Highlights 1995-1996

• International Paper joins TGERC as the 13th Regular Member.

 

• Effective gene transfer method developed. A protocol for gene transfer and plant regeneration has been found to be effective in a variety of cottonwood clones and species. Research projects can therefore focus on commercially valuable clones.

 

• Genes toxic to cottonwood leaf beetles identified. Genes from Bt that are toxic to two Chrysomelid beetle defoliators were identified in laboratory feeding studies. Gene transfer experiments to produce insect resistant trees are underway.

 

• Flowering genes from poplar isolated and transferred into trees. Genomic and cDNA clones of four floral homeotic genes from poplar have been isolated and their expression is being studied; all appear to have strong potential for use in engineering tree sterility. Transgenic trees with strong suppression of the poplar homolog of the floral homeotic gene LEAFY are currently being field tested.

 

• Juvenile trees induced to flower. By overexpressing the LEAFY gene from Arabidopsis, we have produced two poplar lines that produce male flowers in tissue culture. This work independently verifies a method reported earlier. Precocious lines should dramatically speed research on engineering of sterility.

 

• Genome size and low fertility of triploid poplars documented. Flow cytometry was used to verify the triploid nature of a number of hybrid cottonwood clones used in transformation studies and field tests. Low fertility in clones 24-305 and 184-402 was demonstrated in laboratory crosses and/or field grown trees. This indicates they may have adequate levels of innate sterility to be good candidates for rotation length studies of engineered trees.

 

• Two cooperative field trials established. TGERC's first cooperative field trials were established on James River and Potlatch lands in western and eastern Oregon with 40 lines of transgenic hybrid cottonwoods. Growth and survival of the transgenc trees was excellent. The tests were established with approval and collaboration of USDA-APHIS and Monsanto Company, respectively.

 

• High resistance to Roundup® herbicide found in engineered trees. High levels of resistance to glyphosate (active agent of Roundup® herbicide) have been observed in field tests of transgenic hybrid cottonwood and hybrid Leuce (aspen/white poplar) clones. Several highly resistant lines showed no symptoms of damage or dec