水稻不育系‘培矮64S’空间搭载的“双低”选育与应用

【目的】解决水稻Oryza sativa L.两系不育系‘培矮64S’所面临的直链淀粉含量偏高和不育起点温度因遗传漂移而不断上升的问题,选育新的两系不育系。【方法】通过利用‘培矮64S’种子搭载"实践八号"农业卫星、地面种植和跟踪、定向筛选,筛选到具有低直链淀粉含量的稳定不育株系,同时结合水稻光温敏不育系的提纯和原种生产方法,对不育起点温度进行加压选择与鉴定。【结果】育成具有低直链淀粉含量(w为8.69%左右)、低不育起点温度(23.0℃以下)的新型"双低"不育系,命名为‘航17S’。该不育系株高79.62 cm,剑叶长32.54 cm、宽1.82 cm,有效穗数11.4个,穗长22.01 cm,每穗总粒数约181粒。除剑叶宽以外,其他主要性状均与野生型‘培矮64S’没有显著差异。【结论】‘航17S’除了具有"双低"特点以外,其他主要农艺性状表现与野生型‘培矮64S’基本一致,而且保留了‘培矮64S’的异交特性好、配合力强等优良特点,于2015年10月通过了广东省技术鉴定。     

鲈流刺网技术研究

对鲈流刺网的不同目大，网线规格，缩结系数进行了研究试验，结果：以目大１５５ｍｍ、网线规格０．６ｍｍ，水平缩结系数０．６为宜。３只１２马力渔船用此网生产一年半，创产值１９８．４元，利税１８０多万元。专家鉴定认为本成果居国内先进水平。     

果树喷雾机防风罩对喷雾射程的影响

在对果树施药中,为减少风力因素导致的雾滴漂移,经济而有效的方法是采用防风罩。该文对防风罩进行研究与设计,制作了6种防风罩。针对防护罩防风效果,在密闭实验室条件下进行喷雾试验,选用日本池内公司生产的两种喷头;喷头移动速度为：0.51、1.21、1.91、2.60、3.30、4.00 km/h;试验的内容包括喷雾射程和雾滴的沉积均匀度。试验结果表明：两种喷头在不同速度下采用防风罩＃4时的喷雾射程比采用其他防风罩和无防风罩时分别平均提高了1.3%～13.2%和9.1%～17.3%。     

干旱、盐胁迫条件下两种盐生植物生物量分配对策的研究

以2种一年生盐生草本植物钠猪毛菜、盐生草为试验对象,研究干旱和盐分胁迫对2种盐生植物生长和生物量分配的影响。结果表明:不同程度干旱和盐分胁迫显著影响了2种盐生植物的生长、生物量积累和生物量的分割。生长分析表明:2种盐生植物在生长率、根冠比、叶面积比方面皆存在明显可塑性,且根冠比、叶面积比的变化均受到个体发育漂变的影响;在整个营养生长期的不同处理组中,根冠比、叶面积比总体上呈逐渐降低趋势。不同干旱胁迫处理下2种盐生植物的根冠比和叶面积比的变化与最优理论和模型的预测相一致;随干旱胁迫的加重,根冠比增大而叶面积比减小。但在盐分胁迫条件下,2种盐生植物并未出现基于最优分配理论来调节生物量分配模式,且2种盐生植物根冠比和叶面积比的响应表现出明显的种间差异。此外,不同处理组间植物生物量分配特征(根冠比、叶面积比)的差异,往往只存在于生活史的某一时期,在整个营养生长期间,并不自始至终保持一致。     

植保无人机施药沉积飘移监测系统设计与应用

为提升植保无人机施药沉积飘移监测智能化水平,研发植保无人机施药沉积飘移监测系统,该系统机载监测终端实时获取药械状态参数、植保无人机状态参数及位置参数,通过数据处理服务系统将其发送至平台软件,基于作业参数利用沉积飘移预测模型实时监测药液沉积区域及飘移范围。该系统同时具有作业面积计量、飞行轨迹回溯、作业质量空间分析等功能。2015年4月于山东省威海市文登区泽头镇眠虎岭区域对该系统进行性能测试,植保无人机规划靶区作业面积为433 hm²,最终监测作业面积为405 hm²,施药覆盖率为93.5%;施药过程中实时监测沉积区域和飘移范围,受环境侧风影响,药液最大飘移距离可达40 m,系统整体达到预期设计要求。截至目前该系统已在山东、安徽、江苏、云南、河南、浙江、天津等多个省市应用。     

Application of a new wind driving force model in soil wind erosion area of northern China

The shear stress generated by the wind on the land surface is the driving force that results in the wind erosion of the soil. It is an independent factor influencing soil wind erosion. The factors related to wind erosivity, known as submodels, mainly include the weather factor(WF) in revised wind erosion equation(RWEQ), the erosion submodel(ES) in wind erosion prediction system(WEPS), as well as the drift potential(DP) in wind energy environmental assessment. However, the essential factors of WF and ES contain wind, soil characteristics and surface coverings, which therefore results in the interdependence between WF or ES and other factors(e.g., soil erodible factor) in soil erosion models. Considering that DP is a relative indicator of the wind energy environment and does not have the value of expressing wind to induce shear stress on the surface. Therefore, a new factor is needed to express accurately wind erosivity. Based on the theoretical basis that the soil loss by wind erosion(Q) is proportional to the shear stress of the wind on the soil surface, a new model of wind driving force(WDF) was established, which expresses the potential capacity of wind to drive soil mass in per unit area and a period of time. Through the calculations in the typical area, the WDF, WF and DP are compared and analyzed from the theoretical basis, construction goal, problem-solving ability and typical area application; the spatial distribution of soil wind erosion intensity was concurrently compared with the spatial distributions of the WDF, WF and DP values in the typical area. The results indicate that the WDF is better to reflect the potential capacity of wind erosivity than WF and DP, and that the WDF model is a good model with universal applicability and can be logically incorporated into the soil wind erosion models.     

Thunderstorms have species and gear-specific indirect effects on the catchability of Mongolian salmonids

Climate change is predicted to cause increasingly frequent and intense storms. Northern Mongolia is already warming at a rate twice the global average, and thunderstorms, defined as intense, short, patchy rains associated with thunder, lightning and high precipitation rates, are becoming more frequent. Because Mongolia's fish populations are lightly exploited, Mongolia provides a model system in which to study the effects of storms on fish behaviour and fishing vulnerability. The impacts of thunderstorm-related hydrological changes on fishes’ vulnerability to two fishing gears were evaluated. Two thunderstorm-related factors, turbidity and river stage, reduced catch rates of the salmonids lenok Brachymystax lenok (Pallas) and Baikal grayling Thymallus baicalensis Dybowski. Fly-fishing gear was more effective than spinning gear in this fishery and retained higher catch rates in extreme conditions. These gear-specific effects suggest that turbidity and rising river stage affect fishing vulnerability by influencing feeding behaviour.     

Deformation Capacity and Amount of Confining Reinforcement in Potential Plastic Hinge Regions of Rectangular Hollow Bridge Piers

Quasi static test results of 71 rectangular hollow bridge piers were collected to study the deformation capacity and amount of confining reinforcement in the potential plastic hinge region of the bridge piers. The deformation capacity of the hollow bridge piers with different failure modes were analyzed, and current codes provisions for the amount of confining reinforcement in hollow bridge piers were evaluated. Then, main factors influencing the deformation capacity of the piers were discussed based on multiple linear regression analysis and correlation analysis. At last, design equations based on Caltrans code of required confining reinforcement for rectangular hollow bridge piers were proposed. It is found that both the Caltrans and ACI codes show great reliability for the flexural failure mode and deformation capacity of the hollow bridge piers while the Chinese JTG/T B02-01-2008 code is unsafe. Also, the deformation capacity of the hollow bridge piers increases with the increase of the transverse reinforcement, longitudinal reinforcement, and web width, and decreases with the increase of the axial load ratio.     

Ecological effects on estimates of effective population size in an annual plant

Effective population size (N_e) is a critical indicator of the vulnerability of a population to allele loss via genetic drift, and it can also be used to assess the evolutionary potential of a population. While some plant conservation plans have focused on outcrossing through cross-pollination as a way to increase estimated N_e, variance in reproductive output determined by ecological factors such as competition can also strongly affect estimated N_e. We examined the effects of intraspecific and interspecific competition, stressful soils, and local adaptation on estimates of N_e in an annual plant species. While ecological influences on plant growth rate variance have been predicted to influence estimates of N_e/N, we found a significant effect on the estimate of N_e/N, but no significant ecological effects on growth rate variance. Lower survivorship on stressful soil was the most important effect reducing estimates of N_e/N. If stochastic mortality is greater in environments that are abiotically stressful, then populations in these stressful environments may be slower to adapt because of lower census sizes and reduction of N_e/N. In populations of conservation concern, increasing survivorship may be of greater benefit for maximizing N_e than the reduction of variability in reproductive output among surviving adults.