In the animal life cycle, the earliest manifestations of programmed cell death (PCD) can already be seen during embryogenesis. The aim of this work was to determine if PCD is also involved in the elimination of certain cells during plant embryogenesis. We used a model system of Norway spruce somatic embryogenesis, which represents a multistep developmental pathway with two broad phases. The fir...

Prince Rupprecht's larch (Larix principis-rupprechtii Mayr) is a native high-value forest tree species in North China whose clonal propagation through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. To date, research has focused on clarifying the molecular mechanism of SE...

The early events in plant embryogenesis are critical for pattern formation, since it is during this process that the primary apical meristems and the embryo polarity axis are established. However, little is known about the molecular events that are unique to the early stages of embryogenesis. This study of gene expression during plant embryogenesis is focused on identifying molecular markers fr...

In rubber, the current propagation method of grafting on to unselected seedlings, maintains intraclonal heterogeneity for vigour and productivity and hence a great improvement may be expected by using micropropagation in vitro. Micropropagation with nodal and shoot tip explants derived from seedlings are possible as with mature clonal explants. The major problem in using clonal material from ma...

Attempts were made during the 1990 growing season to induce somatic embryos from non-zygotic tissues of five economically important walnut cultivars. The following explants were employed: fertilized and unfertilized ovules; immature and mature catkins; abnormal "spike" flowers; and in vitro-grown leaves and roots. Modifications of the standard induction media were also examined. These included ...

Highly reproducible and simple protocol for cotton somatic embryogenesis is described here by using different concentrations of maltose, glucose, sucrose and fructose. Maltose (30 g/l) is the best carbon source for embryogenic callus induction and glucose (30 g/l) was suitable for induction, maturation of embryoids and plant regeneration. Creamy white embryogenic calli of hypocotyl explants wer...

Assisted reproductive techniques in the horse have been only recently become available compared to other domestic species, in particular ruminants. The scarce availability of abattoir ovaries and the lack of interest from horse breeders and breed associations, and the anatomical and physiological differences have been the main reasons for this delay. Progressively though, the technology of oocy...

The objectives of this work were to evaluate in vitro response of Iranian alfalfa cultivars and select high regenerative genotypes. Somatic embryogenesis response of leaf and petiole explants from five alfalfa cultivars and landraces was studied using six regeneration protocols. Cultivars and landraces exhibited protocol, and explant-specific response and somatic embryo formation occurred only ...