蚕豆（Vicia faba L.）基因组较大（约13 Gb），尚无参考基因组，与其他豆类相比，蚕豆遗传研究落后很多。鉴于此，本研究选择三个蚕豆纯系（云豆8137、H0003712和H000572）作为亲本，构建了两个F₂群体，其中群体1（云豆8137×H0003712）包含167个单株，群体2（H000572×云豆8137）包含204个单株；利用Targeted next-generation sequencing（TNGS）基因分型平台，对两个F₂群体进行基因分型，构建了两个高密度的蚕豆SNP遗传连锁图谱。基于群体1构建的图谱包含5103个SNP标记，长度1333.31 cM，平均标记密度0.26 cM；基于群体2构建的图谱包含1904个SNP标记，覆盖长度1610.61 cM。利用上述两个遗传连锁图谱及两个F₂群体，挖掘了与蚕豆花、荚、株型和籽粒相关的14个农艺性状的98个QTLs。此外，本研究对上述两个遗传连锁图谱进行整合，构建了一张包含6895个SNP标记，覆盖长度3324.48 cM的整合图谱。本研究不仅为蚕豆相关基因的图位克隆奠定了基础，还有助于推动蚕豆分子标记辅助育种的发展。

地膜覆盖已成为干旱、半干旱地区农业生产中维持作物高产的重要手段。然而，农田土壤中残留地膜也引发了更多的关注。为研究残留地膜对土壤养分、土壤微生物、作物生长和产量的影响，共开展了以下三个试验，包括残膜量为0、450、1350和2700 kg ha^-1的7年大田试验和4年盆栽试验，以及残膜量为1350 kg ha^-1时，残膜碎片单边长分别是2–5、5–10、10–15和15–20 cm的6年田间试验。研究发现，残膜对0–2.0（或0–1.8）m的田间土壤水分几乎没有影响，对0-20 cm土壤的有机碳、全氮、无机氮、全磷和速效磷均无显著影响。相对于非膜际土壤，附着于残膜表面的土壤细菌群落的多样性和丰度有所降低，而对离开残膜表面的土壤微生物群落没有显著影响。不同大小的残膜碎片使小麦和小扁豆的田间出苗率偶有显著降低。含有450-2700 kg hm^-1的残膜降低了玉米的株高和茎粗，收获期玉米的地上生物量显著降低11-19%。随着残膜量的增加，玉米和马铃薯的7年平均产量虽然呈下降趋势，但各处理间差异不显著。这些结果为全面科学地认识旱地农业系统中残留地膜对土壤和作物的影响提供了重要数据。

籽粒灌浆速率（GFR）在小麦产量形成过程中起着关键作用，但由于表型调查困难等原因，对其遗传解析研究甚少。本研究测定了1个重组自交系群体和1个自然群体籽粒灌浆性状，基于高密度图谱进行相关性状的连锁分析和全基因组关联分析。在染色体 1B、4B和5A上鉴定到17个稳定的QTLs。 其中IWB19555-IWB56078 连锁区间对性状 GFR₁、GFR_max、KL、KW、KT 和TKW具有多效性，表型变异解释率（PVE）为13.38%（KW）- 33.69%（TKW）。检测到198个显著性状关联位点（MTAs）分布在除了3D和4D之外的染色体上。GFR的主要关联位点包括 IWB44469（11.27%）、IWB8156（12.56%）和IWB24812（14.46%）。检测到IWB41019是籽粒大小相关的重要多效性位点。通过GWAS鉴定到的IWB35850与连锁分析获得的QGFR_max2B.3-11位于同一区域，该区域包含两个高置信候选基因。检测到两个重要的粒重相关 QTL与灌浆速率 QTL定位到同一区间。这些发现有助于解析 GFR 的遗传基础，为小麦产量性状 QTL候选基因预测提供理论依据。

Ten populations of Radopholus similis from different ornamental hosts were tested for their parasitism and pathogenicity to water spinach (Ipomoea aquatic), malabar spinach (Basella rubra), and squash (Cucurbita moschata) in pots. The results showed all three plants were new hosts of R. similis. Growth parameters of plants inoculated with nematodes were significantly lower than those of healthy control plants. All R. similis populations were pathogenic to the three plants, but pathogenicity differed among populations from different hosts. The same R. similis populations also showed different pathogenic effects in the three different plants. RadN5 population from Anthurium andraeanum had the highest pathogenicity to the three studied plants. RadN1 from A. andraeanum had the lowest pathogenicity to squash and RadN7 from Chrysalidocarpus lutesens had the lowest pathogenicity to water spinach and malabar spinach. R. similis is usually associated with root tissues, but here we report that it could be found to move and feed in the stem bases of all three studied plants. Sequence and phylogenetic analyses of DNA markers of the 18S rRNA, 28S rRNA, ITS rRNA, and mitochondrial DNA gene sequences of ten R. similis populations revealed significant genetic diversity. RadN5 and RadN6 populations from anthurium showed a close genetic relationship and could be distinguished from other populations by PCR-RFLP. At the same time, RadN5 and RadN6 populations were the most pathogenic to three studied plants. These results confirm the existence of large biological variability and molecular diversity among R. similis populations from the same or different hosts, and these characteristics are related to pathogenic variability.

Planting grass and legume mixtures on improved grasslands has the potential advantage of realizing both higher yields and lower environmental pollution by optimizing the balance between applied N fertilizer and the natural process of legume biological nitrogen fixation. However, the optimal level of N fertilization for grass-legume mixtures, to obtain the highest yield, quality, and contribution of N2 fixation, varies with species. A greenhouse pot experiment was conducted to study the temporal dynamics of N2 fixation of alfalfa (Medicago sativa L.) grown alone and in mixture with smooth bromegrass (Bromus inermis Leyss.) in response to the addition of fertilizer N. Three levels of N (0, 75, and 150 kg ha–1) were examined using 15N-labeled urea to evaluate N2 fixation via the 15N isotope dilution method. Treatments were designated N0 (0.001 g per pot), N75 (1.07 g per pot) and N150 (2.14 g per pot). Alfalfa grown alone did not benefit from the addition of fertilizer N; dry matter was not significantly increased. In contrast, dry weight and N content of smooth bromegrass grown alone was increased significantly by N application. When grown as a mixture, smooth bromegrass biomass was increased significantly by N application, resulted in a decrease in alfalfa biomass. In addition, individual alfalfa plant dry weight (shoots+roots) was significantly lower in the mixture than when grown alone at all N levels. Smooth bromegrass shoot and root dry weight were significantly higher when grown with alfalfa than when grown alone, regardless of N application level. When grown alone, alfalfa’s N2 fixation was reduced with N fertilization (R2=0.9376, P=0.0057). When grown in a mixture with smooth bromegrass, with 75 kg ha–1 of N fertilizer, the percentage of atmospheric N2 fixation contribution to total N in alfalfa (%Ndfa) had a maximum of 84.07 and 83.05% in the 2nd and 3rd harvests, respectively. Total 3-harvest %Ndfa was higher when alfalfa was grown in a mixture than when grown alone (shoots: |t|=3.39, P=0.0096; root: |t|=3.57, P=0.0073). We believe this was due to smooth bromegrass being better able to absorb available soil N (due to its fibrous root system), resulting in lower soil N availability and allowing alfalfa to develop an effective N2 fixing symbiosis prior to the 1st harvest. Once soil N levels were depleted, alfalfa was able to fix N2, resulting in the majority of its tissue N being derived from biological nitrogen fixation (BNF) in the 2nd and 3rd harvests. When grown in a mixture, with added N, alfalfa established an effective symbiosis earlier than when grown alone; in monoculture BNF did not contribute a significant portion of plant N in the N75 and N150 treatments, whereas in the mixture, BNF contributed 17.90 and 16.28% for these treatments respectively. Alfalfa has a higher BNF efficiency when grown in a mixture, initiating BNF earlier, and having higher N2 fixation due to less inhibition by soil-available N. For the greatest N-use-efficiency and sustainable production, grass-legume mixtures are recommended for improving grasslands, using a moderate amount of N fertilizer (75 kg N ha–1) to provide optimum benefits.

The objective of this study was to establish an efficient system of producing early monozygotic twin bovine embryos in vitro using the blastomere separation and coculture technique. In this study, early eight-cell embryos were chosen to optimize the separation method, and multi-coculture tactics were applied to improve the efficiency of this production system. Bovine embryo blastomeres (groups of at least 30 at the eight-cell stage) were separated into eight segments (to regard an eight-cell embryo as a tangerine, a blastomere as one segment) and one, two and four segments (blastomeres) were cultured respectively in microwells on the bottom of the four-well dish (Nunc, Denmark) with 400 μL of culture medium under paraffin oil. Four different types of coculture tactics (cocultured with nothing, intact embryos, bovine cumulus cells (bCCs), intact embryos & bCCs) were applied to the group of four segments (blastomeres). Finally, diameter and inner cell mass (ICM):trophectoderm (TE) cell ratio was measured as a criterion to assess the quality of the twin embryos which were derived from bovine separated blastomeres. Our results showed that rate of blastocyst formation of the four segments group was significantly greater than one or two group (P<0.05). In addition, rate of blastocyst formation was significantly increased when the four segments were cocultured with intact embryo & bCCs (P<0.05). Although the ICM, TE and total cells of blastocysts derived from separated blastomeres was less than the control group from intact embryo (P<0.05), more important quality indicator of the blastocyst diameter and ICM:TE cell ratio was similar between our experimental group and the control group (P>0.05). Thus, these results suggest that combined with intact embryos & bCCs coculture system, culturing four isolated segments (blastomeres) per microwell is an efficient system of producing early monozygotic twin bovine embryos. Furthermore, our results also indicate that the quality of blastocysts derived from separated blastomere may be similar to those derived from intact eight-cell embryos.

Water shortage is a serious issue threatening the sustainable development of agriculture in the North China Plain, with the winter wheat (Triticum aestivum L.) as its largest water-consuming crop. The effects of tillage practices on the water consumption and water use efficiency (WUE) of wheat under high-yield conditions using supplemental irrigation based on testing soil moisture dynamic change were examined in this study. This experiment was conducted from 2007 to 2010, with five tillage practice treatments, namely, strip rotary tillage (SR), strip rotary tillage after subsoiling (SRS), rotary tillage (R), rotary tillage after subsoiling (RS), and plowing tillage (P). The results showed that in the SRS and RS treatments the total water and soil water consumptions were 11.81, 25.18% and 12.16, 14.75% higher than those in SR and R treatments, respectively. The lowest ratio of irrigation consumption to total water consumption in the SRS treatment was 18.53 and 21.88% for the 2008-2009 and 2009- 2010 growing seasons, respectively. However, the highest percentage of water consumption was found in the SRS treatment from anthesis to maturity. No significant difference was found between the WUE of the flag leaf at the later filling stage in the SRS and RS treatments, but the flag leaf WUE at these stages were higher than those of other treatments. The SRS and RS treatments exhibited the highest grain yield (9 573.76 and 9 507.49 kg ha-1 for 3-yr average) with no significant difference between the two treatments, followed by P, R and SR treatments. But the SRS treatment had the highest WUE. Thus, the 1-yr subsoiling tillage, plus 2 yr of strip rotary planting operation may be an efficient measure to increase wheat yield and WUE.

Transgenic insect-resistant cotton is being increasingly planted in Xinjiang cotton-planting regions, where geographical climate conditions and species composition of pests and natural enemies are greatly unique in China. Limited studies have been conducted on the ecological impacts of transgenic insect-resistant cotton, especially for transgenic double genes (Bt+CpTI) cotton, in this region. In this study, the potential effects of transgenic Bt+CpTI cotton on the seasonal abundance of non-target pests and predators were assessed from 2009 to 2011 in Korla, Xinjiang. The results showed that species composition and seasonal abundance of 5 groups of pests and 5 groups of predators were not significantly different between transgenic Bt+CpTI cotton and non-transgenic cotton every year. It suggests that transgenic Bt+CpTI cotton per se does not affect the population dynamics of non-target pests and predators on this crop in Xinjiang.

To our knowledge, no single study has systemically compared cryopreservation efficiencies of bovine blastocysts derived from in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and somatic cell nuclear transfer (SCNT) by controlled freezing and vitrification. This experiment, therefore, was designed to compare the cryopreservation of these blastocysts with controlled freezing and OPS vitrification. Adenosine-5´-triphosphate (ATP) content and reactive oxygen species (ROS) level in blastocysts were also analyzed. Firstly, for each type of blastocyst (IVF, ICSI or SCNT), significant differences were observed between the survival rates of the controlled freezing ((81.56±2.33), (68.18±4.72) or (47.89±5.83)%) and OPS vitrification groups ((92.24±4.54), (82.40±3.76) or (78.71±5.91)%; P<0.05). Secondly, for each type of blastocyst (IVF, ICSI or SCNT), ATP content was significantly decreased after controlled freezing or vitrification, and the ATP content in the controlled freezing group (0.43±0.06), (0.35±0.05) or (0.21±0.02) pmol) was significantly lower than that found in the OPS vitrification group (0.62±0.04), (0.46±0.03) or (0.30±0.01) pmol; P<0.05). Thirdly, ROS level in fresh IVF ((47.33±3.56) c.p.s (counted photons per second), ICSI ((36.51±2.58) c.p.s) or SCNT blastocysts ((26.44±1.49) c.p.s) was significantly lower than that found in the OPS vitrification group ((72.14±4.31), (58.89±3.89) or (40.11±5.73) c.p.s; P<0.05), but higher than that of the controlled freezing group (34.41±3.32), (23.13±1.26) or (15.46±2.45) c.p.s; P<0.05). The present study indicated that vitrification is more efficient in the cryopreservation of bovine blastocysts derived from IVF, ICSI or SCNT than controlled freezing. Furthermore, both vitrification and controlled freezing significantly altered the ATP content and ROS level in those blastocysts.

Actin and myosin were found to be associated with the cytoplasmic sleeve of plasmodesmata. As cytoskeletal proteins, actin and myosin are believed to regulate the conductivity of plasmodesmata (PDs) in higher plants. Using immunocytochemical methods, we found the two proteins to be co-localized - and closely linked to each other - in plasmodesmata and ectodesmata-like structure in ageing parenchymatous cells of Allium sativum L. We suggest that intercellular communication is affected by the interaction between actin and myosin.

Behaviours of urediospore germtube in Melampsora larici-populina on the leaf surface of Populus purdomii were studied by light microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), and fluorescence microscope. Crab-like fusion cells on leaf surface, intercellular hyphal cells in leaf tissues, as well as nucleus states, were observed and counted up in this study. Under unsaturated humidity, 32% of germinated tubes fused into a distinguishable swollen crab-shaped cell at the merging site, and 10.5% of observed crab-like cells had more than three nuclei. Wedge-shaped mycelia developed and then penetrated the leaf surface directly, or indirectly through stomata. Tips of germtube passed through the intercellular cells of poplar leaves directly were found in TEM. Aniline blue dyeing also showed that the infecting hyphae could invade into the cuticle and epidemic cell wall directly. For the case of infection through stomata, there were two different situations. Short branches and wedge hyphae usually penetrated the leaf surface via opened stomata, whereas, some germtube branches and wedge hyphae penetrated leaves through the guard cell walls or stoma lips. In the latter case, the stomata were always closed. The samples from wild forestlands had the same fused cells and wedge hyphae, but the occurrence rate was much higher than that in the chamber. Even under the saturated air humidity, germtubes could roll back and formed fusion structure, or merged together with their tips. The fusion cells might centralize the plasma of merged germtubes and have a strong survival capacity to protect germtubes from dying under arid circumstances, and provide a chance of genetic variation as well.