China＇s Super Hybrid Rice Breeding Program has made significant progress over the past two decades. In this paper, we reviewed our studies on the yield potential and stability in super hybrid rice and discussed the s...China＇s Super Hybrid Rice Breeding Program has made significant progress over the past two decades. In this paper, we reviewed our studies on the yield potential and stability in super hybrid rice and discussed the strategies for super hybrid rice production. The results of our studies show that rice yield potential has been increased by 12% in super hybrid cultivars as compared with ordinary hybrid and inbred cultivars. The higher grain yields in super hybrid rice cultivars are attributed to larger panicle size coupled with higher biomass production or higher harvest index. However, grain yields in super hybrid rice cultivars vary widely among locations depending on soil and climatic factors. Therefore, it is important to tailor target yield to local conditions in super hybrid rice production. The target yield for super hybrid rice production can be determined by the average yield method or the regression model method. Improving soil quality is critical to achieving the target yield in super hybrid rice production. Favorable crop rotations such as rice-oilseed rape and novel soil management practices, such as biochar addition, are effective approaches to improve soil quality. It is needed to develop simplified cultivation tech- nologies for super hybrid rice to meet the changes in socioeconomic environments during the period of transition. There are such technologies as no-tillage direct seeding and mechanized transplanting at high hill density with single seedling per hill.展开更多
A field experiment was carried out in Cd-contaminated rice fields in a county of Hengyang to explore the effects of different types of remediation agents on the contents of soil available Cd and rice Cd,and rice yield...A field experiment was carried out in Cd-contaminated rice fields in a county of Hengyang to explore the effects of different types of remediation agents on the contents of soil available Cd and rice Cd,and rice yield by using one rice variety Longliangyouhuazhan,and 4 kinds of remediation agents:DG foliar control agent,SMA microbial inoculant,XFJ organic fertilizer and LXM calcium-and silicon-based passivator as test materials.The results showed that compared with CK,after applying DG foliar control agent,soil available Cd content increased rather than decreased,whereas rice Cd content decreased,not reaching a significant level.When applied with SMA microbial inoculant,soil pH value,soil available Cd and rice Cd contents showed a downward then upward trend with the increase of its application rates.Between 3 levels of SMA treatments,the content of soil available Cd in SMA2 was the lowest,decreased by 8.59%in comparison with CK,contrarily,two other SMA treatments were increasing instead of decreasing in the content of soil available Cd.The application of XFJ organic fertilizer and LXM calcium-and silicon-based passivator increased soil pH value,and reduced soil available Cd and rice Cd contents;the contents of soil available Cd and rice Cd decreased with their application rates increasing.Compared with CK,XFJ3 reduced soil available Cd content by 9.40%,and significantly reduced rice Cd content by 57.28%.In LXM3 treatment,soil available Cd content reduced by 14.57%,rice Cd content was 71.57%lower than CK,reaching the lowest level.In general,LXM calcium-and silicon-based passivator had the best Cd reduction effect,with the optimal application amount of 6000 kg/hm^(2).展开更多
基金supported by the Earmarked Fund for China Agriculture Research System(CARS-01)
文摘China＇s Super Hybrid Rice Breeding Program has made significant progress over the past two decades. In this paper, we reviewed our studies on the yield potential and stability in super hybrid rice and discussed the strategies for super hybrid rice production. The results of our studies show that rice yield potential has been increased by 12% in super hybrid cultivars as compared with ordinary hybrid and inbred cultivars. The higher grain yields in super hybrid rice cultivars are attributed to larger panicle size coupled with higher biomass production or higher harvest index. However, grain yields in super hybrid rice cultivars vary widely among locations depending on soil and climatic factors. Therefore, it is important to tailor target yield to local conditions in super hybrid rice production. The target yield for super hybrid rice production can be determined by the average yield method or the regression model method. Improving soil quality is critical to achieving the target yield in super hybrid rice production. Favorable crop rotations such as rice-oilseed rape and novel soil management practices, such as biochar addition, are effective approaches to improve soil quality. It is needed to develop simplified cultivation tech- nologies for super hybrid rice to meet the changes in socioeconomic environments during the period of transition. There are such technologies as no-tillage direct seeding and mechanized transplanting at high hill density with single seedling per hill.
文摘A field experiment was carried out in Cd-contaminated rice fields in a county of Hengyang to explore the effects of different types of remediation agents on the contents of soil available Cd and rice Cd,and rice yield by using one rice variety Longliangyouhuazhan,and 4 kinds of remediation agents:DG foliar control agent,SMA microbial inoculant,XFJ organic fertilizer and LXM calcium-and silicon-based passivator as test materials.The results showed that compared with CK,after applying DG foliar control agent,soil available Cd content increased rather than decreased,whereas rice Cd content decreased,not reaching a significant level.When applied with SMA microbial inoculant,soil pH value,soil available Cd and rice Cd contents showed a downward then upward trend with the increase of its application rates.Between 3 levels of SMA treatments,the content of soil available Cd in SMA2 was the lowest,decreased by 8.59%in comparison with CK,contrarily,two other SMA treatments were increasing instead of decreasing in the content of soil available Cd.The application of XFJ organic fertilizer and LXM calcium-and silicon-based passivator increased soil pH value,and reduced soil available Cd and rice Cd contents;the contents of soil available Cd and rice Cd decreased with their application rates increasing.Compared with CK,XFJ3 reduced soil available Cd content by 9.40%,and significantly reduced rice Cd content by 57.28%.In LXM3 treatment,soil available Cd content reduced by 14.57%,rice Cd content was 71.57%lower than CK,reaching the lowest level.In general,LXM calcium-and silicon-based passivator had the best Cd reduction effect,with the optimal application amount of 6000 kg/hm^(2).
