Six characteristics, i.e., hull color, chaff and leaf pubescences, length of 1st and 2nd rachis, grain length/width ratio andphenol reaction, of rice progenies from indica and japonica crossing were studied using the ...Six characteristics, i.e., hull color, chaff and leaf pubescences, length of 1st and 2nd rachis, grain length/width ratio andphenol reaction, of rice progenies from indica and japonica crossing were studied using the Chengs index classificationmethod. The results indicated that F1 generations performed more like indica, while F2 generations were approximately ina normal distribution. Both of the rice progenies were more affected by indica and female parents than by japonica andmale parents. Among the six Chengs index traits of the parents and F1 generations, and between the traits and Chengsindexes, significant correlations (both at a=0.05 and a=0.01) were found in most cases. No significant correlations werefound among the 6 Chengs index traits of F2 generations in most cases, but significant correlations (a=0.01) existedbetween these traits and Chengs indexes. The six Chengs index traits of F2 ranged successively, and many individualsshowed over-parent genetics, with the same trends in both direct cross and reciprocal cross. Among the 6 index traits,chaff and leaf pubescences almost presented in a two-peak value, while the others in a mono-peak value. The hull color,phenol reaction and length of 1st and 2nd rachis were distributed in deviation, with the first two traits presented more injaponica individuals and the last trait more in indica. The grain length/width ratios were nearly in a normal distribution.展开更多
Comparison of seed setting rate, plant height and Cheng's morphological traits were made between the F_2 progeny of indica-japonica hybrids, 02428/Pei'ai 64 and Taichung 65/Teqing. There existed resemblance no...Comparison of seed setting rate, plant height and Cheng's morphological traits were made between the F_2 progeny of indica-japonica hybrids, 02428/Pei'ai 64 and Taichung 65/Teqing. There existed resemblance normal distribution in plant height, and the distribution had no relationship with the seed setting rate and plant height in F_1 progeny, suggesting that there were no gametic selection for the plant height in the F_2 progeny of indica-japoniea hybrids. An average seed setting rate of the F_2 was equal to the F_1 populations in the recombination of 02428/Pei'ai 64 in which there was an excellent cross compatibility, but the remarkable increase in the seed setting rate from the F_1 to F_2 in Taichung 65/Teqing, indicating that gametic selection only took place in the indica-japonica crosses with low cross compatibility while null or little in the hybrids with high compatibility. There were many intermediate types among the leaf pubescence, color of hull at heading, and length of the first and second panicle internode, and these Cheng's morphological traits was distributed normally; there were also a little intermediate types in hull hairness and phenol reaction with bi-peak distribution; while length to width ratio of grain was inclined to the japonica types obviously showing a skewed distribution in the F2 population. Although Cheng's morphological traits in F_2 populations had inconsistent distribution types, Cheng's morphological traits index showed normal distribution, which suggested that intermediate types, i.e. indicalinous or japonicalinous, were primary in F_2 population.展开更多
New indica and japonica hybrid rice cultivars,such as the Yongyou series,provide farmers with very high yield potential.However,information on their canopy light capture and solar radiation use efficiency in the late ...New indica and japonica hybrid rice cultivars,such as the Yongyou series,provide farmers with very high yield potential.However,information on their canopy light capture and solar radiation use efficiency in the late season is limited.Field experiments were performed to compare the radiation-use parameters of four rice types:indica rice(IR),inbred japonica rice(IJR),hybrid japonica rice(HJR),and hybrid indica/japonica rice(HIJR),from 2016 to 2018 during the late season in Hangzhou,China.The grain yield,aboveground biomass,intercepted solar radiation(SI),and radiation-use efficiency(RUE)of the HIJR were on average respectively 13.4%–53.4%,14.3%–30.6%,7.6%–21.4%,and 8.2%–14.9%higher than those of the HJR,IJR,and IR.The leaf area index(LAI)of the HIJR was 18.2%–57.0%greater than that of the IJR and HJR at four growth stages,resulting in respectively 17.8%–38.5%and 10.7%–42.8%greater canopy light interception rates(LIR)and amount of intercepted solar radiation during the vegetative stage.The prolonged grain-filling stage also led to respectively 33.9%–52.6%and 30.5%–51.4%increases in amounts of incident and intercepted radiation for the HIJR relative to the IR during grain filling.These results indicate that the SI superiority of the HIJR was caused by canopy closure as rapid as that of the IR during the vegetative stage(greater LAI and canopy LIR during the growing season)and a grain-filling stage as long as that of the HJR.For grain-filling stage,differences in leaf Pn between HIJR,IR,and IJR were not significant,suggesting that the greater RUE of the HIJR(12.7%–52.8%higher)than that of the other rice types resulted from improved canopy architecture after flowering(FL).Principal components analysis(PCA)revealed that the superiority of the HIJR in terms of solar radiation use resulted from the greater canopy light capture capability of IR and the prolonged growth period(especially during grain filling)of japonica rice in the late growing season.展开更多
The size of the top three leaves of rice plants is strongly associated with yield; thus, it is important to consider quantitative traits representing leaf size （e.g., length and width） when breeding novel rice varie...The size of the top three leaves of rice plants is strongly associated with yield; thus, it is important to consider quantitative traits representing leaf size （e.g., length and width） when breeding novel rice varieties. It is challenging to measure such traits on a large scale in the field, and little is known about the genetic factors that determine the size of the top three leaves. In the present study, a population of recombinant inbred lines （RILs） and reciprocal single chromosomal segment substitution lines （SSSLs） derived from the progeny of a japonica Asominori x indica IR24 cross were grown under four diverse environmental conditions. Six morphological traits associated with leaf size were measured,namely length and width of the flag, second and third leaves. In the RIL population, 49 QTLs were identified that clustered in 30 genomic region. Twenty-three of these QTLs were confirmed in the SSSL population. A comparison with previously reported genes/QTLs revealed eight novel genomic regions that contained uncharacterized ORFs associated with leaf size. The QTLs identified in this study can be used for marker- assisted breeding and for fine mapping of novel genetic elements controlling leaf size in rice.展开更多
基金financed by the National Natural science Foundation of China(30370866)863 Program of China
文摘Six characteristics, i.e., hull color, chaff and leaf pubescences, length of 1st and 2nd rachis, grain length/width ratio andphenol reaction, of rice progenies from indica and japonica crossing were studied using the Chengs index classificationmethod. The results indicated that F1 generations performed more like indica, while F2 generations were approximately ina normal distribution. Both of the rice progenies were more affected by indica and female parents than by japonica andmale parents. Among the six Chengs index traits of the parents and F1 generations, and between the traits and Chengsindexes, significant correlations (both at a=0.05 and a=0.01) were found in most cases. No significant correlations werefound among the 6 Chengs index traits of F2 generations in most cases, but significant correlations (a=0.01) existedbetween these traits and Chengs indexes. The six Chengs index traits of F2 ranged successively, and many individualsshowed over-parent genetics, with the same trends in both direct cross and reciprocal cross. Among the 6 index traits,chaff and leaf pubescences almost presented in a two-peak value, while the others in a mono-peak value. The hull color,phenol reaction and length of 1st and 2nd rachis were distributed in deviation, with the first two traits presented more injaponica individuals and the last trait more in indica. The grain length/width ratios were nearly in a normal distribution.
文摘Comparison of seed setting rate, plant height and Cheng's morphological traits were made between the F_2 progeny of indica-japonica hybrids, 02428/Pei'ai 64 and Taichung 65/Teqing. There existed resemblance normal distribution in plant height, and the distribution had no relationship with the seed setting rate and plant height in F_1 progeny, suggesting that there were no gametic selection for the plant height in the F_2 progeny of indica-japoniea hybrids. An average seed setting rate of the F_2 was equal to the F_1 populations in the recombination of 02428/Pei'ai 64 in which there was an excellent cross compatibility, but the remarkable increase in the seed setting rate from the F_1 to F_2 in Taichung 65/Teqing, indicating that gametic selection only took place in the indica-japonica crosses with low cross compatibility while null or little in the hybrids with high compatibility. There were many intermediate types among the leaf pubescence, color of hull at heading, and length of the first and second panicle internode, and these Cheng's morphological traits was distributed normally; there were also a little intermediate types in hull hairness and phenol reaction with bi-peak distribution; while length to width ratio of grain was inclined to the japonica types obviously showing a skewed distribution in the F2 population. Although Cheng's morphological traits in F_2 populations had inconsistent distribution types, Cheng's morphological traits index showed normal distribution, which suggested that intermediate types, i.e. indicalinous or japonicalinous, were primary in F_2 population.
基金This research was supported in part by grants from the National Key Research and Development Program of China(2016YFD0300108,2016YFD0300208-02)the National Natural Science Foundation of China(31671638)+1 种基金the China Agriculture Research System(CARS-01-04A)Central Public Interest Scientific Institution Basal Research Fund(2017RG004-1).
文摘New indica and japonica hybrid rice cultivars,such as the Yongyou series,provide farmers with very high yield potential.However,information on their canopy light capture and solar radiation use efficiency in the late season is limited.Field experiments were performed to compare the radiation-use parameters of four rice types:indica rice(IR),inbred japonica rice(IJR),hybrid japonica rice(HJR),and hybrid indica/japonica rice(HIJR),from 2016 to 2018 during the late season in Hangzhou,China.The grain yield,aboveground biomass,intercepted solar radiation(SI),and radiation-use efficiency(RUE)of the HIJR were on average respectively 13.4%–53.4%,14.3%–30.6%,7.6%–21.4%,and 8.2%–14.9%higher than those of the HJR,IJR,and IR.The leaf area index(LAI)of the HIJR was 18.2%–57.0%greater than that of the IJR and HJR at four growth stages,resulting in respectively 17.8%–38.5%and 10.7%–42.8%greater canopy light interception rates(LIR)and amount of intercepted solar radiation during the vegetative stage.The prolonged grain-filling stage also led to respectively 33.9%–52.6%and 30.5%–51.4%increases in amounts of incident and intercepted radiation for the HIJR relative to the IR during grain filling.These results indicate that the SI superiority of the HIJR was caused by canopy closure as rapid as that of the IR during the vegetative stage(greater LAI and canopy LIR during the growing season)and a grain-filling stage as long as that of the HJR.For grain-filling stage,differences in leaf Pn between HIJR,IR,and IJR were not significant,suggesting that the greater RUE of the HIJR(12.7%–52.8%higher)than that of the other rice types resulted from improved canopy architecture after flowering(FL).Principal components analysis(PCA)revealed that the superiority of the HIJR in terms of solar radiation use resulted from the greater canopy light capture capability of IR and the prolonged growth period(especially during grain filling)of japonica rice in the late growing season.
基金supported by the National Natural Science Foundation of China(31471174,and 31271798)
文摘The size of the top three leaves of rice plants is strongly associated with yield; thus, it is important to consider quantitative traits representing leaf size （e.g., length and width） when breeding novel rice varieties. It is challenging to measure such traits on a large scale in the field, and little is known about the genetic factors that determine the size of the top three leaves. In the present study, a population of recombinant inbred lines （RILs） and reciprocal single chromosomal segment substitution lines （SSSLs） derived from the progeny of a japonica Asominori x indica IR24 cross were grown under four diverse environmental conditions. Six morphological traits associated with leaf size were measured,namely length and width of the flag, second and third leaves. In the RIL population, 49 QTLs were identified that clustered in 30 genomic region. Twenty-three of these QTLs were confirmed in the SSSL population. A comparison with previously reported genes/QTLs revealed eight novel genomic regions that contained uncharacterized ORFs associated with leaf size. The QTLs identified in this study can be used for marker- assisted breeding and for fine mapping of novel genetic elements controlling leaf size in rice.
