Nguyen Hoang Loc^*, Le Thi Thinh

Institute of Bioactive Compounds, University of Sciences, Hue University, Hue 530000, Vietnam

Abstract

The study aimed to evaluate some agrobiological properties of ctb transgenic tomatoes under in vivo condition through physiological and biochemical characteristics relate to fruit yield and quality. Agrobiological parameters are determined by weighing, measuring and counting. Photosynthetic rate was determined via uptake carbon dioxide, the spectrophotometric method used to measure chlorophyll and total carotenoid content, vitamin C was determined using the iodine titration method, reducing sugar was determined by dinitrosalicylic acid, degree Brix was measured using an ATAGO N1 refractometer and total acidity in fruit juice was determined by neutralization method. Study results showed that final harvesting time for all tomatoes were 150 days including transgenic plants and control. Plant height (cm) ranged from 80.3 to 83.6, number of compound leaves from 17.6 to 22, and number of inflorescences from 7.3 to 9.3. The chlorophyll content (mg/g) and the photosynthetic rate (µM CO₂/m²/s) peaked at young fruit stage in both transgenic plants and control with values from 0.48 to 0.62 and from 9.08 to 16.77, respectively. The yield, yield components and fruit shape of transgenic plants and control were also similar. Number of fruits ranged from 14.6 to 23, fruit weight (g) ranged from 61.5 to 69.3, and individual yield (kg) varied from 0.99 to 1.53. The main biochemical characteristics of transgenic plants and control were not different, dry matter (%) accounts for 5.45-5.91, reducing sugar (%) of 1.87-2.22, vitamin C (mg/100 g) of 44.01-46.13, acidity (%) of 0.62-0.89, Brix (%) of 5.23-6.01 and carotene (mg/100 g) of 3.01-3.84. In conclusion, six ctb transgenic tomato individuals were able to grow normally under in vivo conditions similar to non-transgenic control plants. Agrobiological properties between transgenic plants and control were insignificantly different with p>0.05.

Keywords: Cholera toxin B subunit (CTB), In vivo ctb transgenic tomato, Lycopersicon esculentum, Vibrio cholerae