籼型超级杂交水稻高产栽培研究进展

对中国籼型超级杂交水稻高产栽培生理、生态适应性和高产栽培技术研究成果进行分析,指出现已育成的籼型超级杂交稻在我国南方多种生态区域作一季稻种植产量达到12t.hm2,表现出根系旺盛、分蘖力强、足穗大穗、源库协调、耐肥抗倒、以及前期能早发和后期抗早衰的潜在高产优势。有关栽培生理、生态适应性和栽培技术的研究结果显示,超级杂交稻在保持较高经济系数的同时,通过增加生物产量是超高产栽培的主要途径。进一步研究超级杂交稻的产量稳定性、产量形成机理、适宜种植区域,群体诊断指标、优质与高产相协调的关键栽培的技术等,对于建立超级杂交稻的栽培理论与技术体系,具有十分重要的科学意义和应用价值。     

土地利用变化对重庆区域经济发展的影响

运用主成分分析法和相关分析法,探讨1999年至2008年重庆市一圈两翼三大区域土地利用变化对经济发展的影响.研究表明:在影响三大区域经济发展主要地类中,都包含城镇建设用地和耕地,城镇建设发展与经济发展相关性最强;两翼地区基础设施建设滞后,对经济发展带动能力不足;因此,各区域应采取不同的土地利用措施,使各类土地供给与区域承载的经济要素相适应,更好地满足不同经济发展阶段区域主体功能对土地供给的需求.     

分布方式对不同穗型水稻产量形成及产量构成因素的影响

试验结果表明，在各个处理中，弯曲穗品种奥羽316比直立穗品种辽粳326增产，无序栽培比有序栽培增产；分布方式、品种与分布方式的互作对产量的影响达到了极显著的程度；一次枝梗数与每穗成粒数、单穗重之间，一次枝梗粒数、每穗成粒数与单穗重之间，二次枝梗数与二次枝梗粒数之间成极显著的正相关。     

双季稻栽培方式对冬闲期杂草生长及土壤养分含量的影响

于2009～2011年,在湖南长沙进行双季稻不同栽培方式（＂三定＂栽培、免耕摆栽、传统栽培）定位试验,研究了双季稻不同栽培方式对冬闲期稻田杂草生长及土壤养分含量的影响。结果表明：与传统栽培相比,＂三定＂栽培和免耕摆栽方式下冬闲期杂草的密度、单株干重和单位面积生物量以及土壤表层（0～5cm）的碱解氮、有效磷和速效钾含量均较高。其中,冬闲期杂草单位面积生物量、单株干重、单位面积密度与土壤表层碱解氮含量呈显著正相关关系,说明冬闲期杂草在双季稻稻田土壤养分循环中起了重要的作用。     

三七根腐病田间分级标准研究及评价

 目前三七[Panax notoginseng (Burk. ) F. H. Chen]根腐病尚无病害分级标准,为发现抗病种质资源和评估病害防控效果,本研究建立了用于三七根腐病的田间分级标准。从云南省文山州收集200株发生根腐病的三年生植株,筛选获得具有代表性不同腐烂程度的98株样本,通过对表面腐烂占比、横截面腐烂、支须根腐烂、芽及芦头腐烂5项指标进行描述,采用SPSS21进行样本聚类分析,制定了如下用于三七根腐病的田间分级标准:0级,健康,无症状;1级,腐烂仅发生在块根表面、且0＜腐烂面积占比≤10%,或腐烂已扩展至内部且5%＜腐烂面积占比≤10%;2级,腐烂已扩展至内部、且10%＜腐烂面积占比≤40%,支须根无腐烂;3级,腐烂已扩展至内部、且40%＜腐烂面积占比≤50%,支须根腐烂;4级,腐烂已扩展至内部、且50%＜腐烂面积占比≤70%,支须根腐烂脱落;5级,腐烂已扩展至内部、且腐烂面积占比＞70%直至整个块根完全腐烂,支须根腐烂。本标准于2016~2017年连续2年被用于评价土壤处理防控三七根腐病害的发生危害和防治效果,结果显示,该标准可以较好地对不同土壤处理的防病效果进行量化和评估,且与传统分级标准相比,其评价结果更优。     

冷浸田条件下不同类型品种的表现和高产栽培方式研究

2009年在宁乡县、桃源县、永兴县3地冷浸田条件下进行了品种筛选和不同栽培方式的比较试验。结果表明:(1)不同品种在3个地点产量表现基本一致,早稻以陆两优996和陵两优211表现较好,平均产量分别达到5.68 t/hm2和5.28 t/hm2,晚稻以钱优1号、天优华占和丰源优299表现较好,产量分别达到5.08,4.94和4.81 t/hm2;(2)不同栽培方式产量表现地点间不一致。桃源点早稻和晚稻以翻耕移栽和免耕抛栽产量较高,永兴点早稻免耕抛栽产量最高,晚稻以垄厢移栽产量最高,宁乡点早稻和晚稻都以翻耕移栽产量最高。     

Relationship Between Grain Yield and Yield Components in Super Hybrid Rice

Chinese super hybrid rice breeding project has developed many new varieties with great yield potential.It is controversial which yield component should be emphasized in super hybrid rice production.The present study was conducted to compare super hybrid rice with common hybrid and super inbred rice and analyze contributions of yield components to grain yield of super hybrid rice under experimental conditions,and evaluate relationships between grain yield and yield components of super hybrid rice in farmer's paddy fields.Field experiments were done in Changsha,Guidong,and Nanxian,Hunan Province,China,from 2007 to 2009.Eight super hybrid varieties,one common hybrid variety,and one super inbred variety were grown in each location and year.Rice production investigation was undertaken in high-yielding (Guidong),moderate-yielding (Nanxian),and low-yielding (Ningxiang) regions of Hunan Province,China,in 2009.Grain yield and yield components were measured in both the field experiments and rice production investigation.Super hybrid rice varieties outyielded common hybrid and super inbred varieties across three locations and years.Yield potential has been increased by 11.4％ in super hybrid rice varieties compared with common and super inbred varieties.The higher yield of super hybrid varieties was attributed to improvement in panicle size.Panicles per m2 had the highest positive contribution to grain yield with the exception under yield level of 10.0 to 12.0 t ha-1,and was positively related to grain yield in farmer's field at all of the high-,moderate-,and low-yielding regions.Our study suggests that panicle per m2 ought to be emphasized in super hybrid rice production.     

Continuous applications of biochar to rice: Effects on grain yield and yield attributes

Biochar is considered as a beneficial soil amendment for crop production. However, limited information is available on the effects of continuous applications of biochar on rice. In this study, a fixed field experiment was conducted in the early and late rice-growing seasons from 2015 to 2017. Grain yield and yield attributes with a widely-grown rice cultivar Zhongzao 39 were compared, with and without applications of biochar in each season. The results showed that grain yield initially decreased with biochar applications in the first three seasons due to decreases in grain weight and harvest index. Although there were further relative decreases in grain weight and harvest index for rice that was supplied with biochar in the fourth to sixth seasons, grain yield was increased(by 4–10%) because of increases in sink size(spikelets per m2) and total biomass. The increased sink size in rice whose soil had been supplied with biochar in the fourth to sixth seasons was achieved by increasing panicle size(spikelets per panicle) or number of panicles, or both. Our study suggests that the positive effects of biochar application on rice yield and yield attributes depend on the duration of biochar application. Further investigations are needed to determine what are the soil and physiological processes for producing yield responses associated with ongoing applications of biochar. Also, it should be evaluated the performance of biochar application combined with other management practices, especially those can increase the grain weight and harvest index in rice production.     

Upregulation of proto-oncogene c-mpl by interleukin-13 in Dami cells

AIM:To investigate the effects of recombinant human interleukin-13 (rhIL-13) on the expression of proto-oncogene c-mpl in Dami cells, a human megakaryobiastic leukemia cell line.METHODS:The expression of c-mpl mRNA in Dami cells was investigated with RT-PCR. The expression of membrane-bound protein c-mpl on Dami cells was investigated with ligand combination experiment.RESULTS:In RT-PCR experiment, we found the quantitis of expression of c-mpl mRNA in 25 μg/L rhIL-13 group increased by 24.8%. In ligand combination experiment, we found quantitis of expression of membrane-bound protein c-mpl in 100 μg/L rhIL-13 group increased by 28.5% (P＜0.05).CONCLUSION:Our data indicate that rhIL-13 enhances the expression of proto-oncogene c-mpl in Dami cells. Membrane-bound protein c-mpl on the surface of Dami cells bind to TPO (thrombopoietin) normally, moreover, the proliferation of Dami cells stimulated by rhIL-13 may be partly due to increasing the proto-oncogene c-mpl expression in Dami cells.