基于EM38长江河口地区土壤盐渍化特征研究

运用电磁感应仪EM38,结合GIS技术和地统计方法对长江河口地区土壤含盐量的空间变异性进行研究,结果表明:EM38所测土壤表观电导率与土壤电导率(EG_(1:5))的相关系数均达到1%显著水平,其中以EM_h+EM_v为自变量的多元回归方程的拟合效果最好.盐分含量统计特征表明,土壤盐分含量变幅较大,且随着深度的增加变化幅度逐渐减小,各层土壤盐分含量均值介于0.713 6～0.813 7 g/kg之间,且随着深度的增加盐分含量均值逐渐增大,总体上盐分分布具有一定的底聚性;各土层含盐量均呈现中等变异强度.变异系数相差较大,在水平方向上含盐量的变异随深度的增加而逐步趋弱.盐分含量空间分布表明,各层土壤盐分含量由南向北、自东向西有逐渐降低的趋势,随着深度的增加土壤含盐量不断升高.盐化土面积百分比表明,该地区大部分为非盐化土,轻度盐化土和中度盐化土所占比例较小,但由于含盐母质和地下水矿化度两个主要因素的影响,土壤盐渍化的发生存在巨大的潜在性威胁,运用EM38测值解译所得土壤盐分含量真实地反映了研究区的土壤盐渍化状况,为该地区土壤盐渍化的改良及防范提供依据.     

时域核磁共振技术在木材科学研究领域的应用

时域核磁共振技术（TD-NMR）作为一种先进的表征手段,能快速、精准测量木材中自由水和吸着水的动态变化,也可以基于水分信息表征木材孔隙分布,因此已被广泛应用于木材科学研究领域。文中归纳了时域核磁共振技术用于测量木材含水率、水分性质、水分分布及木材孔隙分布的方法,并对主要研究结果进行综述,以期为相关领域的研究和应用提供理论参考。     

维生素C复配抗氧化剂对生物柴油氧化稳定性的影响

研究了添加维生素C、维生素C与TBHQ(特丁基对苯二酚)和邻苯二胺复配的抗氧化剂后,生物柴油的诱导期和酸值变化。结果表明,维生素C对生物柴油有微弱的抗氧化作用,添加0.1%维生素C使生物柴油的诱导期延长了29.5%,但使生物柴油的酸值在132 h时提高了5.4%;维生素C与TBHQ存在较弱的协同抗氧化作用,添加0.1%维生素C与0.05%TBHQ复配的抗氧化剂使诱导期延长至7.76 h并使酸值在132 h时较单独添加维生素C降低了11.7%;维生素C与TBHQ、邻苯二胺具有明显的协同抗氧化作用,添加0.1%维生素C与0.05%TBHQ、0.1%邻苯二胺的复配抗氧化剂使诱导期延长至11.6 h并使酸值在132 h时降低了56.8%,但过多添加维生素C会导致生物柴油酸值升高。维生素C与TBHQ、邻苯二胺复配抗氧化剂的适宜添加量是0.2%。     

秋水仙碱处理对鸦胆子幼苗生长的影响

[目的]探讨秋水仙碱处理诱导鸦胆子多倍体的可能性。[方法]以二倍体鸦胆子[Brucea javanica(L.)Merr.]为材料,用0.1%、0.3%、0.5%和1.0%的秋水仙碱对幼苗茎尖生长点进行点滴处理,研究其对鸦胆子生长的影响。[结果]0.1%、0.3%、0.5%、1.0%秋水仙碱处理不同程度地抑制了鸦胆子幼苗植株的生长速度,与对照植株相比,分别平均降低8.3%、36.4%、37.0%和55.4%。各处理鸦胆子幼苗叶片气孔保卫细胞纵径、横径、周长、等视野气孔数及叶绿粒数间存在显著差异;随处理浓度的增加,叶片气孔保卫细胞数减少,气孔变大,叶绿粒数增多。秋水仙碱顶芽生长点诱变处理后形成的瘤块严重影响诱变新梢次年生长。[结论]鸦胆子幼苗生长点秋水仙碱诱变处理获得多倍体植株的途径不可行。     

盐胁迫对航天诱变向日葵生理生化指标的影响

[目的]探究盐胁迫下航天诱变向日葵生理生化指标的变化。[方法]选用航天诱变向日葵作为试验材料,用不同浓度(0、0.3%、0.6%、0.9%、1.2%)Na Cl进行处理,分别测定其SOD活性、POD活性、MDA含量、可溶性蛋白含量、脯氨酸含量,分析盐胁迫对航天诱变向日葵生理生化指标的影响。[结果]随着盐浓度的增加,SOD活性随之上升,当盐浓度为0.6%时,SOD活性下降;POD活性随盐浓度的升高而上升;MDA、可溶性蛋白、Pro的含量随盐浓度的上升而下降,当盐浓度为0.9%时其含量呈增加趋势。[结论]航天诱变向日葵能在0.9%的盐浓度下正常生长。该研究结果可为筛选抗盐的向日葵新材料提供理论支持。     

培养基和pH值对大蒜茎盘不定芽诱导的影响

【目的】研究培养基和pH值对大蒜茎盘不定芽诱导的影响,明确诱导大蒜茎盘不定芽的最适培养基和pH值组合,为提高大蒜组织快繁效率提供参考。【方法】以西北农林科技大学园艺学院大蒜种质资源圃中大蒜品种G064的蒜瓣茎盘为外植体材料,在pH值6.0,6.5,7.0,7.5的MS、LS和B5培养基上进行离体培养并诱导不定芽,统计出芽诱导率和繁殖系数,并观察茎盘在最佳组合下的发育表现。【结果】大蒜茎盘外植体不定芽诱导率在偏碱性培养基中较高,且以pH 7.5的LS培养基最高,为80.3%;其次为pH 7.5的MS培养基,为75.5%。在pH 7.5的MS培养基上,大蒜茎盘不定芽繁殖系数最大,为15.0,明显高于其他组合。【结论】大蒜茎盘不定芽诱导的最佳培养基和其pH值组合为pH 7.5的MS培养基。在此培养基中,诱导2周可分化出芽和根,将不定芽继续培养可得到健壮的大蒜幼苗。     

葡萄成花分子生物学研究进展

开花是植物从营养生长向生殖生长转变的重要时期,而开花调控成为近年来植物分子生物学研究的热点。拟南芥中存在多条调控开花的信号途径如光周期途径、春化途径、赤霉素途径和自主途径等。目前,在葡萄中已经发现了许多葡萄花发育相关的重要基因,是拟南芥花发育相关基因的同源基因,并且绝大多数基因具有与拟南芥相似的功能。本文综述了开花相关基因在葡萄开花时间、花发育过程以及其他过程中的功能,以期为葡萄成花机制的深入研究提供一些参考。     

Sprouted Sorghum Extract Elicits Coleoptile Emergence,Enhances Shoot and Root Acclimatization,and Maintains Genetic Fidelity in indica Rice

The high growth-stimulating effect of plant extract has urged the plant biotechnologists to use natural supplements in the culture media instead of synthetic phytohormones. We advocated the effect of sprouted sorghum extract(SSE) on emergence, in vitro acclimatization, and genetic fidelity in coleoptile derived callus of indica rice variety ADT36. The use of SSE with Murashige Skoog medium efficiently acclimatized the root and shoot apical systems. A higher mat and seminal roots(3.4 g biomass) with an efficient shoot primordium elongation were observed with an increase in the concentration of SSE. Seeds treated with SSE medium showed higher germination and earlier coleoptile maturation about 48 h compared to untreated seeds, and there was a higher expression of e EF-1α with an increase in coleoptile length. B5 medium was effective on inducing embryogenic and nodular callus from 3-day-old coleoptile with 3.0 mg/L 2,4-dichlorophenoxyacetic acid and further proliferated effectively with 0.8 mg/L kinetin with a fresh weight of 180 mg. Highly significant regeneration was observed with combination of 2.5 mg/L 6-benzylamino purine and 3.0 mg/L α-naphthaleneacetic acid. The metabolic and genetic profiles of in vitro and directly cultivated plants were the same, examined through Fourier-transform infrared spectroscopy, random amplified polymorphic DNA(RAPD), inter-simple sequence repeat(ISSR) and R-ISSR(combination of RAPD and ISSR) markers, respectively, and thus confirming the significant efficacy of the SSE incorporated medium. Disarmed T-DNA was transformed to coleoptile derived callus through Agrobacterium tumefaciens LBA4404 and confirmed by GUS assay. The T-DNA integration was confirmed by DNA blot analysis using DNA from transient GUS-expressed explants. Thus, SSE can be used as a natural and organic supplement for organogenesis and efficient acclimatizations of shoot and root apical meristems in regenerated plants.     

Control of rubus stunt and stolbur diseases in Madagascar periwinkle with mycorrhizae and a synthetic antibacterial peptide

Three experimental treatments consisting of inoculation with an arbuscular mycorrhizal fungus, application of a synthetic antimicrobial peptide or application of a resistance inducer, were evaluated in Madagascar periwinkle as control methods for rubus stunt and stolbur diseases caused by ‘Candidatus Phytoplasma rubi’ and ‘Candidatus Phytoplasma solani’, respectively. Two experiments were conducted under controlled environment conditions. In the first experiment, 4 months after graft‐inoculating the phytoplasmas, the root colonization achieved by Rhizophagus irregularis significantly reduced both disease symptoms and the frequency of detection of the pathogens by real‐time PCR. In the second experiment, the antimicrobial peptide BP100 totally prevented disease symptoms, despite the molecular detection of the phytoplasmas in 75% and 50% of the plants inoculated with ‘Ca. Phytoplasma rubi’ and ‘Ca. Phytoplasma solani’, respectively, and was more effective than benzothiadiazole (BTH) at increasing resistance against the pathogenic infections. A potential combination of early mycorrhizal inoculation and BP100 antimicrobial peptide application is envisaged as a future control strategy for phytoplasma diseases.     

唐古特瑞香愈伤组织培养与再生体系建立

以唐古特瑞香幼嫩叶片为材料,进行愈伤组织诱导与植株再生试验,以期建立唐古特瑞香再生体系,为其无性系的快速繁殖奠定基础。将幼嫩叶片进行表面灭菌后接种于初代培养基中,初代培养时,存在褐化现象,愈伤诱导前需进行除褐培养,除褐后的外植体经愈伤诱导、不定芽分化、增殖培养、生根培养和幼苗出瓶移栽的试验过程,筛选出了最佳培养方案。除褐培养基以MS+6-BA 1.0 mg·L^-1+PVP 200 mg·L^-1效果较好,在此培养基上连续转移3次后褐变消失。愈伤诱导培养基为MS+6-BA 3.0 mg·L^-1+2,4-D 2.0 mgL^-1,诱导率95.5%;芽苗分化培养基为MS+ZT 2.0 mg·L^-1+TDZ 0.1 mg·L^-1+NAA 0.5 mg·L^-1,分化率93.2%,平均芽数为8.66条;不定芽增殖培养基为MS+6-BA 2.0 mg·L^-1+IBA 0.3 mg·L^-1,增殖倍数为12.21,平均苗高4.81 cm;生根培养基为1/2 MS+NAA 0.5 mg·L^-1,生根数平均为3.83条,生根率为88.72%以上;组培苗移栽于珍珠岩中生长良好,成活率达90%以上。本研究初步建立了唐古特瑞香再生体系,为其无性繁殖奠定了理论基础。