Fifteen common rice maintainer lines and 26 high-yielding restorer lines were used to evaluate their thermal resistance and fertility during flowering and early grain filling stages. The rice plants were subjected to ...Fifteen common rice maintainer lines and 26 high-yielding restorer lines were used to evaluate their thermal resistance and fertility during flowering and early grain filling stages. The rice plants were subjected to high temperature stress （39-43 ℃） for 1-15 d from main stem flowering. Based on the heat stress index, they were divided into thermal resistant lines, semi-thermal resistant lines, semi-thermal sensitive lines and thermal sensitive lines. Therefore, the maintainer lines K22B, Bobai B and V20B belonged to thermal resistant lines, whereas 11-32B, Zhongzhe B and Zhong 9B belonged to thermal sensitive lines. For rice restorer lines, Minghui 63 had the highest thermal resistance, followed by R207, P32, P929, and the lowest thermal resistant lines P62-2-2, R8006 and P51. The correlation analysis indicated that the heat stress index was significantly correlated with seed-setting rate and abortive grain rate under heat stress, but not under natural conditions. This indicated that heat stress occurred during flowering and early grain filling stages mainly decreased the seed- setting rate and significantly increased the abortive grain rate in both rice maintainer and restorer lines.展开更多
Kehui 36, derived from Minghui 63 / Taiyin 1（♀） // Nuo 89-1（♂）, is a new rice restorer line developed by Chongqing Normal University, which exhibits strong cold tolerance, high restoring ability, large pollen am...Kehui 36, derived from Minghui 63 / Taiyin 1（♀） // Nuo 89-1（♂）, is a new rice restorer line developed by Chongqing Normal University, which exhibits strong cold tolerance, high restoring ability, large pollen amount and other characteristics. In 2013, Kehui 36 was technically identified by Chongqing Crop Variety Appraisal Committee. Gangyou 36, a hybrid line derived from Gang 46 A / Kehui 36,was registered and released for commercial production by Chongqing Crop Variety Appraisal Committee in 2012.展开更多
Six isolates of Magnaporthe grisea were selected to inoculate on 10 Chinese leading maintainer lines (B-lines), 14 restorer lines (R-lines) and their F1 hybrid plants. In the tested rice materials, R-lines were proved...Six isolates of Magnaporthe grisea were selected to inoculate on 10 Chinese leading maintainer lines (B-lines), 14 restorer lines (R-lines) and their F1 hybrid plants. In the tested rice materials, R-lines were proved to be more resistant to blast than B-lines. The resistance frequency of about 25% F1 hybrid plants was less than their parents. In addition, 26 isolates of M. grisea collected from different rice growing areas of China were inoculated on 13 new improved hybrid rice combinations. The resistance frequencies of 5 improved hybrids were better than those of the controls and leading varieties in rice production of China.展开更多
Bt5198, a new rice restorer line containing Bt gene, was developed from the cross and backcross of the elite restorer line Chenghui 177 with Bt Minghui 63, a transgenic Bt restorer line. The inbred lines were evaluate...Bt5198, a new rice restorer line containing Bt gene, was developed from the cross and backcross of the elite restorer line Chenghui 177 with Bt Minghui 63, a transgenic Bt restorer line. The inbred lines were evaluated using PCR amplification, test paper evaluation, insect resistance evaluation in both the laboratory and paddy fields, nursery evaluation of rice blast resistance and pedigree selection of agronomic traits. Larval mortalities on Bt5198 and Bt Minghui 63 were 100% when rice culms were inoculated with the eggs of the striped stem borer （SSB） in the laboratory. Bt5198 was highly resistant against SSB and the yellow stem borer （YSB） under field conditions. The F1 hybrids derived from Bt5198 and four cytoplasmic male sterile （CMS） lines were also highly resistant to SSB and YSB and had a significant heterosis. Two-year evaluation of rice blast resistance confirmed that the resistance levels of Bt5198 to leaf blast and neck blast were similar to those of Chenghui 177 and significantly better than those of Bt Minghui 63. Seed germination ability and pollen yield of Bt5198 were similar with Chenghui 177, suggesting that the introduction of the Bt gene into the new restorer line had no significant effects on seed vitality or the yield of seed production. To identify the presence of the Bt gene, it was effective to combine test paper examination with the evaluation of insect-resistance, both in the laboratory and under field conditions.展开更多
The inheritance of stripe disease resistance in a rice restorer line C224 was analyzed using the mixed effect model of major gene plus polygene for quantitative traits.In addition,the resistance was investigated in se...The inheritance of stripe disease resistance in a rice restorer line C224 was analyzed using the mixed effect model of major gene plus polygene for quantitative traits.In addition,the resistance was investigated in seven crosses of C224 with maintainer lines.The results showed that the stripe resistance of C224 was controlled by two major genes with additive-dominance-epistasis effects plus polygenes with additive-dominance effects （E-1 model）.These two genes had additive effects of-12.47% and-24.75%,respectively,showing negative dominance effects.There were significant epistasis and interaction effects between the two major genes.The heritability of the two major genes was 92.12%,while that of polygenes was 2.74%,indicating that the stripe resistance had dominant major gene effect.Of the seven crosses,five displayed high or medium resistance to the stripe disease.展开更多
The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high...The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high NUE(HYHN).However,it is unclear which restorer lines are HYHN,and neither have the common agronomic traits of the HYHN restorer lines been identified.Aiming to address this issue,we conducted two filed experiments using three nitrogen applications,which screened five HYHN restorer lines from 15 indica restorer lines.Yield,NUE and nutrient transportation of restorer lines with different yields and NUE types were examined.Yield and total nitrogen absorption in aboveground biomass(TNA)increased,whereas NUE for grain production decreased with increasing nitrogen application levels.The HYHN restorer lines had large spikelets and high weight per panicle that were significantly positively correlated with yield and NUE.Therefore,large sink potential may be beneficial for both yield and NUE.We further studied the differences in nutrient transportation to panicles between the HYHN and low yield and low NUE(LYLN)restorer lines and found that the former had a higher nitrogen absorption level and dry matter weight ratios of panicle in maturity.Moreover,the HYHN lines also had a higher root and neck-panicle node bleeding intensity per stem after heading and more developed vascular bundles of neck-panicle nodes and leaves than the LYLN lines,which could contribute to the transportation of nutrients from root to ground and from stem and leaf to spike.Therefore,the advantages of large sink potential of the HYHN restorer lines include large nutrient accumulation in and distribution to the panicles and smooth flow of nutrients along the transportation channels.展开更多
Two bacterial blight （BB） resistance genes, Xa21 and Xa4, from IRBB24 were introduced into hybrid rice restorer line Mianhui 725, which is highly susceptible to BB, by using hybridization and molecular marker-assist...Two bacterial blight （BB） resistance genes, Xa21 and Xa4, from IRBB24 were introduced into hybrid rice restorer line Mianhui 725, which is highly susceptible to BB, by using hybridization and molecular marker-assisted selection technology. Four homologous restorer lines were obtained through testing the R target genes with molecular markers and analyzing parental genetic background. Inoculation of the four lines and their hybrids with the specific strains of Xanthomonas oryzae pv. oryzae, P1, P6 and seven representative strains of Chinese pathotype, C Ⅰ -CⅦ, showed that all of the four lines and their hybrids were highly resistant and presented broad resistance-spectrum to BB. The hybrids of G46A / R207-2 displayed good agronomic characters and high yield potential, and R207-2 was named Shuhui 207.展开更多
Genetic improvement is one of the most effective strategies to prevent rice from blast and bacterial blight （BB） diseases, the two most prevalent diseases jeopardizing rice production. Rice hybrids with dural resist...Genetic improvement is one of the most effective strategies to prevent rice from blast and bacterial blight （BB） diseases, the two most prevalent diseases jeopardizing rice production. Rice hybrids with dural resistance to blast and BB are needed for sustainable production of food. An incomplete diallele design resulted in 25 crosses between five blast and five BB resistant germplasm accessions. Only one pair of parents, DH146 ×TM487, showed polymorphism for all the markers to identify one blast resistance gene Pi25 and three BB resistance genes, Xa21, xa13 and xa5, thus it was used in the marker-assisted selection （MAS）. F2 individuals of DH146× TM487 were genotyped using flanking markers of RM3330 and sequence tagged site （STS） marker SA7 for Pi25. The resistant F2 plants with Pi25 were used for pyramiding BB resistance genes Xa21, xa13 and xa5 identified by the markers pTA248, RM264 and RM153, respectively in subsequent generations. Finally, after selection for agronomic traits and restoration ability among 12 pyramided lines, we acquired an elite restorer line, R8012 including all four target genes （Pi25＋Xa21＋xa13＋xa5）. Hybrid Zhong 9NR8012 derived from the selected line showed stronger resistance to blast and BB, and higher grain yield than the commercial checks uniformally in experimental plots, 2007 state-wide yield trial and 2008 nation-wide yield trial. This study provides a paradigmatic example to show that MAS is a practically feasible tool in effectively pyramiding multiple resistance genes. The resultant restoring line and its hybrid would play an important role in securing rice production in China.展开更多
[Objective] This study was conducted to analyze the difference in the general combining ability of yield traits of rice varieties in China and South Asia and to provide reference for the introduction and utilization o...[Objective] This study was conducted to analyze the difference in the general combining ability of yield traits of rice varieties in China and South Asia and to provide reference for the introduction and utilization of rice restorer lines from South Asia. [Method] A total of 111 hybrids were obtained by crossing 37 restorer lines in China and South Asia with Gang 46A, Lu 98A and Dexiang 074 following a NC II design. The combining ability of eight yield traits of the hybrids was analyzed in Luzhou and Deyang bases of Sichuan Province. [Result] In both bases, the eight yield traits had significant or extremely significant differences between the combina- tions, restorer lines, sterile lines or sterile line^restorer line, suggesting that there were d^erences in the genetic effects between the combinations or lines. The gen- eral combining ability （GCA） variances were all higher than special combining ability （SCA） variances in parents, which indicated that these traits were affected by gene additive effect. Restorer lines contributed more to F1 generation than male sterile liens in the eight yield traits. Nine restorer lines from India and Bangladesh were ranked in the top 15 lines with high GCA in the number of productive tillers in both bases. [Co.cl.siee] There was significant differences in the combining ability in the eight yield traits between the restorer lines from China and South Asia. The lines from India and Bangladesh were better than those from China in the GCA of the number of productive tillers, and the lines from China were better than those from India and Bangladesh in the GCA of other traits.展开更多
Haihui 818 is a new restorer line by cross breeding with Hua 23 S and Huahui 8131.Good plant type,high tillering ability,fine grain quality,strong restoring ability and high yield were shown in hybrid production.After...Haihui 818 is a new restorer line by cross breeding with Hua 23 S and Huahui 8131.Good plant type,high tillering ability,fine grain quality,strong restoring ability and high yield were shown in hybrid production.After artificial inoculation and field stress and molecular market-assisted selection,the results showed that rice-blast resistance genes Pi1,BB resistance genes Xa7,and brown planthopper resistance genes Bph3,Bph14 and Bph15 were pyramided together.Among its hybrids,Bo II You 818(Bo II A/Haihui 818)was approved for commercial production by Hainan Provincial Crop Variety Approval Committee in 2015.展开更多
To facilate breeding process of Brassica napus,a microspore culture and molecular marker-assisted screening combined system were proposed in this research.At early flowering stage,F1 offspring of hybridized combinatio...To facilate breeding process of Brassica napus,a microspore culture and molecular marker-assisted screening combined system were proposed in this research.At early flowering stage,F1 offspring of hybridized combination HY15 A×HF06 was used as donor for microspore culture to analyze effects of colchicine concentration on embryogenic and diploid rates of microspore.Treatment with 50 mg/L colchicine resulted in embryogenic rate of3.56 embryos/bud,which was substantially higher than control(0.78 embryos/bud).A total of 1,387 embryos and 862 single plants were obtained after induction culture.Ploidy detection was performed for the regenerated plants by flow cytometry.Diploid rates of microspores treated with 50 mg/L and 70 mg/L colchicine were 17.2%and 21.0%respectively,which was significantly higher than control(10.5%).Totally 108 single plants that doubled successfully were randomly selected and screened using molecular marker BE10.Approximately 54 of108 plants generated a 305 bp amplification product,whereas the other 54 plants showed a 398 bp band,thereby satisfying 1:1 separation ratio(x0.052=0.0093).These coincided with field identification results.Findings of this study indicated that homozygous breeding material could be obtained by microspore culture in a short time,thereby remarkably accelerate breeding.展开更多
Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withide...Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withideal agronomic characters were identified. Weincorporated the WC gene into restorer linesby crossing these japonica WC lines with ob-tained indica lines. Some WC restorer lineswith indica-japonica medium type were ob-tained and their application value in intersub-specific hybrid rice breeding were evaluated. 1. Effect of crossing methods on selectionefficiencies of WC restorer lines展开更多
Yihui1577 was bred after over 10 generations by crossing R16 and Yunan purple rice. Many new hybrid rice varieties have been bred with Yihui1577, of which Gangyou1577. Ilyou1577, Nyou1577 and Yixiang1577 were certifie...Yihui1577 was bred after over 10 generations by crossing R16 and Yunan purple rice. Many new hybrid rice varieties have been bred with Yihui1577, of which Gangyou1577. Ilyou1577, Nyou1577 and Yixiang1577 were certified by Sichuan Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 have been used widely with accumulated area of 1,200,000 ha. By using Yihui1577 as breeding material, an excellent restore line Yihui3003 and some other restore lines, such as Yihui1979 and Yihui315 with good quality and combination ability have been bred. Analysis of combination ability and stability of restore line Yihui1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made by not complete dual crossing method with 4 CMS lines and 6 restorer lines. It shows that the general combination ability effect value of Yihui1577 is 0.226, while Minghui63 is -0.113. So the general combination ability of Yihui1577 is prior to that of Minghui63. Stability analysis shows that the F value of Gangyou1577 is 1.81378, while Sanyou63 is 1.40327, both doesn＇t reach significant level. So Gangyou1577 has the same stability as Sanyou63.The same conclusion is got in the stability analysis of the breeds of II you 1577, Yixiang1577, Nyou 1577 and so on.展开更多
Blast resistance and grain quality are major problems in hybrid rice production in China. In this study, two resistance （R） genes, Pi46 and Pita, along with the gene Wxb, which mainly affects rice endosperm amylose ...Blast resistance and grain quality are major problems in hybrid rice production in China. In this study, two resistance （R） genes, Pi46 and Pita, along with the gene Wxb, which mainly affects rice endosperm amylose content （AC）, were introgressed into an elite indica restoring line, R8166, which has little blast resistance and poor grain quality through marker-assisted selection （MAS）. Eight improved lines were found to have recurrent genome recovery ratios ranging from 88.68 to 96.23%. Two improved lines, R163 and R167, were selected for subsequent studies. R167, which has the highest recovery ratio （96.23%）, showed no significant differences in multiple agronomic traits. In contrast, R163 with the lowest recovery ratio （88.68%） exhibited significant differences in heading date and yield per plant compared with the recurrent parent. At two developmental stages, R163 and R167 had greatly enhanced resistance to blast over the recurrent parent. Similar trends were also observed for agronomic traits and blast resistance in R163- and R167-derived hybrids when compared with the counterparts from R8166. In addition, R163, R167, and their derived hybrids significantly improved the grain quality traits, including amylose content （AC）, gel consistency （GC）, chalky grain rate （CGR）, and degree of endosperm chalkiness （DEC）. It confirmed the success of efficiently developing elite restoring lines using MAS in this study.展开更多
Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were cert...Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were certified by Sichuan Province Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 had been used widely with accumulated areas of 1 200 000 hm2. By using Yihui1577 as breeding material, an excellent restore line Yihui 3003 and some other restore lines, such as Yihui 1979, Yihui 315 with good rice quality and good combination ability had been bred. Analysis of combination ability and stability about restore line Yihui 1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made in complete dual crossing method with 4 CMS lines and 6 restorer lines. It showed that the general combination ability effect value of Yihui1577 was 0.226, while Minghui63 was -0.113. So the general combination ability ofYihui1577 was prior to that of Minghui 63. Stability analysis showed that the F value of Gangyou1577 was 1.81378, while Sanyou 63 was 1.40327, both didn＇t reach significant level. So Gangyou1577 had the same stability as Sanyou 63. The same conclusion had got in the stability analysis of the breeds of Ⅱ you 1577, Yixiang 1577, Nyou 1577 and so on.展开更多
The seed samples of Yuetai A, a Honglian （HL） type cytoplasmic male sterile （CMS） line in hybrid rice were investigated to assess the seed purity and to analyze the cause of off-type plants by imitating the biolog...The seed samples of Yuetai A, a Honglian （HL） type cytoplasmic male sterile （CMS） line in hybrid rice were investigated to assess the seed purity and to analyze the cause of off-type plants by imitating the biological contaminant to Yuetai A in Nanjing, Jiangsu Province and Lingshui, Hainan Province during 2004-2006. The seed impurity of Yuetai A mainly resulted from the genetic drift of restoring fertility gene （Rt） after biological contamination but not from its sterility unstability. All of the ten maintainer lines, five restorer lines and three thermo-sensitive genic male sterile lines used in the study could pollinate Yuetai A and Yuetai B to produce F1 plants, directly or indirectly resulting in Rf-gene drifting into Yuetai A and generating ＇iso-cytoplasm restoring-generations＇. Furthermore, high outcrossing rate and similar heading date of Yuetai A with many varieties used in rice production might easily result in the biological contamination. After removing all plants with Rf-gene mixed in Yuetai A and preventing Rf-gene drifting into Yuetai A, the seed purity of Yuetai A and Yuetai B had been raised to 100%.展开更多
For the first time, the fertility of rice genic male sterile line was partially restored with the application of chemical regulators at Hainan Rice Breeding Nursery on Mar 1993. A single panicle of the rice plant coul...For the first time, the fertility of rice genic male sterile line was partially restored with the application of chemical regulators at Hainan Rice Breeding Nursery on Mar 1993. A single panicle of the rice plant could bear as many as 27 grains. The chemical agent that could modulate the growth of the rice plants of genic male sterile line was developed by Prof ZHOU Guangqia and his colleagues at the Biology Institute, Hunan Teachers University, China.展开更多
Male sterile NEA plants were identified in progenies of the radiated 92P x Aggregate-silique in Brassica napus L. in 1993. Their progeny plants from test crossing and open pollination were 100% male sterile. The doubl...Male sterile NEA plants were identified in progenies of the radiated 92P x Aggregate-silique in Brassica napus L. in 1993. Their progeny plants from test crossing and open pollination were 100% male sterile. The double-low male sterile lines JL-4 and JL-18 were bred through successive backcrossing of the double -low variety No.4 and No. 18 in Brassica napus L.to NEA. Restorer lines 6720 and 6722 with significant heterosis in F1 were developed. The results from investigating the restoring-ntaintaining relationship and inheritance of the restorer gene indicated that JL-4 and JL-18 were different from both PolCMS and Shan 2A type, and their restorer gene was controlled by a pair of dominant genie genes.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.30871473 and 31101116)the Project from the China National Rice Research Institute(Grant No.2009RG003-5)+1 种基金the Projects from local government of Zhejiang Province, China(Grant Nos.2008C22073,2009C32048 and SN200806)the Zhejiang Provincial Natural Science Foundation,China(Grant Nos.Y3100060 and Y3100090)
文摘Fifteen common rice maintainer lines and 26 high-yielding restorer lines were used to evaluate their thermal resistance and fertility during flowering and early grain filling stages. The rice plants were subjected to high temperature stress （39-43 ℃） for 1-15 d from main stem flowering. Based on the heat stress index, they were divided into thermal resistant lines, semi-thermal resistant lines, semi-thermal sensitive lines and thermal sensitive lines. Therefore, the maintainer lines K22B, Bobai B and V20B belonged to thermal resistant lines, whereas 11-32B, Zhongzhe B and Zhong 9B belonged to thermal sensitive lines. For rice restorer lines, Minghui 63 had the highest thermal resistance, followed by R207, P32, P929, and the lowest thermal resistant lines P62-2-2, R8006 and P51. The correlation analysis indicated that the heat stress index was significantly correlated with seed-setting rate and abortive grain rate under heat stress, but not under natural conditions. This indicated that heat stress occurred during flowering and early grain filling stages mainly decreased the seed- setting rate and significantly increased the abortive grain rate in both rice maintainer and restorer lines.
基金Supported by Chongqing Social Livelihood Innovation Program(cstc2015-shmszx80013)Natural Science Foundation of Chongqing(CSTC2015jcyj BX0091)+1 种基金Project of Special Crop Resource Engineering Technology Research Center of Chongqing Municipality(cqstszwzygcjsyjzx)School-level Fund of Chongqing Normal University(14XYY023,15XZH03)~~
文摘Kehui 36, derived from Minghui 63 / Taiyin 1（♀） // Nuo 89-1（♂）, is a new rice restorer line developed by Chongqing Normal University, which exhibits strong cold tolerance, high restoring ability, large pollen amount and other characteristics. In 2013, Kehui 36 was technically identified by Chongqing Crop Variety Appraisal Committee. Gangyou 36, a hybrid line derived from Gang 46 A / Kehui 36,was registered and released for commercial production by Chongqing Crop Variety Appraisal Committee in 2012.
文摘Six isolates of Magnaporthe grisea were selected to inoculate on 10 Chinese leading maintainer lines (B-lines), 14 restorer lines (R-lines) and their F1 hybrid plants. In the tested rice materials, R-lines were proved to be more resistant to blast than B-lines. The resistance frequency of about 25% F1 hybrid plants was less than their parents. In addition, 26 isolates of M. grisea collected from different rice growing areas of China were inoculated on 13 new improved hybrid rice combinations. The resistance frequencies of 5 improved hybrids were better than those of the controls and leading varieties in rice production of China.
基金supported by the grant from the National Research and Development Project of Transgenic Crops of Ministry of Science and Technology of China (Grant No.JY03-B-11)
文摘Bt5198, a new rice restorer line containing Bt gene, was developed from the cross and backcross of the elite restorer line Chenghui 177 with Bt Minghui 63, a transgenic Bt restorer line. The inbred lines were evaluated using PCR amplification, test paper evaluation, insect resistance evaluation in both the laboratory and paddy fields, nursery evaluation of rice blast resistance and pedigree selection of agronomic traits. Larval mortalities on Bt5198 and Bt Minghui 63 were 100% when rice culms were inoculated with the eggs of the striped stem borer （SSB） in the laboratory. Bt5198 was highly resistant against SSB and the yellow stem borer （YSB） under field conditions. The F1 hybrids derived from Bt5198 and four cytoplasmic male sterile （CMS） lines were also highly resistant to SSB and YSB and had a significant heterosis. Two-year evaluation of rice blast resistance confirmed that the resistance levels of Bt5198 to leaf blast and neck blast were similar to those of Chenghui 177 and significantly better than those of Bt Minghui 63. Seed germination ability and pollen yield of Bt5198 were similar with Chenghui 177, suggesting that the introduction of the Bt gene into the new restorer line had no significant effects on seed vitality or the yield of seed production. To identify the presence of the Bt gene, it was effective to combine test paper examination with the evaluation of insect-resistance, both in the laboratory and under field conditions.
基金supported by the Guiding Plans for Natural Sciences Foundation of Liaoning Province,China(Grant No.20092207)the Special Foundation for Young Scientists of Liaoning Rice Research Institute,Shenyang,China(Grant No.DZS-2008-1)
文摘The inheritance of stripe disease resistance in a rice restorer line C224 was analyzed using the mixed effect model of major gene plus polygene for quantitative traits.In addition,the resistance was investigated in seven crosses of C224 with maintainer lines.The results showed that the stripe resistance of C224 was controlled by two major genes with additive-dominance-epistasis effects plus polygenes with additive-dominance effects （E-1 model）.These two genes had additive effects of-12.47% and-24.75%,respectively,showing negative dominance effects.There were significant epistasis and interaction effects between the two major genes.The heritability of the two major genes was 92.12%,while that of polygenes was 2.74%,indicating that the stripe resistance had dominant major gene effect.Of the seven crosses,five displayed high or medium resistance to the stripe disease.
基金the National Natural Science Foundation of China(31871564)the National Key R&D Program of China(2016YFD0300506 and 2017YFD0301700)the Sichuan Breeding Key Research Project,China(2016NYZ0051)。
文摘The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high NUE(HYHN).However,it is unclear which restorer lines are HYHN,and neither have the common agronomic traits of the HYHN restorer lines been identified.Aiming to address this issue,we conducted two filed experiments using three nitrogen applications,which screened five HYHN restorer lines from 15 indica restorer lines.Yield,NUE and nutrient transportation of restorer lines with different yields and NUE types were examined.Yield and total nitrogen absorption in aboveground biomass(TNA)increased,whereas NUE for grain production decreased with increasing nitrogen application levels.The HYHN restorer lines had large spikelets and high weight per panicle that were significantly positively correlated with yield and NUE.Therefore,large sink potential may be beneficial for both yield and NUE.We further studied the differences in nutrient transportation to panicles between the HYHN and low yield and low NUE(LYLN)restorer lines and found that the former had a higher nitrogen absorption level and dry matter weight ratios of panicle in maturity.Moreover,the HYHN lines also had a higher root and neck-panicle node bleeding intensity per stem after heading and more developed vascular bundles of neck-panicle nodes and leaves than the LYLN lines,which could contribute to the transportation of nutrients from root to ground and from stem and leaf to spike.Therefore,the advantages of large sink potential of the HYHN restorer lines include large nutrient accumulation in and distribution to the panicles and smooth flow of nutrients along the transportation channels.
文摘Two bacterial blight （BB） resistance genes, Xa21 and Xa4, from IRBB24 were introduced into hybrid rice restorer line Mianhui 725, which is highly susceptible to BB, by using hybridization and molecular marker-assisted selection technology. Four homologous restorer lines were obtained through testing the R target genes with molecular markers and analyzing parental genetic background. Inoculation of the four lines and their hybrids with the specific strains of Xanthomonas oryzae pv. oryzae, P1, P6 and seven representative strains of Chinese pathotype, C Ⅰ -CⅦ, showed that all of the four lines and their hybrids were highly resistant and presented broad resistance-spectrum to BB. The hybrids of G46A / R207-2 displayed good agronomic characters and high yield potential, and R207-2 was named Shuhui 207.
基金supported in part by the National Natural Science Foundation of China (Grant No. 30623006,No. 31101209)the National High Technology Research and Development Program of China (Grant No.2006AA10Z1E8)the Program of Introducing International Advanced Agricultural Science and Technologies (948 Program) of Ministry of Agricultureof China (Grant No. 2006-G51)
文摘Genetic improvement is one of the most effective strategies to prevent rice from blast and bacterial blight （BB） diseases, the two most prevalent diseases jeopardizing rice production. Rice hybrids with dural resistance to blast and BB are needed for sustainable production of food. An incomplete diallele design resulted in 25 crosses between five blast and five BB resistant germplasm accessions. Only one pair of parents, DH146 ×TM487, showed polymorphism for all the markers to identify one blast resistance gene Pi25 and three BB resistance genes, Xa21, xa13 and xa5, thus it was used in the marker-assisted selection （MAS）. F2 individuals of DH146× TM487 were genotyped using flanking markers of RM3330 and sequence tagged site （STS） marker SA7 for Pi25. The resistant F2 plants with Pi25 were used for pyramiding BB resistance genes Xa21, xa13 and xa5 identified by the markers pTA248, RM264 and RM153, respectively in subsequent generations. Finally, after selection for agronomic traits and restoration ability among 12 pyramided lines, we acquired an elite restorer line, R8012 including all four target genes （Pi25＋Xa21＋xa13＋xa5）. Hybrid Zhong 9NR8012 derived from the selected line showed stronger resistance to blast and BB, and higher grain yield than the commercial checks uniformally in experimental plots, 2007 state-wide yield trial and 2008 nation-wide yield trial. This study provides a paradigmatic example to show that MAS is a practically feasible tool in effectively pyramiding multiple resistance genes. The resultant restoring line and its hybrid would play an important role in securing rice production in China.
基金Supported by National High Technology Research and Development Program of China(2011AA10A101)Special Fund for Agro-scientific Research in the Public Interest(201100)+1 种基金Rice Breeding Research Program of Sichuan Province during the 12th Five-Year Plan Period(YZGG2011-1)Innovation Skill Improvement Program of Department of Finance of Sichuan Province(2013QNJJ-021)~~
文摘[Objective] This study was conducted to analyze the difference in the general combining ability of yield traits of rice varieties in China and South Asia and to provide reference for the introduction and utilization of rice restorer lines from South Asia. [Method] A total of 111 hybrids were obtained by crossing 37 restorer lines in China and South Asia with Gang 46A, Lu 98A and Dexiang 074 following a NC II design. The combining ability of eight yield traits of the hybrids was analyzed in Luzhou and Deyang bases of Sichuan Province. [Result] In both bases, the eight yield traits had significant or extremely significant differences between the combina- tions, restorer lines, sterile lines or sterile line^restorer line, suggesting that there were d^erences in the genetic effects between the combinations or lines. The gen- eral combining ability （GCA） variances were all higher than special combining ability （SCA） variances in parents, which indicated that these traits were affected by gene additive effect. Restorer lines contributed more to F1 generation than male sterile liens in the eight yield traits. Nine restorer lines from India and Bangladesh were ranked in the top 15 lines with high GCA in the number of productive tillers in both bases. [Co.cl.siee] There was significant differences in the combining ability in the eight yield traits between the restorer lines from China and South Asia. The lines from India and Bangladesh were better than those from China in the GCA of the number of productive tillers, and the lines from China were better than those from India and Bangladesh in the GCA of other traits.
基金Earmarked Fund for China Agriculture Research System(CARS-01-89)Crop Genetics and Breeding-Tropical Characteristic Rice Genetic Breeding(JBKYYNF-2020-03)Identification and Development of Tropical Rice Germplasm Resources in Southeast Asia(KJCX-2020-11)。
文摘Haihui 818 is a new restorer line by cross breeding with Hua 23 S and Huahui 8131.Good plant type,high tillering ability,fine grain quality,strong restoring ability and high yield were shown in hybrid production.After artificial inoculation and field stress and molecular market-assisted selection,the results showed that rice-blast resistance genes Pi1,BB resistance genes Xa7,and brown planthopper resistance genes Bph3,Bph14 and Bph15 were pyramided together.Among its hybrids,Bo II You 818(Bo II A/Haihui 818)was approved for commercial production by Hainan Provincial Crop Variety Approval Committee in 2015.
基金supported by the Youth Talent Development Plan of Shanghai Municipal Agricultural System,China(No.20180103)the National Key Research and Development Program of China(No.2018YFD0100602)the Youth Talent Running Plan of Shanghai Academy of Agricultural Sciences,China(No.2017020)。
文摘To facilate breeding process of Brassica napus,a microspore culture and molecular marker-assisted screening combined system were proposed in this research.At early flowering stage,F1 offspring of hybridized combination HY15 A×HF06 was used as donor for microspore culture to analyze effects of colchicine concentration on embryogenic and diploid rates of microspore.Treatment with 50 mg/L colchicine resulted in embryogenic rate of3.56 embryos/bud,which was substantially higher than control(0.78 embryos/bud).A total of 1,387 embryos and 862 single plants were obtained after induction culture.Ploidy detection was performed for the regenerated plants by flow cytometry.Diploid rates of microspores treated with 50 mg/L and 70 mg/L colchicine were 17.2%and 21.0%respectively,which was significantly higher than control(10.5%).Totally 108 single plants that doubled successfully were randomly selected and screened using molecular marker BE10.Approximately 54 of108 plants generated a 305 bp amplification product,whereas the other 54 plants showed a 398 bp band,thereby satisfying 1:1 separation ratio(x0.052=0.0093).These coincided with field identification results.Findings of this study indicated that homozygous breeding material could be obtained by microspore culture in a short time,thereby remarkably accelerate breeding.
文摘Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withideal agronomic characters were identified. Weincorporated the WC gene into restorer linesby crossing these japonica WC lines with ob-tained indica lines. Some WC restorer lineswith indica-japonica medium type were ob-tained and their application value in intersub-specific hybrid rice breeding were evaluated. 1. Effect of crossing methods on selectionefficiencies of WC restorer lines
基金The study is approved by the state 863 program in China (the program No.2002AA2070002)and Sichuan province 15 rice breeding key project.
文摘Yihui1577 was bred after over 10 generations by crossing R16 and Yunan purple rice. Many new hybrid rice varieties have been bred with Yihui1577, of which Gangyou1577. Ilyou1577, Nyou1577 and Yixiang1577 were certified by Sichuan Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 have been used widely with accumulated area of 1,200,000 ha. By using Yihui1577 as breeding material, an excellent restore line Yihui3003 and some other restore lines, such as Yihui1979 and Yihui315 with good quality and combination ability have been bred. Analysis of combination ability and stability of restore line Yihui1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made by not complete dual crossing method with 4 CMS lines and 6 restorer lines. It shows that the general combination ability effect value of Yihui1577 is 0.226, while Minghui63 is -0.113. So the general combination ability of Yihui1577 is prior to that of Minghui63. Stability analysis shows that the F value of Gangyou1577 is 1.81378, while Sanyou63 is 1.40327, both doesn＇t reach significant level. So Gangyou1577 has the same stability as Sanyou63.The same conclusion is got in the stability analysis of the breeds of II you 1577, Yixiang1577, Nyou 1577 and so on.
基金supported by the grant from the State Scholarship Fund of China (20153069)the National Key R&D Program of China (2016YFD0101100)the earmarked fund for China Agriculture Research System (CARS-01-12)
文摘Blast resistance and grain quality are major problems in hybrid rice production in China. In this study, two resistance （R） genes, Pi46 and Pita, along with the gene Wxb, which mainly affects rice endosperm amylose content （AC）, were introgressed into an elite indica restoring line, R8166, which has little blast resistance and poor grain quality through marker-assisted selection （MAS）. Eight improved lines were found to have recurrent genome recovery ratios ranging from 88.68 to 96.23%. Two improved lines, R163 and R167, were selected for subsequent studies. R167, which has the highest recovery ratio （96.23%）, showed no significant differences in multiple agronomic traits. In contrast, R163 with the lowest recovery ratio （88.68%） exhibited significant differences in heading date and yield per plant compared with the recurrent parent. At two developmental stages, R163 and R167 had greatly enhanced resistance to blast over the recurrent parent. Similar trends were also observed for agronomic traits and blast resistance in R163- and R167-derived hybrids when compared with the counterparts from R8166. In addition, R163, R167, and their derived hybrids significantly improved the grain quality traits, including amylose content （AC）, gel consistency （GC）, chalky grain rate （CGR）, and degree of endosperm chalkiness （DEC）. It confirmed the success of efficiently developing elite restoring lines using MAS in this study.
基金Supported by the State 863 Program in China(2002AA2070002)Sichuan Province 15 Rice Breeding Key Project
文摘Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were certified by Sichuan Province Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 had been used widely with accumulated areas of 1 200 000 hm2. By using Yihui1577 as breeding material, an excellent restore line Yihui 3003 and some other restore lines, such as Yihui 1979, Yihui 315 with good rice quality and good combination ability had been bred. Analysis of combination ability and stability about restore line Yihui 1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made in complete dual crossing method with 4 CMS lines and 6 restorer lines. It showed that the general combination ability effect value of Yihui1577 was 0.226, while Minghui63 was -0.113. So the general combination ability ofYihui1577 was prior to that of Minghui 63. Stability analysis showed that the F value of Gangyou1577 was 1.81378, while Sanyou 63 was 1.40327, both didn＇t reach significant level. So Gangyou1577 had the same stability as Sanyou 63. The same conclusion had got in the stability analysis of the breeds of Ⅱ you 1577, Yixiang 1577, Nyou 1577 and so on.
文摘The seed samples of Yuetai A, a Honglian （HL） type cytoplasmic male sterile （CMS） line in hybrid rice were investigated to assess the seed purity and to analyze the cause of off-type plants by imitating the biological contaminant to Yuetai A in Nanjing, Jiangsu Province and Lingshui, Hainan Province during 2004-2006. The seed impurity of Yuetai A mainly resulted from the genetic drift of restoring fertility gene （Rt） after biological contamination but not from its sterility unstability. All of the ten maintainer lines, five restorer lines and three thermo-sensitive genic male sterile lines used in the study could pollinate Yuetai A and Yuetai B to produce F1 plants, directly or indirectly resulting in Rf-gene drifting into Yuetai A and generating ＇iso-cytoplasm restoring-generations＇. Furthermore, high outcrossing rate and similar heading date of Yuetai A with many varieties used in rice production might easily result in the biological contamination. After removing all plants with Rf-gene mixed in Yuetai A and preventing Rf-gene drifting into Yuetai A, the seed purity of Yuetai A and Yuetai B had been raised to 100%.
文摘For the first time, the fertility of rice genic male sterile line was partially restored with the application of chemical regulators at Hainan Rice Breeding Nursery on Mar 1993. A single panicle of the rice plant could bear as many as 27 grains. The chemical agent that could modulate the growth of the rice plants of genic male sterile line was developed by Prof ZHOU Guangqia and his colleagues at the Biology Institute, Hunan Teachers University, China.
文摘Male sterile NEA plants were identified in progenies of the radiated 92P x Aggregate-silique in Brassica napus L. in 1993. Their progeny plants from test crossing and open pollination were 100% male sterile. The double-low male sterile lines JL-4 and JL-18 were bred through successive backcrossing of the double -low variety No.4 and No. 18 in Brassica napus L.to NEA. Restorer lines 6720 and 6722 with significant heterosis in F1 were developed. The results from investigating the restoring-ntaintaining relationship and inheritance of the restorer gene indicated that JL-4 and JL-18 were different from both PolCMS and Shan 2A type, and their restorer gene was controlled by a pair of dominant genie genes.
