A pot experiment was performed to learn the differences in plant productivity and OH4 emission between two rice cultivars, super rice variety Ningjing 1 and traditional variety Zhendao 11, which were currently commerc...A pot experiment was performed to learn the differences in plant productivity and OH4 emission between two rice cultivars, super rice variety Ningjing 1 and traditional variety Zhendao 11, which were currently commercially appUed in Nanjing, China. Similar seasonal changes of CH4 emission fluxes and soil solution CH4 contents were found between the tested cultivars. Although there was no significant difference in plant biomass production between the cultivars, the grain yield of Ningjing 1 was significantly higher by 35.0% （P 〈 0.05） than that of Zhendao 11, whereas the total CH4 emission from Ningjing 1 was 35.2% lower （P 〈 0.05）. The main difference in the amounts of CH4 emission between the cultivars occurred in the period from the tillering stage to the heading stage. The biomass-scaled and yield-scaled CH4 emissions were respectively 3.8 and 5.2 mg/g for Ningjing 1, significantly lower than those for Zhendao 11 （7.4 and 12.8 mg/g, respectively）. According to the relationships between the plant growth characteristics and the CH4 emission, a stronger root system contributed mainly to the lower CH4 emission of Ningjing 1, as compared with Zhendao 11. Our results demonstrated that super rice has advantages not only in grain productivity but also in CH4 emission mitigation. Further expansion of super rice cropping will enhance rice yield and reduce greenhouse gas emission in China.展开更多
A large number of new varieties, especially hybrid rice, have been developed and released in China since 1998. The yield potential and grain quality of hybrid rice have also been improved significantly both for three-...A large number of new varieties, especially hybrid rice, have been developed and released in China since 1998. The yield potential and grain quality of hybrid rice have also been improved significantly both for three-line and two-line hybrid rice including indica and japonica types as well. The trends on extension of rice varieties in China since 1986 has been marked by the increasing number of new varieties, decreasing annual planting area per variety, decreasing number of varieties with a large-scale extension area, while both the renewal rate and the proportion of core varieties with cross-provincial extension have remained unchanged. This current major problems and future goals of rice breeding and extension in China were also discussed.展开更多
The introduction and use of foreign germplasms have played an important role in the improvement of crop varieties in China. Based on published materials and scientist interviews, we collected data on the sown area, mo...The introduction and use of foreign germplasms have played an important role in the improvement of crop varieties in China. Based on published materials and scientist interviews, we collected data on the sown area, morphological characteristics, and pedigree of the popular rice varieties grown in the 15 major rice production provinces and 1 autonomous region in China, from 1982 to 2011. Results showed that China＇s scientists developed the largest number of rice varieties worldwide, and that rice yield potential and grain quality have substantiality improved during the studied period. In contrast, resistance of newly-released varieties to diseases and insect pests has decreased since the 1990s. Germplasms from the Interna- tional Rice Research Institute （IRRI） and from Japan have contributed 16.4 and 11.2% of genetic materials to China＇s rice varieties developed between 1982 and 2011, respectively. While IRRI＇s materials contributed to the improvement of yield potential, growth duration, and blast and bacterial blight resistance, Japanese materials contributed to the improvement of grain quality. Materials from other countries contributed to the improvement of resistance to diseases and insect pests, particularly to rice blast disease, brown planthoppers, white-backed planthoppers, and striped stem borers.展开更多
Rice is a staple food crop in China.Since the 1950’s,many new varieties havebeen used and resulted in great increase ofyield.However there were still some barriersin the nationwide extension of new varietiesdue to th...Rice is a staple food crop in China.Since the 1950’s,many new varieties havebeen used and resulted in great increase ofyield.However there were still some barriersin the nationwide extension of new varietiesdue to the insufficient information about thecharacteristics of varieties.So,it is impor-tant to find ways of determining the potential展开更多
基金supported by the National Key Technology Support Program of China (Grant No. 2011BAD16B14)Youth Science and Technology Innovation Foundation of Nanjing Agricultural University,Nanjing,China (Grant No. KJ2012002)
文摘A pot experiment was performed to learn the differences in plant productivity and OH4 emission between two rice cultivars, super rice variety Ningjing 1 and traditional variety Zhendao 11, which were currently commercially appUed in Nanjing, China. Similar seasonal changes of CH4 emission fluxes and soil solution CH4 contents were found between the tested cultivars. Although there was no significant difference in plant biomass production between the cultivars, the grain yield of Ningjing 1 was significantly higher by 35.0% （P 〈 0.05） than that of Zhendao 11, whereas the total CH4 emission from Ningjing 1 was 35.2% lower （P 〈 0.05）. The main difference in the amounts of CH4 emission between the cultivars occurred in the period from the tillering stage to the heading stage. The biomass-scaled and yield-scaled CH4 emissions were respectively 3.8 and 5.2 mg/g for Ningjing 1, significantly lower than those for Zhendao 11 （7.4 and 12.8 mg/g, respectively）. According to the relationships between the plant growth characteristics and the CH4 emission, a stronger root system contributed mainly to the lower CH4 emission of Ningjing 1, as compared with Zhendao 11. Our results demonstrated that super rice has advantages not only in grain productivity but also in CH4 emission mitigation. Further expansion of super rice cropping will enhance rice yield and reduce greenhouse gas emission in China.
文摘A large number of new varieties, especially hybrid rice, have been developed and released in China since 1998. The yield potential and grain quality of hybrid rice have also been improved significantly both for three-line and two-line hybrid rice including indica and japonica types as well. The trends on extension of rice varieties in China since 1986 has been marked by the increasing number of new varieties, decreasing annual planting area per variety, decreasing number of varieties with a large-scale extension area, while both the renewal rate and the proportion of core varieties with cross-provincial extension have remained unchanged. This current major problems and future goals of rice breeding and extension in China were also discussed.
基金supported by the National Natural Science Foundation of China (71333006)the International Rice Research Institute (IRRI,Ref:DRPC2012-80)+1 种基金the China Scholarship Councilthe International Graduate Exchange Progress of the Beijing Institute of Technology
文摘The introduction and use of foreign germplasms have played an important role in the improvement of crop varieties in China. Based on published materials and scientist interviews, we collected data on the sown area, morphological characteristics, and pedigree of the popular rice varieties grown in the 15 major rice production provinces and 1 autonomous region in China, from 1982 to 2011. Results showed that China＇s scientists developed the largest number of rice varieties worldwide, and that rice yield potential and grain quality have substantiality improved during the studied period. In contrast, resistance of newly-released varieties to diseases and insect pests has decreased since the 1990s. Germplasms from the Interna- tional Rice Research Institute （IRRI） and from Japan have contributed 16.4 and 11.2% of genetic materials to China＇s rice varieties developed between 1982 and 2011, respectively. While IRRI＇s materials contributed to the improvement of yield potential, growth duration, and blast and bacterial blight resistance, Japanese materials contributed to the improvement of grain quality. Materials from other countries contributed to the improvement of resistance to diseases and insect pests, particularly to rice blast disease, brown planthoppers, white-backed planthoppers, and striped stem borers.
文摘Rice is a staple food crop in China.Since the 1950’s,many new varieties havebeen used and resulted in great increase ofyield.However there were still some barriersin the nationwide extension of new varietiesdue to the insufficient information about thecharacteristics of varieties.So,it is impor-tant to find ways of determining the potential
