Lu Y-Q, Baker J, Preston C
School of Agriculture, Food and Wine, University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia.
Theor Appl Genet. 2007 Aug;115(4):443-50. doi: 10.1007/s00122-007-0576-3. Epub 2007 Jul 13.
Resistance to ALS-inhibiting herbicides in Lactuca serriola first appeared in the northern Yorke Peninsula in South Australia in 1994, with resistance soon observed at a number of additional sites. The rapid appearance of resistance at many sites could be attributed to a number of independent selection events or to movement of resistant seed from the original field. ISSRs were used to genotype plants collected in 1999 and 2004 from roadsides or fields in an attempt to determine the importance of these two factors in the spread of herbicide resistance in L. serriola. In 1999 and 2004, chlorsulfuron-resistant L. serriola plants were found in both fields and roadsides with resistant plants being more frequent in fields than roadsides and more frequent in 2004 than in 1999. Genetic relationships generated using UPGMA analysis indicated the presence of more than one genotype within the herbicide resistant populations sampled for both years and suggested independent selection as well as movement of resistant seed had occurred. DNA extracted from samples collected in 1999 was used to sequence a highly conserved region of the ALS gene that coded for a single amino acid modification within the gene. Four different mutations were identified within the resistant samples and these mutations tended to cluster on a geographical basis. Together these data provide evidence for both multiple independent evolutionary events and for the potential movement of individual genotypes as far as 43 km in the region.
1994年，南澳大利亚约克半岛北部首次出现了对抑制乙酰乳酸合成酶（ALS）类除草剂具有抗性的锯齿莴苣，随后在其他一些地点也很快发现了抗性植株。许多地点抗性的迅速出现可能归因于多个独立的选择事件，或者是抗性种子从最初的田地扩散所致。利用简单序列重复区间（ISSR）对1999年和2004年从路边或田地采集的植株进行基因分型，试图确定这两个因素在锯齿莴苣除草剂抗性传播中的重要性。1999年和2004年，在田地和路边均发现了对氯磺隆具有抗性的锯齿莴苣植株，抗性植株在田地中比在路边更为常见，且在2004年比1999年更为频繁。利用非加权组平均法（UPGMA）分析得出的遗传关系表明，在这两年采集的除草剂抗性种群中存在不止一种基因型，这表明既发生了独立选择，也存在抗性种子的扩散。从1999年采集的样本中提取的DNA，被用于对ALS基因的一个高度保守区域进行测序，该区域编码基因内的一个单一氨基酸修饰。在抗性样本中鉴定出了四种不同的突变，这些突变在地理分布上倾向于聚类。这些数据共同为多个独立的进化事件以及该区域内单个基因型最远达43公里的潜在扩散提供了证据。
