关键词: 凡纳滨对虾 , 虾肝肠胞虫（EHP）, 皮下组织坏死（IHHNV）, 实时荧光定量PCR, Litopennaus vannamei, EHP, IHHNV, real-time PCR

Abstract: In recent years, the growth retardation of white shrimp (Litopenaeus vannamei) has been a common phenomenon in west Guangdong Province. The potential pathogenies of this disease are considered Enterocytozoon Hepatopenaei (EHP) and infectious hypodermal and hematopoietic necrosis virus (IHHNV). The fluorescent quantitative real-time PCR (RT-PCR) methods was founded so as to estimate the epidemic of these two pathogenies. These methods were used to detect 87 samples of junior shrimps, parent shrimps, adult shrimps, fresh feed and water which sampled across the west Guangdong Province. The results show that the positive rate of EHP was 41.38%, the IHHNV positive rate of 12.18%. And in testing samples, EHP and IHNNV have been detected in two water samples in different areas,but have not been detected in cultivation water after sterilized. The highest EHP positive rate of adult shrimps was 93.75% and highest IHHNV positive rate of 38.10%. EHP was detected in both local and imported parent shrimp, positive rate of 80.00% and 33.33% , respectively,but IHHNV was not detected in imported parent shrimp. In the test results of samples with different farms, the shrimp ,which load index of EHP was the highest of 10, the average weight of daily growth was the minimum of 0.039 g. And load index of EHP was the lowest of 2,while the average weight of daily growth was the maximum of 0.090 g. But the load index of EHP was the same with the different size shrimps in the pool of 20.Then it was found that the content of EHP in smaller junior shrimps from different ponds was significantly higher than large ones, indicating that EHP had a significant impact on the growth of the shrimp. It was a similar ogarithmic relationship and the correlation coefficient was R2 = 0.574 6.