隨機採集種植基因轉殖木瓜、非基因轉殖木瓜和鄰近無種植木瓜周圍之表土 (0-15 cm) 及底土 (15-30 cm) 土壤進行分析。結果發現此六種土壤水分含量、pH值、總有機碳及總氮含量，各組間無明顯差異。另外，總菌數、真菌數及放線菌數以基因轉殖木瓜周圍之表土含量最高，鄰近無種植木瓜底土含量最低，且表土之菌數均高於底土。使用三種傳統方法及UltraClean Soil DNA Kit 抽取土壤 DNA，以在 -20℃ 使用異丙醇沉澱 DNA 的方法抽取之 DNA 含量最多，而 kit 抽取的 DNA 純度最高。傳統法抽取之DNA 需進一步純化去除腐植酸，才能進行後續的 PCR 反應。由放大片段長度多型性分析、核醣體 DNA 擴增限制酶分析、端點限制片段長度多型性分析及變性梯度膠體電泳四種分析結果顯示，基因轉殖木瓜及非基因轉殖木瓜周圍之表土菌相較為相近，底土菌相亦有相同的趨勢，相似度均在 80% 以上。由此可知，種植基因轉殖木瓜對土壤微生物的影響不大。
To investigate the influence of transgenic papaya on soil microorganisms, we collected upper layer (0-15 cm) and lower layer (15-30 cm) of soil samples around transgenic papaya, non-transgenic papaya and soils that have not been grown plants. The soil properties of moisture content, pH value, total organic carbon content and total nitrogen content were not significantly different among groups. The population of total count, fungi and actinomycete were highest in upper layer soils around transgenic papaya, but lowest in lower layer soils that have not been grown plants. The microbial populations were all higher in upper layer of soils. We compared the efficiency of three kinds of traditional DNA extraction methods as well as UltraClean Soil DNA Kit. The result showed that the amount of DNA was highest followed the method using isopropanol precipitation at -20℃, but the purity of DNA was better using UltraClean Soil DNA Kit. DNA extracted with traditional methods should be purified to remove humid acid in order to proceed polymerase chain reaction (PCR). Amplified fragment length polymorphism (AFLP), amplified ribosomal DNA restriction analysis (ARDRA), terminal restriction fragment length polymorphism (T-RFLP) and denaturing gradient gel electrophoresis (DGGE) analysis indicated that the similarity of soil microorganisms of upper layer soils around transgenic papaya and around non-transgenic papaya was more than 80%. Similar result was observed in lower layer soils. Thus, planting transgenic papayas do limited impact on soil microorganisms.
