Morphological features of an open flower mutant plant and characterization of their progenies in lentil (Lens culinaris Medik.)

The lentil (Lens culinaris Medik.) is a self-pollinated seed legume with cleistogamous flowers. A spontaneous open flower semi leaf-less mutant, was observed from segregating generation (F₄) of a cross IPL 313 × RKL 1001 in which reproductive organs were not enclosed by the keel petals and thus remained exposed. Leaves on this mutant plant was very less and random with 1–3 pairs of leaf lets whereas in normal plant leaves are present at every reproductive node with 5–7 pairs of leaf lets. A very large number of open flowers (>90 %) remained sterile in mutant plant and their progenies, though its pollen fertility was as high as the standard cultivars. The progenies of the mutant open flower plant were segregates in three morphological different plant types as (1) open flower leaf-less plants, (2) open flower semi leaf-less plants and (3) normal plants having cleistogamous (closed) flowers and normal bearing leaves. The open flower leafless plant were low yielder whereas open flower semi leafless progenies have good yield potential and are important source of rare novel mutant alleles for important economic traits like multiple peduncles per reproductive node, more number of flowers/pods per peduncle and long reproductive phase. The open flower trait offers opportunity for exploring hybrid technology in the lentil and mutant alleles can play a crucial role in understanding the genetics of the target trait and for improvement of lentils.     

Grain Yield and Active Substances of Milk Thistle as Affected by Soil Salinity

The ripe seeds of milk thistle (Silybum marianum L. Gaertn) contain active substances of flavonoides that are important in the pharmaceutical industry. Evidence showed that stress conditions such as salinity can affect growth and development of plants, including active substances of some medicinal plants. Silymarin and silybin are important active materials of milk thistle whose concentrations correspond to some degree of plant stress. To test for this relationship, a pot experiment was conducted using a completely randomized design with seven level of salinities (0.35, 1, 3, 6, 9, 12, and 15 dS/m) for two genotypes, Ahwaz wild type and cultivated German origin (Royston). At the harvest, the results have showed that both genotypes grow satisfactorily and had a normal size in soils up to salinity of 9 dS/m, compared to the control plants. However, growth parameters such as plant height, number of leaves per plant, number of capitula per plant, main shoot capitulum's diameter, and seed yield and yield components per plant was reduced with salinity greater than 9 dS/m in both genotypes. However, concentrations of active substances (silymarin and silybin) in seeds significantly increased compared to the control plants. Results from the high‐performance liquid chromatography (HPLC) analysis indicated that the amount of silybin was approximately four times greater in plants cultivated under a salinity of 15 dS/m than in the plants grown under nonsaline conditions. Our results suggested that both types of milk thistle survive under salinity as high as 15 dS/m levels and produced seeds with rich in active substances.     

Investigation of intergeneric crossability of <Emphasis Type="Italic">Vicia faba</Emphasis> L. and <Emphasis Type="Italic">Thermopsis turcica</Emphasis> Kit Tan,Vural et Küçüködük

An unilocular ovary is often observed in the Fabaceae family. Thermopsis turcica Kit Tan, Vural et Küçüködük is an endemic, rare plant species in Turkey that is distinguished by its multi-carpellary apocarpous ovaries. No research has been conducted on the crossing of T. turcica with other species to date. Vicia faba L. (fababean) (2n = 12), which is one of the oldest crops used for human and animal consumption, and Thermopsis turcica (2n = 18) were selected to explore the possibility of increasing yield in edible crops by intergeneric crossing. When T. turcica was used as a male parent, pollen germination and pollen tube growth appeared to be normal and globular embryo formation was observed, but hybrid seeds aborted due to post-fertilization barriers. In contrast, in all crosses in which T. turcica was used as a maternal parent, an embryo was not obtained, and viability of the pistil did not exceed 10 days after pollination. Also, in the samples left to free pollination, pistils died in a few days after anthers were removed just before pre-anthesis. Inability to obtain viable seeds by hybridization of Vicia faba and T. turcica should not be considered as a demonstration of complete incompatibility of the species in intergeneric crosses. The present report constitutes the first study on this issue.     

Estimation of natural outcrossing rate and genetic diversity in Lima bean (<Emphasis Type="Italic">Phaseolus lunatus</Emphasis> L. var. <Emphasis Type="Italic">lunatus</Emphasis>) from Brazil using SSR markers: implications for conservation and breeding

Lima bean (Phaseolus lunatus L.) is an important food source in Brazil, especially in the northeast region, where its production and consumption are high. The goals of the present study were to estimate natural outcrossing rates and genetic diversity levels of Lima bean from Brazil, using ten microsatellite loci to obtain information for their conservation and breeding. Fourteen accessions were selected from an experiment in field with open-pollinated and with the presence of pollinating insects. Twelve seeds of each of the 14 selected accessions were grown in screenhouse for tissue harvest and DNA extraction. The multilocus model was used to determine the reproductive system. The outcrossing rate was 38.1 % (t_m = 0.381; t_s = 0.078), and the results indicated a mixed mating system with a predominance of selfing (1 ? t_m = 61.9 %). The biparental inbreeding rate was high (t _m  ? t _s  = 0.303) and the multilocus correlated paternity was quite high (r _p(m) = 0.889), indicating that the progeny was mostly composed of full sibs. The average effective number of pollen donors per maternal plant (N _ep ) was low (1.12), and the fixation index for maternal genotypes (F _m ) was 0.945, indicating that most genitors resulted from inbreeding. The studied families presented considerable genetic variability: A = 6.10;  %P = 30; H _e  = 0.60 and H _o  = 0.077. Total diversity was high (H _T = 0.596), and a portion was distributed within families (H _S = 0.058). In addition, diversity was higher between families (D _ST = 0.538), and genetic differentiation was high (G _ST = 0.902). The results presented here can be used in the implementation of Lima bean conservation and breeding programs in Brazil.     

Untapped amaranth (<Emphasis Type="Italic">Amaranthus </Emphasis>spp.) genetic diversity with potential for nutritional enhancement

Significant genetic diversity was observed in 218 out of a total of 1309 accessions of amaranth (Amaranthus hypochondriacus L.) and its seven wild relatives, A. spinosus L., A. dubius Mart. ex Thell., A. hybridus L., A. tricolor L., A. cruentus L., A. caudatus L., A. retroflexus L. for 24 nutritional parameters including total oil content, fatty acid profile, total protein content and amino acid profile. Diversity for total oil content (6.42–12.53%), linoleic acid (25.68–54.34%), oleic acid (21.97–42.01%) of the total fatty acids, total protein content (7.84–18.01%), among important essential amino acids; lysine content (0.66–11.12 g/16 g N), methionine (0.35–4.80 g/16 g N) and half cystine and (0.12–8.32 g/16 g N) was reported. The un-weighted pair-group method using arithmetic average cluster analysis based on pair wise Euclidean genetic distance grouped the accessions into seven major clusters. Histidine, half cystine, tyrosine, essential amino acids, total oil content, linoleic acid and oleic acid content were the major parameters contributing significantly to genetic diversity. Present findings indicate that significant diversity exists for nutritional parameters in amaranth germplasm. The promising accessions with higher multiple nutritive traits; protein content (>16%), oil content (>11%), lysine content (>7.5 g/16 g N) and EAA higher than the FAO reported values, were identified. This is the first report on detailed nutritional analysis of diversity collected worldwide. These could be used as potential breeding material for nutritional enhancement through genetic improvement. This will help in overcoming the “triple burden” of malnourishment, hidden hunger, and obesity.     

<Emphasis Type="Italic">Marsilea quadrifolia:</Emphasis> a New Bioagent for Treating Wastewater

We report for the first time the capability of four-leaf clover (Marsilea quadrifolia), a wetland plant which grows rooted in soil, in efficiently treating sewage. The use of M. quadrifolia was made possible because of the special attributes of the SHEFROL^® (SHEet Flow ROot Level) bioreactor in which it was employed. This bioreactor enables the use of free-floating aquatic plants as well as terrestrial and rooted-in-soil wetland plants by hydroponics. The plants are staked in narrow channels to enable them to support each other while sewage is made to flow rapidly as a sheet of wastewater at a level that covers only the plant roots (hence the name). It was seen that M. quadrifolia was able to treat sewage of strength varying in the chemical oxygen demand (COD) range of 600–1800 mg/L to the extent of >?80% at a hydraulic retention time (HRT) of just 4.5 h. There was a near total removal of biological oxygen demand and suspended solids while total Kjeldahl nitrogen, soluble phosphorous, and heavy metal zinc were also substantially removed. The macrophyte was equally effective when used indoors under artificial lighting, as well as when used outdoors.     

Inter-relation between descriptors and morphine yield in Asian germplasm of opium poppy Papaver somniferum

A set of 208 Indian and two Thai germplasm accessions of opium poppy Papaver somniferum were assessed for variation in 17 morphological characters, seed yield and content and yield of morphine from capsules and peduncles. The germplasm was found to be highly variable for all the characters evaluated. In the harvested peduncles and capsules, 13% was peduncle straw, 61% seeds and the rest capsule husk. The peduncle and capsule straw yields ranged between 0.6–2.2 and 1.4–5.3 g plant^-1, respectively. Morphine content in the peduncle varied between about 0.001–0.24% and that in the capsule from 0.02 to 1.05%. On average basis morphine content in the capsule husk was more than 9-fold higher than the peduncle straw. The plant morphine yields from peduncles and capsules ranged between 1.2 and 28.6 mg plant^-1. Four accessions yielded more than 20 mg of morphine plant^-1. Among these, in one of the accessions about 13% of the morphine was contributed by the peduncle. The plants of high morphine yielding accessions were generally small in height, and bore white flowers and large sized ungrooved capsules with a small number of seeds, on a large peduncle.     

Domestication and saponins contents in a gradient of management intensity of agaves: <Emphasis Type="Italic">Agave cupreata</Emphasis>, <Emphasis Type="Italic">A. inaequidens</Emphasis> and <Emphasis Type="Italic">A. hookeri</Emphasis> in central Mexico

Saponins occur in numerous plants, including agaves, determining benefic and harmful properties to humans; their presence may favor using plants as soap and other products, but also they may cause caustic effects producing contact dermatitis. In domestication, favorable and unfavorable properties of saponins may cause an increase or decrease of their content, respectively. This study quantified and identified saponins among wild and managed populations of three agave species: A. cupreata Trel. et Berger, A. inaequidens Koch with wild and cultivated populations used for mescal production, and A. hookeri Jacobi, existing exclusively cultivated, used for production of the fermented beverage pulque. We studied 272 plants from 19 populations, quantifying contents of crude saponins through spectrometry. In 12 populations, the saponins types were identified by High Performance Liquid Chromatography–Mass-Spectrography-Time-of-Flight HPLC-MS-TOF. The highest crude saponins content was recorded in A. hookeri (26.09 mg/g), followed by A. cupreata (19.85 and 15.17 mg/g in wild and cultivated populations, respectively). For A. inaequidens, we recorded 14.21, 12.95, and 10.48 mg/g in wild, silvicultural managed and cultivated populations, respectively. We identified 18 saponins types, A. inaequidens showing all of them. A hecogenin glycoside (HG1) is found in high amounts in A. hookeri but in low quantities in A. inaequidens and A. cupreata. A. inaequidens had the greatest diversity of saponins. The contents of crude saponins in A. inaequidens and A. cupreata decrease with management intensity, but contrarily to what we expected, it was the highest in A. hookeri. We hypothesize that such high amount could be due to some saponins, probably HG1, may be precursors of sugars.     

Geographical distribution of wild <Emphasis Type="Italic">Daucus</Emphasis> species in the natural grasslands of the Argentinian pampas

Three wild carrot species have been reported in the argentinian flora: Daucus montanus Humb. et Bonpl. ex Schult., D. montevidensis Link ex Sprengel and D. pusillus Michx. There is a discrepancy among authors about the distinctive morphological traits of the last two species; thus, it is difficult to ascertain if they are truly two distinct taxa. Based on the available literature and in the search of a paradigmatic site, four collection trips were carried out in 2004 and 2005 in Buenos Aires and Southern Entre Ríos provinces. Populations were sampled at 30 sites, and local environmental parameters and associated plant species were recorded. Morphological observations and chromosome counts were carried out on 10 plants/population. Three morphological phenotypes were distinguished: one in 18 populations, all with 2n = 2x = 18, and two in the remaining 12, with 2n = 2x = 22 or aneusomaty (2n = 2x = 20, 22). Populations of the first phenotype were assigned to wild D. carota and the rest, tentatively, to D. pusillus (D. montevidensis?), till further evaluations are carried out in test sites to verify this tentative conclusion.     

Simultaneous use of plant growth promoting rhizobacterium and nitrogenous fertilizers may help in promoting growth,yield, and nutritional quality of okra

This study was conducted to evaluate the simultaneous use of plant growth promoting rhizobacterium (QS1) and different combinations of urea-nitrogen and biogas slurry-nitrogen for improving growth, yield, and nutritional quality of field grown okra. The isolate QS1 was identified as Bacillus sp. QS1 based on its ribosomal ribonucleic acid (rRNA) sequence analysis. Results revealed that among the combinations, the application of 50% urea-nitrogen + 50% biogas slurry-nitrogen was optimal for improving crop performance. This combination significantly (p ≤ 0.05) promoted okra growth viz. plant height (69.63–80.03 cm), no of branches per plant (14–18), shoot fresh weight (86.66–136.25 g/plant), root fresh weight (22.5–26.58 g/plant), and fruit yield (8.5–13.5 kg/plot) compared to the plants receiving 100% urea-nitrogen. The interactive effective of this nitrogen combination and QS1 inoculation produced the highest growth and yield response. Similarly, the same treatment improved nitrogen, phosphorus, potassium, and protein contents in shoot and fruit of okra compared to other treatments.     

Agromorphological diversity of local Bambara groundnut (<Emphasis Type="Italic">Vigna subterranea</Emphasis> (L.) Verdc.) collected in Benin

Bambara groundnut (Vigna subterranea (L.) Verdc.) is a neglected and less exploited species in Benin. However, the rational use of the different landraces available involves an appropriate knowledge of their characteristics. This study examined the characteristics of 52 local landraces of Bambara groundnut traditionally cultivated in Benin based on 12 qualitative and 11 quantitative variables, in order to expose those of good qualities. After a classification based on the morphological variables of the seeds, the experimental field was installed in a completely randomized device of blocks repeated three times. The collected data was analyzed with Statistica 7.1 and NTSYS PC 2.2. softwares using qualitative characteristics (Growth’s type, Stem’s hairiness, Flower’s colour, Leave’s shape etc.). As result, the number of morphotypes increased from 18 (out of classification) to 47. Therefore, it appears that the Benin collection of Bambara groundnut is broad in morphological variability. The analysis of the principal component of the quantitative variables revealed three specific classes within the collection. The most efficient variety which belonged to the second class, had a high field yield per hectare (> 1 t/ha). The Souhouloumankpa variety yielded the earliest (103 days after sowing) in addition to the high field yield. The study also showed a positive relationship between 100 seed’s weight, their length, the number of seeds per plant and the seed’s field yield in kg/ha. For a sustainable preservation and an improvement of the available resources, a molecular characterization of the Bambara groundnut landraces in Benin Republic needs to be done.     

High Zn concentration does not impair biomass,cutting radial growth,and photosynthetic activity traits in <Emphasis Type="Italic">Populus alba</Emphasis> L.

Purpose

Evaluate the efficiency of Populus alba clone Villafranca in the uptake and translocation of Zn from contaminated soils.

Materials and methods

The effects of 48 days of zinc treatment (Zn _t ) on the growth and the photosynthetic activities of P. alba L. clone Villafranca were studied using ZnSO₄ (375 ppm per unit of soil dry weight) added in sand and peat moss substrate at the beginning of the treatment (T ₀) and again after 30 days (T ₁) in order to reach a target Zn concentration of 375 ppm at T ₀ and 750 ppm at T ₁ per unit of soil dry weight.

Results and discussion

Zn uptake in the different organs was analyzed after 30 (T ₁) and 48 days (T ₂) from the beginning of treatment, showing the following order: root ? leaves ≥ woody cutting = stem. The leaf area increased by 12 % in comparison to control plants at the end of second treatment (48 days). Cutting radial growth showed a high synchronicity in the growth rate fluctuation among control and Zn _t plants, but a higher increase in radial diameter of Zn _t cutting was observed starting from day 38 (after 8 days of second Zn _t ) reaching after 48 days 38 % higher than control plants.

Conclusions

Although our data of leaf Zn concentration were in the range usually reported as toxic for plants, Villafranca clone in Zn _t substrate were unaffected in terms of net CO₂ assimilation and stomatal conductance to water vapor.

     

Chromatographic fingerprinting of <Emphasis Type="Italic">Lupinus luteus</Emphasis> L. (Leguminosae) main secondary metabolites: a case of domestication affecting crop variability

Secondary metabolites (SMs), such as alkaloids and raffinose oligosaccharides (RFOs), play important roles in plant physiology. Although alkaloid and RFO phenotypic variation has been reported for yellow lupin (Lupinus luteus L.), most evaluations have used a reduced number of accessions; thus, limiting the understanding of accumulation patterns and variation ranges. The main goal of this research was to assess alkaloid and RFO content in a diverse L. luteus sample to understand possible SM accumulation patterns across this legume species. Eighteen yellow lupin accessions were analyzed using high performance thin layer chromatography to provide insights on seed and leaf RFO and alkaloid phenotypic variation. Co-dominant markers (170) were used to examine genetic relationships among L. luteus accessions and possible accumulation patterns across closely related genotypes. Significant differences were observed for seed and leaf RFOs. Total seed RFO accumulation ranged from 79.738 to 131.079 mg g^?1. Raffinose, stachyose, and verbascose were observed in all genotypes’ seeds, but at different RFO concentrations. Raffinose was the only RFO detected in leaves (2.793–0.4224 mg g^?1). Total alkaloid accumulation ranged from 0.22 to 15.12 and 0.00 to 8.007 mg g^?1 for seeds and leaves, respectively. Lupinine, sparteine, and gramine were observed in seeds and leaves, and showed a wide range of variation. Neighbor-Joining (NJ) analysis showed an apparent pattern of seed alkaloid accumulation, most likely due to domestication events. However, high RFO accumulating accessions were scattered across the NJ tree. Alkaloid and RFO significant phenotypic variation will not only help to understand the roles of these SMs in L. luteus, but also to uncover the genetic basis behind their accumulation.     

Conserving seeds of useful wild plants in Mexico: main issues and recommendations

The efficient storage and germination of seeds underpin the effective use of plants for livelihoods and sustainable development. A total of 204 wild species useful for local communities of the Tehuacán–Cuicatlán Valley were collected and stored in seed banks in country for long term conservation, and 66 % (i.e., 134) duplicated in the U.K., as an effective means of ex situ conservation. Of the 204 species, 147 (122 of which also duplicated in the U.K.) were previously listed as useful plants in the ethnofloristic inventory of the Valley. Based on literature surveys, we found that one of the major impediments to the use of stored seeds of wild species is the lack of knowledge of how to germinate the seed. In detailed studies, we found that seeds of 18 useful plant species from 10 different families germinated readily and could be propagated. In contrast, four species (Actinocheita filicina, Bursera submoniliformis, Karwinskia mollis and Lippia graveolens) produced dormant seeds and therefore further studies are needed before their use can be maximised in large scale propagation programmes in support of conservation and livelihoods. Overall, this large-scale study on useful wild plant species in Mexico confirms that conventional seed banking can effectively support sustainable development and livelihood programmes.     

Bioaccumulation and Biosorption of Mercury by <Emphasis Type="Italic">Salvinia biloba</Emphasis> Raddi (Salviniaceae)

Aquatic macrophytes play a key role in nutrient cycling and in the dynamics of aquatic ecosystems. Many species have been evaluated in terms of their potential in phytoremediation processes in environments contaminated by metals. Considering this kind of application, we evaluated the potential for the bioaccumulation and biosorption of mercury by Salvinia biloba as a function of (i) different concentrations of mercury ions in the solution, (ii) the exposure time of live plants and dry biomass to the contaminant, and (iii) different pH’s, besides (iv) analyzing the effects of this metal on morphological and anatomical parameters. Bioaccumulation was evaluated by subjecting live plants to treatments with concentrations of 0.05, 0.1, and 0.2 μg.mL^?1 of mercury in the solution and the control (0 μg.mL^?1), at intervals of 3 days (0, 3, 6, 9, 12, and 15 days) at pH values of 5.5, 6.0, and 6.5. For biosorption, we used the dry biomass applying the same design, only changing the time intervals (0, 4, 8, 12, and 24 h). The bioaccumulated and biosorbed mercury was determined by atomic absorption spectroscopy. High values of mercury were bioaccumulated and biosorbed, and accordingly, as the concentration of mercury ions increases in the solution, the higher the value accumulated by both living plant and dry biomass. The time of exposure and the different pH values presented variation when associated with different concentrations in the bioaccumulation of mercury. Finally, few symptoms of toxicity in living plants were observed, evidencing the resistance of S. biloba to mercury and its potential use as a phytoremediation in water bodies contaminated by this metal.     

Einfluß der Stickstoffdüngung auf Ertrag,Ertragsstruktur und N-Verwertung von Winterweizen - Möglichkeiten und Grenzen der Bestandesführung

Influence of nitrogen level on yield, yield structure and N utilization of winter wheat - Possibilities and limits of crop management In pot experiments the influence of number of plants per pot (10 or 20), nitrogen level (1,2 - 2,4 - 3,6 g N/pot) and application date (DC 21-29-32/37-51) on yield components, grain yield and nitrogen uptake was investigated. Number of stalks per plant were influenced by removing all tillers except one or two compared to untreated. In pots with 10 and 20 plants, yield was uneffected by the number of tillers removed. Similarly, small differences were observed in the number of earbearing stalks, grain per ear and weight of 1000 seeds. Yield components were not influenced by N-application at 2,4 g N/pot. Removal of tillers to one or two per plant resulted in high 1000 seed weight (58 g) and great number of seeds per ear (55) but not in high yields. The importance of a compensatory relation between the number of earbearing shoots, number of seeds per ear and 1000 seed weight for yield formation and N uptake is discussed.     

Diversity of the composition and content of soluble carbohydrates in seeds of the genus <Emphasis Type="Italic">Vicia</Emphasis> (Leguminosae)

Low molecular weight carbohydrates of seeds of 10 species of Vicia, namely: V. angustifolia, V. articulata, V. cordata, V. ervilia, V. johannis, V. macrocarpa, V. monantha, V. narbonensis, V. pannonica and V. sativa were analyzed by the high resolution gas chromatography method. Seeds of the investigated species contain common (glucose, fructose, myo-inositol, sucrose, galactinol, di-galactosyl myo-inositol and raffinose family oligosaccharides—RFOs) and species-specific carbohydrates (d-pinitol and its α-d-galactosides—in V. articulata, V. monantha and V. pannonica or d-ononitol and its galactoside—in V. ervilia). Among the species containing in seeds RFOs as the main α-d-galactosides (V. angustifolia, V. cordata, V. johanensis, V. macrocarpa, V. narbonensis and V. sativa), an additional subgroup can be separated, which contains a set of unknown compounds (found in V. angustifolia, V. cordata and V. macrocarpa). Moreover, several other unidentified carbohydrate-containing compounds were detected exclusively in seeds of V. ervilia. The concentrations of total soluble carbohydrates (TSCs), including sugars, RFOs, cyclitols and galactosyl cyclitols and unknown compounds, in seeds differ significantly (P < 0.05) among the species. RFOs and sucrose are the main fractions in TSCs, with the exception of V. pannonica seeds, containing more galactosyl pinitols, and V. ervilia, in which unknown compounds account for 50% of TSCs. In V. ervilia RFOs occur at the lowest concentration (9.32 mg g^?1 seeds), and the concentration of DGMI (di-galactosyl myo-inositol) is comparable with that of RFOs, which is unusual among all the investigated Vicia species.     

Comparison of ammonium fertilizers,EDTA, and NTA on enhancing the uptake of cadmium by an energy plant,Napier grass (<Emphasis Type="Italic">Pennisetum purpureum</Emphasis> Schumach)

Purpose

The aim of this study was to quantify the effect of enhanced agronomic practices on cadmium (Cd) accumulation in the high-biomass energy plant Napier grass (Pennisetum purpureum Schumach).

Materials and methods

Potted-plant experiments were performed to investigate the effects of ammonium fertilizers and chelating agents, alone or in combination, on the growth, accumulation of Cd, and phytoextraction efficiency of P. purpureum on Cd-contaminated soil. The fertilizers included ammonium nitrate, ammonium sulfate, and ammonium chloride. The chelating agents included ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA).

Results and discussion

The addition of ammonium fertilizers and chelating agents generally stimulated growth of P. purpureum, and the shoots accounted for 90.1–94.1% of the total biomass. The concentrations of Cd in different parts of P. purpureum plants were in the order root > leaf > stem. Ammonium chloride alone showed effectiveness in increasing root and shoot Cd concentrations compared to other amendments alone. Both EDTA alone and NTA alone significantly decreased root Cd concentration and increased shoot Cd concentration, while EDTA alone was more efficient on shoot and total Cd accumulation than that by NTA alone. The total accumulation of Cd in P. purpureum ranged from 1.10 to 2.05 mg per plant with 47.3–73.5% of Cd accumulation concentrated in shoots. The results indicate that P. purpureum can remove more Cd through phytoextraction than that by other hyperaccumulators.

Conclusions

Ammonium chloride led to the highest total Cd accumulation. Ammonium chloride applied alone or in combination with either EDTA or NTA resulted in the most effective agronomic approaches for P. purpureum phytoextraction of soil Cd.

     

Low Concentrations of Glyphosate-Based Herbicide Affects the Development of <Emphasis Type="Italic">Chironomus xanthus</Emphasis>

Glyphosate is an herbicide commonly used worldwide for weed control and generally applied as part of a formulated product, such as Roundup. Contamination of surface water by glyphosate-based herbicides can cause deleterious effects in organisms, mainly in aquatic systems near to intensive agricultural areas (e.g., transgenic soybean crops). Given the lack of toxicological information concerning effects of glyphosate-based herbicides on tropical aquatic ecosystems, we aimed to evaluate the lethal and sub-lethal effects of Roundup Original® on the dipteran Chironomus xanthus. The endpoints evaluated included survival, growth, and emergence. The results showed that the 48 h LC₅₀ for glyphosate to C. xanthus was 251.5 mg a.e./L. Larval growth of C. xanthus was reduced under glyphosate exposure (LOEC for body length = 12.06 mg/L; LOEC for head capsule width = 0.49 mg/L). No effects were observed in terms of cumulative percentage of imagoes emergence. However, low concentrations of glyphosate caused delayed emergence of females (at 1.53 mg/L) and induced fast emergence of males (at 0.49 mg/L), compared to control treatment. The deleterious effects of environmental relevant concentrations of glyphosate (0.7 mg/L) observed in terms of C. xanthus growth and development suggest that glyphosate-based herbicides can have negative consequences for aquatic non-target invertebrates such as Chironomus. Multigerational assays are needed to assess the long term effects of glyphosate on C. xanthus populations. Finally, our study adds ecotoxicological data on the effects of glyphosate-based herbicides on tropical freshwater invertebrates.     

Effects of Solution Nitrogen and Plant Density on Annual Grass Seed Biochemistry and Progeny Phenotypic Plasticity

Abstract

Cogenerational phenotypic plasticity compensation to nutrient limitations and shoot densities (light limitation) among individual plants of the same species could provide an increased fitness. Planting density varying between 4 and 16 plants per container and solution nitrogen varying between 5 and 19 mM were used to test phenotypic plastic responses in oat (Avena sativa cv. Montezuma) seed biochemistry and the resulting progeny. Seed Kjeldahl nitrogen (N), magnesium (Mg), and both albumin–globulin (l M NaCl soluble) and prolamin–glutelin (residue) protein fractions were affected by a solution N × plant density interaction. Phosphorus (P) content was influenced by both treatment variables. The protein fractions, P, N, and Mg, in seeds from parent treatments were generally highest in the two higher planting densities. The contents of N, P, Mg, and the prolamin–glutelin fraction were highest at mid‐N (9 mM), except for the 16 plants per container where they were maximal at high‐N (19 mM). In contrast, the albumin–globulin fraction responded linearly to N availability. Seeds per plant decreased while seed weights increased, as plant density increased. The seed content of N, albumin–globulin, prolamin–glutelin, P, and Mg were all negatively associated with the number of seeds per plant. Germination rates of progeny were inversely related to parent plants N treatment. Progeny from the treatment plants (seeds × germination percent) were inversely related, over a five‐fold range, to parent density. Progeny shoot/root ratios (S/R) were directly influenced by the N treatment of parent plants, with progeny from the highest parent N treatment having the highest S/R. Seed N and P content and the prolamin–glutelin protein fraction concentration were correlated with progeny SR. Seed weight was negatively correlated with progeny S/R. Annual grass seed numbers and weights and the allocation of several seed constituents are environmentally influenced by plant density and solution N. These seed biochemical and physiological effects result in a reproductive fitness change and a cogenerational phenotypic plasticity influenced progeny fitness (S/R attribute).