In ecological zone of Chengdu, Sichuan, microspore culture was carried out in Brassica napus L. to study the influencing factors on microspore culture. The results showed that the temperature on microspore formation s...In ecological zone of Chengdu, Sichuan, microspore culture was carried out in Brassica napus L. to study the influencing factors on microspore culture. The results showed that the temperature on microspore formation stage, day and night temperature, disinfection solution of buds, cultivation concentration on microspore and strain-age were both important influencing factors on microspore culture. At a temperature below 5 ℃ or above 20 ℃, the material had a much lower embryo producing rate or even could not produce any embryo, but at the optimum temperature of 10 -15 ℃ the embryo yield was up to 300 pieces per bud; the best cultivation effect appeared when 0. 1% HgCl2 was used for disin- fection; the best density of microspore was 3 -4 buds per dish; In 2009, while strain-age was from 125 d to 150 d, the microspore embryo yield increased as strain-age increased. When stain-age was 150 days, the microspore embryo yield was up to the highest, but the yield declined after 150 days.展开更多
The behavioral responses of a tilapia (Oreochromis niloticus) school to low (0.13 mg/L), moderate (0.79 mg/L) and high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were monitored using a computer vision...The behavioral responses of a tilapia (Oreochromis niloticus) school to low (0.13 mg/L), moderate (0.79 mg/L) and high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were monitored using a computer vision system. The swimming activity and geometrical parameters such as location of the gravity center and distribution of the fish school were calculated continuously. These behavioral parameters of tilapia school responded sensitively to moderate and high UIA concen-tration. Under high UIA concentration the fish activity showed a significant increase (P<0.05), exhibiting an avoidance reaction to high ammonia condition, and then decreased gradually. Under moderate and high UIA concentration the school’s vertical location had significantly large fluctuation (P<0.05) with the school moving up to the water surface then down to the bottom of the aquarium alternately and tending to crowd together. After several hours’ exposure to high UIA level, the school finally stayed at the aquarium bottom. These observations indicate that alterations in fish behavior under acute stress can provide important in-formation useful in predicting the stress.展开更多
文摘In ecological zone of Chengdu, Sichuan, microspore culture was carried out in Brassica napus L. to study the influencing factors on microspore culture. The results showed that the temperature on microspore formation stage, day and night temperature, disinfection solution of buds, cultivation concentration on microspore and strain-age were both important influencing factors on microspore culture. At a temperature below 5 ℃ or above 20 ℃, the material had a much lower embryo producing rate or even could not produce any embryo, but at the optimum temperature of 10 -15 ℃ the embryo yield was up to 300 pieces per bud; the best cultivation effect appeared when 0. 1% HgCl2 was used for disin- fection; the best density of microspore was 3 -4 buds per dish; In 2009, while strain-age was from 125 d to 150 d, the microspore embryo yield increased as strain-age increased. When stain-age was 150 days, the microspore embryo yield was up to the highest, but the yield declined after 150 days.
基金Project (Nos. 2001AA620104 and 2003AA603140) supported by theHi-Tech Research and Development Program (863) of China
文摘The behavioral responses of a tilapia (Oreochromis niloticus) school to low (0.13 mg/L), moderate (0.79 mg/L) and high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were monitored using a computer vision system. The swimming activity and geometrical parameters such as location of the gravity center and distribution of the fish school were calculated continuously. These behavioral parameters of tilapia school responded sensitively to moderate and high UIA concen-tration. Under high UIA concentration the fish activity showed a significant increase (P<0.05), exhibiting an avoidance reaction to high ammonia condition, and then decreased gradually. Under moderate and high UIA concentration the school’s vertical location had significantly large fluctuation (P<0.05) with the school moving up to the water surface then down to the bottom of the aquarium alternately and tending to crowd together. After several hours’ exposure to high UIA level, the school finally stayed at the aquarium bottom. These observations indicate that alterations in fish behavior under acute stress can provide important in-formation useful in predicting the stress.
