The changes in grain-filling, starch accumulation and activity of enzymes associated with starch synthesis in two different hybrid rice varieties were analyzed at different N supplying dates (earlier-date-emphasized...The changes in grain-filling, starch accumulation and activity of enzymes associated with starch synthesis in two different hybrid rice varieties were analyzed at different N supplying dates (earlier-date-emphasized, mean-date-emphasized and later-date- emphasized). The results showed that the N application of later-date-emphasized could promote grain-filling rate, increase grain weight and amylopectin content. The peak of activity in three enzymes of ADPglusoce pyriphosphorylase (ADPG), starch synthesis enzyme (SSS) and starch branching enzyme (SBE) in grains of two different rice varieties was not changed obviously, but the mean and maximum activity of these three enzymes changed, and the changes of SSS and ADPG were bigger than that of SBE as N supplying date changed. The N application of earlier-date-emphasized increased SSS activity and the N application of later-date-emphasized increased ADPG and SBE activities. The mean SSS activity during whole grain-filling period, and ADPG and SBE activities at middle and late period of grain-filling were significantly or very significantly correlated with grain-filling rate and accumulating rate of amylose and amylopectin. Both of ADPG and SBE played an equal important role in the changes of amylose and amylopectin content. The N application of later-date-emphasized increased amylose and amylopectin accumulating rate.展开更多
Rice samples were scanned with a Foss Tecator Infratec and their amylose content was determinedusing a standard wet chemical method.Calibration software along with several mathematicaltreatments of the sample spectra ...Rice samples were scanned with a Foss Tecator Infratec and their amylose content was determinedusing a standard wet chemical method.Calibration software along with several mathematicaltreatments of the sample spectra and several regression methods was used to optimize a nearinfrared transmittance spectroscopy equation for determining rice amylose content. The standarderror of calibration, standard error of cross-validation and regression squared of thecalibration were 1.489, 1.761 and 0.885,respectively.展开更多
The endogenous hormones (EHs) content of different explants (anther, young panicle, young embryo and mature embryo) and calli with different culture capability were analyzed by means of high performance liquid chromat...The endogenous hormones (EHs) content of different explants (anther, young panicle, young embryo and mature embryo) and calli with different culture capability were analyzed by means of high performance liquid chromatography (HPLC). The results showed that the contents and ratio of endogenous hormones were one of the key factors affecting callus induction frequencies (CIF) and green plantlet differentiation frequencies (GPDF). The influence of endogenous hormones of different explants on CIF represented as: Zoatin ribosile (ZR) showed negative effect, indole-3-acetic acid (IAA) did positive effect, and gibberellic acid (GA) did negative effect except for mature embryos. The influence of endogenous hormones on green plantlet differentiation frequency (GPDF) showed: IAA and GA were negative effect; abscisic acid (ABA) and zeatin+ zeatin riboside (Z+ZR) were positive effect. The mixture ratio of endogenous hormones played a role on CIF and GPDF. IAA/Z+ZR had a positive effect on CIF, and there was a notable positive correlation between Z+ZR/ IAA and GPDF, so was between ABA/IAA and GPDF.展开更多
The genetic diversity of Dongxiang wild rice populations was evaluated by using 14 SSR primer pairs. Twelve of the primer pairs amplified polymorphic bands. A total of 70 polymorphic DNA bands were generated with aver...The genetic diversity of Dongxiang wild rice populations was evaluated by using 14 SSR primer pairs. Twelve of the primer pairs amplified polymorphic bands. A total of 70 polymorphic DNA bands were generated with average 5. 83 polymorphic bands per primer pair, indicating that the genetic diversity of Dongxiang wild rice was high. Cluster analysis showed that there were highly variant individuals within and among populations, while others were highly similar to each other. The within-population genetic distances were 0. 23 - 0.47, being smaller than 0.40 - 0.55 of among-population. Strict management must be taken for the preservation of Dongxiang wild rice.展开更多
The research results of marker aided selection(MAS)for resistant varieties and lines against rice gall midge Orseolia oryzae Wood-Mason successfully in 1999 - 2002 were reported in the present paper. The molecular mar...The research results of marker aided selection(MAS)for resistant varieties and lines against rice gall midge Orseolia oryzae Wood-Mason successfully in 1999 - 2002 were reported in the present paper. The molecular markers linked to the gene Gm6 against rice gall midge were used to select and breed the resistant varieties and lines. The RAPD marker OPM06 was used to verify the existence actually of gene Gm6 in ten developed varieties resistant to gall midge such as Duokang1, Duokang2, Kangwen2, Kangwen3, Kang-wen5, Duokangzaozhan, Kangwenqinzhan, which were derived from Daqiuqi. For resistance breeding through PCRbased marker aided selection(MAS), the polymorphisms in the resistant and susceptible parents were i-dentified by RG476/Alu I and RG476/Sca I respectively. The RAPD marker OPM06(1.4 kb)was used to i-dentify 15 new resistance lines from F3 lines of Fengyinzhan1/Daqiuqi in 1999. 21 and 7 resistance lines were selected from F4 and F6 lines of KWQZ/Gui99(restored line of hybrid rice)using RG476/Alu I in 2000-2001 respectively. The Gm6 gene was transferred into the restored line of hybrid rice. In 2001 - 2002, RG214/ Hha I and G214/Sca I were used for selecting 11 and 5 resistance lines from F3 lines of KWQZ/IR56 and AXZ/KWQZ successfully. The application of the resistance gene through PCR-based marker aided selection is a new and effective approach in resistance breeding.展开更多
In progenies resulting from crosses involving rice cultivar Norin 8m susceptible to bentazon as the donor of ben gene, SCARs tightly linked to ben were utilized for selection of ben. The homozygous and heterozygous ge...In progenies resulting from crosses involving rice cultivar Norin 8m susceptible to bentazon as the donor of ben gene, SCARs tightly linked to ben were utilized for selection of ben. The homozygous and heterozygous genotypes with ben could be identified with the SCARs. The molecular markers offer a powerful tool for indirect selection of ben and can accelerate the introgression of ben into current rice cultivars.展开更多
The plant material used in the study was rice line 162d, a new small grain dwarf mutant. Polymorphic analysis of 221 SSR loci demonstrated that 162d derived from a semidwarf variety Shuhui 162 through mutation, and 16...The plant material used in the study was rice line 162d, a new small grain dwarf mutant. Polymorphic analysis of 221 SSR loci demonstrated that 162d derived from a semidwarf variety Shuhui 162 through mutation, and 162d and Shuhui 162 were just a pair of near isogenic lines. Genetic analysis of F_1 and F_2 populations suggested that dwarfism in 162d was controlled by a single recessive gene. Phenotypic characteristics of the mutant gene were that plant height was about a quarter of normal height, grain size about a quarter of normal size, leaf was short and broad, and seed setting rate was very low, compared with the near isogenic line Shuhui 162. The mutant gene was sensitive to gibberellin (GA_3) treatment and did not located on the region near the centromere of rice chromosome 5, where dl gene located. Therefore, it was concluded that the mutant gene of 162d was a new small grain dwarf gene in rice.展开更多
The grain-filling characteristics of six rice varieties (combinations) and the relationships between their relative biochemistry composition during phytate synthesizing and grain plumpness were studied. Regarding resu...The grain-filling characteristics of six rice varieties (combinations) and the relationships between their relative biochemistry composition during phytate synthesizing and grain plumpness were studied. Regarding results for ISHR1, ISHR2, R198 and JW21, with good grain plumpness, the two-step-filling in superior spikelets and inferior spikelets was not clear, while for ISHR3 and 559, with poor grain plumpness, it was very clear. From booting stage to flowering stage, the contents of phytate and inositol in varieties with good grain plumpness was obviously higher than those in varieties with poor grain plumpness. While at grain filling stage, the content of inorganic phosphorus in varieties with poor grain plumpness was obviously higher than that in varieties with good grain plumpness. The contents of phytate and inositol from booting stage to flowering stage was highly significantly correlated with the initial filling power (R_0), the mean filling rate (R_M) and grain filling percentage (P_(GF)), and the content of inorganic phosphorus at grain filling stage was negatively significantly correlated with R_0, F_M and P_(GF). Furthermore, effective approach to improving grain filling was put forward.展开更多
Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatcllite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphi...Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatcllite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphisms repeatedly, and the polymorphic frequencies were 3.4-11.3% between the mutants and Yuexiangzhan. The polymorphic markers were randomly located on chromosomes. The more similar the plant types of the mutants like their original variety, the less polymorphic loci were detected. In addition, there was variation in the soluble protein contents among the leaves of mutants, and the contents were significantly lower than those of the original variety.展开更多
The study used Waixuan35, a blast resistant rice material adopted widely previously in South China, Yuexiangzhan, a rice variety with the largest planting area in Guangdong Province at present and with the characteris...The study used Waixuan35, a blast resistant rice material adopted widely previously in South China, Yuexiangzhan, a rice variety with the largest planting area in Guangdong Province at present and with the characteristics of horizontal blast resistance and high harvest index, and Qisizhan, the earliest good eating quality variety in Guangdong Province as parent materials, and created an important material systems for studying agricultural characters such as rice blast resistance genes, their resistance mechanisms and quality by hybridization offspring single grain transfer method and DNA hybridization method, namely recombination inbred line RIL, extend recombination inbred line ERIL and transferred-mutant recombination inbred line TRIL assemblages. In RIL assemblage, various materials of resistance gene combinations for identifying rice blast pathogen strains had been identified from the material system, providing direct material evidence for gene to gene theory. Using the same control and same method, in ERIL assemblage, it was proved that there were several main resistance genes and several minor resistance genes in horizontal resistant Yuexiangzhan, providing preliminary evidences for multigene control in horizontal resistance. A set of stable material assemblage for studying future horizontal resistance had been created. A mutation material of Yuexiangzhan from horizontal resistance to vertical resistance was obtained by wild rice external DNA electric stimulation introduction, and variation in mutation assemblage was certified by SSLP. These studies and materials provided important new materials for studying rice blast resistance mechanisms, gene cloning, resistance genes especially horizontal resistance.展开更多
The morphological characters of the newly released super hybrid rice in South China, Yueza 122, Fengyou 428, Peiza 67, and super conventional varieties, Guangchao 3, Shengtai 1 at the active tillering stage in both ...The morphological characters of the newly released super hybrid rice in South China, Yueza 122, Fengyou 428, Peiza 67, and super conventional varieties, Guangchao 3, Shengtai 1 at the active tillering stage in both early and late crops were investigated. Using the analysis of variance and other statistic methods, the ideal morphological characteristics of South China double cropping super-rice at the active tillering stage were determined. They are 55-60 cm in the early crop and 60-76 cm in the late crop for the ideal plant height, about 15 tillers in the early crop and 14-19 tillers in the late crop for the ideal tiller number per plant, 40-44 cm in the early crop and 42-60 cm in the late crop for the ideal length of the first leaf under the top leaf, 1.2-1.4 cm in the early crop and 1.2-1.3cm in the late crop for the ideal width of the first leaf under the top leaf, 39- 44 cm in the early crop and 37-43 cm in the late crop for the ideal length of the second leaf under the top leaf, 1.1-1.4 cm in the early crop and about 1.1 cm in the late crop for the ideal width of the second leaf under the top leaf, 22-58o in the early crop and 4- 12o in the late crop for the ideal top leaf angle at the active tillering stage. Based on these results, a new concept of “dynamic plant type structure” for South China double cropping super rice breeding was suggested.展开更多
A spontaneously occurring rice (Oryza sativa L.) mutant, characterized by homeotic conversionin glumes and stamens, was found in the progeny of a cross. The mutant showed long glumes andglumaceous lodicules and morpho...A spontaneously occurring rice (Oryza sativa L.) mutant, characterized by homeotic conversionin glumes and stamens, was found in the progeny of a cross. The mutant showed long glumes andglumaceous lodicules and morphological transformation of stamens into pistils. Mutant floretsconsisted of 1 to 3 completely developed pistils, some pistilloid stamens with filaments, buttipped by bulged tissue and 0 to 3 stigmas. It seems that the mutant phenotype of the homeoticconversions in glumes and stamens is similar to that of the B loss-of-function mutants inArabidopsis and Antirrhinum. The mutant is controlled by a single recessive gene as asegregation ratio of 3:1 (wild type to mutant plants) was observed in the F2 generation.展开更多
Located in the subtropical zone of South China, Guangdong Province is rich in wild rice genmplasm. The 3 wild rice species, being indigenous to China, O. rufipogon Criff, O. officinalis Wall and O. meyeriana Baill are...Located in the subtropical zone of South China, Guangdong Province is rich in wild rice genmplasm. The 3 wild rice species, being indigenous to China, O. rufipogon Criff, O. officinalis Wall and O. meyeriana Baill are dispersed over the province. About 1,354 habitats of wild taxa have been found scattering over 71 counties in the province ( see table ).展开更多
A spontaneous white panicle mutant was found from the F6 progenies of an indica/japonica cross. The mu-tant exhibits white stripes on its basal leaves while the pani-cles, rachis and pedicel are milky white colored at...A spontaneous white panicle mutant was found from the F6 progenies of an indica/japonica cross. The mu-tant exhibits white stripes on its basal leaves while the pani-cles, rachis and pedicel are milky white colored at flowering stage. Genetic analysis in an F2 population from the cross of Zhi7/white panicle mutant indicates that the white panicle phenotype is controlled by a single recessive nuclear gene, tentatively termed as wp(t). Using microsatellite markers, the wp(t) gene was anchored between the markers of SSR101 and SSR63.9 with a map distance of 2.3 and 0.8 cM, respec-tively, and co-segregated with the marker of SSR17 on rice chromosome 1.展开更多
A rice mutant, G069, characteristic of few tiller numbers, was found in anther culture progeny from the F1 hybrid between an indica-japonica cross, Gui630×02428. The mutant has another two major features: delayed...A rice mutant, G069, characteristic of few tiller numbers, was found in anther culture progeny from the F1 hybrid between an indica-japonica cross, Gui630×02428. The mutant has another two major features: delayed tillering development and yellowing apex and margin on the mature leaves. As a donor parent, G069 was further backcrossed with the recurrent parent, 02428, for two turns to develop a BC2F2 population. Genetic analysis in the BC2F2 population showed that the traits of few-tillering and yellowing apex and margin on the mature leaves were controlled by one recessive gene. A pool of equally mixed genomic DNA, from few-tillering individual plants in BC2F2, was constructed to screen polymorphism with simple sequence repeat (SSR) markers in comparison with the 02428 genome. One SSR marker and three restriction fragment length polymorphism (RFLP) markers were found possibly linked with the recessive gene. By using these markers, the gene of few-tillering was mapped on chromosome 2 between RFLP marker C424 and S13984 with a genetic distance of 2.4 cM and 0.6 cM, respectively. The gene is designated ft1.展开更多
We have analyzed a lax mutant that exhibits altered panicle architecture in rice. The primary and secondary rachis-branches are normally initiated and each branch ends in a terminal spikelet, but all the lateral spike...We have analyzed a lax mutant that exhibits altered panicle architecture in rice. The primary and secondary rachis-branches are normally initiated and each branch ends in a terminal spikelet, but all the lateral spikelets are absent and the terminal spikelet displays variegated structures in the mutant. An F2 population from the cross between the lax mutant and a japonica variety, W11, was constructed and analyzed. Using microsatellite and CAPS markers, the lax locus was mapped on the long arm of chromosome 1, co-segregated with a CAPS marker, LZ1, within an interval of 0.28 cM between a CAPS marker, HB2, and a microsatellite marker, MRG4389. RT-PCR analysis revealed that the expressions of the rice B-function MADS-box genes OsMADS2, OsMADS4, OsMADS16 and OsMADS3 were significantly reduced, whereas the expression of the rice A-function gene RAP1A was not altered.展开更多
文摘The changes in grain-filling, starch accumulation and activity of enzymes associated with starch synthesis in two different hybrid rice varieties were analyzed at different N supplying dates (earlier-date-emphasized, mean-date-emphasized and later-date- emphasized). The results showed that the N application of later-date-emphasized could promote grain-filling rate, increase grain weight and amylopectin content. The peak of activity in three enzymes of ADPglusoce pyriphosphorylase (ADPG), starch synthesis enzyme (SSS) and starch branching enzyme (SBE) in grains of two different rice varieties was not changed obviously, but the mean and maximum activity of these three enzymes changed, and the changes of SSS and ADPG were bigger than that of SBE as N supplying date changed. The N application of earlier-date-emphasized increased SSS activity and the N application of later-date-emphasized increased ADPG and SBE activities. The mean SSS activity during whole grain-filling period, and ADPG and SBE activities at middle and late period of grain-filling were significantly or very significantly correlated with grain-filling rate and accumulating rate of amylose and amylopectin. Both of ADPG and SBE played an equal important role in the changes of amylose and amylopectin content. The N application of later-date-emphasized increased amylose and amylopectin accumulating rate.
基金supported by National Natural Science Foundation of China(39893350)Guangdong Natura1 Science Foundation(020384)funds from the"948"Project of the Ministry of Agriculture,China.
文摘Rice samples were scanned with a Foss Tecator Infratec and their amylose content was determinedusing a standard wet chemical method.Calibration software along with several mathematicaltreatments of the sample spectra and several regression methods was used to optimize a nearinfrared transmittance spectroscopy equation for determining rice amylose content. The standarderror of calibration, standard error of cross-validation and regression squared of thecalibration were 1.489, 1.761 and 0.885,respectively.
文摘The endogenous hormones (EHs) content of different explants (anther, young panicle, young embryo and mature embryo) and calli with different culture capability were analyzed by means of high performance liquid chromatography (HPLC). The results showed that the contents and ratio of endogenous hormones were one of the key factors affecting callus induction frequencies (CIF) and green plantlet differentiation frequencies (GPDF). The influence of endogenous hormones of different explants on CIF represented as: Zoatin ribosile (ZR) showed negative effect, indole-3-acetic acid (IAA) did positive effect, and gibberellic acid (GA) did negative effect except for mature embryos. The influence of endogenous hormones on green plantlet differentiation frequency (GPDF) showed: IAA and GA were negative effect; abscisic acid (ABA) and zeatin+ zeatin riboside (Z+ZR) were positive effect. The mixture ratio of endogenous hormones played a role on CIF and GPDF. IAA/Z+ZR had a positive effect on CIF, and there was a notable positive correlation between Z+ZR/ IAA and GPDF, so was between ABA/IAA and GPDF.
基金supposed by the National Natural Science Foundation of China(39969001)the Program Project of 973 Priority,China(2002CCC00800)+1 种基金the Talent Scientist Training Program Project of Jiangxi Province(20031)the Natural Science Foundation of Jiangxi Province(0330034).
文摘The genetic diversity of Dongxiang wild rice populations was evaluated by using 14 SSR primer pairs. Twelve of the primer pairs amplified polymorphic bands. A total of 70 polymorphic DNA bands were generated with average 5. 83 polymorphic bands per primer pair, indicating that the genetic diversity of Dongxiang wild rice was high. Cluster analysis showed that there were highly variant individuals within and among populations, while others were highly similar to each other. The within-population genetic distances were 0. 23 - 0.47, being smaller than 0.40 - 0.55 of among-population. Strict management must be taken for the preservation of Dongxiang wild rice.
文摘The research results of marker aided selection(MAS)for resistant varieties and lines against rice gall midge Orseolia oryzae Wood-Mason successfully in 1999 - 2002 were reported in the present paper. The molecular markers linked to the gene Gm6 against rice gall midge were used to select and breed the resistant varieties and lines. The RAPD marker OPM06 was used to verify the existence actually of gene Gm6 in ten developed varieties resistant to gall midge such as Duokang1, Duokang2, Kangwen2, Kangwen3, Kang-wen5, Duokangzaozhan, Kangwenqinzhan, which were derived from Daqiuqi. For resistance breeding through PCRbased marker aided selection(MAS), the polymorphisms in the resistant and susceptible parents were i-dentified by RG476/Alu I and RG476/Sca I respectively. The RAPD marker OPM06(1.4 kb)was used to i-dentify 15 new resistance lines from F3 lines of Fengyinzhan1/Daqiuqi in 1999. 21 and 7 resistance lines were selected from F4 and F6 lines of KWQZ/Gui99(restored line of hybrid rice)using RG476/Alu I in 2000-2001 respectively. The Gm6 gene was transferred into the restored line of hybrid rice. In 2001 - 2002, RG214/ Hha I and G214/Sca I were used for selecting 11 and 5 resistance lines from F3 lines of KWQZ/IR56 and AXZ/KWQZ successfully. The application of the resistance gene through PCR-based marker aided selection is a new and effective approach in resistance breeding.
基金This work was supported by grants from Anhui Province Natura1 Science Foundation(0004111O).
文摘In progenies resulting from crosses involving rice cultivar Norin 8m susceptible to bentazon as the donor of ben gene, SCARs tightly linked to ben were utilized for selection of ben. The homozygous and heterozygous genotypes with ben could be identified with the SCARs. The molecular markers offer a powerful tool for indirect selection of ben and can accelerate the introgression of ben into current rice cultivars.
文摘The plant material used in the study was rice line 162d, a new small grain dwarf mutant. Polymorphic analysis of 221 SSR loci demonstrated that 162d derived from a semidwarf variety Shuhui 162 through mutation, and 162d and Shuhui 162 were just a pair of near isogenic lines. Genetic analysis of F_1 and F_2 populations suggested that dwarfism in 162d was controlled by a single recessive gene. Phenotypic characteristics of the mutant gene were that plant height was about a quarter of normal height, grain size about a quarter of normal size, leaf was short and broad, and seed setting rate was very low, compared with the near isogenic line Shuhui 162. The mutant gene was sensitive to gibberellin (GA_3) treatment and did not located on the region near the centromere of rice chromosome 5, where dl gene located. Therefore, it was concluded that the mutant gene of 162d was a new small grain dwarf gene in rice.
文摘The grain-filling characteristics of six rice varieties (combinations) and the relationships between their relative biochemistry composition during phytate synthesizing and grain plumpness were studied. Regarding results for ISHR1, ISHR2, R198 and JW21, with good grain plumpness, the two-step-filling in superior spikelets and inferior spikelets was not clear, while for ISHR3 and 559, with poor grain plumpness, it was very clear. From booting stage to flowering stage, the contents of phytate and inositol in varieties with good grain plumpness was obviously higher than those in varieties with poor grain plumpness. While at grain filling stage, the content of inorganic phosphorus in varieties with poor grain plumpness was obviously higher than that in varieties with good grain plumpness. The contents of phytate and inositol from booting stage to flowering stage was highly significantly correlated with the initial filling power (R_0), the mean filling rate (R_M) and grain filling percentage (P_(GF)), and the content of inorganic phosphorus at grain filling stage was negatively significantly correlated with R_0, F_M and P_(GF). Furthermore, effective approach to improving grain filling was put forward.
文摘Rice variety Yuexiangzhan and its mutants induced by high pressure were studied using microsatcllite markers and soluble protein content analyses. Eleven of the 88 microsatellite primer pairs showed evident polymorphisms repeatedly, and the polymorphic frequencies were 3.4-11.3% between the mutants and Yuexiangzhan. The polymorphic markers were randomly located on chromosomes. The more similar the plant types of the mutants like their original variety, the less polymorphic loci were detected. In addition, there was variation in the soluble protein contents among the leaves of mutants, and the contents were significantly lower than those of the original variety.
基金supported by Important and Kev Project of the National Natural Science Foun—dation of China(39893350 and 30040025)Key Project of Natural Science Fund of Guangdong Province(020384).
文摘The study used Waixuan35, a blast resistant rice material adopted widely previously in South China, Yuexiangzhan, a rice variety with the largest planting area in Guangdong Province at present and with the characteristics of horizontal blast resistance and high harvest index, and Qisizhan, the earliest good eating quality variety in Guangdong Province as parent materials, and created an important material systems for studying agricultural characters such as rice blast resistance genes, their resistance mechanisms and quality by hybridization offspring single grain transfer method and DNA hybridization method, namely recombination inbred line RIL, extend recombination inbred line ERIL and transferred-mutant recombination inbred line TRIL assemblages. In RIL assemblage, various materials of resistance gene combinations for identifying rice blast pathogen strains had been identified from the material system, providing direct material evidence for gene to gene theory. Using the same control and same method, in ERIL assemblage, it was proved that there were several main resistance genes and several minor resistance genes in horizontal resistant Yuexiangzhan, providing preliminary evidences for multigene control in horizontal resistance. A set of stable material assemblage for studying future horizontal resistance had been created. A mutation material of Yuexiangzhan from horizontal resistance to vertical resistance was obtained by wild rice external DNA electric stimulation introduction, and variation in mutation assemblage was certified by SSLP. These studies and materials provided important new materials for studying rice blast resistance mechanisms, gene cloning, resistance genes especially horizontal resistance.
基金This work was supported by the National 863 Program of China(2001AA211191)the Natural Science Foundation of Guangdong Provice,China(990501)100 Scientific Innovation Projects of Guangdong Province,China.(2KB64804N).
文摘The morphological characters of the newly released super hybrid rice in South China, Yueza 122, Fengyou 428, Peiza 67, and super conventional varieties, Guangchao 3, Shengtai 1 at the active tillering stage in both early and late crops were investigated. Using the analysis of variance and other statistic methods, the ideal morphological characteristics of South China double cropping super-rice at the active tillering stage were determined. They are 55-60 cm in the early crop and 60-76 cm in the late crop for the ideal plant height, about 15 tillers in the early crop and 14-19 tillers in the late crop for the ideal tiller number per plant, 40-44 cm in the early crop and 42-60 cm in the late crop for the ideal length of the first leaf under the top leaf, 1.2-1.4 cm in the early crop and 1.2-1.3cm in the late crop for the ideal width of the first leaf under the top leaf, 39- 44 cm in the early crop and 37-43 cm in the late crop for the ideal length of the second leaf under the top leaf, 1.1-1.4 cm in the early crop and about 1.1 cm in the late crop for the ideal width of the second leaf under the top leaf, 22-58o in the early crop and 4- 12o in the late crop for the ideal top leaf angle at the active tillering stage. Based on these results, a new concept of “dynamic plant type structure” for South China double cropping super rice breeding was suggested.
文摘A spontaneously occurring rice (Oryza sativa L.) mutant, characterized by homeotic conversionin glumes and stamens, was found in the progeny of a cross. The mutant showed long glumes andglumaceous lodicules and morphological transformation of stamens into pistils. Mutant floretsconsisted of 1 to 3 completely developed pistils, some pistilloid stamens with filaments, buttipped by bulged tissue and 0 to 3 stigmas. It seems that the mutant phenotype of the homeoticconversions in glumes and stamens is similar to that of the B loss-of-function mutants inArabidopsis and Antirrhinum. The mutant is controlled by a single recessive gene as asegregation ratio of 3:1 (wild type to mutant plants) was observed in the F2 generation.
文摘Located in the subtropical zone of South China, Guangdong Province is rich in wild rice genmplasm. The 3 wild rice species, being indigenous to China, O. rufipogon Criff, O. officinalis Wall and O. meyeriana Baill are dispersed over the province. About 1,354 habitats of wild taxa have been found scattering over 71 counties in the province ( see table ).
文摘A spontaneous white panicle mutant was found from the F6 progenies of an indica/japonica cross. The mu-tant exhibits white stripes on its basal leaves while the pani-cles, rachis and pedicel are milky white colored at flowering stage. Genetic analysis in an F2 population from the cross of Zhi7/white panicle mutant indicates that the white panicle phenotype is controlled by a single recessive nuclear gene, tentatively termed as wp(t). Using microsatellite markers, the wp(t) gene was anchored between the markers of SSR101 and SSR63.9 with a map distance of 2.3 and 0.8 cM, respec-tively, and co-segregated with the marker of SSR17 on rice chromosome 1.
文摘A rice mutant, G069, characteristic of few tiller numbers, was found in anther culture progeny from the F1 hybrid between an indica-japonica cross, Gui630×02428. The mutant has another two major features: delayed tillering development and yellowing apex and margin on the mature leaves. As a donor parent, G069 was further backcrossed with the recurrent parent, 02428, for two turns to develop a BC2F2 population. Genetic analysis in the BC2F2 population showed that the traits of few-tillering and yellowing apex and margin on the mature leaves were controlled by one recessive gene. A pool of equally mixed genomic DNA, from few-tillering individual plants in BC2F2, was constructed to screen polymorphism with simple sequence repeat (SSR) markers in comparison with the 02428 genome. One SSR marker and three restriction fragment length polymorphism (RFLP) markers were found possibly linked with the recessive gene. By using these markers, the gene of few-tillering was mapped on chromosome 2 between RFLP marker C424 and S13984 with a genetic distance of 2.4 cM and 0.6 cM, respectively. The gene is designated ft1.
基金This work was supported by the State High Technology Research and Development Project(Grant No.2001AA21108101).
文摘We have analyzed a lax mutant that exhibits altered panicle architecture in rice. The primary and secondary rachis-branches are normally initiated and each branch ends in a terminal spikelet, but all the lateral spikelets are absent and the terminal spikelet displays variegated structures in the mutant. An F2 population from the cross between the lax mutant and a japonica variety, W11, was constructed and analyzed. Using microsatellite and CAPS markers, the lax locus was mapped on the long arm of chromosome 1, co-segregated with a CAPS marker, LZ1, within an interval of 0.28 cM between a CAPS marker, HB2, and a microsatellite marker, MRG4389. RT-PCR analysis revealed that the expressions of the rice B-function MADS-box genes OsMADS2, OsMADS4, OsMADS16 and OsMADS3 were significantly reduced, whereas the expression of the rice A-function gene RAP1A was not altered.
