菱传粉生物学研究

以6 个菱品种为试材，对花器形态特征、群体花期及单花开花动态、开花时间、柱头可授性、花粉活力、杂交指数 及传粉形式等进行观察测定。结果表明：菱花单生，两性，单花花期15 h，群体花期在5～10 月，盛花期在7～8 月；不同 品种在一天中的开花高峰期存在差异；柱头可授期主要在萼片开裂后2 h 内，结实率在50% 以上；花粉在自然授粉条件下活 力可保持7.5 h；以自花授粉为主，同时存在一定程度的无融合生殖和少量异花授粉。     

不同饲养密度对鳝苗的生长性能研究

本试验以水蚯蚓作为饵料,研究了60日龄鳝苗不同密度下的增重、存活率及饵料转化率。试验分3个密度组,其对应的密度分别为2000尾/m2、3000尾/m2、4000尾/m2,每个密度组设4个平行;试验时间为30d。结果表明:在本试验条件下,3个密度组鳝苗的增重率、存活率随着密度的增大呈下降趋势,而其饵料系数随着密度增大而增大;其中在4000尾/m2的密度下,鳝苗的增重率最低,仅为1.12±0.13;饵料系数最高,为5.71±1.37。     

树木体内水分长距离运输的负压传递机制

蒸腾能使木质部产生不超过-0.1MPa的有限负压,这个负压在木质部内自上而下依次向下传递。水分在导管或管胞内所受的吸附力、毛管力、真空力等综合作用力要大于或等于所受的重力,这个综合作用力可以将水分托住而不受重力作用而下移,使水分在负压作用下以分段移动的方式从根部上升到植物顶端。空穴和栓塞是两个不同的概念,其形成过程、恢复机制都有其本质的不同。空穴的发生与负压和水分的分段移动有密切的关系。     

利用SCoT对甜菜种质资源的鉴定及遗传多样性分析

为了研究SCoT分子标记技术对甜菜种质资源鉴定的可行性。利用80条SCoT引物对48份甜菜种质资源进行鉴别,同时对种质资源进行了遗传多样性分析和亲缘关系的鉴定。结果表明,80条SCoT引物中有6条能够扩增出清晰、且多态性高的条带,分别为SCoT1、SCoT12、SCoT13、SCoT14、SCoT17和SCoT23,其中引物SCoT1、SCoT12、SCoT14和SCoT23单独使用均可鉴别全部的48份种质资源,引物SCoT13和SCoT17共同使用可以鉴别48个种质资源;聚类分析结果表明,在遗传距离0.15处,95.8%的种质资源均聚为一类,从分子角度上表明甜菜种质资源遗传距离较小。本研究为利用SCoT分子标记技术鉴别甜菜种质资源、对种质资源进行亲缘关系鉴定、杂交组合亲本选配以及分子标记辅助育种等提供相关科学依据。     

Short‐term releases of CO2 from newly mixed biochar and calcareous soil

The work aimed to quantify native organic C mobilized in one calcareous soil in the 21 days after addition of biochar at a range of large to very large applications. The experiment was carried out in unplanted microcosms, and CO₂ flux was used as a measure of net mineralization. A rapid methodological approach, which does not require ¹³C as a tracer, was used to assess any priming effects induced by the biochar. The amount of CO₂‐C mobilized was small relative to the amount of biochar C and proportional to the amount of the biochar added. The additional CO₂‐C was similar to the content of the water‐soluble organic carbon in the biochar added with each application. No interaction with native soil C, that is priming effect, was observed.     

水质快速检测设备的硬软件设计及实现

[目的]研制本质快速检测设备,实现水质的现场多指标快速检测.[方法]对设备的硬件及软件进行了设计.硬件设计包含了1P2303芯片、锂电,Cortex-M3型ARM微控制器、树莓派显示系统、光频转换器等的设计;软件设计则包含了软件设置、项目选项、项目测量结果以及测量数据表格输出等模块的设计;并对水质快速检测设备的可靠性进行了试验检验.[结果]通过对该设计的设备硬件和软件合理搭配连接,从而研发出了水质快速检测设备.用该设备与国家标准要求的设备同时测定某一河道水样的5项指标结果发现,3个样点水样中铁、氨态氮、氟化物、硝酸盐和6价铬含量的两组数据值接近,无明显差异.虽然国家标准法检测下限比快测法高一个数量级,但快速设备的测定结果不影响操作员对水质的判断,说明该水质快速检测设备精密度高;两种测定方法的稳定性比较,结果快速测定法的5个指标数据的相对偏差略高于国家标准法(3.92％),但其测定结果能够较好地满足现场测定要求,说明该水质快速检测设备稳定性良好.[结论]该水质快速检测设备的检测精度和稳定性较高,可满足水质的现场快速检测要求.     

苦瓜对白粉病的抗性与相关生理生化指标的关系

为探讨苦瓜抗白粉病的生理生化机制,以对白粉病不同抗性的4个苦瓜品系为材料,研究苗期感染白粉病菌后,苦瓜叶片生理生化指标的变化。结果表明:接种后,叶绿素和可溶性蛋白质量分数均呈先上升后降低的趋势;可溶性糖质量分数呈下降-上升-下降-上升的趋势;抗病品系的可溶性糖、叶绿素质量分数和过氧化物酶(POD)、多酚氧化酶(PPO)活性均高于或显著高于感病品系和高感品系;抗病品系的抗坏血酸(AsA)质量分数的上升和下降的幅度均小于感病品系和高感品系;接种后10~20d,抗坏血酸过氧化物酶(APX)活性表现为抗病品系感病品系高感品系。叶绿素、可溶性糖质量分数和POD、PPO活性与病情指数呈显著或极显著负相关。综上说明,白粉病菌侵染苦瓜后,抗病品系可通过保持较高的叶绿素质量分数,增加可溶性糖、可溶性蛋白、AsA质量分数及增强POD、PPO、APX活性来提高抗病性。叶绿素、可溶性糖质量分数和POD、PPO活性均可作为苦瓜对白粉病抗性早期鉴定的指标。     

新疆甜菜丸粒化单粒种高密高产高糖栽培模式

在新疆适宜种植甜菜的生态区,通过选择甜菜丸粒化单粒种,在高密度种植条件下,依据不同栽培管理阶段特点采用合理的管理措施,以实现甜菜单产97.5～105.0t/hm2、含糖率15%以上的目标,从而构建甜菜丸粒化单粒种高密高产高糖栽培模式。     

水肥耦合对小麦/玉米带田产量及构成因素的影响

采用"3414"最优回归设计方案,于2007-2008年在甘肃省农业科学院张掖节水试验站,开展不同水肥耦合处理小麦/玉米带田产量效应研究。结果表明,不同水肥耦合模式对小麦/玉米带田产量的影响较大,其差异达极显著水平。其中,氮肥对产量的贡献最大,水分次之,磷肥最小,氮肥对带田混合产量的绝对贡献率达79.4%,而水分对带田混合产量的绝对贡献率达为52.9%;水肥耦合效应为:水氮耦合水磷耦合氮磷耦合;获得高产量12 952.5~13 880.0kg/hm2的施氮量为420~630kg/hm2、灌水量为5 550~6 750m3/hm2、施磷量为120kg/hm2。相关分析表明,施氮量和灌水量与间作玉米的穗粒数、千粒质量、穗粒质量、株高均呈极显著正相关,施氮量与间作小麦的穗粒质量、穗粒数呈极显著正相关。     

Design and performance of recirculating aquaculture system for marine finfish broodstock development

Tropical and subtropical climatic conditions in India present an ideal and unique opportunity for being the leader in tropical marine finfish aquaculture. However, the problem persist due to non-availability of marine finfish seed for the culture. In response to this problem, broodstock development of different tropical marine finfishes for seed production was started. The present study was undertaken to design a recirculating aquaculture system (RAS) and studying their performance in managing the various water quality required for the marine finfish broodstock development and breeding. The design of RAS, developed in the present study, included a broodstock tank, egg collection chamber, electrical pump, rapid sand filter, venturi type protein skimmer and biological filter. Two RAS were designed, one was stocked with a demersal fish species, orange spotted grouper (Epinephelus coioides) and the other was stocked with a pelagic fish species, Indian pompano (Trachinotus mookalee) at the rate 1 and 0.5 kg/m³ with a sex ratio of 1:1 and 1:2 (female: male) respectively. Various physio-chemical parameters, viz, total ammonia nitrogen (TAN), nitrite, nitrate, pH, alkalinity, temperature, free carbon dioxide (CO₂) and dissolved oxygen (DO) of both tank water were analyzed to assess the performance of recirculating aquaculture system in maintaining the water quality. Gonadal development of the fishes was assessed and the spawning performance was recorded and finally, economic performance of the system was also evaluated. During the entire experimental period, mean monthly total ammonia nitrogen was less than 0.07 and 0.06 mg L⁻¹ and mean monthly nitrite was less than 0.02 and 0.01 mg L⁻¹ in orange spotted grouper and Indian pompano RAS tanks respectively. The pH (7.8–8.2), DO (>4 mg/L) and alkalinity (100–120 mg/L) were found to be in optimum range in both recirculating aquaculture systems. Carbon dioxide was found to be nil during the entire experimental period in both the systems. In fact these levels were comparable or less than that is reported as the permissible limits for broodstock development. Indian pompano and Orange spotted grouper matured and spawning was obtained with production of fertilized eggs round the year. Economic evaluation showed the price of 10,000 fertilized eggs of orange spotted grouper to be US $ 1.33. The design of RAS devised in the present study is efficient in controlling and maintaining optimum water quality for broodstock development of both demersal and pelagic finfishes. The fishes stocked in RAS attained final maturation and round the year spawning was obtained.