No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Genetic characteristics of progeny of the hybrids between a glufosinate ammonium resistant transgenic rice and weedy rice (Oryza sativa L.)
Abstract
Experiments were conducted for four consecutive years (2004~2007) in the greenhouse of Experiment and Practice Station. Kyungpook National University to determine genetic characteristics of the hybrids in the succeeding generations. F₁ hybrid were obtained by crossing weed rice with the glufosinate-ammonium resistant lines harboring ABC-promoter and ubiquitin promoter transgenic lines. respectively. F₁ hybrid obtained from crossing between weed rice and ABC-promoter transgenic rice found to have greater chances of genetic integration because of its higher rate of spikelet fertility. The response to the recommended dose of glufosinate-ammonium at 30 DAS (days after seeding) in F₂ followed Mendelian pattern of segregation. This indicated that the herbicide-resistant trait acquired from transgenic lines introgressed in the progeny generations. The days to heading and maurity in F₁ was delayed by as much as 30 days than the both parents. However, heading/flowering of F₂ was found highly variable, with approximately one fourth of the tillers maturing earlier like that of weedy rice parent. In this study, segregation to glufosinate response, heading dates and shattering of seeds in F₁, F₂, and F₃ were acquired from weedy parent.
... Hand pollination was performed between weedy rice as pollen recipient and transgenic lines as pollen donor. F1 hybrids and subsequent progenies F2 and F3 were grown and maintained in the greenhouse [4] for pollen collection and viability evaluation. ...
... However, hybridization could occur if foreign pollen arrives earlier than the compatible species pollen and pollen com-petition would not prevent out crossing. Given the less chances of outcrossing in self-pollinated weeds like Milyang weedy rice, the amount of seed set in the progeny carrying undesirable herbicide resistant traits could still pose risk [4]. In our experiment, pollen viability of transgenic lines, F1 and F2 decreased drastically when time elapsed especially from 40 min to 60 min while that of F3 decreased gradually (Table 1). ...
... This study was aimed to identify a transgenic line between the two with ABC and Ubiquitin promoters, respectively, that would be relatively safe. Based on the results that F1 of crossing between weedy rice and ABC-promoter transgenic line showed significantly higher seed set [4] than between weedy rice and Ubi-promoter transgenic line, we chose F1, F2 & F3 of a cross between weedy rice and ABC-promoter transgenic line for further investigation of pollen viability and longevity. Based on those results it is found that out crossing of Milyang weedy rice by ABC-promoter transgenic pollen and subsequent introgression of herbicide resistant gene in the F2 and F3 generation with greater pollen viability, poses risk of herbicide-resistant weedy rice in the field condition than that could be possible from pollen of Ubi-promoter transgenic rice line. ...
This experiment was conducted to evaluate pollen viability of Nakdongbyeo, transgenic rice lines, an F1 hybrid from a cross between Milyang weedy rice and ABC-promoter transgenic rice line containing basta-resistant (bar) gene and subsequent selfed progenies, F₂ and F₃. The reaction of pollen with 3-{4,5 dimethylthiazolyl-2}-2,5-diphenyl monotetrazolium bromide (MTT) as a staining chemical immediately after pollen shedding showed maximum pollen viability of 86% in Nakdongbeyo, 75% in ABC-promoter transgenic rice line, 62% in ubiquitin-promoter transgenic line, 68% in F1, 79% in F₂ and 78% in F₃. Viability gradually declined during subsequent observations at 20-minute intervals. However, there was a drastic decline in pollen viability after 40 minutes of pollen shedding. The mean difference of pollen viability among rice lines and time was highly significant, indicating significantly different pollen viabilities at different time intervals. Maximum viability of 36.2% was observed in F₃ and minimum viability of 3.5% was found in F₂ at 90 min after pollen shedding. Results of this experiment on pollen viability and longevity elucidate potential risks of pollen-mediated flow of herbicide-resistant gene from transgenic rice lines and possible integration of it into the weedy rice population.
ResearchGate has not been able to resolve any references for this publication.