中国农业科学 ›› 2018, Vol. 51 ›› Issue (1): 105-118.doi: 10.3864/j.issn.0578-1752.2018.01.010

• 植物保护 • 上一篇    下一篇

抗除草剂转基因油菜与野芥菜的抗性回交3代子3代的适合度

闫静,王晓蕾,张玉池,张庆玲,王建,强胜,宋小玲   

  1. 南京农业大学生命科学学院,南京 210095
  • 收稿日期:2017-06-12 出版日期:2018-01-01 发布日期:2018-01-01
  • 通讯作者: 宋小玲,E-mail:sxl@njau.edu.cn
  • 作者简介:闫静,E-mail:406251260@qq.com
  • 基金资助:
    国家转基因生物新品种培育科技重大专项(2016ZX08012005-006)、国家自然科学基金(31270579)

Fitness of Herbicide-Resistant BC3F4 between two herbicide-resistant transgenic Brassica napus and wild Brassica juncea

YAN Jing, WANG XiaoLei, ZHANG YuChi, ZHANG QingLing, WANG Jian, QIANG Sheng, SONG XiaoLing   

  1. College of Life Sciences, Nanjing Agricultural University, Nanjing 210095
  • Received:2017-06-12 Online:2018-01-01 Published:2018-01-01

摘要: 【目的】抗除草剂转基因油菜(Brassica napusspan,AACC,2n=38)的抗性基因一旦成功漂移到近缘杂草中,将会给农田杂草防除带来很大的困难。转基因油菜的近缘杂草野芥菜(wild B. juncea,AABB,2n=36)广泛分布于中国西部地区并沿长江流域扩散,因此有必要深入研究抗除草剂转基因油菜与野芥菜回交后代的适合度,为抗性基因是否能成功漂移到近缘杂草中提供试验依据。【方法】在田间以不同密度(低密度为15株/区,高密度为30株/区)单种和混种(野芥菜与回交后代以4﹕1、3﹕2、1﹕1比例混种)野芥菜及抗性回交3代子3代(抗草甘膦转基因油菜及抗草丁膦转基因油菜与野芥菜的抗性正反回交3代子3代分别表示为BC3mF4R、BC3pF4R和BC3mF4L、BC3pF4L,m表示以野芥菜为母本的回交后代,p表示以野芥菜为父本的回交后代),测定抗性正反回交3代子3代的营养生长(株高、茎粗、一次分枝数、地上部单株干生物量)和生殖生长(单株有效角果数、单株种子质量、角果长、每角果饱粒数)的适合度成分,并比较供试回交后代的总适合度与野芥菜的差异。【结果】在单种条件下,BC3mF4R和BC3pF4R的各适合度成分及总适合度均与野芥菜无显著差异;尽管在高密度下BC3mF4L和BC3pF4L的茎粗、地上部单株干生物量和单株有效角果数显著低于野芥菜,但BC3mF4L和BC3pF4L的总适合度仍与野芥菜无显著差异;因此,在单种条件下,抗草甘膦或抗草丁膦的回交3代子3代在低密度和高密度均具有与野芥菜相当的总适合度。当回交后代与野芥菜混种时,在低密度3种比例混种下,抗草甘膦和抗草丁膦的回交3代子3代的总适合度与野芥菜无显著差异;在高密度3种比例混种下,BC3F4R与野芥菜的各适合度成分及总适合度无显著差异,但BC3F4L的株高、茎粗、一次分枝数、地上部单株干生物量、单株有效角果数、单株种子质量及总适合度均显著低于野芥菜。相关性分析结果表明,BC3F4的各适合度成分仅与种植密度相关。【结论】抗草甘膦或抗草丁膦的正反回交3代子3代都具有在野外生存定植的可能性,且抗草甘膦的回交3代子3代比抗草丁膦的回交3代子3代的可能性更大。因此,在防范转基因油菜的基因逃逸时不仅要防范转基因油菜与近缘杂草的初始杂交,而且要防范杂交后代与近缘杂草的不断回交,以免产生适合度较高的回交后代。

关键词: 抗草甘膦转基因油菜, 抗草丁膦转基因油菜, 野芥菜, 回交后代, 适合度

Abstract: 【Objective】 If herbicide-resistant transgenes escape from transgenic oilseed rape (Brassica napus, AACC, 2n=38) to their weedy relatives through pollen flow, weeds with the herbicide-resistant trait might produce new problems for weed control. Wild B. juncea (AABB, 2n=36), relative weed of transgenic B. napus, has become a major weed of crop systems across western China, and extended eastward along the Yangtze River valley. In order to provide experimental data for whether the transgene could successfully escape to wild B. juncea, it is necessary to evaluate the fitness of backcross generation between herbicide-resistant transgenic B. napus and wild B. juncea before it is released. 【Method】Wild B. juncea and herbicide-resistant BC3mF4R, BC3pF4R and BC3mF4L, BC3pF4L (R and L denote glyphosate- and glufosinate-resistant backcross progeny obtained with glyphosate- and glufosinate-resistant transgenic B. napus, respectively. m and p denote backcross progeny obtained with wild B. juncea as maternal plants and paternal plants, respectively) were planted at low (15 plants per plot) and high density (30 plants per plot) in pure and mixed stands (wild B. juncea﹕backcross generation were 4﹕1, 3﹕2 and 1﹕1). the vegetative components (plant height, stem diameter, the first branch number/plant, above-ground dry biomass/plant) and reproductive components (silique number/plant, total seed weight/plant, silique length, seed number/silique) of these backcross generations were measured. The differences of the composite fitness between BC3F4 and wild B. juncea were analyzed. 【Result】 Under pure stands, there was no significant difference in the fitness components and composite fitness of BC3F4R with that of wild B. juncea. The composite fitness of BC3F4L was also similar to wild B. juncea although the stem diameter, above-ground dry biomass/plant, and silique number/plant of BC3F4L at high density were significantly lower than that of wild B. juncea. Therefore, either glyphosate- or glufosinate-resistant BC3F4 was as fit as wild B. juncea regardless of density under pure stands. Under mixed stands, at low density, there was no significant difference in composite fitness of glyphosate- or glufosinate-resistant BC3F4 with that of wild B. juncea. At high density, there was no significant difference in fitness components and composite fitness of BC3F4R with that of wild B. juncea regardless planting proportions. However, the plant height, stem diameter, the first branch number/plant, above-ground dry biomass/plant, silique number/plant, total seed weight/plant and composite fitness of BC3F4L were significantly lower than that of wild B. juncea. The correlation analysis showed that the fitness components of BC3F4 were only related to the planting density. 【Conclusion】Glyphosate- or glufosinate- resistant BC3F4 between glyphosate- or glufosinate-resistant transgenic B. napus and wild B. juncea have a strong survival ability and potential possibility of establishing populations in the field. Moreover, the ecological risk of gene flow is higher from glyphosate-resistant transgenic B. napus than glufosinate-resistant transgenic B. napus. Therefore, preventing gene escape from herbicide-resistant B. napus to wild B. juncea should not only prevent their initial hybrids, but also should prevent the backcross between wild B. juncea and F1 or subsequent generations, so as not to produce higher fitness backcross generation.

Key words: glyphosate-resistant transgenic oilseed rape (Brassica napus), glufosinate-resistant transgenic oilseed rape (Brassica napus), wild Brassica juncea;backcross generations, fitness