Aper J, De Riek J, Mechant E, Bulcke R, Reheul D
Ghent University, Faculty of Bioscience Engineering, Dept. Plant Production, Weed Science Unit, Coupure Links 653, BE-9000 Gent, Belgium.
Commun Agric Appl Biol Sci. 2011;76(3):491-9.
Molecular markers can provide valuable information on the spread of resistant weed biotypes. In particular, tracing local spread of resistant weed patches will give details on the importance of seed migration with machinery, manure, wind or birds. This study investigated the local spread of metamitron resistant Chenopodium album L. patches in the southwest region of the province West-Flanders (Belgium). During the summer of 2009, leaf and seed samples were harvested in 27 patches, distributed over 10 sugar beet fields and 1 maize field. The fields were grouped in four local clusters. Each cluster corresponded with the farmer who cultivated these fields. A cleaved amplified polymorphic sequence (CAPS) procedure identified the Ser264 to Gly mutation in the D1 protein, endowing resistance to metamitron, a key herbicide applied in sugar beet. The majority of the sampled plants within a patch (97% on average) carried this mutation. Amplified fragment length polymorphism (AFLP) analysis was performed with 4 primer pairs and yielded 270 molecular markers, polymorphic for the whole dataset (303 samples). Analysis of molecular variance revealed that a significant part of the genetic variability was attributed to variation among the four farmer locations (12 %) and variation among Chenopodium album patches within the farmer locations (14%). In addition, Mantel tests revealed a positive correlation between genetic distances (linearised phipt between pairs of patches) and geographic distances (Mantel-coefficient significant at p = 0.002), suggesting isolation-by-distance. In one field, a decreased genetic diversity and strong genetic relationships between all the patches in this field supported the hypothesis of a recent introduction of resistant biotypes. Furthermore, genetic similarity between patches from different fields from the same farmer and from different farmers indicated that seed transport between neighbouring fields is likely to have an important impact on the spread of metamitron resistant biotypes.
分子标记可以提供有关抗性杂草生物型传播的有价值信息。特别是，追踪抗性杂草斑块的局部传播将详细说明种子通过机械、粪肥、风或鸟类迁移的重要性。本研究调查了比利时西佛兰德省西南部地区抗苯嗪草酮的藜（Chenopodium album L.）斑块的局部传播情况。2009年夏季，在分布于10个甜菜田和1个玉米田的27个斑块中采集了叶片和种子样本。这些田地被分为四个局部集群。每个集群对应种植这些田地的农民。一种酶切扩增多态性序列（CAPS）方法鉴定出D1蛋白中Ser264到Gly的突变，该突变赋予了对苯嗪草酮（一种用于甜菜的关键除草剂）的抗性。一个斑块内大多数采样植物（平均97%）携带此突变。使用4对引物进行扩增片段长度多态性（AFLP）分析，得到了270个分子标记，对整个数据集（303个样本）具有多态性。分子方差分析表明，相当一部分遗传变异归因于四个农民所在位置之间的变异（12%）以及农民所在位置内藜斑块之间的变异（14%）。此外，Mantel检验显示遗传距离（斑块对之间的线性化phipt）与地理距离之间存在正相关（Mantel系数在p = 0.002时显著），表明存在距离隔离。在一块田地中，该田地所有斑块的遗传多样性降低且遗传关系紧密，支持了抗性生物型近期引入的假设。此外，来自同一农民不同田地以及不同农民不同田地的斑块之间的遗传相似性表明，相邻田地之间的种子传播可能对抗苯嗪草酮生物型的传播有重要影响。
