Genetic Diversity of Ambrosia trifida L. as Revealed by AFLP Markers

Aims: Invasion of alien species has become a global problem. Many invaders appear to thrive even with low levels of sequence-based genetic variation, and genetic patterns might congruent with the spatial arrangement of populations.

Study Design: The genetic diversity of giant ragweed was investigated using amplified fragment length polymorphism (AFLP). There were 5 populations(100 samples), and the distance between the two populations was more than 20 kilometers along with the mainstream of Liaohe.

Place and Duration of Study: Samples were collected from Liaohe Basin. Experiments were done in the College of Biological Science and Technology, between February 2016 and March 2017.

Methodology: The distance between the two populations was more than 20 kilometers. We sampled five populations of Ambrosia trifida L. along Liaohe river in Liaoning province (north-east of China). Leaves for AFLP experiment were stored in discoloration silica gel. Genomic DNA was extracted following the CTAB protocol.

Results: The genetic distances varied with the geographic distances. However, with the influence of many different situations, and many modes of transmission, the discrepancy of genetic distance was reflected. There was low genetic diversity during earlier period of invasion diversity. After a period of invasion, genetic diversity gradually increased. Panshanzha number of polymorphic bands and percentage of polymorphic bands was 98 and 64.47% respectively. Manduhu was 93 and 61.16%, Juliuhe was 100 and 65.79%, Shifosi was 98 and 64.47%, Shuanganqiao was 127 and 83.55%. Shuanganqiao possessed the highest polymorphism.

Conclusion: The source of genetic variation of giant ragweed in Liaohe was gene flow of population. Shuanganqiao might be the spread center.