本研究利用华北平原2年的田间定位试验，研究了条带深旋耕和控释尿素耦合对玉米产量和氮素利用效率的影响，及其氮素积累和产量形成的相关生理过程。与常规旋耕（RT）和免耕（NT）比，由于条带深旋耕（ST）使0-40 cm土层的土壤容重分别降低了10.5%和13.7%，从而显著提高了20-40 cm土层的土壤含水量和土壤矿质氮含量。与普通尿素（CU）比，控释尿素（CR）使开花期和成熟期0-40 cm土层的土壤矿质氮含量分别提高了12.4%和10.3%。因此，ST和CR显著提高了玉米根长和氮素总积累量，从而促进了叶片面积和干物质积累（特别是花后干物质积累）的增加，最终提高了玉米千粒重。ST处理产量比RT和NT处理分别提高了8.3%和11.0%，CR处理产量比CU处理提高8.9%。由于ST和CR耦合处理产量和氮素积累量的增加，显著提高了玉米氮素利用效率。综述可知，ST与CR结合可以通过改善土壤理化特性和氮素供应，进一步提高玉米产量和氮素利用效率，该措施可作为华北平原以及世界上其他类似地区的促进玉米可持续生产发展的有效措施。

MicroRNAs (miRNAs)是一类长度较小的非编码RNAs（约20-24个核苷酸），近年来被认为是基因表达的关键转录后调节因子，参与了植物多种生理生化过程，如根系生长与发育。miRNAs通过参与应答激素信号、营养吸收和生物/非生物胁迫反应来调节根系的伸长、侧根(AR)形成和不定根(AR)的发育。本文汇总了miRNAs参与调控植物根系生长发育的多方面的研究进展，还讨论了根系生长发育过程中miRNAs发挥功能的若干关键调控机制，miRNAs与转录因子的调控关系，以及与其靶基因介导的激素信号之间的相互调控作用。

Yield gap analysis could provide management suggestions to increase crop yields, while the understandings of resource utilization efficiency could help judge the rationality of the management. Based on more than 110 published papers and data from Food and Agriculture Organization (FAO, www.fao.org/faostat) and the Global Yield Gap and Water Productivity Atlas (www.yieldgap.org), this study summarized the concept, quantitative method of yield gap, yield-limiting factors, and resource utilization efficiency of the three major food crops (wheat, maize and rice). Currently, global potential yields of wheat, maize and rice were 7.7, 10.4 and 8.5 t ha^–1, respectively. However, actual yields of wheat, maize and rice were just 4.1, 5.5 and 4.0 t ha^–1, respectively. Climate, nutrients, moisture, crop varieties, planting dates, and socioeconomic conditions are the most mentioned yield-limiting factors. In terms of resource utilization, nitrogen utilization, water utilization, and radiation utilization efficiencies are still not optimal, and this review has summarized the main improvement measures. The current research focuses on quantitative potential yield and yield gap, with a rough explanation of yield-limiting factors. Subsequent research should use remote sensing data to improve the accuracy of the regional scale and use machine learning to quantify the role of yield-limiting factors in yield gaps and the impact of change crop management on resource utilization efficiency, so as to propose reasonable and effective measures to close yield gaps.

花生是重要的油料作物，培育高油品种是花生育种的主要目标之一。研究表明，干旱胁迫下花生叶片渗透压与其籽仁含油量呈显著负相关。基于这一原理，我们创建了利用离体诱变和渗透压定向筛选培育高油花生新品种的有效方法。以花生品种花育20号的种子胚小叶为外植体，平阳霉素(PYM)为诱变剂，羟脯氨酸(HYP)为渗透压调节剂进行离体诱变和定向筛选，最终获得15株HYP耐性再生植株。每个再生植株均有含油量 >55%的后代（而花育20号含油量为49.5%）。从HYP耐性植株后代中培育出3个高产高油花生新品种，宇花4号、宇花9号、宇花14号，含油量分别为57.7%、61.1%、59.3%。结果表明，PYM离体诱变后进行HYP离体定向筛选，是培育高油花生品种的有效途径。

Heat stress seriously affects wheat production in many regions of the world.  At present, heat tolerance research remains one of the least understood fields in wheat genetics and breeding and there is a lack of effective methods to quantify heat stress and heat tolerance in different wheat cultivars.  The objective of this study was to use various wheat cultivars to evaluate stress intensity (δ) and a new method for quantification of heat tolerance and compare this technique with three other currently utilized methods.  This new parameter for heat tolerance quantification is referred to as the heat tolerance index (HTI) and is an indicator of both yield potential and yield stability.  Heat treatments were applied in a controlled setting when anthesis had been reached for 80% of the wheat.  The stress intensity evaluation indicated heat shock was the main factor associated with kernel weight reduction while grain yield reduction was mainly associated with chronic high temperature.  The methods evaluation showed that a temperature difference of 5°C from natural temperatures was a suitable heat treatment to compare to the untreated controls.  HTI was positively correlated with yield under heat stress (r=0.8657, δ₂₀₁₀=0.15, in 2009–2010; r=0.8418, δ₂₀₁₁=0.20, in 2010–2011; P<0.01), and negatively correlated with yield reduction rate (r=–0.8344, in 2009–2010; r=–0.7158, in 2010–2011; P<0.01).  The results of this study validated the use of HTI and temperature difference control for quantifying wheat heat tolerance that included the yield potential and the stability of different wheat cultivars under heat stress.  Additionally, 10 wheat cultivars showed high HTI and should be further tested for their heat confirming characteristics for use in wheat heat tolerance breeding.

    Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars (Oryza sativa L. ssp. japonica) in large-scale cultivation in northeast China were determined to possess Oryza sativa L. ssp. indica-type cytoplasm using cytoplasmic subspecies-specific molecular markers. This was confirmed by cytoplasmic genome-wide single nucleotide polymorphisms (SNPs) and functional gene sequencing. Two of these five japonica cultivars were core breeding parents with high yield and the other three were super-high-yield varieties registered by the Ministry of Agriculture of China. We constructed nuclear substitution lines to further demonstrate whether and how this indica-type cytoplasm contributed to yield improvement by comparing yield components. The results showed that under the same japonica nuclear background, the lines with indica-type cytoplasm had a significant decrease in tillers in exchange for increased grain number per panicle compared with their recurrent parents. Our results implied that botanical basis of this cytoplasmic effect was to reduce the plant’s branching differentiation to produce more floral organs under the constant nutrition. Our findings open another door for the utilization of inter-subspecific hybridization for the improvement of rice cultivar.

The grain yield of maize has increased continuously in past decades, largely through hybrid innovation, cultivation technology, and in particular, recent genetic improvements in photosynthesis. Elite inbred lines are crucial for innovating new germplasm. Here, we analyzed variations in grain yield and a series of eco-physiological photosynthetic traits after anthesis in sixteen parental lines of maize (Zea mays L.) released during three different eras (1960s, 1980s, 2000s). We found that grain yield and biomass significantly increased in the 2000s than those in the 1980s and 1960s. Leaf area, chlorophyll, and soluble protein content slowly decreased, and maintained a higher net photosynthesis rate (Pn) and improved stomatal conductance (Gs) after anthesis in the 2000s. In addition, the parental lines in the 2000s obtained higher actual photochemistry efficiency (ФPSII) and the maximum PSII photochemistry efficiency (Fv/Fm), which largely improved light partitioning and chlorophyll fluorescence characteristic, including higher photochemical and photosystem II (PSII) reaction center activity, lower thermal energy dissipation in antenna proteins. Meanwhile, more lamellae per granum within chloroplasts were observed in the parental lines of the 2000s, with a clear and complete chloroplast membrane, which will greatly help to improve photosynthetic capacity and energy efficiency of ear leaf in maize parental lines. It is concluded that grain yield increase in modern maize parental lines is mainly attributed to the improved chloroplast structure and more light energy catched for the photochemical reaction, thus having a better stay-green characteristic and stronger photosynthetic capacity after anthesis. Our direct physiological evaluation of these inbred lines provides important information for the further development of promising maize cultivars.

Phosphorus (P) is an essential element for plant growth and yield. Improving phosphorus use efficiency of crops could potentially reduce the application of chemical fertilizer and alleviate environmental damage. Soybean (Glycine max (L.) Merr.) is sensitive to phosphorus (P) in the whole life history. Soybean cultivars with different P efficiencies were used to study P uptake and dry matter accumulation under different P levels. Under low P conditions, the P contents of leaf in high P efficiency cultivars were greater than those in low P efficiency cultivars at the branching stage. The P accumulation in stems of high P efficiency cultivars and in leaves of low P efficiency cultivars increased with increasing P concentration at the branching stage. At the late podding stage, the P accumulation of seeds in high and low P efficiency cultivars were 22.5 and 26.0%, respectively; and at the mature stage were 69.8 and 74.2%, respectively. In average, the P accumulation in whole plants and each organ was improved by 24.4% in high P efficiency cultivars compared to low P efficiency cultivars. The biomass between high and low P efficiency cultivars were the same under extended P condition, while a significant difference was observed at late pod filling stage. At the pod setting stage, the biomass of high P efficiency cultivars were significant greater (17.4%) than those of low P efficiency cultivars under high P condition. Meanwhile, under optimum growth conditions, there was little difference of biomass between the two types of cultivars, however, the P agronomic efficiency and P harvest index were significant higher in high P efficiency cultivars than those in low P efficiency cultivars.

Super high-yielding soybean cultivar Liaodou 14, soybean cultivars from Ohio in the United States, and the common soybean cultivars from Liaoning Province, China, with similar geographic latitudes and identical pod-bearing habits were used as the study materials for a comparison of morphological traits and production characteristics to provide a theoretical basis for the breeding of improved super high-yielding soybean cultivars. Using a randomized block design, different soybean cultivars from the same latitude were compared under conventional and unconventional treatments for their production characteristics, including morphological traits, leaf area index (LAI), net photosynthesis rate, and dry matter accumulation. The specific characteristics of the super high-yielding soybean cultivar Liaodou 14 were analyzed. The results showed that the plant height of Liaodou 14 was significantly lower than that of the common cultivars from Liaoning, whereas the number of its main-stem nodes was higher than that of the cultivars from Ohio or Liaoning. A high pod density was observed in Liaodou 14 under conventional treatments. Under both conventional and unconventional treatments, the branch number of Liaodou 14 was markedly higher than that of the common cultivars from Liaoning, and its branch length and leaf inclination angle were significantly higher than those of common cultivars from Liaoning or Ohio. Only small changes in the leaf inclination angle were observed in Liaodou 14 treated with conventional or unconventional methods. Under each treatment, Liaodou 14 exhibited the lowest amplitude of reduction in SPAD values and net photosynthesis rates from the grain-filling to ripening stages; the cultivars from Ohio and the common cultivars from Liaoning exhibited more significant reductions. Liaodou 14 reached its peak LAI later than the other cultivars but maintained its LAI at a higher level for a longer duration. Under both conventional and unconventional treatments, Liaodou 14 produced a higher yield than the other two cultivars, with significant differences from the Ohio cultivars. In summary, super high-yielding soybean cultivars have several main features: suitable plant height, high pod density, good leaf structure with strong functionality, and slow leaf senescence at the late reproductive stage, which is conducive to the accumulation of dry matter and improved yield.

With the rapid increment of the information on the web, traditional information retrieval based on the keywords is far from user’s satisfaction in recall and precision. In order to improve the recall ratio and the precision radio of IR engine in the vegetables e-commerce, an information retrieval model based on the vegetables e-commerce ontology is presented in this paper, vegetables e-commerce ontology was constructed by gathering and the analyzing vegetables e-commerce domain information on the web. The vegetables e-commerce ontology is composed of some kinds of vegetable classes and hierarchy relationship of vegetables classes. In the process of information retrieval, domain ontology helps to index information and information inference. An ontology-based information retrieval model is implemented, and which has more functions than the keyword-based web information retrieval engines. The experiment results show that the recall ratio and the precision ratio of ontology-based information retrieval model are higher than that of the information retrieval engine based on keyword at a certain extent.