Effects of different priming treatments and priming durations on germination percentage of parsley (Petroselinum crispum L.) seeds

The effects of different priming treatments and priming durations on germination percentage at different temperatures in parsley seeds were studied. The seeds were treated for 2, 4, 6 and 8 days with the PEG 6000 (–0.5 MPa, –1.0 MPa and –1.5 MPa), KNO3 (0.30 mol/L and 0.35 mol/L), Mannitol (0.50 mol/L and 0.60 mol/L) and hydropriming (12h, 24h, 36h and 48h) and unprimed (control). Germination studies were made at 5, 10, 15, 20 and 25°C. Percentage of germination at different temperatures was significantly affected by priming treatments. Hydropriming (12h, 24h and 36 h) and mannitol 0.60 mol/L at 2 day generally had the highest germination percentages. In general, the highest germination percentage with priming was determined at 10°C. It may be said that seed priming treatments increased seed germination percentage at both low and high temperatures. The highest germination percentages were observed in both hydropriming and mannitol treatments as compared with PEG and KNO3 treatments. The PEG and KNO3 (2 and 4 days) treatments were better than unprimed treatment in all of the temperatures.

腐植酸+黄腐酸缓解Cd对独行菜植株生长、生理和生化特性的不利影响

镉(Cd)是一种有毒的、流动性很强的重金属,可以被植物大量地吸附和吸收而没有任何明显的迹象。因此,对保护生物多样性和食品安全来说,在植物吸收之前稳定Cd是至关重要的。由于在其结构中含有大量的羧基和酚羟基,腐殖物质与重金属形成强烈的结合,这使它们成为完美的稳定剂。本研究的目的是确定在温室条件下,腐植酸和黄腐酸(HA+FA)的水平(0、3500、5250和7000 mg/L)对减轻独行菜(Lepidium sativum)受Cd(CdSO_(4)•8H_(2)O,0、100和200 Cd mg/kg)污染的Cd毒性的影响。我们的研究结果表明,Cd胁迫对独行菜的生长有负面影响,叶鲜重、叶干重、根鲜重和根干重、叶片相对含水量(LRWC)和除Cd外的矿物质含量均下降,膜渗透性(MP)和酶(CAT、SOD和POD)活性增加。然而,HA+FA的应用减少了Cd污染的不利影响。在200 mg/kg的Cd污染下,HA+FA的应用浓度为7000 mg/L时,与对照组相比,叶鲜重、叶干重、根鲜重、根干重、茎粗、叶面积、叶绿素读取值(CRV)、MP和LRWC值分别增加了262%、137%、550%、133%、92%、104%、34%、537%和32%。尽管在200 mg/L的镉污染下获得了最高的H2O2、丙二醛(MDA)、脯氨酸和蔗糖值,但HA+FA的应用浓度在200 mg/kg的Cd污染水平下,7000 mg/L的HA+FA成功地缓解了Cd胁迫的有害影响,使H2O2、MDA、脯氨酸和蔗糖值分别下降了66%、68%、70%和56%。浓度为7000 mg/L的HA+FA应用成功地缓解了Cd污染的负面影响,使N、P、K、Ca、Mg、Fe、Mn、Cu、Zn和B分别提高75%、23%、84%、87%、40%、85%、143%、1%、65%和115%。此外,HA+FA的应用浓度为7000 mg/L成功地减少了95%的Cd吸收和80%的Cl吸收。考虑到植物生长参数,当HA+FA浓度为7000 mg/L时,确定了最佳结果。我们已经证明,使用高比例的FA的腐殖质是非常关键的,FA的比例为10%,可以达到减轻重金属胁迫对植物生长不利影响的目的。总之,HA+FA的应用可以作为一种有效的解决方案,通过稳定土壤中的Cd,防止Cd从植物的根部转移到其嫩枝和叶片,从而减少植物对Cd的吸收。