【目的】研究光合和氮素互作对大豆生长和光合作用的影响。【方法】以大豆黑农37为供试材料，采用接种根瘤菌和遮光相结合的手段，测定了接根瘤菌大豆在非遮光、遮光和复光条件下的生长及光合指标。【结果】非遮光条件下，接种根瘤菌显著提高了大豆的生物量、叶绿素含量和光合能力；遮光条件下，根瘤菌发挥不出其优越性，受气孔导度和非气孔因素的影响，接菌大豆的光合速率比不接菌的对照低；恢复光照后，接种根瘤菌大豆的光合作用恢复程度也不如不接菌对照。【结论】大豆与根瘤菌的共生固氮需要在合适光照条件下才能发挥其促进生长和促进光合作用的正效应。

研究了不同浓度的重金属Cu2+、Cr6+、Pb2+胁迫对绿豆(Phaseolus radiatus L.)种子萌发和幼苗初期生长的影响.结果表明:低浓度抑或高浓度Cu2+、Pb2+胁迫对绿豆种子发芽率的抑制不明显,但较高浓度(100mg/L)Cr6+胁迫严重抑制种子萌发率,在400mg/L抑制高达66%(表1).低浓度抑或高浓度Cu2+、Pb2+胁迫对绿豆初期生长抑制不明显,而Cr6+胁迫的抑制效应在浓度为50mg/L极为明显,并随浓度升高而加重.在400mg/L浓度时抑制其主根长、侧根数、株高及生物量分别高达93%、96%、75%、76%(鲜重计)57%(干重计)(表2～表6).研究结果表明:3种重金属胁迫对绿豆种子萌发和幼苗初期生长影响有差异,其毒害能力顺序为Cr6+＞Cu2+＞Pb2+.

Taking Phyllostachys edulis seeds as test material, the effects of Pb²⁺ and Cd²⁺ on seed germination and seedling early growth were studied. The results indicated that the germination rate increased at first and decreased subsequently with the increasing of Pb²⁺ and Cd²⁺ concentrations, and these concentrations negatively affected the germination index and vigor index. Meanwhile, there had an inhibitory action between Pb²⁺, Cd²⁺ and roots growth, stems growth and biomass accumulation, and this action was enhanced by the increasing of concentration in solution, especially for seedling roots, the inhibitory ratio could up to 96.20% and 94.00% at most, respectively. Although the increase of Pb²⁺ and Cd²⁺ concentrations in solution significantly increased both on the aboveground part and underground part, the accumulation amount underground were much higher than the former. The maximum differences between the aboveground and underground could be up to 27.21 times (for Pb²⁺) and 6.25 times (for Cd²⁺) at the same concentrations.

Nanoparticles (NPs) have been exploited in a diverse range of products in the past decade or so. However, the biosafety/environmental impact or legislation pertaining to this newly created, highly functional composites containing NPs (otherwise called nanomaterials) is generally lagging behind their technological innovation. To advance the agenda in this area, our current primary interest is focused on using crops as model systems as they have very close relationship with us. Thus, the objective of the present study was to evaluate the biological effects of magnetic iron oxide nanoparticles towards watermelon seedlings. We have systematically studied the physiological effects of Fe2O3 nanoparticles (nano-Fe2O3) on watermelon, and present the first evidence that a significant amount of Fe2O3 nanoparticles suspended in a liquid medium can be taken up by watermelon plants and translocated throughout the plant tissues. Changes in important physiological indicators, such as root activity, activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD), chlorophyll and malondialdehyde (MDA) contents, ferric reductase activity, root apoplastic iron content were clearly presented. Different concentrations of nano-Fe2O3 all increased seed germination, seedling growth, and enhanced physiological function to some degree; and the positive effects increased quickly and then slowed with an increase in the treatment concentrations. Changes in CAT, SOD and POD activities due to nano-Fe2O3 were significantly larger than that of the control. The 20 mg/L treatment had the most obvious effect on the increase of root activity. Ferric reductase activity, root apoplastic iron content, and watermelon biomass were significantly affected by exposure to nano-Fe2O3. Results of statistical analysis showed that there were significant differences in all the above indexes between the treatment at optimal concentration and the control. This proved that the proper concentration of nano-Fe2O3 could not only increase seed germination and seedling growth, but also ultimately improve physiological function and resistance to environmental stresses of watermelon.

以小麦为供试材料，分别采用发芽试验、溶液培养、土柱栽培等毒理试验方法，研究了小麦萌芽期、幼苗期及成株期受重金属污染毒害的指标体系。结果表明， ① 小麦根伸长抑制率可作为萌芽期重金属污染评价的一项生物指标；Cd、Cr、Pb对小麦根生长的7d半效应浓度（EC50）值分别为1.39、0.20mmol?L-1和2.75mmol?L-1，据此得到3种重金属对小麦同一性状的毒性次序为Cr＞Cd＞Pb；此外各性状抑制率与胁迫浓度的关系可用双曲线模型y=x/(a+x/100)或指数曲线模型y= a(1-exp(-bx))较好模拟。 ②Cd、Cr、Pb单一污染胁迫对小麦幼苗性状的毒性次序均以影响叶面积和冠部干重为主，表明叶面积和冠部干重为幼苗期污染监测的敏感指标；重金属对除根干重外所有性状的毒性次序：Cr＞Cd＞Pb，该毒性次序是根据引起50%抑制的临界浓度即EC50值确定的；各性状抑制率与胁迫浓度的关系可用直线模型、或双曲线模型、或指数曲线模型较好模拟。 ③ 重金属单一污染胁迫造成小麦籽粒产量下降幅度是Cd＞Cr＞Pb；二元互作对产量影响的重要性次序为CdCr＞CdPb＞CrPb；在Cd、Cr、Pb复合污染胁迫条件下，穗数可以作为成株期重金属污染监测的首选指标。以上指标可为农田小麦重金属污染的监测和综合治理提供一些理论依据。

以毛竹种子为供试材料,研究4种重金属(Pb²⁺、Zn²⁺、Cu²⁺、Cd²⁺)胁迫对毛竹种子萌发的影响,并考察重金属在毛竹幼苗各组织部分的富集情况.结果表明:(1)Pb²⁺和Cd²⁺对毛竹种子的发芽率、发芽势、发芽指数及活力指数有抑制作用,低浓度下Cu²⁺和Zn²⁺对毛竹种子的发芽势、发芽率、发芽指数等指标有促进作用,高浓度则显著抑制;当浓度达到1600μmol/L时Cd²⁺对种子萌发的抑制效果明显强于其他3种元素;(2)选取根尖数、根表面积、根体积、根系总长4个根系形态指标发现,低浓度处理下Pb²⁺、Zn²⁺对根系生长有促进作用,而Cu²⁺和Cd²⁺起到明显的抑制作用;(3)处理10d后,种子萌发幼苗地上部对Pb²⁺、Zn²⁺、Cu²⁺、Cd²⁺的含量最高可达6810.51、1387.77、951.77、429.33 mg/kg,转移系数Zn²⁺ > Cd²⁺ > Pb²⁺ > Cu²⁺.综上,系统揭示了毛竹种子在重金属胁迫下的萌发和富集情况,为今后的土培、大田试验提供了有益的参考,也为将毛竹作为植物修复材料加以研究开启了新的研究视角,具有重要的研究价值.