Genetic Methods for Mitigating Invasiveness of Woody Ornamental Plants: Research Needs and Opportunities

Abstract

<jats:p>Because cultivation of exotic woody ornamental plants has led to establishment of a number of invasive species, there is considerable interest in breeding methods to reduce the propensity for spread. We review progress in conventional breeding and transgenic biotechnology approaches to producing sterile forms of ornamental woody plants. Conventional forms of inducing sterility, including induction of polyploidy, interspecific hybridization, and mutagenesis, are generally inexpensive and can be applied to a diversity of species at low to moderate cost. They have also been shown to be capable of producing commercially successful cultivars. In contrast, despite a variety of highly promising and rapidly developing approaches using transgenic methods, the inability to efficiently regenerate and genetically transform most ornamental species makes application of these innovations highly problematic. Moreover, because of the fragmented pattern of ornamental nursery ownership, the numerous species and varieties used, and the high regulatory cost for permits to sell most types of transgenic varieties (even when their environmental risk of spread has been reduced by sterility), application of transgenic methods is largely infeasible. A combination of fundamental regulatory reform and expanded biological research on generalized transformation and sterility methods is needed to overcome these barriers.</jats:p>

RNA interference suppression of AGAMOUS and SEEDSTICK alters floral organ identity and impairs floral organ determinacy, ovule differentiation, and seed‐hair development in Populus

“…There are widespread concerns over gene flow and dispersal of genetically engineered and invasive exotic plants (Brunner et al ., ; Vining et al ., ; Strauss et al ., ). The conserved function of AG and STK in Populus , as confirmed by our study, could provide an important tool for genetic containment in Populus , and likely in many other plant taxa.…”

FT overexpression induces precocious flowering and normal reproductive development in Eucalyptus

“…We have shown that overexpression of exogenous FT genes in eucalypts can be an effective means for acceleration of eucalypt tree breeding. This approach is also valuable as a general research tool for genetic studies, as well as for those focused on genetic modification of flower structure and fertility (Brunner et al, 2007;Vining et al, 2012). Its practical implementation will depend on regulations and market restrictions if null segregants are considered GMOs, and on improvements to transformation efficiency.…”

Reproductive modification in forest plantations: impacts on biodiversity and society

“…There are a variety of potential and demonstrated options for GEbased reproduction modification in trees (reviews in Brunner et al, 2007;Vining et al, 2012). In addition to the goal of containment, reproductive modification also has been sought as a means to improve vegetative growth by increased allocation of photosynthetic resources (Strauss et al, 1995), reduce the production of Table 1 Examples of field trials of genetically engineered (GE) trees that have showed efficacy or promise in delivery of target traits Tree species Trait allergenic pollen and decrease nuisance reproductive tissues in urban trees.…”