An experiment using rhizobox was conducted to study Si, Fe and Mn distributions in rice rhizosphcre of red earths and paddy soils. It was found that Si, Fe and Mn distributions in rhizosphere of the paddy soils were c...An experiment using rhizobox was conducted to study Si, Fe and Mn distributions in rice rhizosphcre of red earths and paddy soils. It was found that Si, Fe and Mn distributions in rhizosphere of the paddy soils were characterized by a depleted zone around root surface, beyond which the concentrations gradually rose. From lmm layer to 2mm layer the concentrations dropped and then rose again. Whereas Si and Fe in red earths showed no depleted zone but even accumulated zone around root surface. Mn showed an approximately even distribution in each layer and no depletion was found in root surface layers. This indicated that during rice (Oryza sativa L.)plantation, depletion and accumulation of Si, Fe and Mn in rhizosphere were important features of matured red earths by water culture. The distribution changes of Si, Fe and Mn in relation to soil-root interaction are also discussed.展开更多
In this study, 5 parental rice varieties with different allelopathic potentials were employed in diallel cross [P(P+1)/2] to get a set of genetic materials including parental lines and two generations of F1s. The dyna...In this study, 5 parental rice varieties with different allelopathic potentials were employed in diallel cross [P(P+1)/2] to get a set of genetic materials including parental lines and two generations of F1s. The dynamic heterosis for allelopathy in rice under different environmental conditions, was analyzed by using additive-dominant developmental genetic model. The results indicated that heterosis in both F1 and F2 showed inhibitory effects on shoot and root length of receiver plant(Lactuca sativa L.). Heterosis over mid-parent based on population mean(HMP)in F2 was lower than that in differental environmental conditions, showing 1/2 HMP in F1 The heterosis in rice allelopathy was much higher under the field environmental conditions with lower temperature and weaker sunlight than that under favorable environment, implying that the allel-opthic potential could be increased by stress environment. This finding interpreted the genetic reason that plant could produce more allelochemicals under unfavorable environment.展开更多
The completely dominant earliness was identified in a genie male-sterile and early maturing indica line 6442S-7. F1 progenies from 6442S-7 crossed with thirteen various types of medium- or late-maturing varieties, sha...The completely dominant earliness was identified in a genie male-sterile and early maturing indica line 6442S-7. F1 progenies from 6442S-7 crossed with thirteen various types of medium- or late-maturing varieties, shared the same heading date as 6442S-7. The segregation of heading date in the F2 and B1F1 populations showed that the earliness of 6442S-7 is mainly controlled by two dominant major genes. The local linkage map of one dominant earliness gene harbored in 6442S-7 was constructed with F2 population and four kinds of molecular marker techniques. The results showed that the gene was located between a RFLP marker C515 and a RAPD marker OPI 11.557 on the terminal region of short arm of rice chromosome 3, 10.9cM and 1.5cM from C515 and OPI11.557, respectively. The genetic distances from the target gene to two SSR markers, RM22 and RM231, and one AFLP marker, PT671, were 3.0, 6.7 and 12.4 cM, respectively. This gene, being identified and mapped first, is designated tentatively as Ef-cd(t). As a new genetic resource of completely dominant earliness, 6442S-7 has splendid future in rice improvement.展开更多
The straw of Grain-Straw-Dual-Use-Rice (GSDUR) variety 201 of which the grain quality and yield were equivalent to that of common rice variety (the grain yield approximately 7.5 t ha-1), but straw protein content was ...The straw of Grain-Straw-Dual-Use-Rice (GSDUR) variety 201 of which the grain quality and yield were equivalent to that of common rice variety (the grain yield approximately 7.5 t ha-1), but straw protein content was 9.31% (common rice straw i. e. CK was approximately 4.0%), and other eight fodder indexes were better than CK to some extent, was employed to feed animals. 15N tracing result suggested that the protein in 201 straw could be effectively transformed into fish body protein and white mouse body protein. The digestibility of fodder, the 15N recovery rate of animal body and the absorption of fodder protein were 13. 8, 9. 6, 24.49% and 16. 5, 6.0, 47. 2% higher than those of common rice straw respectively when feeding grass carp and white mice with 201 rice straw, whereas the 15N recovery rates of animal manure were 3. 25, 6. 5% lower than those of common rice straw, respectively. The results of feeding animals with 201 straw were as follows: (1)The milk yield of cow was increased by 8.3 % as compared to that of common rice straw. 843. 8 kg milk could be produced with 7. 5 t ha-1 of dry 201 straw. (2)Fish daily weight gain, straw consumption of grass carp, fish weight gain per kg fresh rice straw were increased by 60.0, 16.8 and 37.0 % respectively when 201 fresh straw was used to feed grass carp compared to feeding CK, and fish yield could be increased by 297.5 kg with 25.0 t ha-1 of fresh 201 straw. (3)The goose daily weight gain and the ratio of fodder and meat were increased by 33. 9 and 26.8 % respectively when 201 rice straw was used as the main raw material of the compound fodder to feed white geese compared to feeding CK, and geese weight could be increased by 2 358.0 kg with one hectare of 201 straw. (4)Not only were the feeding results identical when high quality 201 rice straw powder substituting for wheat bran which made up of 5 % compound fodder to feed cross bred pigs compared to CK, but 0.11 kg fine fodder could be saved when 1 kg cross bred pig weight was increased.展开更多
基金Project supported by the National Natural Science Foundation of Chinathe Laboratory of Material Cycling in Pedosphere.Academia Sinica.
文摘An experiment using rhizobox was conducted to study Si, Fe and Mn distributions in rice rhizosphcre of red earths and paddy soils. It was found that Si, Fe and Mn distributions in rhizosphere of the paddy soils were characterized by a depleted zone around root surface, beyond which the concentrations gradually rose. From lmm layer to 2mm layer the concentrations dropped and then rose again. Whereas Si and Fe in red earths showed no depleted zone but even accumulated zone around root surface. Mn showed an approximately even distribution in each layer and no depletion was found in root surface layers. This indicated that during rice (Oryza sativa L.)plantation, depletion and accumulation of Si, Fe and Mn in rhizosphere were important features of matured red earths by water culture. The distribution changes of Si, Fe and Mn in relation to soil-root interaction are also discussed.
基金supported by the National Natural Science Foundation of China(30070068)Provincial Key Scientific and Technological Program(2002F012)Provincial Natural Science Foundation(D0110012)of Fujfan,China.
文摘In this study, 5 parental rice varieties with different allelopathic potentials were employed in diallel cross [P(P+1)/2] to get a set of genetic materials including parental lines and two generations of F1s. The dynamic heterosis for allelopathy in rice under different environmental conditions, was analyzed by using additive-dominant developmental genetic model. The results indicated that heterosis in both F1 and F2 showed inhibitory effects on shoot and root length of receiver plant(Lactuca sativa L.). Heterosis over mid-parent based on population mean(HMP)in F2 was lower than that in differental environmental conditions, showing 1/2 HMP in F1 The heterosis in rice allelopathy was much higher under the field environmental conditions with lower temperature and weaker sunlight than that under favorable environment, implying that the allel-opthic potential could be increased by stress environment. This finding interpreted the genetic reason that plant could produce more allelochemicals under unfavorable environment.
基金the National NatureScience Foundation of China(No.30070469).
文摘The completely dominant earliness was identified in a genie male-sterile and early maturing indica line 6442S-7. F1 progenies from 6442S-7 crossed with thirteen various types of medium- or late-maturing varieties, shared the same heading date as 6442S-7. The segregation of heading date in the F2 and B1F1 populations showed that the earliness of 6442S-7 is mainly controlled by two dominant major genes. The local linkage map of one dominant earliness gene harbored in 6442S-7 was constructed with F2 population and four kinds of molecular marker techniques. The results showed that the gene was located between a RFLP marker C515 and a RAPD marker OPI 11.557 on the terminal region of short arm of rice chromosome 3, 10.9cM and 1.5cM from C515 and OPI11.557, respectively. The genetic distances from the target gene to two SSR markers, RM22 and RM231, and one AFLP marker, PT671, were 3.0, 6.7 and 12.4 cM, respectively. This gene, being identified and mapped first, is designated tentatively as Ef-cd(t). As a new genetic resource of completely dominant earliness, 6442S-7 has splendid future in rice improvement.
文摘The straw of Grain-Straw-Dual-Use-Rice (GSDUR) variety 201 of which the grain quality and yield were equivalent to that of common rice variety (the grain yield approximately 7.5 t ha-1), but straw protein content was 9.31% (common rice straw i. e. CK was approximately 4.0%), and other eight fodder indexes were better than CK to some extent, was employed to feed animals. 15N tracing result suggested that the protein in 201 straw could be effectively transformed into fish body protein and white mouse body protein. The digestibility of fodder, the 15N recovery rate of animal body and the absorption of fodder protein were 13. 8, 9. 6, 24.49% and 16. 5, 6.0, 47. 2% higher than those of common rice straw respectively when feeding grass carp and white mice with 201 rice straw, whereas the 15N recovery rates of animal manure were 3. 25, 6. 5% lower than those of common rice straw, respectively. The results of feeding animals with 201 straw were as follows: (1)The milk yield of cow was increased by 8.3 % as compared to that of common rice straw. 843. 8 kg milk could be produced with 7. 5 t ha-1 of dry 201 straw. (2)Fish daily weight gain, straw consumption of grass carp, fish weight gain per kg fresh rice straw were increased by 60.0, 16.8 and 37.0 % respectively when 201 fresh straw was used to feed grass carp compared to feeding CK, and fish yield could be increased by 297.5 kg with 25.0 t ha-1 of fresh 201 straw. (3)The goose daily weight gain and the ratio of fodder and meat were increased by 33. 9 and 26.8 % respectively when 201 rice straw was used as the main raw material of the compound fodder to feed white geese compared to feeding CK, and geese weight could be increased by 2 358.0 kg with one hectare of 201 straw. (4)Not only were the feeding results identical when high quality 201 rice straw powder substituting for wheat bran which made up of 5 % compound fodder to feed cross bred pigs compared to CK, but 0.11 kg fine fodder could be saved when 1 kg cross bred pig weight was increased.
