This study aims to investigate the variation in occurrence of white-belly rice kernel（WBRK） and white-core rice kernel（WCRK） among different positions within a panicle. Twenty-four M4 mutants involved in four pani...This study aims to investigate the variation in occurrence of white-belly rice kernel（WBRK） and white-core rice kernel（WCRK） among different positions within a panicle. Twenty-four M4 mutants involved in four panicle types, namely the compact, intermediate, loose, and chicken foot panicle were used. They derived from a japonica rice cultivar Wuyujing 3. Considerable differences in morphological characters existed among the four types of panicle, especially in panicle length, the secondary branch number and ratio of grain number to total branch length. Marked differences were found in WBRK and WCRK among different positions within a panicle for all types of panicle. In general, grains located on the primary rachis and top rachis branches had higher WBRK and WCRK percentage than those on the secondary rachis and bottom rachis branches. WCRK exhibited larger variation among grain positions than WBRK did. Moreover, there was a significant difference in WCRK/WBRK among grain positions within a panicle, with primary rachis and top rachis branches having higher values than the secondary and bottom rachis. In addition, panicle type showed no significant effect on the pattern of WBRK and WCRK occurrence within a panicle. The results indicated the difference in mechanism of WBRK and WCRK formation in grain position within a panicle, and are valuable for breeding and agronomic practices aimed at lowering chalky grain rate.展开更多
Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . I...Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . In our feeding trials, four experimental temperatures were applied: 17℃,22℃,27℃ and 32℃. The energy requirements of N. confucianus under different temperature were:107 43±6 44 KJ/animal/day (17℃),94 76±4 46 KJ/animal/day (22℃),73 96±5 65 KJ/animal/day(27℃),and 62 80±5 15 KJ/animal/day(32℃),respectively. Moreover, the energy intake, digested and assimilated energy of N. confucianus decreased with temperature increase. However, no significant differences on digestibility and assimilation rate of N. confucianus were found among four experimental temperatures. It indicated that, during a range of particular temperatures, N. confucianus might maintain relatively high digestibility by change of digest tract morphology.展开更多
Digested energy, metabolizable energy, digestibility and assimilation rate were quantified at different photoperiods in Niviventer confucianus using the food balance method. Three photoperiods were applied: a short ph...Digested energy, metabolizable energy, digestibility and assimilation rate were quantified at different photoperiods in Niviventer confucianus using the food balance method. Three photoperiods were applied: a short photoperiod (8L∶16D), normal photoperiod(12L∶12D) and a long photoperiod(16L∶8D). The results show that digestibility and assimilation rate were highest in the short photoperiod with values of 83 97%±1 16% and 80 46%±1 34%, and lowest in the normal photoperiod with values of 81 74%±1 76% and 78 45%±1 41%. Moreover, the energy intake, digestibility and assimilated energy of N. confucianus decreased with the amount of daylight. The statistical significance of the results obtained by a one-factor analysis of variance were all less than 0 01 or 0 05 except for digested energy. This indicates that photoperiod is an important environmental factor to affect the energy metabolism of Niviventer confucianus .展开更多
The scatter-hoarding behavior of granivorous rodents plays an important role in seed dispersal and seedling regeneration of trees,as well as the evolution of several well-known mutualisms between trees and roden...The scatter-hoarding behavior of granivorous rodents plays an important role in seed dispersal and seedling regeneration of trees,as well as the evolution of several well-known mutualisms between trees and rodents in forest ecosystems.Because it is difficult to identify seed hoarders and pilferers under field conditions by traditional methods,the full costs incurred and benefits accrued by scatter-hoarding have not been fully evaluated in most systems.By using infrared radiation camera tracking and seed tagging,we investigated the benefits and losses of scatter-hoarded seeds(Camellia oleifera)for 3 sympatric rodent species(Apodemus draco,Niviventer confucianus and Leopoldamys edwardsi)in a subtropical forest of Southwest China during 2013 to 2015.We established the relationships between the rodents and the seeds at the individual level.For each rodent species,we calculated the cache recovery rate of cache owners,as well as conspecific and interspecific pilferage rates.We found that all 3 sympatric rodent species had a cache recovery advantage with rates that far exceeded average pilferage rates over a 30-day tracking period.The smallest species(A.draco)showed the highest rate of scatter-hoarding and the highest recovery advantage compared with the other 2 larger species(N.confucianus and L.edwardsi).Our results suggest that scatter-hoarding benefits cache owners in food competition,supporting the pilferage avoidance hypothesis.Therefore,scatter-hoarding behavior should be favored by natural selection,and plays a significant role in species coexistence of rodent community and in the formation of mutualism between seeds and rodents in forest ecosystems.展开更多
基金supported by the Program for New Century Excellent Talents in University, China (NCET-10-0472)the National Natural Science Foundation of China (30971733 and 31171485)
文摘This study aims to investigate the variation in occurrence of white-belly rice kernel（WBRK） and white-core rice kernel（WCRK） among different positions within a panicle. Twenty-four M4 mutants involved in four panicle types, namely the compact, intermediate, loose, and chicken foot panicle were used. They derived from a japonica rice cultivar Wuyujing 3. Considerable differences in morphological characters existed among the four types of panicle, especially in panicle length, the secondary branch number and ratio of grain number to total branch length. Marked differences were found in WBRK and WCRK among different positions within a panicle for all types of panicle. In general, grains located on the primary rachis and top rachis branches had higher WBRK and WCRK percentage than those on the secondary rachis and bottom rachis branches. WCRK exhibited larger variation among grain positions than WBRK did. Moreover, there was a significant difference in WCRK/WBRK among grain positions within a panicle, with primary rachis and top rachis branches having higher values than the secondary and bottom rachis. In addition, panicle type showed no significant effect on the pattern of WBRK and WCRK occurrence within a panicle. The results indicated the difference in mechanism of WBRK and WCRK formation in grain position within a panicle, and are valuable for breeding and agronomic practices aimed at lowering chalky grain rate.
文摘Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . In our feeding trials, four experimental temperatures were applied: 17℃,22℃,27℃ and 32℃. The energy requirements of N. confucianus under different temperature were:107 43±6 44 KJ/animal/day (17℃),94 76±4 46 KJ/animal/day (22℃),73 96±5 65 KJ/animal/day(27℃),and 62 80±5 15 KJ/animal/day(32℃),respectively. Moreover, the energy intake, digested and assimilated energy of N. confucianus decreased with temperature increase. However, no significant differences on digestibility and assimilation rate of N. confucianus were found among four experimental temperatures. It indicated that, during a range of particular temperatures, N. confucianus might maintain relatively high digestibility by change of digest tract morphology.
文摘Digested energy, metabolizable energy, digestibility and assimilation rate were quantified at different photoperiods in Niviventer confucianus using the food balance method. Three photoperiods were applied: a short photoperiod (8L∶16D), normal photoperiod(12L∶12D) and a long photoperiod(16L∶8D). The results show that digestibility and assimilation rate were highest in the short photoperiod with values of 83 97%±1 16% and 80 46%±1 34%, and lowest in the normal photoperiod with values of 81 74%±1 76% and 78 45%±1 41%. Moreover, the energy intake, digestibility and assimilated energy of N. confucianus decreased with the amount of daylight. The statistical significance of the results obtained by a one-factor analysis of variance were all less than 0 01 or 0 05 except for digested energy. This indicates that photoperiod is an important environmental factor to affect the energy metabolism of Niviventer confucianus .
基金supported by the key project of the Chinese Academy of Sciences(XDB11050300,KSZD-EW-TZ-008)the key project of the National Natural Science Foundation of China(31330013).
文摘The scatter-hoarding behavior of granivorous rodents plays an important role in seed dispersal and seedling regeneration of trees,as well as the evolution of several well-known mutualisms between trees and rodents in forest ecosystems.Because it is difficult to identify seed hoarders and pilferers under field conditions by traditional methods,the full costs incurred and benefits accrued by scatter-hoarding have not been fully evaluated in most systems.By using infrared radiation camera tracking and seed tagging,we investigated the benefits and losses of scatter-hoarded seeds(Camellia oleifera)for 3 sympatric rodent species(Apodemus draco,Niviventer confucianus and Leopoldamys edwardsi)in a subtropical forest of Southwest China during 2013 to 2015.We established the relationships between the rodents and the seeds at the individual level.For each rodent species,we calculated the cache recovery rate of cache owners,as well as conspecific and interspecific pilferage rates.We found that all 3 sympatric rodent species had a cache recovery advantage with rates that far exceeded average pilferage rates over a 30-day tracking period.The smallest species(A.draco)showed the highest rate of scatter-hoarding and the highest recovery advantage compared with the other 2 larger species(N.confucianus and L.edwardsi).Our results suggest that scatter-hoarding benefits cache owners in food competition,supporting the pilferage avoidance hypothesis.Therefore,scatter-hoarding behavior should be favored by natural selection,and plays a significant role in species coexistence of rodent community and in the formation of mutualism between seeds and rodents in forest ecosystems.
