摘要:
China's super hybrid rice breeding project has developed many new cultivars with great yield potential. However, rice yield depends not only on genotype but also on environment. In 2008 and 2009, field experiments were conducted to compare super hybrid rice grown in Changsha (normal-yielding) and Guidong (high-yielding), Hunan Province, China. Eight super hybrid rice cultivars, namely II-you 084, II-youhang 1, D-you 527, Liangyoupeijiu, Nei-2-you 6, Y-liangyou 1, Zhongzheyou 1 and Zhunliangyou 527, were evaluated in each site. Grain yield and some yield attributes were determined for each cultivar. On the average across cultivars, Guidong produced higher grain yield than Changsha by 18% in 2008 and 41% in 2009. The higher grain yields were mainly attributed to a simultaneous increase in sink and source. For the sink, Guidong had both more panicles per m2 and larger panicle size (spikelets per panicle) than Changsha, which resulted in larger sink size (spikelets per m2). For the source, Guidong produced greater biomass than Changsha. Longer growth duration, more tillers (panicles) per m2 and higher biomass per unit tiller height were responsible for the greater biomass production in Guidong. Liangyoupeijiu and Zhunliangyou 527 performed well in both sites. Liangyoupeijiu was characterized by large panicle size, while Zhunliangyou 527 had high spikelet filling percentage and grain weight. Our study suggests that further improvement in both sink and source should be possible in the normal-yielding subtropical environments if new rice cultivars are to be bred by selection for tillering (tiller number and size), and developing cultivars with high spikelet filling percentage and grain weight may also be a feasible approach to achieve high rice yield.
关键词:
crop growth rate;biomass production;hybrid rice;leaf area duration;leaf area index;real-time nitrogen management
摘要:
To compare the grain yield and growth behaviors of hybrid rice, field experiments were conducted in a subtropical environment in Changsha, Hunan Province, China, and in two tropical environments in Gazipur and Habiganj in Bangladesh during 2009 to 2011. Three hybrid rice cultivars were grown under three nitrogen (N) management treatments in each experiment. The results showed that grain yield was significantly affected by locations, N treatments and their interaction but not by cultivars. Changsha produced 8-58% higher grain yields than Bangladesh locations. Sink size (spikelet number per unit land area) was responsible for these yield differences. Larger panicle size (spikelet number per panicle) contributed to greater sink size in Changsha. Aboveground total biomass was greater in Changsha than in Bangladesh locations, whereas harvest index was higher in Bangladesh locations than in Changsha. Crop growth rate (CGR) was greater at Changsha than Bangladesh locations during vegetative phase, while the difference was relatively small and not consistent during the later growth phases. Higher leaf area index and leaf area duration were partly responsible for the greater CGR in Changsha. Real-time N management (RTNM) produced lower grain yields than fixed-time N management in more than half of the experiments. Our study suggested that further improvement in rice yield in the tropical environments similar to those of Bangladesh will depend mainly on the ability to increase panicle size as well as CGR during vegetative phase, and the chlorophyll meter threshold value used in RTNM needs to be modified according to environmental conditions and cultivar characteristics to achieve a desirable grain yield.
摘要:
Super hybrid rice, Liangyoupeijiu was grown in conventional tillage transplanting (CTTP) and no tillage transplanting (NTTP) at a spacing of 20 x 20 cm with one seedling per hill and conventional tillage direct-seeding (CTDS) and no tillage direct seeding (NTDS) at a seeding rate of 22.5 kg/ha to compare the growth and physiological responses during 2011-12, in Changsha, Hunan Province, China. Our results indicated that leaf area index (LAI) was higher at booting stage (BT) in transplanting (TP) and at HD stage in direct seeding method (DS) both CT (conventional tillage system) and NT (no tillage system). Leaf area duration (LAD) was higher in DS both CT and NT. Specific leaf area (SLA) and leaf area ratio (LAR) were higher at early growth stage both TP and DS either CT or NT then gradually decreased with advancement of time. DS produced more above ground biomass than TP but at maturity, both CTTP and NTDS had higher above ground biomass and N'TTP was the lowest. Crop growth rate (CGR) was higher at PI-BT stage in TP either CT or NT but it was higher at PI-HD in DS. Net assimilation rate (NAR) was 15 and 24% higher in NTTP than CTTP at PI-BT and BT-HD, respectively, but CTTP had 15% higher NAR than NTTP at HD-12 DAH. In CTTP, higher leaf N concentration (2.04%) and uptake (5.9 g/m(2)) were observed at BT stage. In DS, N concentration and uptake were always higher in NT at all growth stages. It was found in the present study that CGR was closely related with LAD at BT-HD stage and grain yield was closely associated with leaf N (%) at HD stage. In DS either CT or NT had higher heat use efficiency (HUE) than TP as well as CT either TP or DS. Though DS had about 24% more number of panicles than TP but grain yield was higher in CTTP due to higher LAI, LAD, above ground biomass and bigger sink size (about 17% higher weight of panicle, higher number of spikelets per unit area and more number of grains per panicle) than DS.
作者:
Li Di-qin;Tang Qi-yuan*;Zhang Yun-bo;Qin Jian-quan;Li Hu;...
期刊:
农业科学学报(英文),2012年11(1):134-143 ISSN:2095-3119
通讯作者:
Tang Qi-yuan
作者机构:
[Yang Sheng-hai; Qin Jian-quan; Chen Li-jun; Tang Qi-yuan; Zhang Yun-bo; Li Di-qin; Zou Ying-bin; Li Hu] Hunan Agr Univ, State Key Lab Hybrid Rice, Changsha 410128, Hunan, Peoples R China.;[Peng Shao-bing] Huazhong Agr Univ, CPPC, Wuhan 430070, Peoples R China.
通讯机构:
[Tang Qi-yuan] H;Hunan Agr Univ, State Key Lab Hybrid Rice, Changsha 410128, Hunan, Peoples R China.
会议名称:
全国第十四届水稻优质高产理论与技术研讨会
会议时间:
2011-08-01
会议地点:
长沙
会议论文集名称:
全国第十四届水稻优质高产理论与技术研讨会论文集
关键词:
super hybrid rice;real-time N management;fixed-time adjustable-does N management;grain yield;sheath blight;radiation use efficiency;agronomic-nitrogen use efficiency
摘要:
Poor nitrogen use efficiency in rice production is a critical issue in China. Site-specific N managements (SSNM) such as real-time N management (RTNM) and fixed-time adjustable-dose N management (FTNM) improve fertilizer-N use efficiency of irrigated rice. This study was aimed to compare the different nitrogen (N) rates and application methods (FFP, SSNM, and RTNM methods) under with- and without-fungicide application conditions on grain yield, yield components, solar radiation use efficiency (RUE), agronomic-nitrogen use efficiency (AEN), and sheath blight disease intensity. Field experiments were carried out at Liuyang County, Hunan Province, China, during 2006 and 2007. A super hybrid rice Liangyou 293 (LY293) was used as experimental material. The results showed that RTNM and SSNM have great potential for improving agronomic-nitrogen use efficiency without sacrificing the grain yield. There were significant differences in light interception rate, sheath blight disease incidence (DI) and the disease index (ShBI), and total dry matter among the different nitrogen management methods. The radiation use efficiency was increased in a certain level of applied N. But, the harvest index (HI) decreased with the increase in applied N. There is a quadratic curve relationship between grain yield and applied N rates. With the same N fertilizer rate, different fertilizer-N application methods affected the RUE and grain yield. The fungicide application not only improved the canopy light interception rate, RUE, grain filling, and harvest index, but also reduced the degree of sheath blight disease. The treatment of RTNM under the SPAD threshold value 40 obtained the highest yield. While the treatment of SSNM led to the highest nitrogen agronomic efficiency and higher rice yield, and decreased the infestation of sheath blight disease dramatically as well. Nitrogen application regimes and diseases control in rice caused obvious effects on light interception rate, RUE, and HI. Optimal N rate is helpful to get higher light interception rate, RUE, and HI. Disease control with fungicide application decreased and delayed the negative effects of the high N on rice yield formation. SSNM and RTNM under the proper SPAD threshold value obtained high-yield with high efficiency and could alleviate environmental pollution in rice production.
摘要:
Good progress has been made in the super hybrid rice (Oryza sativa L.) breeding in China. However, rice yield not only depends on the genetic characteristics but also on the agronomic practices. No-tillage and direct seeding (NTDS) is a simplified cultivation technology that greatly simplifies both land preparation and crop establishment. Aiming to determine the grain yield performance of super hybrid rice under NTDS and to identify critical factors that determine grain yield, field experiments were conducted in Nanxian, Hunan Province, China in 2009 and 2010. Two super hybrid cultivars, Liangyoupeijiu and Y-liangyou 1, were grown under conventional tillage and transplanting (CTTP) and NTDS. Grain yield, yield components, biomass production, crop growth rate and biomass accumulation during sowing to heading (HD) and HD to maturity were measured for each cultivar. There was no difference in grain yield under NTDS and CTTP. However, grain yield differed with cultivar and year. Y-liangyou 1 produced 4 % higher grain yield than Liangyoupeijiu in 2009, whereas in 2010 both cultivars yielded similarly. Grain yields of both cultivars were higher in 2009 than in 2010. Higher grain yield of Y-liangyou 1 in 2009 was associated with higher spikelet filling (spikelet filling percentage and grain weight), which resulted from higher biomass production. Crop growth rate after HD was critical for biomass production by the super hybrid rice. We suggest that increasing the crop growth rate after HD is an effective approach to increase grain yield of super hybrid rice under NTDS.
摘要:
To indentify the key factors that are critical to the high grain yield of loosepanicle super hybrid rice, grain yield, yield components and grain-filling characteristics were compared between a loose-panicle (Zhunliangyou 527) and a compact-panicle (Y-liangyou 1) super hybrid rice by using data from three field experiments conducted in Hunan province, China during 2007 to 2011. Average grain yields were 9.56 t/ha for Zhunliangyou 527 and 9.44 t/hafor Y-liangyou 1, showing no significant difference between the two cultivars. Zhunliangyou 527 produced significantly less spikelets per panicle than Y-liangyou 1, which resulted in smaller sink size (spikelets/m2). However, spikelet filling percentage and especially grain weight of Zhunliangyou 527 were significantly higher than those of Y-liangyou 1. High grain capacity, grain-filling rate and source capacity were responsible for the high grain weight of Zhunliangyou 527. Our study suggests that developing cultivars with high grain weight through breeding programme may also be a feasible approach to achieve high rice yield.
通讯机构:
[Yin, Xiaohong] W;Wuzhou Res Inst Agr Sci, Wuzhou 450404, Peoples R China.
关键词:
Grain yield;N-use efficiency;No-till direct seeded rice;SPAD-based N management
摘要:
This study was aimed at determining whether chlorophyll meter (SPAD) can be used to increase N-use efficiency in no-till direct seeded rice. Field experiments were conducted in Yongzhou and Nanxian, Hunan Province, China in 2010. Two N management treatments were imposed in each site : SPAD-based N management (SBNM) and recommended fix-timing N management (FTNM). Partial factor productivity of applied N (PFPN), grain yield, yield components, biomass production and related physiological traits were measured for each N management. Averaged across two sites, SBNM increased PFPN by 26% compared with FTNM. The higher PFPN in SBNM was attributed to reduced N application rate. Moreover, PFPN differed with site. Nanxian had higher PFPN than Yongzhou, especially in SBNM (a more than 50% increase), because of both lower N application rate and higher grain yield. High soil fertility contributed to the increased grain yield in Nanxian. Nanxian had more panicle number per m(2) and larger panicle size (spikelets per panicle) than Yongzhou, which resulted in greater sink size (spikelets per m(2)). Nanxian produced more aboveground biomass during pre-heading period but less aboveground biomass during post-heading period than Yongzhou, and the former led to higher total aboveground biomass accumulation. Low photosynthetic rate and accelerated leaf senescence were partly responsible for the low aboveground biomass accumulation during post-heading period in Nanxian. Our study suggests that increased PFPN is possible using a SPAD to guide N application on no-till direct seeded rice, and it will be more effective to increase PFPN by using SBNM combined with improving soil fertility and optimizing canopy development.
关键词:
Direct seeding;internal N efficiency;no-tillage;super hybrid rice
摘要:
This study was conducted to compare internal nitrogen (N) efficiency of super hybrid rice among different. tillage and crop establishment methods. Field experiments were done in Changsha, Hunan Province, China during 2004-09. Super hybrid rice Liangyoupeijiu was grown under a factorial combination of two tillage practices (conventional tillage and no-tillage) and two crop establishment methods (transplanting and direct seeding) in each year. Grain yield, total N accumulation in aboveground biomass, internal N efficiency and N distribution percentage in different plant organs (straw, filled and unfilled spikelets) were measured at maturity for each combination. The results showed that the differences in grain yield, total N accumulation in aboveground biomass and internal N efficiency were insignificant among different tillage and crop establishment methods but were significant among years. Grain yield was closely related with internal N efficiency but not with total N accumulation in aboveground biomass. There was a tight positive correlation between internal N efficiency and N distribution percentage in straw at maturity. Our study suggests that adoption of N management practices that increase the N distribution percentage in straw at maturity will be effective to increase both internal N efficiency and grain yield in super hybrid rice production.
摘要:
This study was conducted to compare super hybrid varieties with inbred varieties. Three varieties from each varietal group were grown under three sowing dates in Changsha, Hunan Province, China in 2010. Grain yield and some-yield-attributes such as tillering process, panicle traits and biomass production were measured for each variety. Averaged across three sowing dates, grain yield of super hybrid varieties was 26% higher than that of inbred varieties. The high grain yield of super hybrid varieties was attributed to improvement in both sink and source. Super hybrid varieties had large panicle size than inbred varieties, which was achieved not at the expense of panicle number. The large panicles of super hybrid varieties were attributed to more spikelets per panicle due to more secondary branches per panicle or spikelet volume. Strong tillering ability played a critical role in maintaining the panicle number for super hybrid varieties. Super hybrid varieties produced more biomass than inbred varieties, and this advantage was observed as early as seedling stage. High seed amylase activity was partially responsible for high biomass production for seedlings of super hybrid varieties. Canopy structure was improved in super hybrid varieties and reflected in large top three leaves and panicle position within the canopy. Higher total biomass production of super hybrid varieties resulted from both ,long growth duration and high crop growth rate.