Elm Improvement Via Biotechnological Methods

Abstract

Rapid progress has been made over the past two decades in in vitro culture and manipulation of forest tree tissues, cells and protoplasts. It is now possible to micropropagate elms from many different types of cells and tissues; cryogenically preserve rare or unusual elm genotypes; isolate, culture and obtain whole trees from elm protoplasts and produce somatic elm hybrids via protoplast fusion. This paper will provide an overview of the significant advances in elm in vitro culture and will speculate as to how the rapidly evolving genetic engineering technologies will be used in genetic improvement for elms. Over the next decade, we envision significant biotechnological progress in: 1) determining the targets and receptors for the fungus-host responses in Dutch elm disease via in vitro disease challenge studies, 2) isolating molecular mechanisms for resistance to Dutch elm disease, and 3) introducing Dutch elm disease-resistant genes into ornamentally desirable but disease-susceptible elms.