大气CO2浓度升高对黄花蒿生长和氮磷钾养分吸收的影响

Annual wormwood (Artemisia annua L.) is the only viable source of artemisinin, an antimalarial drug. There is a pressing need to optimize production per cultivated area of this important medicinal plant; however, the effect of increasing atmospheric carbon dioxide (CO₂) concentration on its growth is still unclear. Therefore, a pot experiment was conducted in a free-air CO₂ enrichment (FACE) facility in Yangzhou City, China. Two A. annua varieties, one wild and one cultivated, were grown under ambient (374 μmol mol^-1) and elevated (577 μmol mol^-1) CO₂ levels to determine the dry matter accumulation and macronutrient uptake of aerial parts. The results showed that stem and leaf yields of both A. annua varieties increased significantly under elevated CO₂ due to the enhanced photosynthesis rate. Although nitrogen (N), phosphorus (P), and potassium (K) concentrations in leaves and stems of both varieties decreased under elevated CO₂, total shoot N, P, and K uptake of the two varieties were enhanced and the ratios among the concentrations of these nutrients (N:P, N:K, and P:K) were not affected by elevated CO₂. Overall, our results provided the evidence that elevated CO₂ increased biomass and shoot macronutrient uptake of two A. annua varieties.     

The roles of cytokinins and abscisic acid in the pericarp of litchi (Litchi chinensis Sonn.) in determining fruit size

Summary

Variations in the concentrations of cytokinins (CTKs) and abscisic acid (ABA) were studied in the pericarp of litchi (Litchi chinensis Sonn.) fruit using the large-fruited cv. ‘Erdanli’ (55.3 g per fruit) and the small-fruited cv. ‘Huaizhi’ (20.9 g per fruit), as well as large fruit (32.4 g) from early blooms and small (20.8 g) fruit from late blooms on the same inflorescences of cv. ‘Feizixiao’ from the same commercial orchard in Guangdong, China in 2000. ‘Erdanli’ had higher concentrations of CTKs than cv. ‘Huaizhi’ on three out of six sampling dates during fruit development, and lower concentrations of abscisic acid (ABA) from 40 d after anthesis. In cv. ‘Feizixiao’, fruit from early blooms had higher concentration of CTKs than fruit from late blooms at all sampling dates, and lower concentrations of ABA on three out of five sampling dates. Therefore, the former had a higher CTK:ABA ratio. These data suggest that a high CTK:ABA ratio favours fruit growth in litchi.     

花生籽仁蔗糖含量近红外模型构建及在高糖品种培育中的应用

含糖量是决定和影响花生食用品质和加工特性的重要指标,蔗糖含量占成熟花生籽仁总糖量的90%以上,建立蔗糖含量的高效检测技术,有助于加快高蔗糖甜味食用型花生品种培育进程。本研究利用蔗糖含量差异显著的185份花生材料,利用近红外仪(波长范围1100~2500 nm),配合小样品杯,扫描和采集自然干燥籽仁的近红外光谱,采用液相色谱(HPLC)结合标准曲线法测定试验材料的蔗糖含量,利用偏最小二乘法(partial least squares,PLS)构建了花生籽仁蔗糖含量的近红外定标模型,模型的决定系数R2=0.962,均方差为0.383。利用20份材料对模型进行外部验证,预测值和化学值的决定系数达0.947,表明该模型可较好地预测蔗糖含量,可以高效地测定杂交早期世代的单株花生蔗糖含量。利用该模型在“吉花02-1-4×中花26”杂交后代中发掘出6份含糖量7%以上、油酸78%以上、含油量48%以下,且农艺性状优良的食用花生新品系。     

水分调控对梨枣果实品质与投入产出效益的影响分析

本试验以梨枣为试验材料, 设置5 个灌水梯度(保持70%、60%、50%、40%的田间持水量和不灌水对照), 分别在梨枣萌芽展叶期、开花坐果期与果实膨大期各灌水2 次, 研究水分调控对梨枣果实品质的影响,并进行投入产出效益的比较分析。结果表明: (1)梨枣果实膨大期与开花坐果期是影响果实品质与经济效益的关键需水时期。(2)适当灌溉可以明显改善果实的风味品质与营养品质, 并显著提高梨枣树的果实单果重与果实收获数; 但灌水过多, 产量与品质未得到明显改善, 却增加了成本。(3)合理调控“高产”与“优质”的关键需水时期, 可以均衡达到“高产和优质”。综合分析认为: 对陕北梨枣树灌溉至田间持水量的60%比较适宜,既改善梨枣果实品质, 并显著提高经济产量。     

性信息素技术在高粱鳞翅目害虫发生动态监测中的应用

为研究高粱鳞翅目害虫发生动态,解决防治适期问题,通过3年田间试验,利用性诱技术诱集鳞翅目害虫,探索黏虫、条螟、玉米螟、桃蛀螟、草地贪夜蛾和二化螟的发生动态。研究发现,玉米螟和条螟发生最为严重,占鳞翅目害虫数的70%以上,各类鳞翅目害虫的发生时段在5月初—8月初,其中主要集中在5月底—7月中下旬大量发生。研究结果可为更加科学合理预测高粱鳞翅目害虫的发生危害提供依据,也为本地有机高粱生产过程中的鳞翅目害虫制定防控方法提供实践基础。     

四川省草地贪夜蛾发生为害特点

为探明草地贪夜蛾在四川的发生为害特点,利用田间调查数据对草地贪夜蛾在四川的发生分布范围、受害作物种类、幼虫种群动态和扩散过程进行了分析。结果表明,草地贪夜蛾在四川除阿坝州外的20个市州都有发生,重发区域集中在川东和攀西地区;受害作物以玉米为主,甘蔗、高粱、小麦和油菜零星受害;在攀西地区和川东北地区观察到2个幼虫为害高峰,其余地区只有1个幼虫为害高峰;草地贪夜蛾在攀枝花市和凉山州局部地区为周年繁殖区,其在四川的扩散总体上呈现出由南向北、由东向西的过程。     

The Distribution of Piezometric Head along Wedge-shaped Fractures

Rock masses have defects,such as joints and fractures, which are the main seepage passages.Joints and fractures often are treated as parallel plates with the seepage state kept steady and the ground stress constant. When changes take place in joints and fractures as a result of stress changes induced by excavation,joints or fractures may be wedge-shaped,and the distribution of piezometric head along the fracture will be nonlinear.A distribution function of piezometric head is suggested and compared with the results of previous research.The influence of this function on the calculation of the slope safety factor is investigated.The study shows that this function is reasonable.     

神木县三元杂交肉牛肥育试验

以秦蒙二元杂交牛为对照组,丹秦蒙、利秦蒙和安秦蒙3个三元杂交肉牛分别为试验组,每组6头周岁左右阉牛进行为期100d的肥育对比试验,试验组平均日增重1341.10g、比对照组提高35.90%,精料增重比3.09、降低26.50%,千克增重效益4.78元、提高60.90%。试验组与对照组间各项指标的差异均达显著以上水平(P<0.05-0.001)。在肥育期增长率、饲料报酬和单位增重效益等重要指标上,均以安秦蒙组相对最高,因而红安格斯可做为当地肉牛三元杂交之首选终端父本。     

用近红外反射光谱法分析稻米3种必需氨基酸含量的研究

采用近红外反射光谱分析技术来测定水稻精米粉样的3种必需氨基酸含量,揭示不同数学处理方法、光谱散射校正和回归统计方法对建立回归方程的影响.研究表明,光谱数据的数学预处理对发展定标回归方程有很大影响,对于不同的氨基酸,通过比较均可找到一些定标效果较理想的数学处理组合,如"2,3,3,1"等.光谱散射处理对氨基酸的定标改