Chlorophyll Stability is an Indicator of Drought Tolerance in Peanut

Chlorophyll stability during drought might be a promising criterion for selection for drought resistance in peanut. The study describes two field trials conducted at Khon Kaen University, Thailand which investigate genotype × drought interactions in a wide range of peanut germplasm in general and assess the relationship between chlorophyll stability and genotypic performance in particular, under drought. Two field experiments (during 2003/2004 and 2004/2005 dry seasons) were conducted in a split plot design with three water regimes [field capacity, 2/3 available water (AW) and 1/3 AW] as main, and 12 peanut genotypes as subtreatments, replicated four times. Observations on total dry matter (TDM), chlorophyll density (ChlD) (chlorophyll content per unit leaf area), chlorophyll content (chlorophyll content per plant) and SPAD chlorophyll meter readings (SCMR) were recorded at 30, 60 and 90 days after emergence. Transpiration (T) and transpiration efficiency (TE) were computed using the data on amount of water input and TDM. Drought stress significantly reduced TDM, T and chlorophyll content across genotypes but significantly increased TE and ChlD in peanut. However, there were significant differences among genotypes for TE and chlorophyll parameters. The genotype × drought interaction effects for chlorophyll characters (content and density) were not significant suggesting a strong genetic effect. The correlation coefficients between TDM and chlorophyll content (r = 0.51, P = 0.01 to r = 0.91, P = 0.01) and between TE and ChlD (r = 0.46, P = 0.05 to r = 0.77, P = 0.01) were positive and significant. These findings suggest that chlorophyll parameters are strongly linked with drought tolerance in peanut. There were highly significant and positive relationships between ChlD and SCMR (r = 0.67, P = 0.01 to r = 0.93, P = 0.01), between SCMR and TE (r = 0.41, P = 0.05 to r = 0.80, P = 0.01) suggesting that SCMR could be used as a tool for rapid assessment of relative chlorophyll status in peanut genotypes as well as for the indirect selection of drought tolerance in peanut.     

叶绿素仪与植株硝酸盐浓度测试对冬小麦氮营养诊断准确性的比较研究

通过研究不同土壤氮素供应对冬小麦拔节期叶绿素仪SPAD读数和植株硝酸盐浓度的影响,以及两种方法在冬小麦拔节期与土壤Nmin、植株全氮和吸氮量的关系,比较了SPAD叶绿素仪和植株硝酸盐测试两种氮素营养诊断方法的准确性。认为两种方法都可以比较好的反映冬小麦的氮素营养状况,植株硝酸盐浓度与SPAD读数相比能更好的反映作物的氮素营养状况。     

Development of Heat Flow Meter and Research on Amelioration of International Advanced Technique

Heat flow meter is an apparatus measuring the transfer of heat energy. In developed countries it is used in detection of energy consumption and safety system of electricity generation, steel making, chemical engineering and building heating and air-conditioning, but it is just a start for its application in China. The research of heat flow meter with own intellectual property is based on the urgent need of energy saving in China. The innovational research must be based on improvement of current technique. In this paper, the progress of heat flow meter is reviewed and the sort and principle of heat flow meter is introduced. The best feeler and the crucial technique of thermopile for heat flow meter in thermal resistance are selected. The disadvantage and ameliorative method is pointed out. At last, a Chinese patent is granted to the authors.     

变应传感器在甜菜根茎测定中的应用

将变应传感器应用在甜菜根茎生长测定中,测定地表下5cm处甜菜块根直径以期观测甜菜根部生长状态。试验结果表明,2点法测量的误差小于1点法,年度间差异变化不大,并且没有在甜菜表面造成损伤和形成生育障碍,说明2点法可以在生产中应用。     

Evaluation of a Rapid Field Test Method for Assessing Nitrogen Status in Potato Plant Tissue in Rural Communities in the Bolivian Andean Highlands

The relatively poor accessibility, high costs, long turnaround time for analysis, and lack of information about soil and plant testing in the Andean highland region (Altiplano) of Bolivia has hampered informed and timely nutrient management decisions for potato (Solanum tuberosum L.) crops. The objective of this study was to determine if the Cardy nitrate meter (Horiba Ltd., Kyoto, Japan), a low-cost, portable, and rapid field test method, could be used to improve nitrogen (N) fertility management among isolated rural indigenous communities at different elevations in this rugged semi-arid environment. Fully matured leaf petioles were sampled at blooming time from potato trials established in three communities during the 2006–2007 and 2007–2008 growing seasons. Those trials were composed of 12 fertility treatments (i.e., an unfertilized control and different combinations of sheep and cow manure, inorganic fertilizer, commercial household/urban compost, and a commercial microbial activator soil amendment) arranged in a randomized complete block design with four replications. In general, in both growing seasons and in all communities, nitrate measured in the sap of leaf petioles by the Cardy meter had relatively low but significant correlations with leaf petiole total N (ranging from r² = 0.07 to r² = 0.60 across seasons and communities) and with total fresh tuber yield (ranging from r² = 0.11 to r² = 0.50 across seasons and communities). However, some problems were encountered with being able to consistently calibrate the meter with supplied standards prior to each use of the meter. These results indicate that the Cardy ion meter might be an effective tool for potato growers or agricultural professionals working in the Altiplano of Bolivia if further research can be conducted to determine if the meter is consistent for diverse sites in the Altiplano and is practical for the cultural, economic, and environmental conditions of the region.     

Identification of quantitative trait loci associated with iron deficiency chlorosis resistance in groundnut (Arachis hypogaea)

Iron deficiency chlorosis is an important abiotic stress affecting groundnut production worldwide in calcareous and alkaline soils with a pH of 7.5–8.5. To identify genomic regions controlling iron deficiency chlorosis resistance in groundnut, the recombinant inbred line population from the cross TAG 24 × ICGV 86031 was evaluated for associated traits like visual chlorosis rating and SPAD chlorophyll meter reading across three crop growth stages for two consecutive years. Thirty-two QTLs were identified for visual chlorosis rating (3.9%–31.8% phenotypic variance explained [PVE]) and SPAD chlorophyll meter reading [3.8%–11% PVE] across three stages over 2 years. This is the first report of identification of QTLs for iron deficiency chlorosis resistance-associated traits in groundnut. Three major QTLs (>10% PVE) were identified at severe stage, while majority of other QTLs were having small effects. Interestingly, two major QTLs for visual chlorosis rating at 60 days (2013) and 90 days (2014) were located at same position on LG AhXIII. The identified QTLs/markers after validation across diverse genetic material could be used in genomics-assisted breeding.     

SPAD-502叶绿素仪在烤烟生产中的应用研究

采用田间试验的方法,研究了SPAD-502叶绿素仪与烤烟叶绿素含量的关系,探讨SPAD-502叶绿素仪在烤烟生产中的应用前景。研究结果表明:叶绿素仪在烤烟上的最佳测量部位为叶片基部;不同叶位、不同成熟度烟叶的叶绿素仪读数与叶绿素含量之间呈显著相关,其线性关系可用方程y=ax b来拟合。     

调教训练对伊犁马1600m速度赛步态特征的影响

【目的】研究调教训练对伊犁马1 600 m速度赛步态特征的影响,为速度赛伊犁马调教训练提供数据支撑。【方法】挑选8匹未经调教训练的3岁伊犁马(公马)为试验对象,采用3个月的速度调教训练,采集不同训练阶段马匹速度赛直道、弯道、冲刺处的步态特征,分析不同训练阶段伊犁马步态特征的差异。【结果】伊犁马训练后期平均速度显著大于训练初期(P<0.05);后位后蹄支撑相在训练初期显著低于训练中期(P<0.05),前位前蹄支撑相在训练初、后期显著低于训练中期(P<0.05),后肢双支撑相在训练初期显著低于训练中、后期(P<0.05);后位后蹄摆动相在训练中期显著低于训练后期(P<0.05),前位后蹄摆动相在训练中期显著低于训练初、后期(P<0.05),后位前蹄摆动相在训练中期显著低于训练初期(P<0.05),前位前蹄摆动相在训练中期显著低于训练初、后期(P<0.05);腾空期在训练中期显著低于训练前、后期(P<0.05);瞬时速度在训练初期显著低于训练后期(P<0.05);前肢步幅在训练初、中期显著小于训练后期(P<0.05),腾空期步...     

灵石山米槠(Castanopsis carlessi)林优势种群不同年龄叶片SPAD值的差异及其与叶绿素、氮含量的关系

采用便携式叶绿素仪SPAD-502对灵石山米槠林不同海拔优势种群不同年龄叶片的SPAD值进行野外测定,分别对各海拔不同年龄不同优势种以及各年龄不同海拔不同优势种的叶片SPAD值进行差异性分析,结果表明,灵石山米槠林优势种群叶片SPAD值存在叶龄、种间以及海拔梯度问的差异。对不同海拔米槠林优势种群不同年龄叶片SPAD值与室内分光光度法测定的叶绿素含量以及叶片氮含量进行相关分析,结果表明,SPAD值与叶片单位面积叶绿素及氮含量有显著的相关性。SPAD值是叶绿素含量的真实反映,利用叶绿素仪SPAD-502可以快速有效的诊断种群氮素营养状况。