Genetic segregation analysis for flag leaf angle was conducted using six generations of P1, P2, F1, B1, B2 and F2 derived from a cross of 863B （a maintainer line of japonica rice） and A7444 （a germplasm with large ...Genetic segregation analysis for flag leaf angle was conducted using six generations of P1, P2, F1, B1, B2 and F2 derived from a cross of 863B （a maintainer line of japonica rice） and A7444 （a germplasm with large flag leaf angle）. Genotypes and phenotypes of flag leaf angle were investigated in 863B （P1）, A7444 （P2） and 141 plants in BC^F~ （863BIA744411863B） population. An SSR genetic linkage map was constructed and QTLs for flag leaf angle were detected. The genetic map containing 79 information loci was constructed, which covers a total distance of 441.6 cM, averaging 5.6 cM between two neighboring loci. Results showed that the trait was controlled by two major genes plus polygene and the major genes were more important. Fifteen markers showed highly significant correlations with flag leaf angle based on single marker regression analysis. Two QTLs （qFLA2 and qFLA8） for flag leaf angle were detected by both composite interval method in software WinQTLCart 2.5 and composite interval method based on mixed linear model in QTL Network 2.0. The qFLA2 explained 10.50% and 13.28% of phenotypic variation, respectively, and was located at the interval of RM300 and RM145 on the short arm of chromosome 2. The qFLA8 explained 9.59% and 7.64% of phenotypic variation, respectively, and was located at the interval flanking RM6215 and RM8265 on the long arm of chromosome 8. The positive alleles at the two QTLs were both contributed from A7444.展开更多
The Arctic is highly sensitive to climate change,and the rise in its near-surface air temperatures has been almost twice the global average.The increased growth of the Arctic tundra and its changing seasonality have b...The Arctic is highly sensitive to climate change,and the rise in its near-surface air temperatures has been almost twice the global average.The increased growth of the Arctic tundra and its changing seasonality have been observed,largely in response to the impacts of climate change.In this study,we investigated the temporal and spatial variations of the start of the growing season(SOS)using various remote sensing indices,including Normalized Difference Vegetation Index,Normalized Difference Water Index,and Normalized Difference Snow Index from 2000 to 2018 in Arctic tundra regions.The SOS was derived at 29 sites from ground observations,including CO2 flux data,phenological images,and field records that were used to validate the SOS from remote sensing indices.Our results revealed that the SOS was delayed by approximately 3.86 days per degree of latitude along the northward latitudinal gradient.From 2000 to 2018,the start of the growing season and the interannual variability differed greatly among tundra types.Although the overall trends were not significant from 2000 to 2018,the start of the growing season in different plant communities was consistently delayed after 2016.High Arctic vegetation,including(1)low wetland complexes(5–10 cm)dominated by sedges,grasses,and mosses,and(2)slightly higher prostrate and hemi-prostrate shrubs(<15 cm),experienced a delayed start of the growing season.The start of the growing season of Low Arctic vegetation,comprising(1)wetland complexes(10–40 cm)dominated by sedges,grasses,mosses,and dwarf shrubs,(2)moist tundra(20–50 cm)dominated by tussock cottongrass and dwarf shrubs,and(3)transition zones containing tundra and taiga,displayed no obvious trend.展开更多
基金supported by the National High Technology Research and Development Program of China(Grant No. 2010AA101300)the Platform Construction for Science and Technology Basic Condition from Science and Technology Ministry,China (Grant No.505005)
文摘Genetic segregation analysis for flag leaf angle was conducted using six generations of P1, P2, F1, B1, B2 and F2 derived from a cross of 863B （a maintainer line of japonica rice） and A7444 （a germplasm with large flag leaf angle）. Genotypes and phenotypes of flag leaf angle were investigated in 863B （P1）, A7444 （P2） and 141 plants in BC^F~ （863BIA744411863B） population. An SSR genetic linkage map was constructed and QTLs for flag leaf angle were detected. The genetic map containing 79 information loci was constructed, which covers a total distance of 441.6 cM, averaging 5.6 cM between two neighboring loci. Results showed that the trait was controlled by two major genes plus polygene and the major genes were more important. Fifteen markers showed highly significant correlations with flag leaf angle based on single marker regression analysis. Two QTLs （qFLA2 and qFLA8） for flag leaf angle were detected by both composite interval method in software WinQTLCart 2.5 and composite interval method based on mixed linear model in QTL Network 2.0. The qFLA2 explained 10.50% and 13.28% of phenotypic variation, respectively, and was located at the interval of RM300 and RM145 on the short arm of chromosome 2. The qFLA8 explained 9.59% and 7.64% of phenotypic variation, respectively, and was located at the interval flanking RM6215 and RM8265 on the long arm of chromosome 8. The positive alleles at the two QTLs were both contributed from A7444.
基金supported by the National Natural Science Foundation of China(Grant No.41875107)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19070203)。
文摘The Arctic is highly sensitive to climate change,and the rise in its near-surface air temperatures has been almost twice the global average.The increased growth of the Arctic tundra and its changing seasonality have been observed,largely in response to the impacts of climate change.In this study,we investigated the temporal and spatial variations of the start of the growing season(SOS)using various remote sensing indices,including Normalized Difference Vegetation Index,Normalized Difference Water Index,and Normalized Difference Snow Index from 2000 to 2018 in Arctic tundra regions.The SOS was derived at 29 sites from ground observations,including CO2 flux data,phenological images,and field records that were used to validate the SOS from remote sensing indices.Our results revealed that the SOS was delayed by approximately 3.86 days per degree of latitude along the northward latitudinal gradient.From 2000 to 2018,the start of the growing season and the interannual variability differed greatly among tundra types.Although the overall trends were not significant from 2000 to 2018,the start of the growing season in different plant communities was consistently delayed after 2016.High Arctic vegetation,including(1)low wetland complexes(5–10 cm)dominated by sedges,grasses,and mosses,and(2)slightly higher prostrate and hemi-prostrate shrubs(<15 cm),experienced a delayed start of the growing season.The start of the growing season of Low Arctic vegetation,comprising(1)wetland complexes(10–40 cm)dominated by sedges,grasses,mosses,and dwarf shrubs,(2)moist tundra(20–50 cm)dominated by tussock cottongrass and dwarf shrubs,and(3)transition zones containing tundra and taiga,displayed no obvious trend.
