26个玉米杂交组合农艺性状的相关性与主成分分析

为有效筛选杂交玉米种F1代的优势种,以内蒙古奈曼旗当地的推广品种‘京科958’(’JK958’)作为对照样品,观察和测量了26个玉米杂交组合F1代16个不同的农艺性状,通过统计学分析筛选出品系57、品系582、品系264、品系320等与对照样品‘JK958’农艺性状相近。应用多元统计分析,将多维彼此无关的杂交玉米的多个农艺性状数据线性简化,得出的结果更加直观易懂。通过分析结果可更加直观地看出品系(品种)之间的亲缘关系,这一分析方法可为玉米杂交种多个农艺性状的量化分析提供一个全新的思路,能够有效缩短培育周期,简化选育过程,也可为日后玉米杂交育种的筛选工作给予参考。     

Effect of a Chemical Modified Urea Fertilizer on Soil Quality: Soil Microbial Populations Around Corn Roots

Slow‐release nitrogen (N) fertilizers are used to increase N‐use efficiency and extend N availability over a plant‐growing season. One formula of this fertilizer commonly used in turf and horticultural crops is methylene–urea–triazone. After this compound is applied in the soil, it is subject to bacterial degradation and becomes available for uptake by plants. The objective of this work is to elucidate the application of methylene–urea–triazone in the soil microbial population as well as effects on soil quality. Zea mays was planted in a silty loam soil. Urea and methylene–urea–triazone were incorporated into the soil. Two weeks and 6 weeks after inoculation, soil samples were collected and used to inoculate agar plates and for DNA extraction. Bacterial colony morphology was examined. Denaturing gradient gel electrophoresis (DGGE) was performed with the polymerase chain reaction (PCR) amplicons from the internal transcribed spacer (ITS) of the rRNA gene cluster. The Shannon Wiener index was determined for colony morphology and DGGE bands. There was a difference between urea and the slow‐release fertilizer on both plant responses and bacterial diversity. Although for the first 2 weeks DGGE did not show any difference in bacterial diversity, after 6 weeks, differences in the composition of the bacterial community were observed. There were concomitant effects on plant growth and microorganism population and diversity, probably reflecting changes in the richness and in the eveness of the bacterial population in the rhizosphere caused by the fertilizers. Therefore, both soil microorganisms and plant growth respond to environmental changes over time.     

2013年怀来县二代粘虫的发生与防控

介绍了2013年怀来县二代粘虫的发生情况和防控效果，总结了防治工作中采取的措施和存在的主要问题，并提出了今后有效防控粘虫的对策。     

Crop management and phenology trends in the U.S. Corn Belt: Impacts on yields, evapotranspiration and energy balance

Crop yields are affected by many factors, related to breeding, management and climate. Understanding these factors, and their relative contributions to historical yield increases, is important to help ensure that these yield increases can continue in the future. Two important factors that can affect yields are planting dates and the crop's growing degree day (GDD) requirements. We analyzed 25 years of data collected by the USDA in order to document trends in planting dates, lengths of the vegetative and reproductive growth periods, and the length of time between maturity and harvest for corn and soybeans across the United States. We then drove the Agro-IBIS agroecosystem model with these observations to investigate the effects of changing planting dates and crop GDD requirements on crop yields and fluxes of water and energy. Averaged across the U.S., corn planting dates advanced about 10 days from 1981 to 2005, and soybean planting dates about 12 days. For both crops, but especially for corn, this was accompanied by a lengthening of the growth period. The period from corn planting to maturity was about 12 days longer around 2005 than it was around 1981. A large driver of this change was a 14% increase in the number of GDD needed for corn to progress through the reproductive period, probably reflecting an adoption of longer season cultivars. If these changes in cultivars had not occurred, yields around 2005 would have been 12.6 bu ac⁻¹ lower across the U.S. Corn Belt, erasing 26% of the yield increase from 1981 to 2005. These changes in crop phenology, together with a shortening of the time from maturity to harvest, have also modified the surface water and energy balance. Earlier planting has led to an increase in the latent heat flux and a decrease in the sensible heat flux in June, while a shorter time from maturity to harvest has meant an increase in net radiation in October.     

Hardware-based image processing for high-speed inspection of grains

A high-speed, low-cost, image-based sorting device was developed to detect and separate grains having slight color differences or small defects. The device directly combines a complementary metal–oxide–semiconductor (CMOS) color image sensor with a field-programmable gate array (FPGA) which was programmed to execute image processing in real-time, without the need of an external computer. Spatial resolution of the imaging system is approximately 16 pixels/mm. The system includes three image sensor/FPGA combinations placed around the perimeter of a single-file stream of kernels, so that most of the surface of each kernel is be inspected. A vibratory feeder feeds kernels onto an inclined chute that kernels slide down in a single-file manner. Kernels are imaged immediately after dropping off the end of the chute and are diverted by activating an air valve. The system has a throughput rate of approximately 75 kernels/s per channel which is much higher than previously developed image inspection systems. This throughput rate corresponds to an inspection rate of approximately 8 kg/h of wheat and 40 kg/h of popcorn. The system was initially developed to separate white wheat from red wheat, and to remove popcorn having blue-eye damage, which is indicated by a small blue discoloration in the germ of a popcorn kernel. Testing of the system resulted in accuracies of 88% for red wheat and 91% for white wheat. For popcorn, the system achieved 74% accuracy when removing popcorn with blue-eye damage and 91% accuracy at recognizing good popcorn. The sorter should find uses for removing other defects found in grain, such as insect-damaged grain, scab-damaged wheat, and bunted wheat. Parts for the system cost less than $2000, suggesting that it may be economical to run several systems in parallel to keep up with processing plant rates.     

朝特Ⅵ多效复合种衣剂在玉米上的应用效果

[目的]探讨朝特Ⅵ多效复合种衣剂在玉米生产中的应用效果,为玉米抗旱保苗增产提供有效措施。[方法]采用朝特Ⅵ多效复合种衣剂对玉米种子进行包衣与不包衣处理,对包衣玉米与未包衣玉米生育期土壤水分、生长状况及产量进行对比观测。[结果]玉米种子包衣吸水抗旱,提早出苗率27%,提高出苗率19%,3叶期株高平均增加1.4 cm,茎粗平均增加0.1 cm,根长增加1.6 cm,根系多2.5条,根重多2.4 g;拔节期平均株高增加2.7 cm,茎粗增加0.1 cm,平均每株叶面积增加126.4 cm2;虫害减少12个百分点,平均增产14.9%。[结论]朝特Ⅵ多效复合种衣剂具有蓄水保墒、提高种子活力、防止芽干、增加出苗率的效果,适合在辽西干旱地区推广。     

Spatial and Temporal Variability of Soil Organic Carbon in the Corn Belt of Northeastern China, 1980s–2005: A Case Study in Four Counties

Estimates of changes and possible causes of regional soil organic carbon (SOC) are critical for evaluation of potential responses of terrestrial biosphere to global changes. A total of 382 soil samples, collected in the 1980s from four counties in the Corn Belt of northeastern China, and of 1,514 samples collected in 2005 from the same area, were examined for SOC concentrations. Spatial and temporal SOC concentrations were evaluated after the 25-year interval using geostatistics and kriging interpolation method. Results indicated that the average topsoil SOC concentrations of the study area increased from 1.24% in the 1980s to 1.47% in 2005. Spatial distributions of SOC in the two separate evaluations showed greater SOC concentrations in the middle part of the study area and lower SOC concentrations in the remaining areas. From the 1980s to 2005, SOC concentrations in the central part increased, whereas those in the northeastern and southwestern parts decreased. The increasing trend of SOC concentrations might be attributed to the land-use and land cover changes, crop productivity increase, and agricultural management.     

Effect of pH on soil magnesium and its absorption by corn

Abstract

Lime induced depression of exchangeable Mg had been observed previously and it was postulated that yield decreases, which frequently occur at high pH levels may in some instances be due to Mg deficiency. This study was conducted to evaluate the influence of pH on exchangeable Mg in a wide range of acid soils and to determine the effects on recovery of Mg by corn (Zea mays L.) in the greenhouse. Treatments consisted of five pH levels, three P levels, and three Mg levels. Soil Mg was extracted with two neutral salt solutions and double acid. Salt extractable Mg decreased markedly at near neutral pH values, but double acid extractable Mg remained essentially unchanged. In several of the soils where yields were depressed at the highest pH levels, plant Mg content was also significantly lower. However, yield depressions were not ameliorated by Mg applications and could not be ascribed to induced Mg deficiency. Decreased plant uptake of Mg at both low and high pH levels was considered to have resulted from competitive effects between Mg and Al. The evidence suggested that salt extractable Mg did not accurately reflect plant availability.

Because soil reaction has profound effects on the availability of aluminum and many elements essential to plants, liming should be practiced primarily to optimize the utilization of the nutrient resources of soil. While pH values near neutrality are regarded as optimal in many areas of the world, particularly where legumes have traditionally been part of the rotational system, yield depressions have sometimes been reported at such pH levels on highly weathered acid soils of tropical and subtropical origin.     

Response of Corn Growth in Salt‐Affected Soils of Northeast China to Flue‐Gas Desulfurization By‐product

Abstract

In semiarid and arid regions, plant growth is limited by high pH, salinity, and poor physical properties of salt‐affected soils. A field experiment was conducted in the semiarid region of Kangping in northeast China (42°70′ N, 123°50′ E) to evaluate a soil‐management system that utilized a by‐product of flue‐gas desulfurization (FGD). Soil was treated with 23,100 kg ha^?1 of the by‐product. Results of corn growth were grouped into three grades (GD) according to stages of corn growth: GD1, seeds did not germinate; GD2, seeds germinated but corn was not harvested; and GD3, plants grew well and corn was harvested. The pH, electrical conductivity (EC), bicarbonate (HCO₃ ^?), carbonate (CO₃ ^2?), exchangeable and soluble calcium (Ca²⁺), chloride (Cl), and sulfate (SO₄ ^2?) in surface soils of the three grades (>20 cm) was measured to assess the correlation between corn growth and soil properties. Vertical differences in subsoil properties (0‐100 cm) between GD1 and GD3 were compared to known benchmark soil profiles. The FGD by‐product significantly increased EC, exchangeable and soluble Ca²⁺, and SO₄ ^2? and decreased CO₃ ^2?, exchangeable sodium (Na⁺), and soluble Na⁺. pH, EC, HCO₃ ^?, CO₃ ^2?, and Cl^? were higher in surface soils of GD1 than GD3. Soil hardness, soil moisture content, Cl^?, and calcium carbonate (CaCO₃) were higher in GD1 than in GD3, whereas the amount of available P was lower in GD1. Interestingly, the concentration of Cl^?, a toxic element for plant growth, was 2.5 and 1.5 times higher in GD1 than in GD3 and control soil, respectively. In the comparison study of subsoils, GD1 and GD3 were classified as having typical characteristics of saline‐alkali soil (pH>8.5; exchangeable‐sodium‐percentage [ESP]>15; EC>4.0) and alkali soil (pH>8.5; ESP>15; EC<4.0), respectively.     

先玉335对吉林省玉米产业发展的机遇与挑战

先玉335的推广极大地提高了吉林省玉米产量和质量,耐密品种得到全面普及,精量播种技术得到农民认可,品种广适安全的概念被强化。先玉335促进吉林省玉米种业建立工程化育种体系,提升企业育种技术与方法,种子质量全面提高,玉米品种示范网络和售后服务体系更加完善。