魔芋葡甘聚糖对丝素蛋白纺丝液及其膜稳定性的影响

以魔芋葡甘聚糖(KGM)和丝素蛋白(SF)为原料,以KGM/SF纺丝液凝胶强度为响应值,溶胀温度、底物配比和凝胶时间为影响因子,进行响应面优化设计。同时,调节底物配比,采用静电纺丝技术制备纳米纤维膜,通过力学测试、差式扫描量热分析分别对纳米纤维膜的拉伸强度和热特性进行研究。结果表明,KGM有效的提高SF纳米纤维膜的强度及热稳定性;溶胀温度、底物配比和凝胶时间为纺丝液凝胶强度的显著影响因子,两两交互作用对其纺丝液凝胶强度影响极显著,其数值分别为49.87℃、84.41%和58.80 min时,模型预测纺丝液凝胶强度达到最大值828.231 g·mm。     

玉米淀粉糖纳米纤维的制备及性质表征

采用高压静电纺丝法制备柠檬酸酯化交联的玉米淀粉糖的纳米纤维。通过扫描电镜可以看出,该方法可直接获得具有较好结构的玉米淀粉糖纳米纤维。经过70℃的热处理后,纤维的刚性降低,韧性增强,形貌可长时间保持不变。红外光谱和X-射线粉末衍射显示,玉米淀粉糖与柠檬酸发生了酯化交联反应。从纤维直径分布图中可以看出,柠檬酸含量增加,纤维直径变小,纤维均匀程度有所提高。     

晚稻根际土壤特性对CH4和N2O排放的影响

为进一步揭示水稻根际土壤特性对CH4和N2O排放的影响机理,采用静态暗箱/气相色谱法对晚稻不同品种的CH₄和N₂O排放通量进行了原位观测,并对CH₄和N₂O排放通量与水稻根际土壤特性的相关性进行了分析。结果表明：不同品种CH₄、N₂O季平均排放通量间存在差异,变化范围分别为9.27～14.57 mg/（m²·h）、7.16～15.28 μg/（m²·h）;CH₄排放通量与5 cm处土壤Eh值呈极显著负相关（p<0.01）,与pH值呈显著正相关（p<0.05）;N2O排放通量与5 cm处土壤Eh呈负相关,但不显著,与pH值呈显著负相关（p<0.05）。CH₄排放通量与0～7、7～13、13～20处土壤溶液中CH4浓度均呈显著正相关（p<0.05）,N₂O排放通量与7～13 cm处N₂O浓度呈显著正相关（p<0.05）;CH₄、N₂O排放通量与0～7、7～13、13～20 cm处土壤溶液pH值均呈显著负相关（p<0.05）,CH₄排放通量与电导率呈极显著正相关（p<0.01）,N₂O与电导率呈负相关,但不显著。因此,水稻根际土壤Eh、pH、电导率以及CH₄浓度是影响CH₄排放的重要因素,根际土壤pH与N₂O排放密切相关。     

Evaluation of A1, A2, A3, A4(M), A4(G) and A4(VZM) cytoplasms in iso-nuclear backgrounds for grain mold resistance

Breeding for resistance to grain mold, an economically important disease of sorghum, has been only partially successful. Hybrid technology is well developed in sorghum due to availability of the cytoplasm male sterility (CMS) system and at present almost all commercial hybrids are based on the A₁ CMS system. To compare the available alternate CMS systems for grain mold resistance, 72 hybrids were produced by crossing 36 A-lines (six CMS systems; A₁, A₂, A₃, A_4(M), A_4(G), A_4(VZM) each in six nuclear backgrounds) with two common restorers, and were evaluated during the 2006 and 2007 rainy seasons in grain mold nursery at ICRISAT. Data analyses indicated influence of cytoplasm on the responses of hybrids to grain mold infection as measured by panicle grain mold resistance (PGMR) score. The A₁ cytoplasm seemed to contribute to grain mold resistance followed by A_4(VZM) and A₂ cytoplasms. The A_4(M) cytoplasm had superior general combining ability (GCA) effects while the A₁ and A_4(VZM) cytoplasm based hybrids had superior specific combining ability (SCA) effects on the PGMR score. Almost all hybrids had significant mid-parent heterosis. The A₁ cytoplasm is the best suited for the development of sorghum hybrids for the rainy season adaptation with grain mold resistance. However, use of alternate cytoplasms (A₂ and A_4(VZM)) for hybrid development will not increase susceptibility to grain mold in commercial grain production.     

不同赤霉素和聚乙二醇处理对非洲狗尾草种子萌发和幼苗的影响

分别采用100、200、400mg/L赤霉(GA_3) 10%、15%、20%、25%的聚乙二醇(PEG)处理非洲狗尾草种子,研究GA_3和PEG对非洲狗尾草种子萌发的效应.结果表明,在适当浓度和处理时间范围内,GA_3和PEG溶液处理对非洲狗尾草种子的萌发有促进作用,可显著提高非洲狗尾草种子发芽率、芽长、根长、幼苗生长势、简化活力指数及活力比,其中以200mg/LGA3浸种24 h和10%PEG浸种24 h效果最好.     

NaCl和Na2SO4胁迫对玉米幼苗渗透调节物质含量的影响

研究了NaCl和Na₂SO₄胁迫对玉米幼苗电解质渗漏、根系活力及脯氨酸、可溶性糖、可溶性蛋白等渗透调节物质含量的影响。结果表明，玉米在NaCl作用下其电解质渗漏、根系活力及渗透调节物质含量的变化和Na₂SO₄胁迫相似，电解质渗漏、根系活力及渗透调节物质含量均随着盐浓度的增加而加剧。NaCl胁迫下增幅大于Na₂SO₄胁迫，表明NaCl胁迫对玉米幼苗的伤害大于Na₂SO₄胁迫。     

玉米ZmCOL3pro217启动子的克隆及功能分析

ZmCOL3是玉米开花期光周期调控网络中一个重要的功能基因,研究发现自然群体中该基因的启动子存在遗传变异,推测这些变异可能参与玉米开花调控。研究从热带血缘玉米材料CIMBL119中克隆了ZmCOL3启动子,命名为ZmCOL3pro217。序列比对发现,该启动子序列与温带血缘玉米B73序列存在1个217 bp大片段置换。生物信息学分析表明,ZmCOL3pro217含有分生组织特异性、光响应、胁迫响应等多个顺势作用元件,预测ZmCOL3pro217可能具有组织特异性,并通过响应光和胁迫反应参与玉米开花调控。进一步构建ZmCOL3pro217驱动gus报告基因表达载体,转化玉米,实时荧光定量PCR、酶联免疫吸附剂测定、GUS组织化学染色等研究结果发现,转基因植株中ZmCOL3pro217驱动gus基因在根和叶器官中高表达,而在茎、花丝和子粒中几乎不表达,证实ZmCOL3pro217是1个新的组织特异性表达启动子。     

Responses of C3 and C4 grasses to application of nitrogen and phosphorus fertilizer at two dates in the spring

In grasslands composed of C₃ and C₄ plants, a different pattern of response by the two photosynthetic types to fertilizer may change the floristic composition of the community. In this study, we evaluated the effects of an application of nitrogen (N) and phosphorus (P) fertilizer at two dates in the spring on the aerial growth of C₃ and C₄ grasses. Danthonia montevidensis and Stipa neesiana ( C₃), and Setaria geniculata and Sporobolus indicus (C₄), were selected from a native grassland of the Flooding Pampa, Argentina. Two consecutive experiments (early and late spring) were conducted in pots filled with the local soil. The C₃ grasses showed no response in aerial biomass, and only minor responses in aerial concentrations of N and P, numbers of leaves and tillers, and nutrient use efficiency to an application of P or N fertilizer. In contrast, their C₄ counterparts showed a consistent positive response. C₄ species performance was considerably influenced by date of fertilizer application in the spring. There was on average a 1·8 and a 2·5 increase in aerial biomass in early and late spring, respectively, to fertilizer application. The later date in spring was associated with higher ambient temperatures and it appeared that temperature rather than fertilizer application was the main limiting factor for C₃ species. It was concluded that the positive response in C₄ species to an application of P and N fertilizer indicates that the differences between C₃ and C₄ species were related to a higher demand to sustain greater growth rates in C₄ species.     

抗稻瘟病Pid3/Pid3-A4基因特异InDel分子标记开发与应用

为更加高效利用抗稻瘟病基因Pid3/Pid3-A4,通过分析3K水稻测序数据中Pid3基因等位变异,设计了Pid3和Pid3-A4基因特异InDel分子标记Pdg-C与PA4-C,利用这2个标记对中国杂交水稻常用亲本材料或品种以及美国水稻微核心种质资源进行检测.结果 显示,Pdg-C和PA4-C能够分别快速、准确、经济地区分Pid3和Pid3-A4基因;通过克隆测序、表达分析及接菌鉴定,明确了水稻品种华占携带Pid3基因,栽培稻311100携带Pid3-A4基因,它们作为抗病基因供体更便于在水稻育种中利用.     

The effects of nitrogen rate and the ratio of NO3:NH4 on Bemisia tabaci populations in hydroponic tomato crops

Nitrogen fertilization is one of the factors that influences Bemisia tabaci (Gennadius) population density. The aim of this study was to determine the effects of three N application rates (75, 205 and 335 mg/l) and three ratios of NO₃⁻:NH₄⁺ ions (92:8, 75:25 and 55:45) in standard nutrient solution (205 mg/l N) on the population density of B. tabaci. The experiments were conducted on spring-summer hydroponic crops of tomato. The effect of plant stratum on the whitefly population was also determined. The aggregation of B. tabaci adults as well as their oviposition rate was higher at 205 and 335 mg/l N than on plants grown at 75 mg/l N. By the end of the experiment (60 d after infestation), the number of nymphs on plants at 205 mg/l N was higher than on plants at 75 mg/l N. The number of pupae was lowest on plants supplied with 75 mg/l N. An increase in NH₄⁺ percentage in standard nutrient solution (from 25% to 45% of the total N) reduced adult population density and oviposition rate. The density of nymphs and pupae, at 60 d after infestation, was lower on the tomato plants grown at 75:25 and 55:45 NO₃⁻:NH₄⁺ ratios compared to the 92:8 ratio. The 75:25 and 55:45 NO₃⁻:NH₄⁺ ratios resulted in a higher incidence of blossom-end rot of tomato fruit, with a lower incidence of disorder at 75:25 than at the 55:45 ratio. Plant stratum influenced adult whitefly distribution in two years of the study. Middle stratum leaves were more attractive to adults in both years. The results demonstrate the effects of N fertilization (N rate and the ratio of NO₃⁻:NH₄⁺) and plant stratum on B. tabaci population density.     

QTL identification of kernel composition traits with popcorn using both F2:3 and BC2F2 populations developed from the same cross

Quantitative trait loci (QTL) influencing three main kernel composition traits, starch, protein and oil concentrations, in unselected F_2:3 and selected BC₂F₂ maize populations derived from the same cross of a dent corn inbred Dan232 × an elite popcorn inbred N04 under the same conditions were detected. Four and two QTL for starch, four and three QTL for protein, and four and one QTL for oil were detected in the two populations, respectively, with three QTL jointly detected. The proportion of phenotypic variation explained by a single QTL was 5.2–10.6%, 5.0–14.3%, and 6.2–8.5% for the three traits. Ten QTL had favorable alleles contributed by Dan232. Several QTL detected in this study had identical or similar chromosome regions to those previously identified with other maize germplasms. No QTL with opposite effects for kernel composition traits and popping characteristics were detected in the same or near marker intervals. This reflected that some QTL detected in this study seemed to contribute to trait variation in a diverse array of maize populations and environments, and the opportunity existed for improving popcorn's nutritional quality while maintaining acceptable popping characteristics. Inconsistent broad sense heritability and trait correlation estimates were also observed in the two populations.     

肥料增效剂对夏玉米植物学性状、产量构成及土壤中NH4+-N和NO3--N的动态影响

2014、2015年夏季,试验采用单因素随机区组设计,以先玉335为材料,设置两种肥料增效剂、7种施肥方式,研究大喇叭口期和抽雄期植物学性状、施肥后0、14、28、42 d时0~30 cm和31~60 cm土壤中NH_4~+-N和NO_3~--N含量以及收获时玉米穗部性状和产量差异。结果表明,分期施肥比全部氮肥作底肥更能促进夏玉米茎粗、叶面积、气生根数量、穗长、穗行数和行粒数等增加。与对照和不施用肥料增效剂相比,0~30 cm和31~60 cm土层中施用两种肥料增效剂的NH_4~+-N含量较高,NO_3~--N含量较低,控制了NH_4~+/NO_3~-比例。两种肥料增效剂相比,Entrench效果明显优于NMAX。