples.
Blanpied, G. D.;
Acta Horticulturae Year: 1993 Issue: No. 343 Pages: 6-11 Ref: 14 ref.
1993
บทคัดย่อ
Five experiments were carried out to study the tree factor (TF, an unknown compound(s) reported to be synthesized in apple leaves and transported to fruits where it inhibits ripening). The experiments studied (1) the effects of limb defoliation and ringing on ethylene production by ripening McIntosh apples; (2) the effects of limb ringing, fruit thinning and limb defoliation (to various leaf:fruit ratios) on fruit growth and days to EC (ethylene climacteric) in Jerseymac and Paulared apples; (3) the effect of growth regulator (IAA, benzyladenine and GA4+7) treatment on fruit growth and days to EC in 5 apple cultivars; (4) the effects of limb ringing, defoliation and defruiting on fruit growth and days to EC in Cortland, Idared and Law Rome apples; and (5) fruit internal ethylene concentration and starch content in Jerseymac apples picked and held in an ethylene-free room at 20 deg C. In (1), fruits receiving photosynthate from normal leaves ripened on the same dates as fruits receiving photosynt hate from leaves that were 6 weeks older than normal. Delay in ripening and fruit growth were positively correlated with leaf:fruit ratios on ringed limbs in (2). Growth regulator treatment did not replace TF on ringed/defoliated limbs. Compared with fruits on normal limbs, fruits attached to defoliated limbs grew more slowly but had similar ripening dates in (4). Attached and detached apples in (5) initiated starch loss several days before EC, indicating that TF may repress sequential transcription for many ripening enzymes, not just the enzymes associated with ethylene production.