Vol. 51—1997 - NorthEastern Weed Science Society

176
it can at ti es be a weed in Kentucky blue grass lawns. The literature on attempts to hybridize
species of grostis that are commonly found in North America is limited (Stucky and Banfield,
1946; Jon s, 1956; Bradshaw, 1958). A wide range of divergent types and intermediate forms
exist amo g creeping, colonial, and velvet bentgrasses, with chromosome numbers ranging from
2n = 14 to 46, X =7. It appears likely that most interspecific hybrids involving A palustris are
sexually s erile and thus very unlikely to contribute to the relevant gene pools. In any case very
few of th other Agrostis spp. have been reported as weeds. We plan to use herbicide resistant
transgeni forms of A. palustris to establish the frequency with which this species hybridizes with
other Agr stis species commonly found in North America. If, as we expect, the frequency of
hybrid 1'0 ation is low this will be significant and important in establishing policies for the future
release of herbicide resistant and other transgenic forms of this species. If the frequency is high,
and intro ression of the gene appears to be likely because fertile hybrids are produced, this will call
for more aution before proceeding with releases that could result in grasses that are difficult to
control a d which, through subsequent rounds of introgression with other transgenics, may be
resistant t several different herbicides.
References
Bradsha , AD. 1958. Natural hybridization ofAgrostis tenuis Sibth. andA. stolonifera L. New
Phytolog t 57:66-84.
Jones, K. 1956. Species differentiation in Agrostis. I. Cytological relationship in Agrostis canina.
II. The si nificance of chromosome pairing in the tetraploid hybrids of Agrostis canina subsp.
montana artmn., A. tenuis Sibth. and A. stolonifera L. III. Agrostis gigantea Roth and its
hybrids ith A. tenuis Sibth. and A. stolonifera L. J. Genet. 54:370-376, 377-393, 394-399 .
. Laramore, P. Day, and N. Turner. 1996. Transformation and regeneration of creeping
(Agrostis palustris Huds.) protoplasts. Crop Sci. (in print)
Sanford, J.C., P.O. Smith, and J.A. Russell. 1993. Optimizing the biolistic process for different
biologic applications. Methods in Enzymology. 217:483-509.
Stucky, . H. and W. G. Banfield. 1946. The morphological varieties and the occurrence of
aneuploi s in some species ofAgrostis in Rhode Island. American 1. of Botany. 33:185-190.
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