Spontaneous hybridizations between oilseed rape and wild radish

Abstract

The occurence of spontaneous hybridization between Brassica napus (oilseed rape) and Raphanus raphanistrum (wild radish) was investigated under different density conditions in cages and open‐field experiments. Hybrids with wild radish as the seed parent were identified by screening for herbicide resistance belonging to rape. Small seed size and intermediate morphology were used to screen for hybrids with rape as the seed parent. Leaf isozyme patterns and flow cytometry provided confirmation of hybrids. Wild radish in an oilseed rape field produced as many as three interspecific hybrids per 100 plants. This is the first report of such a spontaneous event. The frequency of hybrids is expected to range from 0.006 to 0.2% of the total seed produced, at P = 0.05. Male‐sterile oilseed rape plants surrounded by wild radish can produce up to 37 hybrids per plant. Seed production of the F1 hybrids and their F2 descendants was up to 0.4% and 2%, respectively, of that of wild radish. Gene escape from transgenic oilseed rape to wild related species is discussed.

The Biology of Canadian Weeds. 137. Brassica napus L. and B. rapa L.

“…Cheng et al (2002) Bn)Raphanus raphanistrum L. (n09) Eber et al (1994), Baranger et al (1995), Chadoeuf et al (1998), Che`vre et al (1998a, Darmency et al (1998), Lefol et al (1997), Rieger et al (2001), Gue´ritaine et al (2003a, b), Che`vre et al (2003Che`vre et al ( , 2007 [Bn)Raphanus raphanistrum F 1 ] R. raphanistrum Che`vre et al (1997Che`vre et al ( , 1998a Bn)Raphanus sativus L. (n09) Gupta ( (1991, 1996b), Alam et al (1992), Sharma and Singh (1992), Vijayakumar et al (1994), Frello et al (1995), Rao and Shivanna (1997), Gupta (1997), Sandhu and Gupta (2000), Choudhary and Joshi (2001a) et al (1985), Ringdahl et al (1987), Salisbury (1989), Gupta (1997) Diplotaxis siifolia Kunze (n010))Bn Gupta (1997) Hirschfeldia incana)Bn Lefol et al (1996b), Darmency and Fleury (2000) Raphanus raphanistrum)Bn Eber et al (1994), Baranger et al (1995), Darmency et al (1998), Che`vre et al (1997, 1998a, 2000, Gue´ritaine and Darmency (2001), Rieger et al (2001), Gue´ritaine et al (2002Gue´ritaine et al ( , 2003a Leckie et al (1993): Jorgensen and Andersen (1994), Bin...…”

“…Studies in France and Australia have indicated that hybridization between R. raphanistrum and B. napus is very rare. Only three hybrids were detected in numerous field experiments in France when R. raphanistrum served as the maternal parent Baranger et al 1995;Darmency et al 1998;Che`vre et al 2000). The hybridization rate was estimated at between 10 (7 and 10 (5 (Che`vre et al 2000).…”

The biology of Canadian weeds. 132. Raphanus raphanistrum L.

“…Hybrids (Table 2) have also been produced between R. raphanistrum and Brassica species, B. napus and B. juncea by normal sexual means (e.g., Darmency et al 1995Darmency et al , 1998Lefol et al 1997;Guéritaine and Darmency 2001;Guéritaine et al 2003b). Two B. napus × R. raphanistrum hybrids were obtained in greenhouse crosses using a Quebec population of wild radish (Lefol et al 1997); these were vigorous but mostly sterile.…”

“…In France, interspecific hybrids were produced under natural field conditions between male-sterile Brassica napus and R. raphanistrum (Eber et al 1994;Darmency et al 1998;Guéritaine et al 2003b), and between transgenic glufosinate-resistant B. napus and R. raphanistrum (Baranger et al 1995;Chèvre et al 1997Chèvre et al , 1998Chèvre et al , 2000Darmency et al 1998). Hybridization occurred in both directions, with hybridization frequency estimated at between 10 -7 and 10 -5 (Chèvre et al 2000).…”

Ecological Impacts of Genetically Modified Crops: Ten Years of Field Research and Commercial Cultivation

“…The considerable differences in the hybridization rates found in the two studies have not been elucidated yet. They could possibly be due to several factors: The probability of gene flow from OSR to S. arvensis [111] and R. raphanistrum [112][113][114] seems to be very low (Tables 4, 5). The occurrence of spontaneous hybrids in commercial fields is therefore unlikely [105,110].…”