We genotyped 74 rice germplasms including Tripura＇s local landraces, improved varieties, cultivars and breeding lines and other rice varieties using molecular markers for genetic diversity, drought QTLs, and blast re...We genotyped 74 rice germplasms including Tripura＇s local landraces, improved varieties, cultivars and breeding lines and other rice varieties using molecular markers for genetic diversity, drought QTLs, and blast resistance genes. The number of alleles per locus ranged from 2 to 5 with an average of 2.9. The polymorphic information content value per locus ranged from 0.059（RM537） to 0.755（RM252） with an average of 0.475. Cluster analysis based on 30 simple sequence repeat markers revealed 5 clusters and also indicated the presence of variability within the rice accessions. The drought QTL q DTY2.1 was found in 56.0% of germplasms and q DTY1.1 was detected in only 6.8% of the germplasms. Out of seven rice blast resistance genes screened, only two rice varieties, RCPL-1-82 and Buh Vubuk（Lubuk）, were positive for four blast resistance genes while only Releng possessed two blast resistance genes. Among 74 rice germplasms, only three accessions, Releng, RCPL1-82 and Buh Vubuk（Lubuk）, possessed both drought-related QTLs and blast resistance genes. Overall, the 74 indigenous rice genotypes showed low level of genetic diversity, which is in contrast to high level of genetic diversity among rice varieties in northeast India, where highlights the good farming practice, conservation of germplasms and the limitation of molecular markers employed in this study. The presence of both drought related QTLs and blast resistance genes in some of the germplasms can be useful in future breeding programmes.展开更多
We investigated the correlation of large fires（[300 ha） from 1992 to 2013 within the borders of the Antalya Regional Directorate of Forestry using the Keetch–Byram drought index（KBDI）. Daily KBDI values were calc...We investigated the correlation of large fires（[300 ha） from 1992 to 2013 within the borders of the Antalya Regional Directorate of Forestry using the Keetch–Byram drought index（KBDI）. Daily KBDI values were calculated for each year, and values for the period before the year 2000 differed significantly from those after2000. After 2000（large fires occurred in 2004, 2006, 2007,2008, 2010, and 2013）, when KBDI values increased, the KBDI, but not the number of fires, was inversely correlated with the natural log of the burned area（NLBA）. While there were both high and low KBDI values when the NLBA was small, only high KBDI values were associated with high NLBA values. Particularly for logarithmic values of 4 and higher, KBDI values increased in parallel with increases in NLBA values. On the basis of a Mann–Whitney U test done in addition to a Pearson correlation test, we found that when the burned areas were grouped according to small and large areas, the KBDI could be used to distinguish the two groups. Using a conditional probability analysis, we found that 4th, 5th and 6th class KBDI values may lead to large fires at the 60 % possibility.Similarly, the possibility of large fires greater than the median burned area in any given 6 years was found to be48 %. In addition, while the mean value of KBDI is 390.51 for the period from May to September for these 6 years, it is 359.93 for the other years. Consequently, the area burned also increased as the KBDI classes（Class 0： 0–99, Class 1：100–199, Class 2： 200–299, Class 3： 300–399, Class 4：400–499, Class 5： 500–599, Class 6： 600–699, and Class 7：700–800） increase.展开更多
文摘We genotyped 74 rice germplasms including Tripura＇s local landraces, improved varieties, cultivars and breeding lines and other rice varieties using molecular markers for genetic diversity, drought QTLs, and blast resistance genes. The number of alleles per locus ranged from 2 to 5 with an average of 2.9. The polymorphic information content value per locus ranged from 0.059（RM537） to 0.755（RM252） with an average of 0.475. Cluster analysis based on 30 simple sequence repeat markers revealed 5 clusters and also indicated the presence of variability within the rice accessions. The drought QTL q DTY2.1 was found in 56.0% of germplasms and q DTY1.1 was detected in only 6.8% of the germplasms. Out of seven rice blast resistance genes screened, only two rice varieties, RCPL-1-82 and Buh Vubuk（Lubuk）, were positive for four blast resistance genes while only Releng possessed two blast resistance genes. Among 74 rice germplasms, only three accessions, Releng, RCPL1-82 and Buh Vubuk（Lubuk）, possessed both drought-related QTLs and blast resistance genes. Overall, the 74 indigenous rice genotypes showed low level of genetic diversity, which is in contrast to high level of genetic diversity among rice varieties in northeast India, where highlights the good farming practice, conservation of germplasms and the limitation of molecular markers employed in this study. The presence of both drought related QTLs and blast resistance genes in some of the germplasms can be useful in future breeding programmes.
文摘We investigated the correlation of large fires（[300 ha） from 1992 to 2013 within the borders of the Antalya Regional Directorate of Forestry using the Keetch–Byram drought index（KBDI）. Daily KBDI values were calculated for each year, and values for the period before the year 2000 differed significantly from those after2000. After 2000（large fires occurred in 2004, 2006, 2007,2008, 2010, and 2013）, when KBDI values increased, the KBDI, but not the number of fires, was inversely correlated with the natural log of the burned area（NLBA）. While there were both high and low KBDI values when the NLBA was small, only high KBDI values were associated with high NLBA values. Particularly for logarithmic values of 4 and higher, KBDI values increased in parallel with increases in NLBA values. On the basis of a Mann–Whitney U test done in addition to a Pearson correlation test, we found that when the burned areas were grouped according to small and large areas, the KBDI could be used to distinguish the two groups. Using a conditional probability analysis, we found that 4th, 5th and 6th class KBDI values may lead to large fires at the 60 % possibility.Similarly, the possibility of large fires greater than the median burned area in any given 6 years was found to be48 %. In addition, while the mean value of KBDI is 390.51 for the period from May to September for these 6 years, it is 359.93 for the other years. Consequently, the area burned also increased as the KBDI classes（Class 0： 0–99, Class 1：100–199, Class 2： 200–299, Class 3： 300–399, Class 4：400–499, Class 5： 500–599, Class 6： 600–699, and Class 7：700–800） increase.
