Maritime Pine Pinus Pinaster Aiton

Opening of apical and axillary buds of mature Douglas-fir and sugar pine trees was obtained on a newly formulated basal medium (DCR) without growth regulators. Elongation of buds was observed on 1/2 strength DCR with 0.3% activated charcoal (DCR-1). In sugar pine, multiple shoots were obtained when explants on DCR with 0.5 mg/1 BAP for 5-6 weeks were transferred to DCR-1 medium. On subculture, axillary buds again developed when shoots were cultured on DCR with 0.2 mg/1 BAP for Douglas-fir and 0.5 mg/1 BAP for sugar pine. These buds were again elongated on DCR-1 medium. By subculturing 7-10 shoots of Douglas-fir and 2-3 shoots of sugar pine, over 100 shoots can be obtained in a year.

Rapidly accumulating evidence shows that herbivore and pathogen attack of plants can generate particular defense phenotypes across generations. What was once thought to be an oddity of plant defense induction now appears to be a taxonomically widespread phenomenon with strong potential to impact the ecology and evolution of species interactions. DNA methylation, histone modifications, and small RNAs each contribute to transgenerational defense initiation; examples in several species demonstrate that this induction can last for multiple generations. Priming of the offspring generation for more rapid induction following subsequent attack has also been reported. The extent to which transgenerational induction is predictable, detectable in nature, and subject to manipulation will determine the ability of researchers to decipher its role in plant-herbivore and plant-pathogen interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

In this study, several improvements and simplifications of SE protocols in Pinus pinaster (Ait.), a species of economic importance in the regions of Western Europe, are described. These improvements pertained to all stages of SE including high initiation frequencies in eight control pollinated seed families, relatively high somatic embryo maturation yield when cells were coated with particles of activated charcoal and a rapid production of plants directly in a shade house. The SE initiation frequency from isolated zygotic embryos was high (up to 100%) and plants were produced from 11 embryogenic lines representing all crosses. Based on these results, the estimated number of somatic embryos required to produce 1,000 plants varied from slightly more than the required number of plants to more than double this number depending on the line. Such an estimate is critical in developing plant production strategy when a number of embryogenic lines are considered for production of clonal plants.