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...

abstract among the propagation methods of mango, grafting is the most common method, but growers do not have enough knowledge about the suitable time and grafting methods of this fruit tree. this problem is the most important factor in production of grafted mango plants. this experiment was conducted in a randomized complete block design with factorial arrangement and 10 replications. factors i...

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...

Red light, which produces the physiologically active form of phytochrome (Pfr), inhibited epicotyl elongation in intact dark-grown Alaska pea seedlings. This red light response was detectable 3 hours after the light treatment and became pronounced after 5 hours. The growth inhibition was completely reversed by far red light applied immediately after the red or by pretreatment of the seedlings w...

The present study was carried out to investigate micropropagation possibility and determine the optimal medium composition and plant growth regulators (PGRs) combinations under in vitro conditions. The cotyledon and epicotyl explants obtained from 1 month old in vitro grown seedlings were used in MS medium containing BA (0.1, 0.2, 0.5, 1, 2 and 3 mg-1) and TDZ (0.1, 0.2, 0.5, 1, 2 and 3 mg-1) e...

Following excision, etiolated epicotyl segments of Pisum sativum L. cv. Alaska exhibit a marked hyperpolarization of membrane potential which is followed by a linear accumulation of K(+) when segments are incubated in Higinbotham nutrient solution. Segments aged for several hours and then reexcised display only a slight depolarization of membrane potential and no delay in ion accumulation; thus...

A cDNA encoding a xyloglucan endotransglycosylase (XET) homolog was isolated from nasturtium (Tropaeolum majus) epicotyl RNA. The deduced protein encoded by the corresponding gene, termed XET1, was substantially divergent from a previously isolated nasturtium XET (NXG1) expressed in germinating seed cotyledons but was highly homologous to XET genes isolated from vegetative tissues of several di...