Root systems froze bidirectionally while freezing in shoots and leaves proceeded only acropetally
. Freezing propagated quickly through tissues, particularly roots (several centimeters in 1 to 2 s).
On the other hand, the sheath/ stem ratio increased threefold acropetally
from Phytomer 6 to Phytomer 3.
Roots absorbed 2% of applied [sup.14]C-trinexapac-ethyl in 24 h and translocated acropetally 50% of what was absorbed (Table 3).
One percent of absorbed [sup.14]C moved acropetally while 32% moved basipetally and accumulated in a variety of tissues.
Greater than 75% of [sup.14]C absorbed by leaf sheaths at the base of the plant was translocated acropetally to the plant foliage over 24 h.
Translocation of [sup.14]C absorbed by leaf sheaths at the base of the plant was as follows: 61% translocated acropetally, 3% translocated to the roots, and 3% translocated to the rhizome/ daughter plant after 24 h (Table 4).
The initiation, ontogeny, and subsequent anthesis of the secondary capitulum is homologous to that of a synflorescence or collection of primary capitula (Classen-Bockhoff, 1992; Harris, 1994; Kunze, 1969; Rauh & Reznik, 1953); that is, the individual or primary capitula are initiated in an acropetal sequence and develop acropetally, but they then undergo anthesis basipetally.
The syncephalium subunit primordia (SSPs) are initiated acropetally in orderly parastichies on the capitulum.
Regardless, floral initiation proceeds acropetally, while development and anthesis take place basipetally.
In soybean (Bhuvaneswari et al., 1980) and the tropical legume Macroptilium (Ridge & Rolfe, 1985), it has been determined that the infective zone is an acropetally
moving region located between the root tip and the smallest emerging root hairs.