Hybridisation between wheat and Aegilops geniculata and hybrid fertility for potential herbicide resistance transfer

LOUREIRO, I.; ESCORIAL, C.; GARCÍA BAUDIN, J-M.; CHUECA, M-C.

Hybridisation between wheat and Aegilops geniculata and hybrid fertility for potential herbicide resistance transfer

2008

LOUREIRO, I. | ESCORIAL, C. | GARCÍA BAUDIN, J-M. | CHUECA, M-C.

Hybridisation between wheat and Aegilops geniculata was quantified in a 4-year crossing experiment in the glasshouse, using three wheat cultivars as pollen donors and herbicide resistance as a phenotypic marker. Hybridisation rates ranged from 5% to 74%. Most of the hybrids were self-sterile. However, seven F₂ seeds were obtained from 165 A. geniculata-wheat hybrids. Hybrid seeds were found in all backcross (BC₁) combinations at average rates of 4.2% (0-26.3%) and 5.88% (0-34%) under glasshouse and field experiments, respectively, with significant differences among years and cultivars. Wheat cultivars, F₁ and BC₁ plants, were resistant to herbicides while A. geniculata plants were susceptible. In the subsequent generations, although few plants were available, the BC₁F₁ had a certain degree of fertility and the fertility increased in the F₂ plants, with one plant that reached 66.7%. The commercial growing of genetically modified herbicide-tolerant wheat is expected to have the potential for the inserted gene to escape from the crop and become incorporated in a closely related wild species, conferring a competitive advantage to these conferring weeds. Determining the frequency of crop-wild transgene flow and the fertility of the formed hybrids is a necessity for risk assessment. Data presented here provide new knowledge on the potential A. geniculata-wheat herbicide resistance transfer.

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