Seed vigor is a more promising seed quality character reflecting potential seed germination, field emergence and seed storage ability under different conditions than standard germination. Standard germination is influ...Seed vigor is a more promising seed quality character reflecting potential seed germination, field emergence and seed storage ability under different conditions than standard germination. Standard germination is influenced by genetic background and environmental effects during seed development and storage conditions. The latest research on physiological mechanism in seed vigor showed that at the late stage of seed development, the development of seed vigor involves some stress-resistant substances including late embryogenesis abundant （LEA） protein, oligosaccharides and abscisic acid （ABA）. Whereas the loss of seed vigor, or seed aging and deterioration, could be attributed to lipid peroxidation, chromosome deformation and genes aberrance, and embryo protein degradation, etc. Seed vigor is a quantitative character controlled by multi-genes. Genetic and quantitative trait locus （QTL） analyses on seed-vigor trait in model plants, such as Arabidopsis and rice, are mostly concentrated on related morphology traits, whereas few physiological traits have been researched. It was concluded that, all of the QTL genetic characteristics of seed vigorincluding QTL quantities, its locus on chromosome, genetic effects, and interaction effects between genetic and environment, differed with plant species and used seed-vigor traits.展开更多
In May of 2007,the second generation selected （SS） and control （SC） groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the...In May of 2007,the second generation selected （SS） and control （SC） groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the first generation selected group.Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8,18,60,95,195 and 365.On Day 365,100 individuals （60.0–75.0 mm at shell length） were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate,oxygen consumption and ammonia excretion were measured at 15,20,25 and 30°C.The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8,18,60,95,195 and 365 （P 0.05）.The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height,respectively.At 15,20,25 and 30 ° C,the SS groups had significantly larger filtrate rate than the SC group （P 0.05）.At 15 and 25 °C,the differences in oxygen consumption rate between the SS and SC groups were not significant （P 0.05）.At 20 and 30 °C,however,the oxygen consumption rate of the SS group was significantly larger than the SC group （P 0.05）.At 15,20,25 and 30 °C,there were no significant differences in ammonia excretion rate between the SS and SC groups （P 0.05）.The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful.Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior.展开更多
文摘Seed vigor is a more promising seed quality character reflecting potential seed germination, field emergence and seed storage ability under different conditions than standard germination. Standard germination is influenced by genetic background and environmental effects during seed development and storage conditions. The latest research on physiological mechanism in seed vigor showed that at the late stage of seed development, the development of seed vigor involves some stress-resistant substances including late embryogenesis abundant （LEA） protein, oligosaccharides and abscisic acid （ABA）. Whereas the loss of seed vigor, or seed aging and deterioration, could be attributed to lipid peroxidation, chromosome deformation and genes aberrance, and embryo protein degradation, etc. Seed vigor is a quantitative character controlled by multi-genes. Genetic and quantitative trait locus （QTL） analyses on seed-vigor trait in model plants, such as Arabidopsis and rice, are mostly concentrated on related morphology traits, whereas few physiological traits have been researched. It was concluded that, all of the QTL genetic characteristics of seed vigorincluding QTL quantities, its locus on chromosome, genetic effects, and interaction effects between genetic and environment, differed with plant species and used seed-vigor traits.
基金The National Key Technology R&D Program in the 11th Five Year Plan of China under contract No. 2007BAD29B01-2National Department Public Benefit Research Foundation under contract No. nyhyzx 07-048Guangdong Marine and Fishery Bureau under contract Nos A200708C01, A200908A02 and A200908A05
文摘In May of 2007,the second generation selected （SS） and control （SC） groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the first generation selected group.Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8,18,60,95,195 and 365.On Day 365,100 individuals （60.0–75.0 mm at shell length） were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate,oxygen consumption and ammonia excretion were measured at 15,20,25 and 30°C.The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8,18,60,95,195 and 365 （P 0.05）.The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height,respectively.At 15,20,25 and 30 ° C,the SS groups had significantly larger filtrate rate than the SC group （P 0.05）.At 15 and 25 °C,the differences in oxygen consumption rate between the SS and SC groups were not significant （P 0.05）.At 20 and 30 °C,however,the oxygen consumption rate of the SS group was significantly larger than the SC group （P 0.05）.At 15,20,25 and 30 °C,there were no significant differences in ammonia excretion rate between the SS and SC groups （P 0.05）.The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful.Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior.
