Allelic diversity for five genetic loci (DL, FON4, OsMADS24, OsMADS45 and Spw1) associated with floral organ development were investigated among a small heterogeneous rice population which included one wild species (O...Allelic diversity for five genetic loci (DL, FON4, OsMADS24, OsMADS45 and Spw1) associated with floral organ development were investigated among a small heterogeneous rice population which included one wild species (O. rufipogon Griffiths), one indigenous less popular natural floral organ mutant (O. sativa var. indica cv. Jugal), one indigenous normal line (O. sativa var. indica cv. Bhutmoori) and one improved high yielding line (O. sativa var. indica cv. IR 36). Detailed spikelet morphology showed that var. Jugal had variable number (1 - 3) of carpels within a single spikelet which was unique and resulted in variable (1 - 3) number of kernels within a single matured spikelet (grain). The genomic DNA of each investigated line was amplified with primer sequences designed from the selected genetic loci and the derived polymorphism profiles were used for study of allelic diversity for the studied loci. The derived genetic distances among the rice lines were used for dendrogram construction. In constructed dendrogram, the mutant genotype (Jugal) showed highest similarity with the wild rice (O. rufipogon) instead of the rice lines. To verify this finding, the genomic DNA of each studied line was also amplified with four SSR loci, tightly linked to saltol QTL, mapped to rice chromosome 1. The amplified products were screened for polymorphism and another dendrogram was constructed to reveal the genetic distance among the lines for selected salt tolerance linked SSR loci. In SSR derived dendrogram, the wild rice (O. rufipogon) got totally separated from the all three rice genotypes though all the studied four lines showed equal sensitivity for salt sensitivity in a physiological screening experiment. From the combined experiment, it can be concluded that genetic architecture of floral organ development loci in var. Jugal may have some uniqueness which is not present in normal rice but common to O. rufipogon, a species which is regarded as immediate progenitor of present day modern rice (O. sativa). Though this uniqueness was not confirmed by second set genetic loci associated with salt tolerance in rice, the information resulted from this experiment was preliminary and based only on allelic size (molecular weight of amplicon), which should be confirmed through sequence analysis for further analysis.展开更多
In the present study a group of four indigenous and less popular rice genotypes (Meghi, Panibhasha, Jabra and Sholey) reported by growers as submergence tolerant lines from flood prone areas of south Bengal were explo...In the present study a group of four indigenous and less popular rice genotypes (Meghi, Panibhasha, Jabra and Sholey) reported by growers as submergence tolerant lines from flood prone areas of south Bengal were explored through study of nodal anatomy, physio-biochemical screening under submergence and genotyping with submergence tolerance linked rice microsatellite loci (RM loci). To identify the different allelic forms of different Sub1 compnents (Sub1A, Sub1B and Sub1C) among the studied lines, the genomic DNA of individual genotypes was amplified with three ethylene response factor like genes from Sub1 loci, located on rice chromosome 9. From the different physio-biochemical experiments performed in this investigation, it has been shown that Meghi and Jabra are the two probable potent genotypes which share common properties of both submergence tolerant and deep water nature whereas rest two genotypes (Sholey and Panibhasha) behave like typical deep water rice. The submergence tolerance property of Meghi was also confirmed from submergence tolerance linked SSR based genotyping by sharing with FR13A for some common alleles as reflected in fingerprint derived dendrogram. The rest of the genotypes shared a number of alleles and were included in a separate cluster. The common behaviour of Meghi and FR13A under submergence was also confirmed from genetic study of Sub1 loci through sharing of some common alleles for three Sub1 components (Sub1A, Sub1B and Sub1C loci). One SSR loci (RM 285) was identified as a potent molecular marker for submergence tolerance breeding programme involving these two selected rice lines (Meghi and Jabra) as donor plant through marker assisted selection.展开更多
文摘Allelic diversity for five genetic loci (DL, FON4, OsMADS24, OsMADS45 and Spw1) associated with floral organ development were investigated among a small heterogeneous rice population which included one wild species (O. rufipogon Griffiths), one indigenous less popular natural floral organ mutant (O. sativa var. indica cv. Jugal), one indigenous normal line (O. sativa var. indica cv. Bhutmoori) and one improved high yielding line (O. sativa var. indica cv. IR 36). Detailed spikelet morphology showed that var. Jugal had variable number (1 - 3) of carpels within a single spikelet which was unique and resulted in variable (1 - 3) number of kernels within a single matured spikelet (grain). The genomic DNA of each investigated line was amplified with primer sequences designed from the selected genetic loci and the derived polymorphism profiles were used for study of allelic diversity for the studied loci. The derived genetic distances among the rice lines were used for dendrogram construction. In constructed dendrogram, the mutant genotype (Jugal) showed highest similarity with the wild rice (O. rufipogon) instead of the rice lines. To verify this finding, the genomic DNA of each studied line was also amplified with four SSR loci, tightly linked to saltol QTL, mapped to rice chromosome 1. The amplified products were screened for polymorphism and another dendrogram was constructed to reveal the genetic distance among the lines for selected salt tolerance linked SSR loci. In SSR derived dendrogram, the wild rice (O. rufipogon) got totally separated from the all three rice genotypes though all the studied four lines showed equal sensitivity for salt sensitivity in a physiological screening experiment. From the combined experiment, it can be concluded that genetic architecture of floral organ development loci in var. Jugal may have some uniqueness which is not present in normal rice but common to O. rufipogon, a species which is regarded as immediate progenitor of present day modern rice (O. sativa). Though this uniqueness was not confirmed by second set genetic loci associated with salt tolerance in rice, the information resulted from this experiment was preliminary and based only on allelic size (molecular weight of amplicon), which should be confirmed through sequence analysis for further analysis.
文摘In the present study a group of four indigenous and less popular rice genotypes (Meghi, Panibhasha, Jabra and Sholey) reported by growers as submergence tolerant lines from flood prone areas of south Bengal were explored through study of nodal anatomy, physio-biochemical screening under submergence and genotyping with submergence tolerance linked rice microsatellite loci (RM loci). To identify the different allelic forms of different Sub1 compnents (Sub1A, Sub1B and Sub1C) among the studied lines, the genomic DNA of individual genotypes was amplified with three ethylene response factor like genes from Sub1 loci, located on rice chromosome 9. From the different physio-biochemical experiments performed in this investigation, it has been shown that Meghi and Jabra are the two probable potent genotypes which share common properties of both submergence tolerant and deep water nature whereas rest two genotypes (Sholey and Panibhasha) behave like typical deep water rice. The submergence tolerance property of Meghi was also confirmed from submergence tolerance linked SSR based genotyping by sharing with FR13A for some common alleles as reflected in fingerprint derived dendrogram. The rest of the genotypes shared a number of alleles and were included in a separate cluster. The common behaviour of Meghi and FR13A under submergence was also confirmed from genetic study of Sub1 loci through sharing of some common alleles for three Sub1 components (Sub1A, Sub1B and Sub1C loci). One SSR loci (RM 285) was identified as a potent molecular marker for submergence tolerance breeding programme involving these two selected rice lines (Meghi and Jabra) as donor plant through marker assisted selection.
