Life Table of Aphis craccivora and Quantitative Study of Its Endosymbiont Buchnera 16S rDNA

• Main Authors: Chia-Yu Chen, 陳佳郁
• Other Authors: Mei-Hwa Kuo
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/47631886139519673007

碩士 === 國立中興大學 === 昆蟲學系 === 93 === The development, longevity, fecundity and population parameters of the cowpea aphid, Aphis craccivora, were studied at six constant temperatures (10, 15, 20, 25, 30 and 35℃) on the asparagus bean, Vigna sesquipedalis, in the laboratory. The results showed that the development time of immature stage shortened from 28.1 days at 10℃ to 4.2 days at 30℃. According to the linear regression analysis of development rate and temperature between 10 and 30℃, the overall immature development required 97.2 day-degrees above 7.4℃. The adult longevity shortened from 42.2 days at 15℃ to 6.2 days with increasing temperature to 35℃. At 15 to 25℃, the fecundity was more than 82 (offspring/♀/life). The intrinsic rate of increase (r) and the finite rate of increase (λ) were the lowest at 10℃ (r = 0.0437/d, λ= 1.0447/d), and highest at 30℃ (r = 0.4330/d, λ= 1.5419/d). The population reared at 25℃ had the highest net reproductive rate (R0 = 97.1 offspring/♀/generation). The mean generation time (T) shortened as the temperature increased from 41.1 days at 10℃ to 8.3 days at 35℃. The sequence of bacterial 16S rDNA of A. craccivora revealed that it belongs to primary symbionts, Buchnera sp. According to the RFLP maps of Buchnera 16S rDNA, cowpea aphid seems not to have secondary symbionts. We designed specific primers, AcPS128F and AcPS453R, based on non-conserved regions of 16S rDNA, to quantify the Buchnera 16S rDNA of A. craccivora by real-time PCR technique. The result indicated that the related contents of Buchnera 16S rDNA of older nymphs were higher than those of young nymphs at 10 to 30℃. When temperature was lower, the tendency of such phenomenon was more obvious. In the whole reproduction stage of A. craccivora, the related contents of Buchnera 16S rDNA was higher at 10-25℃than at 30℃ and 35℃.