Effect of seaweed liquid fertilizer on yield and quality of Capsicum annum L.

In the present study, intensive investigation was made on the effect of seaweed liquid fertilizer (SLF) of Codium decorticatum on the seed germination yield biochemical and pigment characteristic of Capsium annum under laboratory conditions and in pots. Different concentrations such as 10%, 20%, 30%, 40% and 50% of SLF were prepared using distilled water. The seeds were soaked in 10 h for each SLF concentration then placed in separate Petri plates. Similarly, water soaked seeds were used as controls. Application of a lower concentration (20%) of SLF Showed maximum seed germination, fresh weight, dry weight, root and shoot length, number of branches, leaf area, number of pods and content of total chlorophyll, chl a, and chl b, protein, carbohydrate and lipids were observed. Therefore, the results of the present study suggested that the SLF of C. decortianum could serve as an alternative bio-fertilizer as is eco-friendly, cost-effective, deliver substantial economic and environmental benefits to farmer.     

乡土植物白刺花对紫茎泽兰化感作用的响应

为了解乡土植物白刺花对紫茎泽兰化感作用的耐受程度及抵御机理,以2—3年生紫茎泽兰叶片为供体材料,用不同浓度的紫茎泽兰叶片浸提液处理白刺花种子及幼苗。结果表明:紫茎泽兰叶片浸提液对白刺花的影响为低浓度促进,高浓度抑制。当浓度为0.5%时促进效应最强,当浓度大于2.0%时抑制效应明显增加。白刺花种子萌发速率比萌发率对紫茎泽兰化感作用反应敏感,胚轴比胚根敏感,随着幼苗的生长,其抵御紫茎泽兰化感作用的能力逐渐增强,丙二醛的含量与植株生长响应规律相对应,并且经紫茎泽兰浸提液处理能极大的增加白刺花幼苗菌根率,缩短菌根形成的时间。     

Effects of <Emphasis Type="Italic">Pinus pinea</Emphasis> litter on seed germination and seedling performance of three Mediterranean shrub species

Pinus pinea L. is a coniferous tree inhabiting the Mediterranean Basin, which appears widely distributed in the Iberian Peninsula, frequently associated to Mediterranean shrub species, such as Cistus salvifolius L., C. libanotis L. and Halimium halimifolium (L.) Willk. (Cistaceae). This study investigated the effects (chemical and physical) of P. pinea needles on the seed germination and early growth of these three shrub species. Laboratory experiments were carried out in order to assess an expected negative effect by using different treatments to seeds (physical layer and two aqueous extracts concentrations). Seed germination of all species was inhibited when treated with aqueous extracts and the degree of inhibition was higher when using the extract with the highest concentration, while no effect was observed with the physical layer treatment. Seedling performance was also sensitive to the different treatments, showing the most stressed values with the high concentration extract. The results from this study highlight the importance of allelopathy of P. pinea needles as a mechanism for controlling seed germination and seedling performance of some Mediterranean shrub species.     

毛竹各器官和根际土浸提液对杉木种子萌发的化感作用

随着毛竹杉木混交林面积的不断扩大,它们之间既会产生促进作用,又会产生抑制作用。本研究对比分析了不同浓度毛竹各器官(鲜叶、干叶、枝条、竹杆、竹鞭和鞭根)的浸提液及枯落物、根际土浸提液对杉木种子发芽率的影响,探讨了毛竹各器官浸提液及枯落物、根际土浸提液对杉木种子萌发的化感作用。结果表明:(1)处理前期,毛竹各器官浸提液对杉木种子萌发具有抑制作用,且当浸提液浓度为1∶25和1∶50的高浓度时,相对于低浓度浸提液对杉木种子萌发的抑制作用更为持久;(2)处理后期,低浓度的毛竹各器官浸提液对杉木种子萌发促进作用较快,而高浓度的浸提液仍呈现抑制作用,促进作用出现较为缓慢;(3)枯落叶浸提液总体上对杉木种子萌发具有抑制作用,在整个实验过程中低于对照组的发芽率,仅在1∶50浓度时略高对照组实验;而根际土浸提液对杉木种子萌发自始至终都具有促进作用,其中低浓度的促进作用十分显著。故在实际的毛竹杉木混交林生产营林过程中可选用毛竹根际土制备浸提液,促进杉木种子萌发,为毛竹杉木混交林的生产经营提供参考。     

黄瓜种子及其萌发期的化感作用研究

以大白菜、萝卜、番茄和黄瓜种子为受体,采用实验室培养皿种子发芽生物测试法研究了黄瓜种子浸提液、种子萌发、胚根和芽苗分泌物、芽苗腐解物和芽苗浸提液的化感效应。结果表明:(1)黄瓜种子浸提液对大白菜、萝卜、番茄和黄瓜种子萌发均有化感抑制作用,即黄瓜种子内含有某些化感抑制物质。(2)在水浸提过的黄瓜种子萌发过程中,它不仅对其近邻套种的大白菜、萝卜和番茄种子萌发产生化感抑制作用,而且其胚根和芽苗分泌物对后茬播种的4种蔬菜种子发芽也表现出不同程度的化感抑制作用;黄瓜芽苗腐解物和芽苗水浸提液也对各受体蔬菜种子发芽与生长产生不同程度的化感抑制作用,且随着腐解芽苗量的增加或浸提液浓度的升高,各受体蔬菜种子的发芽指标值、化感效应指数值和综合效应值随之降低。(3)黄瓜种子浸提液及芽苗各器官的化感物质对黄瓜种子的萌发与生长产生了自毒作用,且黄瓜芽苗腐解物、芽苗浸提液、胚根及芽苗分泌物对受体黄瓜的自毒作用均为最大。研究发现,黄瓜种子浸提液、种子萌发时期以及芽苗各器官的化感物质主要是通过抑制受体胚根的生长而起化感抑制作用,即受体蔬菜种子胚根对化感效应最为敏感;因黄瓜种子及萌发期释放化感物质的途径有所不同,导致受体大白菜、萝卜、黄瓜和番茄的化感响应也不相同;在黄瓜种子萌发和芽苗生长的早期,化感物质即开始在芽苗体内进行合成与积累,一部分可通过胚根和芽苗分泌途径释放到环境中,另一部分可通过芽苗腐解途径释放化感物质,并对受体蔬菜种子萌发与生长表现出较强的化感抑制作用。     

黄土丘陵区退耕还草植被恢复阶段优势种铁杆蒿的化感效应

为揭示黄土丘陵区退耕还草植被恢复阶段植被群落结构的形成与植物化感作用之间的关系,阐明退耕还草植被恢复阶段铁杆蒿群落形成的原因,采用种子萌发实验,对黄土丘陵区退耕还草中后期群落优势种铁杆蒿(恢复10 a、15 a、20 a、30 a)浸提液(水浸提液和甲醇浸提液)对其伴生种达乌里胡枝子(Lespedeza davurica,LD)、狗尾草(Setaria viridis,SV)、茵陈蒿(Artemisia capillaries,AC)以及铁杆蒿(Artemisia sacrorum,AS)自身化感作用进行研究。结果表明:铁杆蒿浸提液对3种伴生种以及自身种子萌发的化感作用差异显著(P0.05),总体表现出低促高抑"浓度效应",且根受到的抑制作用要强于芽。茎叶浸提液的浓度为0.1 g/mL时,对茵陈蒿种子萌发和幼苗生长的化感指数RI为-1.00,达到完全抑制。铁杆蒿不同器官的化感作用差异显著(P0.05),茎叶及根系浸提液不同程度的抑制LD、AC种子的萌发和幼苗生长,且在同一浓度下抑制作用随着恢复时间的增长逐渐增强。根际土浸提液促进了伴生植物及铁杆蒿自身种子的萌发,抑制了LD和AC幼苗的生长。铁杆蒿种群的化感作用可能是导致铁杆蒿在退耕还草中后期成为优势种的原因之一。     

Effects of Nano-Cerium Oxide on Seed Germination and Seedling Growth of <i>Vitex negundo</i>

Cerium oxide nanoparticles (CeO₂NPs) are likely to have dramatic impacts on plant performances, yet the effects of CeO₂NPs on seed germination and seedling growth have not been fully explored. In this study, the seed germination and seedling growth of subshrub species Vitex negundo under different concentrations of CeO₂NPs (low-1 mg/L, medium-100 mg/L, high-500 mg/L) have been discussed. Results showed that: (1) The seed germination rate reduces by 11.25% and 2.5% under the low and medium concentrations of CeO₂NPs, respectively, but increased by 7.08% under the high concentration; (2) CeO₂NPs had significant effects on the growth traits (root length, shoot height and biomass) of seedlings, being the highest under the medium concentration and the lowest under the highest concentration; (3) The superoxide dismutase activity was the maximum (355.91 U/g), but the protein concentration was the minimum (3.85 ug/mL) under the high concentration of CeO₂NPs. Our results indicated that the effects of CeO₂NPs on seed germination and seedling growth are concentrationdependency, i.e., low and medium concentrations inhibited while high concentration promoted seed germination, however, seedling growth showed opposite responses. Therefore, appropriate CeO₂NPs concentrations are beneficial to the seed germination and seedling growth of Vitex negundo and improve the physiological performance of seedlings and enhance their adaptability to environmental adversity.     

Effect of aqueous extract of Sargassum johnstonii Setchell & Gardner on growth, yield and quality of Lycopersicon esculentum Mill.

Experiments were conducted on tomato to study the potential of brown alga Sargassum johnstonii as a biofertilizer. Seaweed extract was applied as a foliar spray, soil drench, and soil drench + foliar spray to assess its effect on plant growth, yield, and concentration of lycopene and vitamin C. The main objective of the study was to enhance the biochemical constituents with neutraceutical and antioxidant values in tomato fruit. Different concentrations (0.1%, 0.4%, 0.8%, 2%, 6%, 8%, and 10%; v/v) of seaweed extract were used and growth was observed over a period of 7 months. A total of 14 sprays/drenches were applied at 15-day intervals during the entire vegetative and reproductive phase. A statistically significant increase in vegetative growth (plant height, shoot length, root length, and number of branches), reproductive parameters (flower number, fruit number, and fresh weight), and biochemical constituents (photosynthetic pigments, proteins, total soluble sugars, reducing sugars, starch, phenols, lycopene, and vitamin C) was recorded following all three methods of treatment at higher concentrations of seaweed extract. The study also reports auxin- and cytokinin-like activity, and the presence of macro- (Ca, Mg, Na, and K) and micronutrients (Fe, Cu, Zn, and Mn), in seaweed extract of S. johnstonii, which makes it a potential biofertilizer.     

Biological control of sunflower necrosis virus disease with powder and liquid formulations of plant growth promoting microbial consortia under field conditions

Sunflower necrosis virus disease (SNVD) was reported to cause a significant damage to sunflower production in India. Based on the biocontrol efficacy against SNVD observed in the previous greenhouse experiments, two plant growth promoting microbial consortia (PGPMCs) viz., PGPMC-1 consisting of Bacillus licheniformis strain MML2501 + Bacillus sp. strain MML2551 + Pseudomonas aeruginosa strain MML2212 + Streptomyces fradiae strain MML1042 and PGPMC-2 consisting of B. licheniformis MML2501 + Bacillus sp. MML2551 + P. aeruginosa MML2212 were used in the present study. Powder and liquid formulations of the above plant growth promoting microorganisms (PGPMs) were evaluated along with farmers’ practice (imidacloprid + mancozeb) and control in farmers’ fields. Significant disease reduction, increase of seed germination, plant height and yield parameters with an additional seed yield of 840 kg/ha, an additional income of Rs. 10,920/ha and benefit cost ratio of 6.1 were recorded following treatment with a powder formulation of PGPMC-1 compared to control. Further, liquid formulation of PGPMC-1 significantly reduced SNVD up to 51.4% compared to control. Besides, this treatment improved the seed germination (24.4%), plant height (61.3%), yield parameters with an additional seed yield of 936 kg/ha and an additional income of Rs. 12,168/ha. Benefit cost ratio was calculated as 6.8 in this treatment compared to 4.6 and 3.7, respectively for PGPMC-2 liquid formulation and farmers’ practice compared to control. This is the first report of PGPMCs mediated biological control of SNVD under field conditions.     

Effects of powder and aqueous extracts of Euphorbia hirta on Phelipanche ramosa germination and haustorium initiation

Abstract

Phelipanche ramosa, a root parasitic weed, is a copious seed producer. A series of laboratory experiments was undertaken to investigate the effects of powder and aqueous extracts from Euphorbia hirta on germination, and haustorium initiation in P. ramosa. P. ramosa seeds conditioned in water and subsequently treated with diluted E. hirta extract (10–25% v/v) displayed considerable germination (47–62%). Increasing extract concentration to 50% or more reduced germination in response to the synthetic germination stimulants GR24 and Nijmegen^?i in a concentration dependent manner. P. ramosa germlings treated with diluted Euphorbia extract (10–75% v/v) displayed haustorium initiation comparable to the synthetic haustorium factor 2, 6-dimethoxybenzoquinone (DMBQ) at 20 µM. Euphorbia extract applied during conditioning reduced haustorium initiation in a concentration dependent manner. E. hirta extract or air-dried powder, applied to soil, induced considerable P. ramosa germination. The results indicate the plausibility of using E. hirta air-dried powder or extract as spot treatments to induce suicidal germination of Striga hermonthica.     

Reactive oxygen species,ABA and nitric oxide interactions on the germination of warm-season C<Subscript>4</Subscript>-grasses

Hydrogen peroxide (H₂O₂) as a source of reactive oxygen species (ROS) significantly stimulated germination of switchgrass (Panicum virgatum L.) seeds with an optimal concentration of 20 mM at both 25 and 35°C. For non-dormant switchgrass seeds exhibiting different levels of germination, treatment with H₂O₂ resulted in rapid germination (<3 days) of all germinable seeds as compared to seeds placed on water. Exposure to 20 mM H₂O₂ elicited simultaneous growth of the root and shoot system, resulting in more uniform seedling development. Seeds of big bluestem (Andropogon gerardii Vitman) and indiangrass [Sorghastrum nutans (L.) Nash] also responded positively to H₂O₂ treatment, indicating the universality of the effect of H₂O₂ on seed germination in warm-season prairie grasses. For switchgrass seeds, abscisic acid (ABA) and the NADPH-oxidase inhibitor, diphenyleneiodonium (DPI) at 20 μM retarded germination (radicle emergence), stunted root growth and partially inhibited NADPH-oxidase activity in seeds. H₂O₂ reversed the inhibitory effects of DPI and ABA on germination and coleoptile elongation, but did not overcome DPI inhibition of root elongation. Treatment with H₂O₂ appeared to enhance endogenous production of nitric oxide, and a scavenger of nitric oxide abolished the peroxide-responsive stimulation of switchgrass seed germination. The activities and levels of several proteins changed earlier in seeds imbibed on H₂O₂ as compared to seeds maintained on water or on ABA. These data demonstrate that seed germination of warm-season grasses is significantly responsive to oxidative conditions and highlights the complex interplay between seed redox status, ABA, ROS and NO in this system.     

小麦秸秆水浸提液对五种植物化感作用的研究

该文研究了不同浓度的小麦秸秆水浸提液对徐州地区2种玉米(郑单958和农大108)和3种常见玉米田间杂草(马唐、稗草和反枝苋)种子萌发和幼苗生长的影响。结果表明:当小麦秸秆浸提液浓度分别大于75、50和25 g·L~-1时,马唐、稗草和反枝苋种子的萌发受到显著的抑制;当小麦秸秆浸提液浓度分别大于50和37.5 g·L~-1时,玉米郑单958和农大108种子的萌发受到显著的抑制;但当小麦秸秆浸提液浓度大于37.5 g·L~-1时,马唐、稗草和反枝苋幼苗根和芽的生长均受到明显的抑制;当小麦秸秆浸提液浓度小于75 g·L~-1时,玉米郑单958和农大108幼苗根与芽的生长受到明显的促进,且郑单958幼苗叶片中叶绿素的含量以及郑单958的POD酶活性均得到提高。该研究结果表明较高浓度的小麦秸秆浸提液(50 g·L~-1)会抑制杂草的生长,有利于玉米郑单958的生长,为小麦秸秆还田和玉米田杂草的生态防治提供了理论基础。     

PEG模拟干旱胁迫对栓皮栎种子萌发及生长生理的影响

为了阐明栓皮栎种子萌发期对水分胁迫的耐受性,以当年采集的栓皮栎种子为材料,采用培养皿滤纸萌发的方法研究了不同浓度（0%、5%、10%、20%、30%）PEG-6000溶液对其种子萌发、生长、保护酶活性和有机渗透调节物质的影响,并对种子萌发率、胚根生长速率等与PEG浓度进行了回归分析。结果表明:（1）随着干旱胁迫程度的加剧,栓皮栎种子的发芽率、发芽指数、胚根长度、胚根生长速率和活力指数均呈先升高后下降趋势,说明低浓度（5%、10%）PEG胁迫可以促进栓皮栎种子萌发及生长,而高浓度（20%、30%）则具有抑制作用。（2）建立水分胁迫条件下种子萌发率、胚根生长速率等与PEG浓度的回归方程发现,栓皮栎种子在PEG胁迫下的萌发临界值和极限值分别为32.01%和36.99%,胚根生长速率的临界值和极限值分别为30.1%和33.35%。（3）随着PEG浓度的升高,栓皮栎种子中3种保护酶（SOD、POD、CAT）活性和3种有机渗透调节物质（可溶性蛋白、脯氨酸、可溶性糖）含量呈现不同的变化,但均有不同程度升高趋势。由此可见,栓皮栎种子可通过增加保护酶活性和体内渗透调节物质来适应水分胁迫环境,使自身萌发和生长受抑制程度降到最低。     

盐磷胁迫对木麻黄和台湾相思种子萌发及幼苗生长的影响

恶劣环境下,人工海防林因面临养分胁迫而经营困难。为探讨盐、磷胁迫对主要海防林树种木麻黄和台湾相思种子萌发及生长的影响,该研究分别用不同浓度的NaCl(盐)和KH₂PO₄(磷)溶液处理种子和浇灌幼苗,测定种子萌发和幼苗生长指标。结果表明：(1)高盐胁迫显著抑制种子萌发,对幼苗生长有一定影响,但两种植物影响程度不同;台湾相思种子萌发耐盐性高于木麻黄,前者相对盐害率最大值为23.03%,后者为89.15%;随着盐浓度增加,木麻黄和台湾相思种子的发芽率、发芽势、发芽指数和活力指数均降低,对应最大值分别为38.70%、34.67%、18.70、0.055和76.67%、62.22%、48.46、6.11。(2)两种植物的株高和根长随盐浓度增加而降低,木麻黄和台湾相思株高分别为12.29～6.01 mm和48.27～17.33 mm,根长分别为8.57～1.45 mm和33.41～5.88 mm;台湾相思根、茎、叶生物量及根冠比均随盐浓度的增加逐渐减小,木麻黄各处理差异较小。(3)台湾相思的种子和幼苗较木麻黄更耐低磷环境,二者最适磷浓度存在差异;木麻黄种...     

Direct effects of nitrogen addition on seed germination of eight semi‐arid grassland species

Seed germination plays an important role in mediating plant species composition of grassland communities under nitrogen (N) enrichment. Shifts of plant community structure with N‐enhanced deposition in terrestrial ecosystems have occurred globally. Despite numerous studies about the effects of enhanced N deposition on mature plant communities, few studies have focused on seed germination. Using a laboratory experiment, we report the effects of five N concentrations, including 0, 5, 10, 20, and 40 mM N (NH₄NO₃) on seed germination of eight semi‐arid grassland species. Results showed that low N concentrations (5‐ and 20‐mM N) promoted mean final germination proportion of all eight species by 4.4% and 6.4%, but high concentrations (40 mM N) had no effect. The mean germination rate was decreased 2.1% and 5.1% by higher N concentration (20‐ and 40‐mM N) levels, but germination start time showed the opposite trend, delayed by 0.7, 0.9, and 1.8 d for the 10, 20, and 40 mM N treatments. Final germination proportion, mean germination rate, and germination start time were significantly different among species in response to N concentration treatments. The final germination proportion of Allium tenuissimum and Chenopodium glaucum were suppressed by increased N concentration, whereas it increased for Potentilla bifurca, Plantago asiatica, and Setaria viridis. Our findings provide novel insights into N deposition‐induced species loss based on seed germination factors in semi‐arid grassland communities.     

In vitro inhibitory effects of rosemary and sage extracts on mycelial growth and sclerotial formation and germination of Sclerotinia sclerotiorum

The anti-fungal efficacy for two Labiate plants, rosemary (Rosmarinus officinalis L.) and Greek sage (Salvia fructicosa Mill.), against Sclerotinia sclerotiorum fungus (Lib.) de Bary has been investigated. The inhibitory effect of these plants as crude leaf ethanolic extract on the radial mycelial growth as well as on sclerotial production and germination was measured in vitro at various concentrations (stock?=?0.5?g dry leaf powder/ml ddH₂O) in the growth medium. In general, rosemary extract revealed a remarkable anti-fungal effect against the fungus, being more inhibitory than Greek sage in this respect. This was evident as total inhibition of radial mycelial growth by rosemary occurred at 10% extract concentration, while sage was half as potent producing such an effect at double the concentration (20%). Both rosemary and sage extracts were more inhibitory to sclerotial formation than to mycelial growth as the fungus ceased to produce any sclerotia at the lower concentrations of 5 and 5–10%, respectively. In addition, rosemary was highly effective in inhibiting sclerotia germination as total inhibition of germination occurred at 20% extract concentration at three?days and onward after incubation. Moreover, at this level, the survival of sclerotia was totally lost when examined after 12?days of incubation. For sage, inhibition of sclerotial germination/death was only 20% at 12th day of incubation. The results of this study indicate that the extracts of rosemary and Greek sage leaves could become natural alternatives to synthetic fungicides to manage diseases of S. sclerotiorum.     

The effect of humic substances on germination and early growth of Lamb’s Quarters (<Emphasis Type="Italic">Chenopodium album</Emphasis> agg.)

In order to understand the biological activity of humic substances (HS), the effect of four humic acids (HA) and one fulvic acid (FA) on seed germination and early growth of cosmopolitan weed Chenopodium album agg. were tested. Humic substances of diverse origin were used, namely purified commercial HA, HA isolated from lignite, cambisol and podzol, and FA from mountain spruce forest soil. Data processing by two-way ANOVA has shown that type of the tested substances was a more important factor on seed development than used concentration. The major differences in germination and length of shoots were found in the first days of the experiment. Commercial and lignite HA stimulated the seed germination and growth, while podzol HA inhibited them. After this initial phase, all humic substances stimulated the seed development, but these stimulations were not significant (P < 0.05). At the end of germination test, the greatest stimulation effect (up to 20%) was achieved with the lignite HA.     

Allelopathic effects of sunflower extracts on mustard seed germination and seedling growth

The allelopathic potential of two cultivars of sunflower (Helianthus annuus L.) Lech and Ogrodowy was studied. Leaf aqueous extracts of sunflower at 2.5, 5, and 10 % (m/v) concentrations were applied to determine their effect on mustard (Sinapis alba) seed germination and seedlings growth under laboratory conditions. Increasing concentration of aqueous extracts of sunflower inhibited seed germination, up to almost complete failure of germination, observed in the presence of 10 % extract from sunflower cv. Ogrodowy. The decrease in germinability was well correlated with increased membrane deterioration, assayed as electrical conductivity and enhanced lipid peroxidation, detected as increased malondialdehyde content.     

Increased growth response of strawberry roots to a commercial extract from <Emphasis Type="Italic">Durvillaea potatorum</Emphasis> and <Emphasis Type="Italic">Ascophyllum nodosum</Emphasis>

The withdrawal of soil fumigants like methyl bromide is forcing strawberry growers to consider supplementary and alternative ways of producing crops. In addition to controlling soil-borne pests, soil fumigation causes an increased growth response in strawberry roots, and the use of biostimulants may offer an alternative to replace this response. We tested the hypothesis that treatment with a commercial extract (Seasol®) from the seaweeds Duvillaea potatorum and Ascophyllum nodosum can increase root growth, and transplant (runner) and fruit yields of strawberry. From 2014 to 2016, we conducted three field trials on strawberry farms in the nursery sector at Toolangi and in the fruiting sector at Coldstream in Victoria, Australia. We applied the seaweed extract as a monthly drench (10 L ha^?1) to two cultivars of strawberry (‘Albion’ and ‘Fortuna’), compared with an untreated control. In the nursery sector, use of the extract significantly increased the density of secondary roots (feeder roots) on harvested runners by up to 22%. Treatment with the extract also significantly increased yields of marketable runners by 8–19%. In the fruit sector, use of the extract significantly increased the root length density (root length per volume of soil) of strawberry plants by 38% and marketable fruit yields by 8%. Root length density at final harvest and marketable fruit yield of strawberry were highly correlated (r?=?0.94). This relationship provides an insight into the mode of action of seaweed extracts and is discussed. Overall, the results show the potential benefits of the integrated use of seaweed extracts in strawberry production across the nursery and fruit sectors, and their promise for supplementing or replacing the increased growth response provided by soil fumigants.     

Water-soluble phenolic compounds in the coat control germination and peroxidase reactivation in <Emphasis Type="Italic">Triticum aestivum</Emphasis> seeds

In this work, we investigated the inhibitory effects of water-soluble phenolic compounds (WSPCs) in the coat of after-ripening wheat (Triticum aestivum L.) seeds on the processes of germination and peroxidase reactivation. Wheat bran has a WSPC content of 862.5 μg gallic acid equivalent g⁻¹ dry weight. When seeds were incubated in the water extract of bran, germination, peroxidase reactivation, and coleoptile and radicle growth were suppressed in a WSPC concentration-dependent manner. The inhibitory effects were significantly ameliorated by removing WSPCs from bran extract by treating with 1% insoluble polyvinylpolypyrrolidone. Pretreatment of seeds with 0.1% H₂O₂ reduced the WSPC content in the coat, which was confirmed using Fourier transform infrared microspectroscopy. With H₂O₂ pretreatment, seed germination, peroxidase reactivation, and post-germination seedling growth were significantly stimulated. Application of the known phenolics caffeic acid, feruic acid, or vanillin to the germination medium blocked seed germination and suppressed peroxidase reactivation. The results described here indicate that WSPCs act as endogenous inhibitors in the coat to control germination of Triticum aestivum seeds, and that inhibition of germination is at least partially caused by suppressing peroxidase reactivation.