Ten healthy weaning piglets of Landrace x Yorkshire (LY) in good body condition with body weight of (24 ± 1.27) kg were selected, and ten weaning piglets of Berkshire × LY (BLY) and Duroc × LY (...Ten healthy weaning piglets of Landrace x Yorkshire (LY) in good body condition with body weight of (24 ± 1.27) kg were selected, and ten weaning piglets of Berkshire × LY (BLY) and Duroc × LY (DLY) with similar situation were also selected respectively to study the growth performance of different cross combinations. Three groups of experimental pigs were bred with conventional diet. The results showed that the average dry matter intakes of combinations of BLY and DLY were slightly decreased by 4.97% and 5.47% compared with the combination of LY, while average daily gain was significantly increased by 3.13% and 1.14%, and feed-weight ratio was decreased by 7.94% and 6.35%, respectively; economic benefit per pig was increased by 0.61 and 0.41 yuan, respectively. The combinations of BLY and DLY have better growth performance, which can be promoted in the production.展开更多
A 3×3 complete diallel cross comprising three families of the clam Meretrix meretrix(P1, P2 and P3) was used to determine the combining ability of parental families and heterosis of F1 under indoor and openair ...A 3×3 complete diallel cross comprising three families of the clam Meretrix meretrix(P1, P2 and P3) was used to determine the combining ability of parental families and heterosis of F1 under indoor and openair environments for growth traits. Analysis of variance for shell length and whole body weight indicated highly significant cross effects, environment effects and the interaction of cross by environment. General combining ability(GCA) and specific combing ability exhibited great variation among crosses and between two environments. Pooled over environments, P2 was the top combiner among the three parental families for both traits studied. The cross of P1 and P3 had the highest SCA. Additionally, significant reciprocal effects were observed. For individual environment, about half of the crossbred combinations showed favorable Mid-parent heterosis(MPH)(〉1%) for the shell length and whole body weight. Our data has shown that non-additive genetic and reciprocal effects constituted the major sources of genetic variation for both shell length and whole body weight, which indicates that crossbreeding among selective families could further explore the heterotic effects.展开更多
Twenty-five species and hybrids in Populus were used as parents, and 26 cross combinations, including more than 5000 seedlings, were obtained by artificial cross breeding. The length of infructescence, number of seeds...Twenty-five species and hybrids in Populus were used as parents, and 26 cross combinations, including more than 5000 seedlings, were obtained by artificial cross breeding. The length of infructescence, number of seeds per infructescence, thousand-seed weight, germination rate of seeds among these cross combinations were tested. The results indicated that the cross combinational effects were significant for these traits, and demonstrated that the length of infructescence, thousand-seed weight were positively affected by female parent. In addition, seedling height, diameter above ground, diameter at breast height (DBH) of 17 cross combination progenies were investigated. The analysis of mean and standard deviation of these three traits showed that seedling height, diameter above ground, DBH had extensive variation among combinations and individuals within combination. Variance analysis and estimate of heritability indicated that the three traits had wide variation and were controlled by heredity. It was feasible to select superior cross combinations and seedlings. Further more, the result of multiple comparison showed that P.deltoides ‘Lux'× P.deltoides ‘D324', P.ussuriensis cl. ‘U4'× P deltoides ‘T66', P.ussuriensis cl. ‘U4'× P. deltoides ‘T26', P.deltoides ‘Lux'× P.ussuriensis cl. ‘U3', (P.tomentosa×P.bolleana)×(P.alba×P.glandulosa), (P.alba×P.tomentosa)×(P.alba×P.glandulosa), and (P.alba×P.glandulosa‘No.2')× P. tomentosa ‘Lumao 50' were superior cross combinations with higher growth rate. Finally, 123 elite seedlings were selected for further test.展开更多
in order to improve the acquired level of heat acclimatization (HA) by training, on the basis of singlemode march training (SMT) or single-mode cross-country race training (SCT) , combined training method of march and...in order to improve the acquired level of heat acclimatization (HA) by training, on the basis of singlemode march training (SMT) or single-mode cross-country race training (SCT) , combined training method of march and cross-country race in the heat was adopted in this experiment ,and the effect of the training on heat tolerance was analyzed. Eight young males were asked to perform a simulated SMT and SCT for 90 min on a treadmill in a hot climate chamber (Td 32. 7℃ , WBGT 28. 4℃ ) once daily for 10 to 12 d within two weeks. The results showed that rectal temperature (Tr) was reduced by 0. 61℃ , heart rate (Hr) by 8. 5 b/min,sweat volume (SV)by 0. 220 kg, physiological strain index (PSI)by 0. 620,systolic pressure (SP)and diastolic pressure (DP) had a little change, pulse pressure (PP) and stroke volume (StV) increased , and cardiac output (CO) decreased a little at the middle stage and increased at the late stage due to Hr change. The standardized bicycle ergometer test (SBE test) in the heat (Td 37℃)has proved that these physiological indexes post-training had significant improvements ,as compared with those pre-training, suggesting that the combined training could raise heat-tolerance and was superior to the SMT in improving acquired heat acclimatization in same training duration and times , and to the SCT in regulating body temperature and cardiovascular function and in prolonging heat tolerance duration.展开更多
The wheatgrass, Thinopyrum intermedium (Host) Barkworth & DR Dewey, shows many beneficial characteristics, such as big spikes and high resistance to many diseases. To transfer the beneficial genes of this species, ...The wheatgrass, Thinopyrum intermedium (Host) Barkworth & DR Dewey, shows many beneficial characteristics, such as big spikes and high resistance to many diseases. To transfer the beneficial genes of this species, many wheat- Thinopyrum intermedium alien chromosome lines were developed. Of them, Shannong 0095 (SN0095), a disomic substitution, has long spikes and flag-leaves, and thus may be an important genetic resource for wheat yield improvement. In order to realize its heterosis and combining ability on major yield traits, a 7 ×7 complete diallel design was made according to Griffing's Method-1. The results showed that heterosis for spike length (SPL), flag-leaf area (FLA), number of spikes per plant (NSP), number of spikelets per spike (NSL), kernels per spike (KPS), 1 000-kernel weight (TKW) and grain yield per plant (GYP) existed in all the crosses by SN0095, but heterobeltiosis occurred only for KPS, TKW, and GYP. The relative mid-parent heterosis (RMH) and relative high-parent heterosis (RHH) for GYP, which valued as high as 35.32 and 29.92% respectively, were the highest among all the traits mearsured. Though additive and non-additive gene effects and cytoplasmic effects (or cytoplasmic-nuclear interaction effects) were found in governing all the traits measured above, additive gene action played a predominant role. The results also showed that SN0095 was the best-general combiner for SPL and FLA, and high-general combiner for NSP amongst all the parents. Estimates of specific combining ability (SCA) showed that SN0095 could also make high-SCA combinations for GYP, such as SN0095 × Jimai 19 (JMI9). SN0095 could be a unique and important parent in hybrid wheat breeding programs.展开更多
Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reason...Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reasonable improvement programs.There were six germination traits investigated on combining ability and heritability using complete diallel crossing method designed for 30 combinations from those six cultivars and lines.The traits included relative root length,stem length,fresh weight per plant,survival rate,electrical conductivity,and vigor index.After flooding treatment,the six traits of parents and F1 were analyzed.The general combining ability(GCA) and special combining ability(SCA) of germination traits were analyzed using Griffing I method.Among 30 cross combinations,the GCA was significantly different among six waterlogging resistance traits.The SCA of these traits was significantly different except the SCA of electrical conductivity.As a representative trait of waterlogging tolerance in rapeseed,relative vigor index had the highest narrow heritability and relatively low broad heritability.The cultivars Zhongshuang 9 and P79 had higher tolerance potential to waterlogging stress.It can be concluded that combining ability and genetic effects of relative vigor index during germination stage could be used to identify the waterlogging tolerance of rapeseed in breeding program.展开更多
Vitamin A deficiency has become a worldwide problem.Biofortified foods can potentially be an inexpensive,locally adaptable,and long-term solution to dietary-nutrient deficiency.In order to improve the β-carotene cont...Vitamin A deficiency has become a worldwide problem.Biofortified foods can potentially be an inexpensive,locally adaptable,and long-term solution to dietary-nutrient deficiency.In order to improve the β-carotene content in maize grain by breeding and minimize vitamin A deficiency,a complete diallel cross was designed with eight inbred lines of maize,and 64 combinations were obtained in this study.The experimental combinations were planted in Yunnan and Sichuan provinces,respectively,with a random complete block design.The β-carotene contents in the grains of the experimental materials were analyzed by high-performance liquid chromatography.Among the tested materials,the effect difference of general combining ability of the β-carotene content was significant;however,the effect difference of the special combining ability and the reciprocal effect were not significant.The β-carotene content of maize grain was not influenced significantly by the cross and the reciprocal cross.There was a significant correlation about the β-carotene content in the maize grains between the F 1 and their parents.The combinations with high β-carotene content were obviously influenced by the environment,and the mean value of β-carotene content for the experimental materials planted in Ya'an of Sichuan was higher than that planted in Yuanjiang of Yunnan,with the results being significant at the 0.01 level.展开更多
Pseudomonas aeruginosa(P:aeruginosa)is a major opportunistic pathogen in hospital-acquired infections.Thus,carly diagnosis is the best strategy for fighting against these infections.In this report,we incorporated mult...Pseudomonas aeruginosa(P:aeruginosa)is a major opportunistic pathogen in hospital-acquired infections.Thus,carly diagnosis is the best strategy for fighting against these infections.In this report,we incorporated multiple crOsS displacement amplification(MCDA)combined with the malachite green(MG)for rapid,sensitive,specific and visual detection of P.aeruginosa by targeting the oprl gene.The MCDA-MG assay was conducted at 67°C for only 40 min during the amplification stage,and then products were directly detected by using colorimetric indicators(MG),eliminating the use of an electrophoresis instrument or amplicon analysis equipment.The entire process,including specimen processing(35 min),amplification(40 min)and detection(5 min),can be finished within 80 min.All 30 non-P.aeruginosa strains tested negative,indicating the high specificity of the MCDA primers.The analytical sensitivity of the MCDA-MG assay was 100 fg of genomic templates per reaction in pure culture,which was in complete accordance with MCDA by gel clectrophoresis and real-time turbidity.The assay was also successfully applied to detecting P.aeruginosa in stool samples.Therefore,the rapidity,simplicity,and nearly equipment free platform of the MCDA-MG technique make it possible for clinical diagnosis,and more.展开更多
基金Supported by Research Program of Science and Technology Department of Guizhou Province(QKH[2011]5020)
文摘Ten healthy weaning piglets of Landrace x Yorkshire (LY) in good body condition with body weight of (24 ± 1.27) kg were selected, and ten weaning piglets of Berkshire × LY (BLY) and Duroc × LY (DLY) with similar situation were also selected respectively to study the growth performance of different cross combinations. Three groups of experimental pigs were bred with conventional diet. The results showed that the average dry matter intakes of combinations of BLY and DLY were slightly decreased by 4.97% and 5.47% compared with the combination of LY, while average daily gain was significantly increased by 3.13% and 1.14%, and feed-weight ratio was decreased by 7.94% and 6.35%, respectively; economic benefit per pig was increased by 0.61 and 0.41 yuan, respectively. The combinations of BLY and DLY have better growth performance, which can be promoted in the production.
基金The National High-Tech R&D Program of China(863 Program)under contract No.2012AA10A410the Key Technologies R&D Program of Jiangsu Province under contract No.BE2011372
文摘A 3×3 complete diallel cross comprising three families of the clam Meretrix meretrix(P1, P2 and P3) was used to determine the combining ability of parental families and heterosis of F1 under indoor and openair environments for growth traits. Analysis of variance for shell length and whole body weight indicated highly significant cross effects, environment effects and the interaction of cross by environment. General combining ability(GCA) and specific combing ability exhibited great variation among crosses and between two environments. Pooled over environments, P2 was the top combiner among the three parental families for both traits studied. The cross of P1 and P3 had the highest SCA. Additionally, significant reciprocal effects were observed. For individual environment, about half of the crossbred combinations showed favorable Mid-parent heterosis(MPH)(〉1%) for the shell length and whole body weight. Our data has shown that non-additive genetic and reciprocal effects constituted the major sources of genetic variation for both shell length and whole body weight, which indicates that crossbreeding among selective families could further explore the heterotic effects.
文摘Twenty-five species and hybrids in Populus were used as parents, and 26 cross combinations, including more than 5000 seedlings, were obtained by artificial cross breeding. The length of infructescence, number of seeds per infructescence, thousand-seed weight, germination rate of seeds among these cross combinations were tested. The results indicated that the cross combinational effects were significant for these traits, and demonstrated that the length of infructescence, thousand-seed weight were positively affected by female parent. In addition, seedling height, diameter above ground, diameter at breast height (DBH) of 17 cross combination progenies were investigated. The analysis of mean and standard deviation of these three traits showed that seedling height, diameter above ground, DBH had extensive variation among combinations and individuals within combination. Variance analysis and estimate of heritability indicated that the three traits had wide variation and were controlled by heredity. It was feasible to select superior cross combinations and seedlings. Further more, the result of multiple comparison showed that P.deltoides ‘Lux'× P.deltoides ‘D324', P.ussuriensis cl. ‘U4'× P deltoides ‘T66', P.ussuriensis cl. ‘U4'× P. deltoides ‘T26', P.deltoides ‘Lux'× P.ussuriensis cl. ‘U3', (P.tomentosa×P.bolleana)×(P.alba×P.glandulosa), (P.alba×P.tomentosa)×(P.alba×P.glandulosa), and (P.alba×P.glandulosa‘No.2')× P. tomentosa ‘Lumao 50' were superior cross combinations with higher growth rate. Finally, 123 elite seedlings were selected for further test.
文摘in order to improve the acquired level of heat acclimatization (HA) by training, on the basis of singlemode march training (SMT) or single-mode cross-country race training (SCT) , combined training method of march and cross-country race in the heat was adopted in this experiment ,and the effect of the training on heat tolerance was analyzed. Eight young males were asked to perform a simulated SMT and SCT for 90 min on a treadmill in a hot climate chamber (Td 32. 7℃ , WBGT 28. 4℃ ) once daily for 10 to 12 d within two weeks. The results showed that rectal temperature (Tr) was reduced by 0. 61℃ , heart rate (Hr) by 8. 5 b/min,sweat volume (SV)by 0. 220 kg, physiological strain index (PSI)by 0. 620,systolic pressure (SP)and diastolic pressure (DP) had a little change, pulse pressure (PP) and stroke volume (StV) increased , and cardiac output (CO) decreased a little at the middle stage and increased at the late stage due to Hr change. The standardized bicycle ergometer test (SBE test) in the heat (Td 37℃)has proved that these physiological indexes post-training had significant improvements ,as compared with those pre-training, suggesting that the combined training could raise heat-tolerance and was superior to the SMT in improving acquired heat acclimatization in same training duration and times , and to the SCT in regulating body temperature and cardiovascular function and in prolonging heat tolerance duration.
基金supported by the National Natural Science Foundation of China (30571156)
文摘The wheatgrass, Thinopyrum intermedium (Host) Barkworth & DR Dewey, shows many beneficial characteristics, such as big spikes and high resistance to many diseases. To transfer the beneficial genes of this species, many wheat- Thinopyrum intermedium alien chromosome lines were developed. Of them, Shannong 0095 (SN0095), a disomic substitution, has long spikes and flag-leaves, and thus may be an important genetic resource for wheat yield improvement. In order to realize its heterosis and combining ability on major yield traits, a 7 ×7 complete diallel design was made according to Griffing's Method-1. The results showed that heterosis for spike length (SPL), flag-leaf area (FLA), number of spikes per plant (NSP), number of spikelets per spike (NSL), kernels per spike (KPS), 1 000-kernel weight (TKW) and grain yield per plant (GYP) existed in all the crosses by SN0095, but heterobeltiosis occurred only for KPS, TKW, and GYP. The relative mid-parent heterosis (RMH) and relative high-parent heterosis (RHH) for GYP, which valued as high as 35.32 and 29.92% respectively, were the highest among all the traits mearsured. Though additive and non-additive gene effects and cytoplasmic effects (or cytoplasmic-nuclear interaction effects) were found in governing all the traits measured above, additive gene action played a predominant role. The results also showed that SN0095 was the best-general combiner for SPL and FLA, and high-general combiner for NSP amongst all the parents. Estimates of specific combining ability (SCA) showed that SN0095 could also make high-SCA combinations for GYP, such as SN0095 × Jimai 19 (JMI9). SN0095 could be a unique and important parent in hybrid wheat breeding programs.
基金supported by the National High-Tech Research and Development Program of China (863 Program,2006AA10Z1C2)the Key Technologies R&D Program of China during the 10th Five-Year Plan period (2009BADA8B01,2110BAD01B09)the Natural Science Foundation of Hubei Province,China(2009CDA089)
文摘Cross combinations from six rapeseed cultivars and lines were evaluated under waterlogging stress condition in order to understand the genetic mechanism of waterlogging tolerance of Brassica napus L.and provide reasonable improvement programs.There were six germination traits investigated on combining ability and heritability using complete diallel crossing method designed for 30 combinations from those six cultivars and lines.The traits included relative root length,stem length,fresh weight per plant,survival rate,electrical conductivity,and vigor index.After flooding treatment,the six traits of parents and F1 were analyzed.The general combining ability(GCA) and special combining ability(SCA) of germination traits were analyzed using Griffing I method.Among 30 cross combinations,the GCA was significantly different among six waterlogging resistance traits.The SCA of these traits was significantly different except the SCA of electrical conductivity.As a representative trait of waterlogging tolerance in rapeseed,relative vigor index had the highest narrow heritability and relatively low broad heritability.The cultivars Zhongshuang 9 and P79 had higher tolerance potential to waterlogging stress.It can be concluded that combining ability and genetic effects of relative vigor index during germination stage could be used to identify the waterlogging tolerance of rapeseed in breeding program.
基金supported by the Harvest-Plus China Program,the National High-Tech R&D Program of China(2011AA10A103)the Sichuan Maize Breeding Program in the 12th Five-Year Plan,China
文摘Vitamin A deficiency has become a worldwide problem.Biofortified foods can potentially be an inexpensive,locally adaptable,and long-term solution to dietary-nutrient deficiency.In order to improve the β-carotene content in maize grain by breeding and minimize vitamin A deficiency,a complete diallel cross was designed with eight inbred lines of maize,and 64 combinations were obtained in this study.The experimental combinations were planted in Yunnan and Sichuan provinces,respectively,with a random complete block design.The β-carotene contents in the grains of the experimental materials were analyzed by high-performance liquid chromatography.Among the tested materials,the effect difference of general combining ability of the β-carotene content was significant;however,the effect difference of the special combining ability and the reciprocal effect were not significant.The β-carotene content of maize grain was not influenced significantly by the cross and the reciprocal cross.There was a significant correlation about the β-carotene content in the maize grains between the F 1 and their parents.The combinations with high β-carotene content were obviously influenced by the environment,and the mean value of β-carotene content for the experimental materials planted in Ya'an of Sichuan was higher than that planted in Yuanjiang of Yunnan,with the results being significant at the 0.01 level.
文摘Pseudomonas aeruginosa(P:aeruginosa)is a major opportunistic pathogen in hospital-acquired infections.Thus,carly diagnosis is the best strategy for fighting against these infections.In this report,we incorporated multiple crOsS displacement amplification(MCDA)combined with the malachite green(MG)for rapid,sensitive,specific and visual detection of P.aeruginosa by targeting the oprl gene.The MCDA-MG assay was conducted at 67°C for only 40 min during the amplification stage,and then products were directly detected by using colorimetric indicators(MG),eliminating the use of an electrophoresis instrument or amplicon analysis equipment.The entire process,including specimen processing(35 min),amplification(40 min)and detection(5 min),can be finished within 80 min.All 30 non-P.aeruginosa strains tested negative,indicating the high specificity of the MCDA primers.The analytical sensitivity of the MCDA-MG assay was 100 fg of genomic templates per reaction in pure culture,which was in complete accordance with MCDA by gel clectrophoresis and real-time turbidity.The assay was also successfully applied to detecting P.aeruginosa in stool samples.Therefore,the rapidity,simplicity,and nearly equipment free platform of the MCDA-MG technique make it possible for clinical diagnosis,and more.