The Morphological Variations and the Occurrence of Aneuploids in Some Species of Agrostis in Rhode Island

Stuckey, Irene H.; Banfield, William G.

doi:10.2307/2437134

Cited by 13 publications

(12 citation statements)

References 5 publications

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“…Different sizes of the pollen grains were observed when pollen grains were stained using aceto-carmine solution. The triad formation might have resulted from lack of second division in one cell of a dyad (Stuckey and Banfield 1946). Another possibility of the large pollen grain formation might be due to unequal segregation of the laggards or prematurely disjuncted chromosomes.…”

Section: Chromosome Behavior During Meiosismentioning

confidence: 99%

Cytology and pollen grain fertility in creeping bentgrass interspecific and intergeneric hybrids

2007

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Section: Chromosome Behavior During Meiosismentioning

confidence: 99%

Cytology and pollen grain fertility in creeping bentgrass interspecific and intergeneric hybrids

2007

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“…Even though individual A. stolonifera interspecific F 1 hybrids may have low fertility, they can still undergo extensive clonal propagation via spread of stolons and/or rhizomes (Edgar & Connor 2000). Furthermore, there is evidence for persistence and adaptability of naturally occurring Agrostis hybrids ( A. gigantea × A. capillaris ) in hybrid swarms (Stuckey & Banfield 1946;Meerts & Lefèbvre 1989). Agrostis species are found in a remarkable variety of agronomic and nonagronomic habitats (Grime et al .…”

Section: Introductionmentioning

confidence: 99%

Establishment of transgenic herbicide‐resistant creeping bentgrass (Agrostis stolonifera L.) in nonagronomic habitats

et al. 2006

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Concerns about genetically modified (GM) crops include transgene flow to compatible wild species and unintended ecological consequences of potential transgene introgression. However, there has been little empirical documentation of establishment and distribution of transgenic plants in wild populations. We present herein the first evidence for escape of transgenes into wild plant populations within the USA; glyphosate-resistant creeping bentgrass (Agrostis stolonifera L.) plants expressing CP4 EPSPS transgenes were found outside of cultivation area in central Oregon. Resident populations of three compatible Agrostis species were sampled in nonagronomic habitats outside the Oregon Department of Agriculture control area designated for test production of glyphosate-resistant creeping bentgrass. CP4 EPSPS protein and the corresponding transgene were found in nine A. stolonifera plants screened from 20,400 samples (0.04 +/- 0.01% SE). CP4 EPSPS-positive plants were located predominantly in mesic habitats downwind and up to 3.8 km beyond the control area perimeter; two plants were found within the USDA Crooked River National Grassland. Spatial distribution and parentage of transgenic plants (as confirmed by analyses of nuclear ITS and chloroplast matK gene trees) suggest that establishment resulted from both pollen-mediated intraspecific hybridizations and from crop seed dispersal. These results demonstrate that transgene flow from short-term production can result in establishment of transgenic plants at multi-kilometre distances from GM source fields or plants. Selective pressure from direct application or drift of glyphosate herbicide could enhance introgression of CP4 EPSPS transgenes and additional establishment. Obligatory outcrossing and vegetative spread could further contribute to persistence of CP4 EPSPS transgenes in wild Agrostis populations, both in the presence or absence of herbicide selection.

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“…Distinguishing Agrostis species and subspecies was difficult in the past because the species are very similar to one another and often confused in botanical works (Piper, 1918). Even today, with better references of the taxonomic classifications (Hitchcock, 1971), the similarities between species and the known existence of hybrids and natural variation (Bradshaw, 1957; Stuckey and Banfield, 1946) make separating species difficult (Monteith, 1930; Shildrick, 1976). This is especially problematic to turfgrass breeding programs interested in studying several Agrostis species.…”

mentioning

confidence: 99%

Ploidy Determination in Agrostis Using Flow Cytometry and Morphological Traits

Bonos¹,

Plumley²,

Meyer³

2002

Crop Science

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The taxonomic classification of the genus Agrostis is one of the most complicated of the grass genera. Classification based upon morphological and anatomical characters is difficult and complicated by the presence of intermediate forms and the misapplication of names. Determining ploidy levels of new germplasm can assist in species determination and is necessary before initiating breeding or genetics studies. The objectives of this study were to (i) evaluate the use of laser flow cytometry as a quick, reliable tool to determine ploidy level and aid in Agrostis species determination, and (ii) identify morphological characters associated with DNA content or ploidy level. The six Agrostis species evaluated were A. canina L. subsp. canina, A. canina L. subsp. montana (Hartm.) Hartm., A. palustris Huds. [= A. stolonifera var. palustris (Huds.) Farw.], A. tenuis Sibth. (= A. capillaris L.), A. castellana Boiss. & Reut., and A. alba L. Ploidy level was determined by flow cytometry and root tip chromosome counts. Plant height, panicle height, flag leaf length, flag leaf width, and highest internode length of mature field-grown spaced plants were measured. Significant differences in 2C DNA content were found between species (P < 0.01) differing in ploidy level. Flow cytometry was effective in differentiating between diploid, tetraploid, and hexaploid species. Chromosome numbers previously reported and those observed in this study were positively correlated with 2C nuclear DNA content (r = 0.98, P < 0.01). Flag leaf length was the only morphological measurement taken that was significantly positively correlated to DNA content (r = 0.98, P < 0.001). The results of this study indicate that laser flow cytometry is a quick, reliable tool to determine ploidy levels and infer certain species of AGROSTIS: This technique will aid breeders to quickly and accurately determine ploidy levels of new germplasm collections.

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The Morphological Variations and the Occurrence of Aneuploids in Some Species of Agrostis in Rhode Island

Cited by 13 publications

References 5 publications

Cytology and pollen grain fertility in creeping bentgrass interspecific and intergeneric hybrids

Cytology and pollen grain fertility in creeping bentgrass interspecific and intergeneric hybrids

Establishment of transgenic herbicide‐resistant creeping bentgrass (Agrostis stolonifera L.) in nonagronomic habitats

Ploidy Determination in Agrostis Using Flow Cytometry and Morphological Traits

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