Experiments were conducted to examine the effects of salinity fluctuation on the intermolt period and growth of Fenneropenaeus chi- nensis with an initial body weight of (0.553 2±0.000 1)g (mean plus or minus SE)...Experiments were conducted to examine the effects of salinity fluctuation on the intermolt period and growth of Fenneropenaeus chi- nensis with an initial body weight of (0.553 2±0.000 1)g (mean plus or minus SE). The salinity (S0) of the control treatment is 30 throughout the experiment, while the treatments S2, S4, S7 and S10 are subjected to different salinity fluctuations, and the ranges are 2, 4, 7 and 10, respectively. After a 30-day feeding trial, the longest and the shortest intermolt periods of the shrimp occur under Treatments S10 and S2, respectively (difference 37.14%). The special growth rates (SGR) of the shrimp under the five treatments are ranked as S7> S4> S2> S10> S0, and the SGR of the shrimp under Treatment S0 is lower than that under Treatments S4 and S7 by 22.36% and 28.11%, respectively (P< 0.05). The minimal feed intake (FI) of the experimental animals occurs in Treatment S0 (84.04% and 88.54% of that under Treatments S4 and S7, respectively) (P< 0.05). There are no significant differences in the food conversion efficiency (FCE) of the shrimp under the five treatments (P> 0.05).展开更多
After continuous breeding gametophyte of Laminaria, then breaking protonema, heterosis seedling is got by bilineal hybridization. The result shows that the weight-increasing rate of female and male gametophyte clone c...After continuous breeding gametophyte of Laminaria, then breaking protonema, heterosis seedling is got by bilineal hybridization. The result shows that the weight-increasing rate of female and male gametophyte clone cells are 14.03% and 13.87%, after 16 d crossbreeding, the rate of ovulation is up to100%; the length of juvenile sporophyte after 40 d breeding is 2-3 cm. By farming on the sea, a hybrid combination is primarily screened.展开更多
Physiological indices related to PS II photochemical efficiency (Fv/Fm) and membrane lipid peroxidation were measured in leaves of indica rice cv Shanyou 63 and japonica rice 9516 at different temperatures and light i...Physiological indices related to PS II photochemical efficiency (Fv/Fm) and membrane lipid peroxidation were measured in leaves of indica rice cv Shanyou 63 and japonica rice 9516 at different temperatures and light intensities for four days. No obvious changes in Fv/Fm and MDA were observed in both indica and japonica rice at moderate temperature and medium PFD, implying neither photoinhibition nor photooxidation happened in these cases. In indica rice either at medium temperature with higher PFD or at lower temperature with medium PFD Fv/Fm dropped obviously with no changes in MDA contents, and photoinhibition appeared while photooxidation did not occur. However, D1 protein, Fv/Fm, (A+Z)/(A+Z+V), and SOD activities dropped, and O2 - production and MDA content increased accordingly, as well as both photoinhibition and photooxidation appeared in two rice varieties at lower temperature and higher PFD. Experiment with inhibitors at lower temperature and higher PFD showed that as compared with japonica rice the decrements appeared in D1 protein contents, SOD activities, and (A+Z)/(A+Z+V) ratios, the xanthophyll cycle and non-photochemical quench (qN) were inhibited in a more degree, as well as increments of MDA content were greater, thus exhibiting more distinct photoinhibition and photooxidation in indica rice. It is suggested that Fv/Fm and membrane lipid peroxidation product-MDA were the key indices to predict and diagnose photooxidation.展开更多
文摘Experiments were conducted to examine the effects of salinity fluctuation on the intermolt period and growth of Fenneropenaeus chi- nensis with an initial body weight of (0.553 2±0.000 1)g (mean plus or minus SE). The salinity (S0) of the control treatment is 30 throughout the experiment, while the treatments S2, S4, S7 and S10 are subjected to different salinity fluctuations, and the ranges are 2, 4, 7 and 10, respectively. After a 30-day feeding trial, the longest and the shortest intermolt periods of the shrimp occur under Treatments S10 and S2, respectively (difference 37.14%). The special growth rates (SGR) of the shrimp under the five treatments are ranked as S7> S4> S2> S10> S0, and the SGR of the shrimp under Treatment S0 is lower than that under Treatments S4 and S7 by 22.36% and 28.11%, respectively (P< 0.05). The minimal feed intake (FI) of the experimental animals occurs in Treatment S0 (84.04% and 88.54% of that under Treatments S4 and S7, respectively) (P< 0.05). There are no significant differences in the food conversion efficiency (FCE) of the shrimp under the five treatments (P> 0.05).
文摘After continuous breeding gametophyte of Laminaria, then breaking protonema, heterosis seedling is got by bilineal hybridization. The result shows that the weight-increasing rate of female and male gametophyte clone cells are 14.03% and 13.87%, after 16 d crossbreeding, the rate of ovulation is up to100%; the length of juvenile sporophyte after 40 d breeding is 2-3 cm. By farming on the sea, a hybrid combination is primarily screened.
文摘Physiological indices related to PS II photochemical efficiency (Fv/Fm) and membrane lipid peroxidation were measured in leaves of indica rice cv Shanyou 63 and japonica rice 9516 at different temperatures and light intensities for four days. No obvious changes in Fv/Fm and MDA were observed in both indica and japonica rice at moderate temperature and medium PFD, implying neither photoinhibition nor photooxidation happened in these cases. In indica rice either at medium temperature with higher PFD or at lower temperature with medium PFD Fv/Fm dropped obviously with no changes in MDA contents, and photoinhibition appeared while photooxidation did not occur. However, D1 protein, Fv/Fm, (A+Z)/(A+Z+V), and SOD activities dropped, and O2 - production and MDA content increased accordingly, as well as both photoinhibition and photooxidation appeared in two rice varieties at lower temperature and higher PFD. Experiment with inhibitors at lower temperature and higher PFD showed that as compared with japonica rice the decrements appeared in D1 protein contents, SOD activities, and (A+Z)/(A+Z+V) ratios, the xanthophyll cycle and non-photochemical quench (qN) were inhibited in a more degree, as well as increments of MDA content were greater, thus exhibiting more distinct photoinhibition and photooxidation in indica rice. It is suggested that Fv/Fm and membrane lipid peroxidation product-MDA were the key indices to predict and diagnose photooxidation.
