To understand the male sterility mechanism of photoperiod/thermo-sensitive genic male sterile [P(T)GMS] lines in rice, the research progress on genetics of photoperiod and/or temperature sensitive genic male sterili...To understand the male sterility mechanism of photoperiod/thermo-sensitive genic male sterile [P(T)GMS] lines in rice, the research progress on genetics of photoperiod and/or temperature sensitive genic male sterility in rice was reviewed. A new idea was proposed to explain the sterility mechanism of P(T)GMS rice. The fertility transition from sterile to fertile is the result of cooperative regulation of major-effect sterile genes with photoperiod and/or temperature sensitive genes, but not the so-called pgms gene in P(T)GMS rice. The minor-effect genes, which exhibit accumulative effect on sterility, are the important factors for the critical temperature of sterility transition. The more minor-effect genes the sterile line holds, the lower the critical temperature of sterility transition is. The critical temperature of sterility transition will be invariable if all the minor-effect genes are homozygous. The strategies for breeding P(T)GMS rice were also proposed. The selective indices of critical photoperiod and temperature for sterility transition should be set according to varietal type and ecological region. Imposing selection pressure is a key technology for breeding P(T)GMS rice with lower critical temperature for sterility, and improving the comprehensive performance of the whole traits and combining ability is vital for breeding P(T)GMS rice lines.展开更多
Plant temperature (Tp) and its relations to the microclimate of rice colony and irrigation water were studied using a thermo-sensitive genic male sterile (TGMS) rice line, Pei'ai 64S. Significant differences in t...Plant temperature (Tp) and its relations to the microclimate of rice colony and irrigation water were studied using a thermo-sensitive genic male sterile (TGMS) rice line, Pei'ai 64S. Significant differences in the daily change of temperature were detected between Tp and air temperature at the height of 150 cm (TA). From 8:00 to 20:00, Tp was lower than TA, but they were similar during 21:00 to next 7:00. The maximum Tp occurred one hour earlier than the maximum TA, though they both reached the minimum at 6:00. Tp fluctuated less than TA. At the same height, during 6:00-13:00, Tp was higher than air temperature (Ta), and Tp reached the maximum one hour earlier than Ta. During the rest time on sunny day, Tp was close to or even a little lower than Ta. On overcast day, Tp was higher than Ta in the whole day, and both maximized at the same time. In addition, Tp was regulated by solar radiation, cloudage and wind speed in daytime, and by irrigation water at night. The present study indicated that a TA of 29.6℃ was the critical point, at which Tp was increased or decreased by irrigation water. Tp and the difference between water and air temperatures showed a conic relation. Tp fluctuation was also regulated by the absorption or reflection of solar radiation by leaves during daytime and release of heat energy during nighttime. By analysis on correlation and regression simulation, two models of Tp were established.展开更多
An investigation was carried out with three newly developed temperature sensitive genic male sterile (TGMS) lines for their floral traits, seed production potential and outcrossing ability in ten cross combinations....An investigation was carried out with three newly developed temperature sensitive genic male sterile (TGMS) lines for their floral traits, seed production potential and outcrossing ability in ten cross combinations. In the TGMS lines, fertile pollens had an average diameter of 0.89 mm while the sterile pollens was with 0.02 mm diameter.TS-29-150GY produced the biggest fertile pollens with 0.92 mm and other two lines produced relatively smaller pollens with 0.91 and 0.85 ram. Pollen fertility during the fertility reversion period was an average of 60.7%. TS-29-150GY had the maximum of 66.9% spikelet fertility whereas other two lines (TNAU18S and TNAU60S) had relatively lower spikelet fertility of 27.8% and 26.7%, respectively. Average of 17.00 g of seed yield was obtained in the TGMS lines during the fertility reversion period. TS-29- 150GY had the highest value of 21.20 g of seed yield while TNAU18S and TNAU60S produced 16.6 g and 13.2 g of seed yield, respectively. The low seed production ability of these three TGMS lines was attributed only to the environmental conditions prevailing during the period. All three TGMS lines had considerable outcrossing potential of 41.2%, 24.6% and 25.0%, respectively. The cross combinations viz. TNAU18S/IET21508 (36 g/plant), TNAU18S/IET21044 (13 g/plant), TNAU18S/IET21009 (26.5 g/plant), TNAU60S/CB-09-106 (26.2 g/plant), TNAU60S/IET21009 (14 g/plant) and TS29-150-GY/DRR 3306 (39.2 g/plant) showed perfect synchronization with acceptable hybrid seed yield, indicating suitability of TGMS system under Indian condition. Based on the outcrossing related traits viz. panicle exertion, angle of glume opening, stigma length and pollen size, TNAU18S was identified as the best, followed by TS-29-150GY.展开更多
The discovery of thermo-sensitive genic male sterility(TGMS) has led to development of a simple and highly efficient two-line breeding system. In this study, genetic analysis was conducted using three F_2 populations ...The discovery of thermo-sensitive genic male sterility(TGMS) has led to development of a simple and highly efficient two-line breeding system. In this study, genetic analysis was conducted using three F_2 populations derived from crosses between IR68301 S, an indica TGMS rice line, and IR14632(tropical japonica), Supanburi 91062(indica) and IR67966-188-2-2-1(tropical japonica), respectively.Approximately 1:3 ratio between sterile and normal pollen of F_2 plants from the three populations revealed that TGMS is controlled by a single recessive gene. Bulked segregant analysis using simple sequence repeat(SSR) and insertion-deletion(InDel) markers were used to identify markers linked to the tms gene. The linkage analysis based on the three populations indicated that the tms locus was located on chromosome 2 covering the same area. Using IR68301S × IR14632 F_2 population, the results showed that the tms locus was located between SSR marker RM12676 and InDel marker 2gAP0050058. The genetic distance from the tms gene to these two flanking markers were 1.10 and 0.82 cM, respectively.InDel marker 2gAP004045 located between these two markers showed complete co-segregation with the TGMS phenotype. In addition, InDel marker vf0206114052 showed 2.94 cM linked to the tms gene using F_2 populations of IR68301S × Supanburi 91062. These markers are useful tool for developing new TGMS lines by marker-assisted selection. There were ten genes located between the two flanking markers RM12676 and 2gAP0050058. Using quantitative real-time PCR for expression analysis, 7 of the 10 genes showed expression in panicles, and response to temperatures. These genes could be the candidate gene controlling TGMS in IR68301S.展开更多
The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast...The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast, by using backcross breeding and molecular marker-assisted selection. Five elite improved male sterile lines, RGD8S-1, RGD8S-2, RGD8S-3, RGD8S-4 and RGD8S-5, were selected based on the results of molecular marker analysis, spikelet sterility, recovery rate of genetic background and agronomic traits. Thirty-three representative blast isolates collected from Guangdong Province, China were used to inoculate the improved lines and the original line GD-8S artificially. The resistance frequencies of the improved lines ranged from 76.47% to 100%, much higher than that of the original line GD-8S (9.09%). On the agronomic characters, there were no significant differences between the improved lines and GD-8S except for flag leaf length and panicle number per plant. The improved lines could be used for breeding hybrid rice with high blast resistance.展开更多
The major male sterile genes in a new photo/thermo-sensitive genie male sterile (PTGMS) line B06S of rice were analyzed by the manipulation of mixture distribution theory. The results indicated that a pair of major ma...The major male sterile genes in a new photo/thermo-sensitive genie male sterile (PTGMS) line B06S of rice were analyzed by the manipulation of mixture distribution theory. The results indicated that a pair of major male sterile nuclear genes with large effects were responsible for controlling the male sterility of B06S.展开更多
Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the fact...Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the factors affecting outcrossed seed-setting were analyzed. The PTGMS had obstacles in outcrossed seed setting influenced by inheritance and environment at varying degrees. Environmental temperature was regarded as the main factor that resulted in the outcrossed seed-setting obstacles. The sensitive stage was at the early stage of grain filling for outcrossed seed setting. There existed remarkable differences at the sensitivity stage, the duration of sensitive period, the sensitive level and the effective level of outcrossed seed-setting obstacles caused by environmental temperature among different PTGMS lines. Therefore, attention should be paid to outcrossed seed-setting obstacles in selection and utilization of PTGMS lines.展开更多
In this study population improvement or random polycross plus mass selection was adopted with using N8S, Huaizao4, Xiang2B and Zaoyou1 as parents. To help comprehensively improve the important characters such as combi...In this study population improvement or random polycross plus mass selection was adopted with using N8S, Huaizao4, Xiang2B and Zaoyou1 as parents. To help comprehensively improve the important characters such as combining ability, grain quality, resistance, stigma exsertion rate, etc. The stigma exsertion rate of ZhunS, an elite TGMS line, is 78.6%, 72.4% higher than that of V20A. Hybrids produced by crossing ZhunS with R402, Minhui77 and Minhui63 increased the yield by 3.8%~5.8% and decreased grain chalkiness by 82.1%~84.4% compared with those from crossing V20A with the corresponding R lines.展开更多
Changxuan 3S, a thermo-sensitive genic male sterile (TGMS) rice line with eui gene, is derived from the TGMS rice line Pei'ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elo...Changxuan 3S, a thermo-sensitive genic male sterile (TGMS) rice line with eui gene, is derived from the TGMS rice line Pei'ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elongation of the TGMS line with eui gene, Changxuan 3S and its parent Pei'ai 64S were used to study the effects of temperature on panicle exsertion. At 24℃, the uppermost internode of Changxuan 3S elongated the fastest from the 4^th day before flowering to 0 day (flowering), being 2.1-fold as that of Pei'ai 64S, whereas it elongated slowly during the 12^th day to the 4^th day before flowering and the 1^st to the 3^rd day after flowering. The uppermost internode of Changxuan 3S exserted from the flag leaf sheath at 22℃, 24℃ and 26℃, and the length of elongated uppermost internode increased with the decreasing temperatures. At 28℃, though the panicles of Changxuan 3S were still enclosed in the leaf sheath, the degree of panicle enclosure was significantly lower compared with Pei'ai 64S. Cytological studies on Changxuan 3S showed that the uppermost internode elongation was attributed to the increase of cell number and cell elongation, and the latter was more significant. Moreover, the numbers of outermost and innermost parenchyma cells and the cell length of the uppermost internode reduced with the increasing temperatures.展开更多
For the two-line hybrid rice system, pol en sterility is regulated by recessive gene that responds to temperature. The recessive gene controlling thermo-sensitive genetic male sterility (TGMS) is expressed when the ...For the two-line hybrid rice system, pol en sterility is regulated by recessive gene that responds to temperature. The recessive gene controlling thermo-sensitive genetic male sterility (TGMS) is expressed when the plants are grown in conditions with higher or lower critical temperatures. To transfer tgms gene(s) control ing TGMS to Thai rice cultivars by backcross breeding method, a male sterile line was used as a donor parent while Thai rice cultivars ChaiNat 1, PathumThani 1, and SuphanBuri 1 were used as recurrent parents. The BC2F2 lines were developed from backcrossing and selfing. Moreover, the simple sequence repeat (SSR) markers were developed for identifying tgms gene and the linked marker was used for assisting selection in backcrossing. The identification lines were confirmed by pol en observation. The results showed the success of introgression of the tgms gene into Thai rice cultivars. These lines will be tested for combining ability and used as female parent in hybrid rice production in Thailand.展开更多
With the cDNA suppression subtraction hybridization method, a spikelet-specific cDNA library was constructed that expressed at meiosis stage in rice. A total of 121 cDNA fragments were selected from the library and us...With the cDNA suppression subtraction hybridization method, a spikelet-specific cDNA library was constructed that expressed at meiosis stage in rice. A total of 121 cDNA fragments were selected from the library and used as EST (expressed se-quence tags) markers to detect the polymorphism between Annong N, a normal fertile Indica rice line and Annong S-1, its spontaneous mutant with thermo-sensitive genic male sterility, using the RFLP (restriction fragment length polymorphism) technique. HN57, one of the EST probes, could detect poly-morphism between them. The results of segregation analysis with the F2 population developed from An-nong S-1 and Annong N indicate that HN57 co-seg- regates with the thermo-sensitive genic male-sterility controlled by tms5, the recessive gene in Annong S-1. This marker is located on the 31.2-cM region of the chromosome 2 of RGP (rice genome research pro-gram) genetic map. To further determine the location of tms5, 80 SSR (simple sequence repeat) markers around this region were developed, and 12 of them were polymorphic. And finally, the tms5 was mapped within region of 181 kb by using these new markers.展开更多
With the AMMI (additive main effects and multiplicative interaction) analysis model, thedetermination of the sensitivity to temperature among different TGMS (thermo-sensitivegenic male sterile) lines was performed. To...With the AMMI (additive main effects and multiplicative interaction) analysis model, thedetermination of the sensitivity to temperature among different TGMS (thermo-sensitivegenic male sterile) lines was performed. To assess the genetic differences due to hightemperature stress at the fertility-sensitive stage (10-20d before heading), sevengenotypes (six TGMS lines and the control Pei-Ai64S) were grown from May 4 at sevendifferent stages with 10d intervals. The temperatures at the fertility-sensitive stagesinvolved twelve levels from<20 to>℃ under the regime natural conditions in Hangzhou,China. There was considerable variation in pollen fertility among genotypes in responseto high temperature. Five genotypes identified as TGMS lines as their percentages offertile pollens were lower than or close to that of the control except for the unstableline RTS19 (V6). When the temperatures at the fertility-sensitive stage were at Ⅰ-Ⅳ,Ⅴ-Ⅵ and Ⅶ-Ⅻ, the percentages of fertile pollens varied in the ranges of 46.46-48.49%,19.62-22.79% and 3.49-5.87%, respectively. The critical temperatures of sterility andfertility in the five TGMS lines were 25.1 and 23.0℃, respectively. Considering theamounts and directions of main effect and their IPCA (interaction principal componentsanalysis), we can classify the lines and temperature levels into different groups, anddescribe the characteristics of genotypetemperature interaction, offering the informationand tools for the development and utility of thermo-sensitive male sterile lines.Several TGMS rice lines with their reproductive sensitivity to high temperature that canbe screened using the AMMI model may add valuable germplasm to the breeding program ofhybrid rice.展开更多
The generation fertility of 51 F1, 19 F2 and 6 BC1 between 3 thermo-sensitive genic male sterile lines (TGMS-lines) Pei'ai 64S, 6311S and 360S, and the three lines of hybrid rice including 7 indica cytoplasmic male...The generation fertility of 51 F1, 19 F2 and 6 BC1 between 3 thermo-sensitive genic male sterile lines (TGMS-lines) Pei'ai 64S, 6311S and 360S, and the three lines of hybrid rice including 7 indica cytoplasmic male sterile lines (CMS-lines) and their corresponding maintainer lines (B-lines) and 3 indica restorer lines (R-lines) were investigated to study the expression of TGMS-genes in the backgrounds of the three lines of hybrid rice. Pei'ai 64S has stronger fertility restoring (Rf) genes for CMS-lines and its TGMS trait is governed by 2 pairs of independent recessive genes; The TGMS trait of 6311S is governed by a single recessive gene with weaker Rf-gene in 6311S and the TGMS trait of 360S is governed by a single recessive gene with no Rf-gene in 360S. The investigation on the fertility of F1 plants between 5 CMS-lines and 4 TGMS generations selected from F2 plants of 4 CMS-lines x 6311S confirmed that the expression of TGMS-gene was controlled by Rf-gene in the genetic background of cytoplasm of CMS-lines, but not affected by Rf-gene in the genetic background of normal fertile cytoplasm. The potential breeding strategies of TGMS-lines with cytoplasm of CMS-lines and CMS-lines with the nucleus of TGMS-genes were discussed.展开更多
基金supported by the National High Technology Research and Development Program of China (Grant No.2006AA100101)the Natural Science Foundation of Hunan Province of China (Grant Nos.03JJY3033 and 08JJ1003)
文摘To understand the male sterility mechanism of photoperiod/thermo-sensitive genic male sterile [P(T)GMS] lines in rice, the research progress on genetics of photoperiod and/or temperature sensitive genic male sterility in rice was reviewed. A new idea was proposed to explain the sterility mechanism of P(T)GMS rice. The fertility transition from sterile to fertile is the result of cooperative regulation of major-effect sterile genes with photoperiod and/or temperature sensitive genes, but not the so-called pgms gene in P(T)GMS rice. The minor-effect genes, which exhibit accumulative effect on sterility, are the important factors for the critical temperature of sterility transition. The more minor-effect genes the sterile line holds, the lower the critical temperature of sterility transition is. The critical temperature of sterility transition will be invariable if all the minor-effect genes are homozygous. The strategies for breeding P(T)GMS rice were also proposed. The selective indices of critical photoperiod and temperature for sterility transition should be set according to varietal type and ecological region. Imposing selection pressure is a key technology for breeding P(T)GMS rice with lower critical temperature for sterility, and improving the comprehensive performance of the whole traits and combining ability is vital for breeding P(T)GMS rice lines.
基金supported by the National Natural Science Foundation of China (Grant No. 30370830)
文摘Plant temperature (Tp) and its relations to the microclimate of rice colony and irrigation water were studied using a thermo-sensitive genic male sterile (TGMS) rice line, Pei'ai 64S. Significant differences in the daily change of temperature were detected between Tp and air temperature at the height of 150 cm (TA). From 8:00 to 20:00, Tp was lower than TA, but they were similar during 21:00 to next 7:00. The maximum Tp occurred one hour earlier than the maximum TA, though they both reached the minimum at 6:00. Tp fluctuated less than TA. At the same height, during 6:00-13:00, Tp was higher than air temperature (Ta), and Tp reached the maximum one hour earlier than Ta. During the rest time on sunny day, Tp was close to or even a little lower than Ta. On overcast day, Tp was higher than Ta in the whole day, and both maximized at the same time. In addition, Tp was regulated by solar radiation, cloudage and wind speed in daytime, and by irrigation water at night. The present study indicated that a TA of 29.6℃ was the critical point, at which Tp was increased or decreased by irrigation water. Tp and the difference between water and air temperatures showed a conic relation. Tp fluctuation was also regulated by the absorption or reflection of solar radiation by leaves during daytime and release of heat energy during nighttime. By analysis on correlation and regression simulation, two models of Tp were established.
文摘An investigation was carried out with three newly developed temperature sensitive genic male sterile (TGMS) lines for their floral traits, seed production potential and outcrossing ability in ten cross combinations. In the TGMS lines, fertile pollens had an average diameter of 0.89 mm while the sterile pollens was with 0.02 mm diameter.TS-29-150GY produced the biggest fertile pollens with 0.92 mm and other two lines produced relatively smaller pollens with 0.91 and 0.85 ram. Pollen fertility during the fertility reversion period was an average of 60.7%. TS-29-150GY had the maximum of 66.9% spikelet fertility whereas other two lines (TNAU18S and TNAU60S) had relatively lower spikelet fertility of 27.8% and 26.7%, respectively. Average of 17.00 g of seed yield was obtained in the TGMS lines during the fertility reversion period. TS-29- 150GY had the highest value of 21.20 g of seed yield while TNAU18S and TNAU60S produced 16.6 g and 13.2 g of seed yield, respectively. The low seed production ability of these three TGMS lines was attributed only to the environmental conditions prevailing during the period. All three TGMS lines had considerable outcrossing potential of 41.2%, 24.6% and 25.0%, respectively. The cross combinations viz. TNAU18S/IET21508 (36 g/plant), TNAU18S/IET21044 (13 g/plant), TNAU18S/IET21009 (26.5 g/plant), TNAU60S/CB-09-106 (26.2 g/plant), TNAU60S/IET21009 (14 g/plant) and TS29-150-GY/DRR 3306 (39.2 g/plant) showed perfect synchronization with acceptable hybrid seed yield, indicating suitability of TGMS system under Indian condition. Based on the outcrossing related traits viz. panicle exertion, angle of glume opening, stigma length and pollen size, TNAU18S was identified as the best, followed by TS-29-150GY.
基金supported by Center for Agricultural Biotechnology, Kasetsart University, Center of Excellence on Agricultural Biotechnology (AG-BIO/PERDOCHE)Agricultural Research Development Agency (ARDA)National Science and Technology Development Agency, Thailand
文摘The discovery of thermo-sensitive genic male sterility(TGMS) has led to development of a simple and highly efficient two-line breeding system. In this study, genetic analysis was conducted using three F_2 populations derived from crosses between IR68301 S, an indica TGMS rice line, and IR14632(tropical japonica), Supanburi 91062(indica) and IR67966-188-2-2-1(tropical japonica), respectively.Approximately 1:3 ratio between sterile and normal pollen of F_2 plants from the three populations revealed that TGMS is controlled by a single recessive gene. Bulked segregant analysis using simple sequence repeat(SSR) and insertion-deletion(InDel) markers were used to identify markers linked to the tms gene. The linkage analysis based on the three populations indicated that the tms locus was located on chromosome 2 covering the same area. Using IR68301S × IR14632 F_2 population, the results showed that the tms locus was located between SSR marker RM12676 and InDel marker 2gAP0050058. The genetic distance from the tms gene to these two flanking markers were 1.10 and 0.82 cM, respectively.InDel marker 2gAP004045 located between these two markers showed complete co-segregation with the TGMS phenotype. In addition, InDel marker vf0206114052 showed 2.94 cM linked to the tms gene using F_2 populations of IR68301S × Supanburi 91062. These markers are useful tool for developing new TGMS lines by marker-assisted selection. There were ten genes located between the two flanking markers RM12676 and 2gAP0050058. Using quantitative real-time PCR for expression analysis, 7 of the 10 genes showed expression in panicles, and response to temperatures. These genes could be the candidate gene controlling TGMS in IR68301S.
基金supported by the grants from the High-Tech Research and Development Program of China (Grant No. 2001AA241011 and No. 2003AA212052)the Major Sci-Tech Program of Guangdong Province, China (Grant No. 2003A2010101 and No. 2006A2020201)the Agricultural Scientific Program of Guangdong Province, China (Grant No. 2005B20101006)
文摘The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast, by using backcross breeding and molecular marker-assisted selection. Five elite improved male sterile lines, RGD8S-1, RGD8S-2, RGD8S-3, RGD8S-4 and RGD8S-5, were selected based on the results of molecular marker analysis, spikelet sterility, recovery rate of genetic background and agronomic traits. Thirty-three representative blast isolates collected from Guangdong Province, China were used to inoculate the improved lines and the original line GD-8S artificially. The resistance frequencies of the improved lines ranged from 76.47% to 100%, much higher than that of the original line GD-8S (9.09%). On the agronomic characters, there were no significant differences between the improved lines and GD-8S except for flag leaf length and panicle number per plant. The improved lines could be used for breeding hybrid rice with high blast resistance.
文摘The major male sterile genes in a new photo/thermo-sensitive genie male sterile (PTGMS) line B06S of rice were analyzed by the manipulation of mixture distribution theory. The results indicated that a pair of major male sterile nuclear genes with large effects were responsible for controlling the male sterility of B06S.
文摘Using photo-thermo sensitive genie male rice (PTGMS) Pei' ai 64S, W7415S, W6154S, N26S, Annong S, Nongken 58S, 7001S and 5088S as female parents and conventional indica lines 8258 and U89 as male parents, the factors affecting outcrossed seed-setting were analyzed. The PTGMS had obstacles in outcrossed seed setting influenced by inheritance and environment at varying degrees. Environmental temperature was regarded as the main factor that resulted in the outcrossed seed-setting obstacles. The sensitive stage was at the early stage of grain filling for outcrossed seed setting. There existed remarkable differences at the sensitivity stage, the duration of sensitive period, the sensitive level and the effective level of outcrossed seed-setting obstacles caused by environmental temperature among different PTGMS lines. Therefore, attention should be paid to outcrossed seed-setting obstacles in selection and utilization of PTGMS lines.
文摘In this study population improvement or random polycross plus mass selection was adopted with using N8S, Huaizao4, Xiang2B and Zaoyou1 as parents. To help comprehensively improve the important characters such as combining ability, grain quality, resistance, stigma exsertion rate, etc. The stigma exsertion rate of ZhunS, an elite TGMS line, is 78.6%, 72.4% higher than that of V20A. Hybrids produced by crossing ZhunS with R402, Minhui77 and Minhui63 increased the yield by 3.8%~5.8% and decreased grain chalkiness by 82.1%~84.4% compared with those from crossing V20A with the corresponding R lines.
文摘Changxuan 3S, a thermo-sensitive genic male sterile (TGMS) rice line with eui gene, is derived from the TGMS rice line Pei'ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elongation of the TGMS line with eui gene, Changxuan 3S and its parent Pei'ai 64S were used to study the effects of temperature on panicle exsertion. At 24℃, the uppermost internode of Changxuan 3S elongated the fastest from the 4^th day before flowering to 0 day (flowering), being 2.1-fold as that of Pei'ai 64S, whereas it elongated slowly during the 12^th day to the 4^th day before flowering and the 1^st to the 3^rd day after flowering. The uppermost internode of Changxuan 3S exserted from the flag leaf sheath at 22℃, 24℃ and 26℃, and the length of elongated uppermost internode increased with the decreasing temperatures. At 28℃, though the panicles of Changxuan 3S were still enclosed in the leaf sheath, the degree of panicle enclosure was significantly lower compared with Pei'ai 64S. Cytological studies on Changxuan 3S showed that the uppermost internode elongation was attributed to the increase of cell number and cell elongation, and the latter was more significant. Moreover, the numbers of outermost and innermost parenchyma cells and the cell length of the uppermost internode reduced with the increasing temperatures.
文摘For the two-line hybrid rice system, pol en sterility is regulated by recessive gene that responds to temperature. The recessive gene controlling thermo-sensitive genetic male sterility (TGMS) is expressed when the plants are grown in conditions with higher or lower critical temperatures. To transfer tgms gene(s) control ing TGMS to Thai rice cultivars by backcross breeding method, a male sterile line was used as a donor parent while Thai rice cultivars ChaiNat 1, PathumThani 1, and SuphanBuri 1 were used as recurrent parents. The BC2F2 lines were developed from backcrossing and selfing. Moreover, the simple sequence repeat (SSR) markers were developed for identifying tgms gene and the linked marker was used for assisting selection in backcrossing. The identification lines were confirmed by pol en observation. The results showed the success of introgression of the tgms gene into Thai rice cultivars. These lines will be tested for combining ability and used as female parent in hybrid rice production in Thailand.
文摘With the cDNA suppression subtraction hybridization method, a spikelet-specific cDNA library was constructed that expressed at meiosis stage in rice. A total of 121 cDNA fragments were selected from the library and used as EST (expressed se-quence tags) markers to detect the polymorphism between Annong N, a normal fertile Indica rice line and Annong S-1, its spontaneous mutant with thermo-sensitive genic male sterility, using the RFLP (restriction fragment length polymorphism) technique. HN57, one of the EST probes, could detect poly-morphism between them. The results of segregation analysis with the F2 population developed from An-nong S-1 and Annong N indicate that HN57 co-seg- regates with the thermo-sensitive genic male-sterility controlled by tms5, the recessive gene in Annong S-1. This marker is located on the 31.2-cM region of the chromosome 2 of RGP (rice genome research pro-gram) genetic map. To further determine the location of tms5, 80 SSR (simple sequence repeat) markers around this region were developed, and 12 of them were polymorphic. And finally, the tms5 was mapped within region of 181 kb by using these new markers.
基金supported by the National Natural Science Foundation of China(39870421)the Key Research Project of Zhejiang Province,China(2003C22007 and 8812).
文摘With the AMMI (additive main effects and multiplicative interaction) analysis model, thedetermination of the sensitivity to temperature among different TGMS (thermo-sensitivegenic male sterile) lines was performed. To assess the genetic differences due to hightemperature stress at the fertility-sensitive stage (10-20d before heading), sevengenotypes (six TGMS lines and the control Pei-Ai64S) were grown from May 4 at sevendifferent stages with 10d intervals. The temperatures at the fertility-sensitive stagesinvolved twelve levels from<20 to>℃ under the regime natural conditions in Hangzhou,China. There was considerable variation in pollen fertility among genotypes in responseto high temperature. Five genotypes identified as TGMS lines as their percentages offertile pollens were lower than or close to that of the control except for the unstableline RTS19 (V6). When the temperatures at the fertility-sensitive stage were at Ⅰ-Ⅳ,Ⅴ-Ⅵ and Ⅶ-Ⅻ, the percentages of fertile pollens varied in the ranges of 46.46-48.49%,19.62-22.79% and 3.49-5.87%, respectively. The critical temperatures of sterility andfertility in the five TGMS lines were 25.1 and 23.0℃, respectively. Considering theamounts and directions of main effect and their IPCA (interaction principal componentsanalysis), we can classify the lines and temperature levels into different groups, anddescribe the characteristics of genotypetemperature interaction, offering the informationand tools for the development and utility of thermo-sensitive male sterile lines.Several TGMS rice lines with their reproductive sensitivity to high temperature that canbe screened using the AMMI model may add valuable germplasm to the breeding program ofhybrid rice.
文摘The generation fertility of 51 F1, 19 F2 and 6 BC1 between 3 thermo-sensitive genic male sterile lines (TGMS-lines) Pei'ai 64S, 6311S and 360S, and the three lines of hybrid rice including 7 indica cytoplasmic male sterile lines (CMS-lines) and their corresponding maintainer lines (B-lines) and 3 indica restorer lines (R-lines) were investigated to study the expression of TGMS-genes in the backgrounds of the three lines of hybrid rice. Pei'ai 64S has stronger fertility restoring (Rf) genes for CMS-lines and its TGMS trait is governed by 2 pairs of independent recessive genes; The TGMS trait of 6311S is governed by a single recessive gene with weaker Rf-gene in 6311S and the TGMS trait of 360S is governed by a single recessive gene with no Rf-gene in 360S. The investigation on the fertility of F1 plants between 5 CMS-lines and 4 TGMS generations selected from F2 plants of 4 CMS-lines x 6311S confirmed that the expression of TGMS-gene was controlled by Rf-gene in the genetic background of cytoplasm of CMS-lines, but not affected by Rf-gene in the genetic background of normal fertile cytoplasm. The potential breeding strategies of TGMS-lines with cytoplasm of CMS-lines and CMS-lines with the nucleus of TGMS-genes were discussed.