An alternative to the leaf disk system for studies of the metabolism of senescence is described. The progress of senescence of soybean (Glycine max L.) cotyledons is arrested when the epicotyl is removed. Epicotyl removal at 16 or 17 days reversed the decline in nucleic acid, protein, and chlorophyll content in the cotyledon. Epicotyl removal at 18 days did not reverse the decline in the above ...

BACKGROUND AND AIMS Physiological epicotyl dormancy in which the epicotyl elongates inside the seed before the shoot emerges has been reported for only a few tropical rainforest species, all of which are trees that produce recalcitrant seeds. In studies on seeds of Fabaceae in Sri Lanka, we observed a considerable time delay in shoot emergence following root emergence in seeds of the introduced...

Brassinosteroids promote soybean epicotyl elongation and regulate expression of BRU1, a gene with homology to xyloglucan endotransglycosylases (XETs). Recombinant BRU1 protein possesses XET activity and in situ hybridization reveals highest BRUl transcript accumulation in inner epicotyl tissue, particularly the phloem and paratracheary parenchyma cells. These results suggest a role for BRUl in ...

Yunnanopilia longistaminea is an endangered monotypic species belonging to Opiliaceae. This edible plant is an important germplasm source with a high economic value in China if propagation were less difficult. Seed dormancy and germination of this species were investigated to improve propagation. Considering seeds have a fully developed embryo and mature and are dispersed in summer, and radicle...

Grafting on epicotyl of young seedlings has been introduced as a simple and rapid method for walnut propagation. Although this technique improves the grafting success and propagation efficiency, it is technically more demanding than the conventional walnut grafting procedures and is yet to be optimized. This study was aimed to investigate the influence of rootstock type (dwarf and standard geno...

Morphological characters of soybean can be influenced by shading which are occasionally caused in plants. Thus, this study aimed to evaluate the effect different levels on epicotyl length, diameter and height The experiments were conducted a greenhouse. When plants reached V2 development stage, measurements taken length experiment I (conducted autumn); diameter, plant II (spring/summer) III (su...

Explants were isolated from 6-day-old etiolated bean seedlings (Phaseolus vulgaris L. cv. Black Valentine) containing the cotyledons with 4 mm of hypocotyl just below the node and/or the epicotyl. During incubation on distilled water, uneven growth of the hypocotyl or epicotyl occurred resulting in the formation of a hook. The more rapid growth of the side which became convex was not dependent ...

The formation of the apical hook in dicotyledonous seedlings is believed to be effected by gravity in the dark. However, this notion is mostly based on experiments with the hook formed on the hypocotyl, and no detailed studies are available with the developmental manners of the hook, particularly of the epicotyl hook. The present study aims at clarifying the dynamics of hook formation including...

BACKGROUND AND AIMS The shrub Viburnum tinus is widely distributed in mattoral vegetation of the Mediterranean basin. The purpose of the present study was to classify the seed dormancy type and examine the requirements for embryo growth, root protrusion and shoot emergence. METHODS Overwintered fruits were collected in western Spain in April 2001 and prepared in three ways: entire pericarp wa...

Sucrose, supplied to detached pea (Pisum sativum L. var Alaska) epicotyls through cut bases, supported better growth of apical tissue than supplied glucose and/or fructose. The hexoses were converted mainly to sucrose in basal regions of the epicotyl but some moved as such through the epicotyl and accumulated at the apex (plumule) at a rate faster than sucrose. A greater proportion of the carbo...