滇中冷凉山区不同播期反季花椰菜产量效益分析     

李艳兰  张云明  李祥  胡新洲  段永华  刘坚坚  安正云  易丽华  蔡述江  王爱明  陶春红  史兰芬  李文静  杨进成 《农学学报》2021,11(9):58-63

为摸索滇中高海拔冷凉山区反季节栽培花椰菜的最佳播期以集成高效栽培技术推广应用,于2017—2018年选择海拔2250 m的云南省峨山县塔甸镇大西村地块进行9个播期的2年随机区组试验。结果表明,花椰菜生育期随播期推迟而延长,而花球采收期除播期7月10日外随播期推迟而逐渐增长;花椰菜株高、外叶数、开展度、球高、球径和单球重等农艺性状有随播期延迟呈现先逐渐减小而后又逐渐增大的趋势;莲座期黑腐病和霜霉病的病情指数随着播期的延迟呈现先逐渐升高而后又逐渐下降的趋势;花椰菜小区产量随着播期的延迟呈现先逐渐下降而后又逐渐提高的趋势,播期4月20日和4月30日与其余7个播期产量之间的差异达极显著水平。综合花椰菜在冷凉山区反季节栽培的生产实际和各播期产量产值及商品性表现,推荐滇中高海拔冷凉山区反季节栽培花椰菜的最佳播期为4月20—30日。  相似文献   

Changes of urinary albumin and N-acetyl-beta-glucosaminidase in high altitude polycythemia at different altitudes and its mechanism     

XI Ai-qi  CHU Yi-de 《园艺学报》2003,19(6):815-817

AIM:To study the changes of excretive amount of albumin(ALB), N-acetyl-beta-D-glucosaminidase(NAG) in patients with high altitude polycythemia(HAPC) at different altitude and its mechanism.METHODS:Urinary ALB, NAG, activity of red blood cell superoxide dismutase(RBC-SOD), malonyldialdehyde(MDA) and erythrocyte filtration index(EFI) of 231 healthy subjects and 86 patients with HAPC at different altitude were detected.RESULTS:Excretive amount of urinary ALB, NAG, and plasma MDA, EFI were higher, and RBC-SOD was lower in patients with HAPC than those in healthy subjects, the changes were significantly obvious, with increasing altitude. Urinary ALB and NAG were negatively correlates to EFI, and no correlated to the content of MDA and RBC-SOD.CONCLUSIONS:EFI exertes an independent influence on urinary ALB and NAG. The decrease in erythrocyte deformability caused by the increase of peroxidation of lipids might participate in the pathogenesis and progress of the increase of excretive amount of ALB and NAG in HAPC.  相似文献   

The Relationship Between Vegetation Characteristics and Altitudes in Transitional Permafrost Zone in Xidatan,Qinghai-Tibetan Plateau     

Zhiwei WANG  Bentian MO  Leilei DING  Puchang WANG  Qian WANG  Ruixia LU 《农业科学与技术》2016,(6):1462-1467

Many studies showed that permafrost has profound influence on alpine ecosystem. However, former researches were mainly focused on typical points by temporal scales. There were few studies about the correlation between vegetation characteristics and different altitudes covering a large region in spatial pattern, especially in transitional permafrost(TP). There were continuous permafrost(CP) discontinuous permafrost(DCP) and seasonal frozen ground(SFG) in this study region. The types of permafrost changed from SFG to DCP, and finally become CP as the altitudes of Xidatan increase. In this paper, 112 845 points interpreted by HJ1-B(environment and disaster monitoring and prediction small satellite constellation), vegetation investigation points, thawing layer thickness research sites, ground temperature and water content observation plots were used to examine the spatial pattern of vegetation which were located in different altitudes in Xidatan, a typical TP region, in Qinghai-Tibetan Plateau. Vegetation characteristics, soil moisture content(SMC) and thaw depths were collected in 15 August to 25 August2012. Characteristics of vegetation were mainly represented by fractional vegetation cover(FVC) derived from the normalized difference vegetation index(NDVI), as well as above ground biomass(AGB). In this paper, we analyzed that the distinction of vegetation characteristics in each range through statistics data. These ranges were divided by varied altitudes. For examples, the ranges were divided into 50 m or 100 m. In this study we use a large area plots method to further discuss the relationship between the features of vegetation and the different regions of permafrost based on altitudes shifts in Xidatan. A diagram described the vegetation characteristics variability with rising altitudes in transitional permafrost region was drawn in this paper. Our results illustrated the FVCs first increased in SFG region and then decreased in DCP zone slowly, and in CP region FVCs soared then dropped dramatically. With the altitudes increased, the curve of FVCs indicated a parabolic distribution except a little difference in the first 200 m range.  相似文献   

Response of the soil fungal community to multi-factor environmental changes in a temperate forest     

《Applied soil ecology》2014

Both environmental and climatic changes are known to influence soil microbial biomes in terrestrial ecosystems. However, there are limited data defining the interactive effects of multi-factor environmental disturbances, including N-deposition, precipitation, and air temperature, on soil fungal communities in temperate forests. A 3-year outdoor pot experiment was conducted to examine the temporal shifts of soil fungal communities in a temperate forest following N-addition, precipitation and air temperature changes. The shifts in the structure and composition of soil fungal communities were characterized by denaturing gradient gel electrophoresis and DNA sequencing. N-addition regimen induced significant alterations in the composition of soil fungal communities, and this effect was different at both higher and lower altitudes. The response of the soil fungal community to N-addition was much stronger in precipitation-reduced soils compared to soils experiencing enhanced precipitation. The combined treatment of N-addition and reduced precipitation caused more pronounced changes in the lower altitude versus those in the higher one. Certain fungal species in the subphylum Pezizomycotina and Saccharomycotina distinctively responded to N fertilization and soil water control at both altitudes. Redundancy discrimination analysis showed that changes in environmental factors and soil physicochemical properties explained 43.7% of the total variability in the soil fungal community at this forest ecosystem. Variations in the soil fungal community were significantly related to the altitude, soil temperature, total soil N content (TN) and pH value (P < 0.05). We present evidence for the interactive effects of N-addition, water manipulation and air temperature to reshape soil fungal communities in the temperate forest. Our data could provide new insights into predicting the response of soil micro-ecosystem to climatic changes.  相似文献   

不同大气压下直喷式柴油机的性能研究     

陈贵升  沈颖刚  兰阳  翁家庆  张韦 《拖拉机与农用运输车》2009,36(1)

在大气模拟试验台架上对运行在不同大气压下的直喷式柴油机的经济性、动力性、烟度及噪声特性进行对比试验研究与分析。试验结果表明:随着大气压力的减少,柴油机有效燃油消耗率、小时燃油消耗量、排气温度、烟度及噪声声功率增加,动力性下降。  相似文献   

宝天曼植物群落物种多样性研究   总被引：33，自引：5，他引：33  

史作民  程瑞梅  刘世荣  蒋有绪  陈宝金 《林业科学》2002,38(6):17-23

对宝天曼保护区植物群落物种多样性进行了研究。结果表明 ,物种丰富度指数、多样性指数和均匀度指数在群落梯度上的分布趋势基本一致 ,较好地反映了不同植物群落类型在物种组成方面的差异。草本层物种丰富度指数明显高于乔木层和灌木层 ,草本层物种丰富度指数在群落梯度上的变异最大 ,灌木层次之 ,乔木层最小。乔木层物种多样性指数小于灌木层和草本层 ,草本层和乔木层物种多样性指数在群落梯度上的变异程度明显大于灌木层。灌木层物种均匀度指数大于乔木层和草本层 ,草本层和乔木层均匀度指数在群落梯度上的变异程度大于灌木层。物种丰富度指数和多样性指数的较大值出现在高海拔和低海拔群落 ,较小值多出现在中等海拔群落。物种均匀度指数的较小值多出现在中等海拔群落 ,但其较大值在各海拔群落都有分布。草本层物种丰富度指数和多样性指数的较高值多分布在低海拔群落 ,较小值多分布在中等海拔群落 ;乔木层和灌木层的各种指数以及草本层的物种均匀度指数在海拔梯度上的分布规律不明显  相似文献   

华中神农架箭竹(Fargesia spathacea)群落之海拔多样性(英文)   总被引：5，自引：0，他引：5  

李兆华  曼丹里奇 《林业研究》2002,(3)

通过对华中神农架海拔1500米至2600米之间11个箭竹样方的研究,阐述了箭竹群落物种丰富度,物种多样性,物种均匀性,生活型谱及群落类型的海拔变化。从最低样方(1680米)到最高样地(2570米),微管束植物从30种降为7种,服从线性模型:Y=55.991.83X(R2=0.84,P<0.001);物种多样性从3.18降为1.78,服从线性模型:Y=4.670.10X (R2=0.72,P=0.001;物种均匀度在0.83至0.99之间变化,但与海拔并不相关。在生活型谱中,一年生植物,地下芽植物和大高位芽树木的百分比随海拔升高而升高;灌木和中高位芽树木随海拔升高而降低;多年生草本和半灌木与海拔关系不大。箭竹群落可分为5种类型:常绿阔叶林下,落叶阔叶林下,温性针叶林下,寒温性针叶林与混交林下,纯箭竹林。图4表2参19。  相似文献   

温度与再生稻农艺性状的相关性研究   总被引：2，自引：0，他引：2  

任天举  王培华  段基文  李世华  唐前国 《中国农业气象》2002,23(1):4-8

1987-1988年用杂交稻汕优63和冈矮63，在重庆市渝北区同一坡面海拔250-450m作中稻种植，使其再生稻在不同的自然温度下生长发育，结果表明：再生季日均温随海拔高度递增而逐渐下降，它与再生稻全生育日数和千粒重均呈显著负相关，与再生苗数、有效穗数、株高、穗长、穗着粒数、穗实粒数、结实率等农艺性状以及单位面积产量均呈显著正相关；再生稻长苗期和抽穗开花期的日均温与再生稻单产亦呈显著正相关。据此提出重庆地区中迟熟杂交稻品种再生稻稳定较高产量的适宜种植区海拔高度上限约为340m，其对应的年均温为17.8C，稳定通过10C初至连续5d≥22C终日间的日均温为22.8C。  相似文献   

高原夏季无公害西芹专家系统的开发与应用     

杨永岗 《甘肃农业科技》2005,(7):27-28

介绍了甘肃省首次研发的高原夏季无公害西芹专家系统的开发过程、主要技术及系统功能。该系统在金昌市永昌县示范,示范田西芹平均产量为12.915万kg/hm2,较对照增产19.9%,产值达51660元/hm2,较对照增值9360元/hm2。  相似文献   

青海玉树不同海拔高度草毡土微生物数量及影响因子   总被引：3，自引：0，他引：3  

于健龙  石红霄 《中国草地学报》2011,33(6)

应用稀释平板法探讨了不同海拔高度土壤细菌、真菌和放线菌数量与生境的关系.结果表明,不同海拔样地真菌数量差异显著;AM-2样地细菌、真菌数量最大;AM-3的放线菌数量最大;而AM-4的细菌数量、真菌数量、放线菌数量均为最小值;相关性分析表明,细菌、真菌、放线菌与海拔、地下生物量呈显著正相关;与土壤含水量呈极显著负相关.这表明,土壤微生物受到地下生物量及土壤含水量影响最大.  相似文献