Batches Of Seeds Research Articles

Avaliação da morfologia interna de sementes de Terminalia argentea (Combretaceae) pelo teste de raios X

Forest species, especially those from the Cerrado, are characterised by a high incidence of predation, empty fruit and deficiency in embryo formation. The objective of the present work was to evaluate the internal morphology of seeds of Terminalia argentea Mart. et Zucc. by X-ray testing, and to verify its relationship to germination. The experiment was conducted at the Laboratory for Image Analysis of the Department for Plant Production, at the Escola Superior Luis de Queiroz, in the city of Piracicaba, in the state of Sao Paulo, Brazil. Three batches of seeds of T. argentea were collected and taken to the laboratory, where radiographic analysis of 200 seeds from each lot was carried out. The seeds were placed 28.0 cm from the source of the X-ray emissions, digital equipment from Faxitron X-ray, model MX-20 DC 12. The seeds were then classified according to their internal morphology as seen in the radiographs, with three categories being established: full, empty and misshapen seeds. Germination tests were performed for each category of seed. The statistical design employed was a factorial scheme of three groups and three categories. From the results obtained in this work, use of X-ray testing of seeds of Terminalia argentea is promising for the detection of the fruit quality of the seed lots, aiding in the separation of empty seeds and those with embryonic abnormalities, and precluding their storage or immediate use. X-ray testing at an intensity of 26 kV for 1.2 seconds was effective in assessing the internal morphology of seeds of Terminalia argentea.

Controlled synthesis and visible light photocatalytic activity of Bi12GeO20 uniform microcrystals.

We successfully synthesized uniform Bi12GeO20 microspheres and microtetrahedrons enclosed by four {111} facets using a controlled hydrothermal method for the first time. The photocatalytic activity of these regular-shaped products was further investigated by the degradation of RhB and gaseous formaldehyde under visible light irradiation (λ>420 nm). The Bi12GeO20 microtetrahedrons (s) exhibited enhanced photocatalytic activity and stability which is closely related to the high capacity of exposed {111} facets for uptake of O2. The formation mechanism studies indicate that the Bi12GeO20 seeds were directed to grow into truncated microcubes, truncated microtetrahedrons, and then microtetrahedrons when the NaOH concentration was 5 M. The same batch of seeds only evolved into microspheres when the NaOH concentration was switched to 3 M. The difference in Bi12GeO20 morphology could be attributed to the rates of both crystal nucleation and crystal growth.

Uneven drying of zygotic embryos and embryonic axes of recalcitrant seeds: Challenges and considerations for cryopreservation

Cryopreservation is the most promising option for the long-term germplasm conservation of recalcitrant-seeded species. However, the variable post-cryo success achieved with the excised zygotic explants traditionally used for cryopreservation has been a concern for some time. Differential drying rates amongst explants of different species, uneven drying amongst explants within a batch of seeds and uneven drying across tissues within individual embryos could be contributory factors to this variable success and these phenomena form the foci of the present study. Using zygotic explants from a range of recalcitrant-seeded species, which included sub-tropical dicotyledonous trees and sub-tropical monocotyledonous geophytes, the study showed that embryo morphology and anatomy are critical determinants of the drying characteristics of the different tissues composing the explant and hence, post-cryo survival. The results suggest that the rates of drying of explants to water contents (WCs) in the theoretically optimal range for successful cryopreservation are species-specific, and that more rapid drying rates may promote post-cryo survival. However, the large variation in WC amongst individual explants in bulk samples challenges the selection of the theoretically optimum WC for cryopreservation. As a consequence of differential drying rates across the different tissues composing explants, either lethal ice crystal damage or desiccation damage may sometimes be likely in tissues responsible for the onwards development of the embryo. Drying times for cryopreservation of such explants should, therefore, be selected on the basis of WC of segments containing root or shoot meristem, rather than embryo bulk WC. Drying intensity and duration also interact with explant morphology and embryo/axis size and anatomy to bring about – or preclude – post-cryo survival.

Detection and quantification of three distinct Neotyphodium lolii endophytes in Lolium perenne by real time PCR of secondary metabolite genes

Perennial ryegrass (Lolium perenne) is a widely used pasture grass, which is frequently infected by Neotyphodium lolii endophytes that enhance grass performance but can produce alkaloids inducing toxicosis in livestock. Several selected endophyte strains with reduced livestock toxicity, but that confer insect resistance, are now in common use. Little is known regarding the survival and persistence of these endophytes when in competition with common toxic endophytes. This is mainly because there are currently no assays available to easily and reliably quantify different endophytes in pastures or in batches of seeds infected with multiple strains. We developed real time PCR assays, based on secondary metabolite genes known to differ between N. lolii endophyte strains, to quantify two selected endophytes, AR1 and AR37, and a common toxic ecotype used in New Zealand. A duplex PCR allowed assessment of endophyte:grass DNA ratios with high sensitivity, specificity and precision. Endophyte specific primers/probes could detect contamination of AR37 seeds with other endophytes down to a level of 3–25%. We demonstrated that it is possible to quantify different endophyte strains simultaneously using multiplex PCR. This method has potential applications in management of endophytes in pastures and in fundamental research into this important plant-microbe symbiosis.

Fatty Acid Profile of Cucumis melo var. acidulus (Culinary Melon) Seed Oil

Sir, The melons (Cucumis melo, Cucurbitaceae) are a diverse group of fresh, dessert fruits including C. melo var. cantalupensis, with a rough and warty skin, not netted (cantaloupe), C. melo var. inodorus, with a green, yellow or orange skin (winter melons), C. melo var. reticulatus, with a netted skin (true muskmelon). However, some other melons are considered ‘culinary vegetables’ (C. melo var. acidulus) and they are used as vegetables rather than fruits. C. melo var. acidulus is widely cultivated in India and used as a vegetable throughout the year since it has a long shelf life. The seeds of melons are normally treated as waste products. Some reports available on the composition of melon seeds [1–3] and authors have reported lipid and protein contents of proximally 30 and 54 %, respectively. We were interested in the possibility of extending the range of products from melons and therefore examined the oil content and the fatty acid profile of oil extracted from culinary melon seeds. Prior to extraction of the oil, approximately 50 g of seeds were dried overnight at 80 C and ground in a coffee grinder. The oil was extracted by a heat reflux method using 100 ml of petroleum ether (b.p. 40–60 C). Three extractions were carried out from three different batches of seeds of the same melon accession/variety. The mass of oil was determined gravimetrically after removal of the solvent and results are expressed as a percentage of the seed dry weight. Oil from the seed was subjected to physical characterization. The color and state of the oil at room temperature were noted by visual inspection, while the specific gravity was determined by the AOCS method given in [4]. The refractive index of the oil at room temperature was measured using the Abbe refractometer as outlined in AOCS method. The acid value, free fatty acids, iodine value, saponification number, peroxide value and unsaponifiable matter were measured by AOCS methods [5]. The fatty acid composition of the oil sample was analyzed by GC after transesterification. Fatty acid methyl esters was analyzed on a Chemito GC 8610 gas chromatograph equipped with a flame ionization detector and a capillary column BP 9 70 (50 m 9 0.32 mm 9 0.25 lm films). The detector temperature was programmed for 260 C with flow rate of 0.3 ml/min. The injector temperature was set at 240 C. Nitrogen (purity 99.95 %) was used as the carrier gas. Identification of the peaks was performed by comparing retention times with those of genuine standards analyzed under the same conditions. The oil content obtained from the seeds was 34.68 % on a dry weight basis. Compared to results obtained in different varieties of melon (30.83–33.92 %) the oil content in C. melo var. acidulus was higher [1–3]. The oil was consistently liquid at room temperature (25 C); colorless, and the specific gravity and refractive index of the oil were 0.92 and 1.48, respectively. The total acidity (0.76 mg NaOH/ g), free fatty acid (0.88 %), peroxide values (8.21 mg/g) are within the allowable limits for edible oil. The saponification (186.21 mg KOH/g) and iodine values (109.2 mg/ 100 g) of the seed oil in our study were lower than the values reported by Ramakrishna et al. [6] and de Melo et al. [1]. Table 1 shows that there are nine kinds of fatty acids in C. melo var. acidulus seed oil with a high concentration of polyunsaturated fatty acids (80.54 %) and a low concentration of monounsaturated fatty acids (19.43 %). Linoleic S. H. Manohar H. N. Murthy (&) Department of Botany, Karnatak University, Dharwad 580003, India e-mail: hnmurthy60@gmail.com; nmurthy60@yahoo.co.in

Accelerated Aging in Tomato Seeds

The tomato plant (Lycopersicum esculentum L.) is a perennial, shrubby-like vegetable with high reproductive ability, which behaves like a typical annual crop. The aim of this work was to select suitable tests to assess the quality of different lots of tomato seeds. Six batches of tomato seeds were assessed for parameter values: moisture content, germination, first count, accelerated aging (standard: 40 mL of water; saline solution: 11 g NaCl/100mL of water and saturated saline solution: 40 g NaCl/100mL water) and seedling emergence in soil. Accelerated aging through the use of saturated salt solution for 48 h or 72 h at 41°C resulted in an alternative and efficient way to evaluate the physiological quality of tomato seeds. The standard accelerated aging test was less efficient and exhibited higher moisture variation.

Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HILIC-UPLC–TQ-MS/MS) in multiple-reaction monitoring (MRM) for the determination of nucleobases and nucleosides in ginkgo seeds

In this study, a rapid, simple and sensitive analytical method was developed for the quantitative determination of 20 nucleosides and nucleobases in functional foods at trace levels using hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HILIC-UPLC–TQ-MS/MS) in multiple-reaction monitoring (MRM) mode. Under optimised chromatographic conditions, good separation of 20 target compounds was achieved using a Waters Acquity UPLC BEH Amide column and gradient elution in 11min. The limits of detection (LODs) and quantification (LOQs) were between 0.02–42.54ng/mL and 0.05–98.18ng/mL for the 20 analytes, respectively. This is the first report about simultaneous analysis of nucleosides and nucleobases in functional foods using this method, which afforded good linearity, precision, repeatability and accuracy. The method developed was successfully applied to quantify target compounds in batches of ginkgo seeds. The method potentially could be used to determine polar and trace-level nucleosides and nucleobases in ginkgo seeds.

Effects of seed burial on germination, protein mobilisation and seedling survival in Dodonaea viscosa

Ecological restoration of disturbed areas requires substantial knowledge of the germination of native plants and the creation of novel methods to increase seedling establishment in the field. We studied the effects of soil matrix priming on the germination of Dodonaea viscosa seeds, which exhibit physical dormancy. To this end, we buried both pre-scarified (in H2SO4, 3 min) and non-pre-scarified seeds in the Parque Ecológico de la Ciudad de México. After seeds were unearthed, they were post-scarified for 0, 2, 6 and 10 min and their germination percentages compared to the germination of a control batch of laboratory-stored seeds. For both control and unearthed seeds, the protein pattern was determined in the enriched storage protein fraction in SDS-PAGE gels stained with Coomassie blue. Percentage germination increased as the scarification time increased. Pre-scarification significantly increased percentage germination of post-scarified seeds in relation to the control and non-pre-scarified seeds. In seeds unearthed from the forest site, the buried pre-scarified seeds had relatively high percentage germination, even in the absence of post-scarification treatment. A 48-kDa protein was not found in unearthed, pre-scarified seeds nor in the control germinated seeds, indicating that mobilisation of this protein occurred during soil priming. Burying seeds for a short period, including the beginning of the rainy season, promoted natural priming, which increased protein mobilisation. Functionally, priming effects were reflected in high percentage seedling survival in both the shade house and the field. Seed burial also reduced the requirement for acidic post-scarification.

Evaluation of the Germination Potential of Citrus Seeds during the Harvesting Season

The effects of fruit age on the seed quality and germination percentage of ‘Duncan’ and ‘Flame’ grapefruit and ‘Hamlin’ sweet orange were investigated. Our results suggested that seed germination varied from 98% to 100% for the two grapefruit cultivars and 85% to 100% for ‘Hamlin’ regardless of time of harvest. Within the first 5 months of the harvest season, chilling of ‘Duncan’ and ‘Hamlin’ seeds at 4 °C for 7 days after fruit sampling resulted in a lower germination percentage only with the ‘Hamlin’ seeds. Seed moisture content of all three cultivars varied slightly through the season and remained steady at 60% and 70% for batches of fresh seeds stored at room temperature or at 4 °C. Our results suggest that high seed viability and germination percentage can allow the use of these seeds for experimentation regardless of the time the fruit were picked during the harvest season.

Shape-Controlled Synthesis of Palladium Nanocrystals: A Mechanistic Understanding of the Evolution from Octahedrons to Tetrahedrons

Palladium octahedrons and tetrahedrons enclosed by eight and four {111} facets have been synthesized from cuboctahedral Pd seeds by using Na2PdCl4 and Pd(acac)2, respectively, as the precursors. Our mechanistic studies indicate that the cuboctahedral seeds were directed to grow into octahedrons, truncated tetrahedrons, and then tetrahedrons when Pd(acac)2 was used as a precursor. In contrast, the same batch of seeds only evolved into octahedrons with increasing sizes when the precursor was switched to Na2PdCl4. The difference in growth pattern could be attributed to the different reduction rates of these two precursors. The fast reduction of Pd(acac)2 led to a quick drop in concentration for the precursor in the very early stage of a synthesis, forcing the growth into a kinetically controlled mode. In comparison, the slow reduction of Na2PdCl4 could maintain this precursor at a relatively high concentration to ensure thermodynamically controlled growth. This work not only advances our understanding of the growth mechanism of tetrahedrons but also offers a new approach to controlling the shape of metal nanocrystals.

SIMULTANEOUS DETERMINATION OF TEN STILBENES IN THE SEEDS OF PAEONIA SPECIES USING HPLC-DAD

A rapid, sensitive, and accurate HPLC-DAD method was developed and validated for simultaneous determination of 10 stilbenes, which include suffruticosol A, suffruticosol B, suffruticosol C, resveratrol (E)-form, cis-ϵ-viniferin, trans-ϵ-viniferin, cis-suffruticosol D, cis-gnetin H, trans-suffruticosol D and gnetin H, in 44 plant samples from 9 different Paeonia species. In this optimized method, separations were carried out on an YMC-pack ODS-A column with water and methanol as mobile phase. The flow rate was set at 1.0 mL/min and the detector wavelength was set at 230 nm. The results showed that all the 10 analytes showed good linearity (r2 > 0.9994). The recoveries, measured at three concentration levels, varied from 97.19% to 102.89%. This method was also validated with respect to precision, repeatability, stability, and successfully applied to simultaneous determination of 10 stilbenes in 44 batches of peony seeds from 9 Paeonia species collected from different areas.

Rapid analysis of multi-pesticide residues in lotus seeds by a modified QuEChERS-based extraction and GC–ECD

A modified quick, easy, cheap, efficient, rugged and safe method (QuEChERS) coupled to gas chromatography with electron capture detector (GC–ECD) was developed for rapid extraction and simultaneous determination of 36 pesticides in lotus seeds. The extraction solvent (acetone, ethyl acetate, acetonitrile, n-hexane and n-hexane in combination with ethyl acetate) and purifying agent (neutral alumina, primary secondary amine, graphite carbon block and florisil) for QuEChERS extraction were optimized. The GC–ECD method was in-house validated in terms of linearity, selectivity, reproducibility, stability and recovery. The limits of detection (LODs) of the developed GC–ECD method for all investigated pesticides ranged from 0.01 to 3.0μgL−1 and limits of quantification (LOQs) from 0.05 to 10.0μgL−1. The satisfactory data demonstrated the good reproducibility and stability of the method with relative standard deviations (RSDs) lower than 15%. Recoveries for spiked lotus seed samples were from 60.84% to 119.91% with RSDs lower than 13.06%. Two out of 24 batches of lotus seeds collected in China were found to be contaminated with trans-chlordane, which were below LOQ. This is the first attempt in China using QuEChERS to GC–ECD to determine 36 major pesticides with differences in physio-chemical properties in lotus seeds. The method described here was found to be practicable in the routine residue analysis of pesticides in lotus seeds.

Isolation of a unique dipyridodiazepinone metabolite nevirapine during large scale extraction of Cliv-92 from the seeds of Cleome viscosa

Natural nevirapine (1), a dipyridodiazepinone metabolite has been isolated as a minor constituent with a yield of 0.00397% from the ethyl acetate extract during large scale extraction of Cliv-92 at a level of 100kg/batch from the seeds of Cleome viscosa. Column chromatographic purification of the ethyl acetate extract afforded the molecule which was characterized as nevirapine through spectral analysis and confirmed by single crystal X-ray crystallography. The molecule also has been re-isolated from the same batch of seeds to confirm its presence in the seeds of C. viscosa. The molecule nevirapine has been fully characterized by co-TLC, prep-TLC-MS/MS and chiral HPLC analysis. Isotope Ratio Mass Spectrometric (IRMS) analysis of natural nevirapine and the synthetic drug revealed it to be different. It is an interesting discovery to find out that the natural nevirapine exists as an endogenous metabolite of the plant. This paper also reports the isolation of salicylic acid from the same batch of seeds which afforded nevirapine which may have been due to some plant–pathogenic interaction.

Improvement Tests on the Germination in Lippia Multiflora: Influence of Some Factors Related to Soil on Germination and Seedling Development

Studies on the germination and growth of seedlings of Lippia multiflora were conducted on several types of substrates. They consisted of germination tests and monitoring of seedling growth. The results showed that the best germination rates were recorded with the batch of seeds germinated on substrates made of a mixture of soil and manure (S2 = 82.67% and S3 = 65.33%). After 60 days of culture, the most significant heights of the plants of Lippia multiflora were recorded in culture media S2 (7.48 cm) and S3 (5.46 cm), with an average number of leaves 7; 12 and 6, respectively for the circles S1, S2 and S3. The root elongation is more important in substrates S2 (6.3 cm) and S3 (4.74 cm). The Pearson correlation tests carried out indicate that the contribution of organic matter in the substrates improves seedling development in Lippia multiflora.

Effect of age and planting site on survival and growth of seedlings of Juniperus thurifera L.

L’objectif de cette étude était de comparer la survie et la croissance des plants de Juniperus thurifera d’une saison de croissance cultivés dans des conteneurs de deux capacités (200 ml et 300 ml) à des plants de deux saisons de croissance cultivés dans une seule taille de conteneur (300 ml). Les plants ont été cultivés en 2006 et 2007 à partir du même lot de semences et suivant le même schéma annuel de fertilisation. Ainsi une dose de 135,05 mg de N a été appliquée pour les plants d’un an et une dose de 271 mg de N pour les plants de deux ans. Les plants ont été transplantés en février 2008 dans deux sites localisés à Monreal del Campo (Teruel) et Buenhache de la Sierra (Cuenca) pour étudier leur survie et leur développement. La survie au cours de la première année était de 100 % dans tous les traitements à Monreal del Campo, tandis qu’à Buenhache la mortalité des plants d’un an cultivés dans des conteneurs de 300 ml a été significativement plus élevée que dans les deux autres traitements. Le choix du site de plantation et du type de culture des plants influence donc la réussite du reboisement.

Seed dormancy and germination of an endangered coastal plantEryngium maritimum(Apiaceae)

INTRODUCTION Eryngium maritimum L. is a littoral species growing on sand dunes and shingle beaches. Although it is listed among the species widespread in western and southern Europe, overall its population is declining (Van der Maarel & Van der Maarel-Versluys, 1996). The species is included in the Red Data Book of Latvia (Fatare, 2003) and is protected in several other European countries. In northern Europe and in the Baltic Region it grows near the limits of its current area of distribution and therefore is at a greater risk of extinction because in small and isolated populations there is a risk of inbreeding depression. For example, in Eryngium alpinum partial self-incompatibility causes lower seed set in selfing plants and selfing negatively affects seed mass and germination (Gaudeul & Till-Bottraud, 2003). A survey of E. maritimum populations along the Skagerrak coast was conducted and the persistence prospects of this species were evaluated as low in these localities due to the small size and fragmentation of individual populations (Curle et al., 2007). Population surveys were also conducted in Poland and Lithuania (Olsauskas, 1996; Labuz, 2007). While in some cases the decline of E. maritimum is linked to habitat disturbance, a population can be threatened also due to limited generative reproduction, affected both by low seed production and low germination as well as high juvenile mortality (Curle et al., 2007; Aviziene et al., 2008). It was suggested also that a decrease of the physiological fitness of E. maritimum individuals in northern populations is associated with lower photosynthetic productivity due to high precipitation and low air temperature (Andersone et al., 2011). Seeds of the Apiaceae family are often morphologically or morphophysiologically dormant (Finch-Savage & Leubner-Metzger, 2006). Seeds with morphological dormancy have small, differentiated embryos that need time to develop before a seed can start to germinate (Baskin & Baskin, 2004). Morphophysiologically dormant seeds also have a physiological component of dormancy and therefore require a dormancy-breaking pretreatment. Depending on the type of the physiological component, different combinations and length of warm and cold stratification can be required (Baskin & Baskin, 2004). Preliminary research on E. martimum seeds (J. Necajeva, unpublished results) confirmed that seeds of this species have underdeveloped embryos at the time of maturation and seed dispersal and, in addition, seeds require dormancy-breaking treatment (cold stratification) to germinate. Other researchers also reported that cold stratification is necessary to break the dormancy of E. maritimum seeds (Walmsley & Davy, 1997; Curle et al., 2007). The results of previous studies probably give sufficient information to develop an effective method of germinating E. maritimum seeds. However, to our knowledge, there have not been any detailed studies of the physiology of the germination process in E. maritimum. The physiological component of seed dormancy is related to the effect of temperature on dormancy breaking and germination. From the point of view of seed physiology, this action of temperature is related to changes in the activity of gibberellins and abscisic acid in the seed. This is why exogenous gibberellins can in some cases substitute for the effect of dormancy-breaking temperatures (Nikolaeva et al., 1985; Finch-Savage & Leubner-Metzger, 2006). When seeds have complicated physiological mechanisms of dormancy release and germination, it is difficult to predict or model germination in natural conditions because the effects of temperature and soil moisture are not straightforward. The morphological component of dormancy can be studied using embryo size-class structure, and is a way to understanding the dynamics of germination within a batch of seeds. We can put forward the hypothesis that the germination rate depends on the degree of embryo development at the time of maturation. …

Determination of chemical variability of phenolic and monoterpene glycosides in the seeds of Paeonia species using HPLC and profiling analysis

A rapid, sensitive, and accurate HPLC-DAD method was developed and validated for simultaneous determination of one phenolic glycoside and seven monoterpene glycosides, including 1-O-β-d-(4-hydroxybenzoyl)glucose (1), pyridylpaeoniflorin (2), (8R)-piperitone-4-en-9-O-β-d-glucopyranoside (3), oxypaeoniflorin (4), 6′-O-β-glucopyranosylalbiflorin (5), albiflorin (6), β-gentiobiosylpaeoniflorin (7), and paeoniflorin (8), in 44 batches of peony seeds from nine Paeonia species collected from different areas. Using the optimised method, separations were conducted with a YMC-pack ODS-A column with water/formic acid and methanol as the mobile phase. All eight analytes demonstrated good linearity (r2>0.9993). The recoveries, measured at three concentration levels, varied from 98.20% to 103.81%. Six compounds including 1 and 4–8 occur ubiquitously in all the seeds of nine Paeonia species, and compounds 2 and 3 showed undetectable levels or very low content in several samples. The seed samples were classified into several groups, which coincide with the taxonomy of Paeonia at the section level. Peony seed might be a useful resource in developing new herbal or food products.

Pearl millet downy mildew as affected by integrating seed dressing, sowing date and cultivar

The effects of seed dressing, sowing date and cultivar on incidence and severity of downy mildew of pearl millet induced by Sclerospora graminicola and yield were studied in a two-year field trial conducted at the Research farm of University of Maiduguri. The millet cultivars, Ex-Borno, SOSAT-C88, GB 8735 and Gwagwa were each dressed with metalaxyl at 0.75 and 1.50 g a.i./kg seed; and a batch of undressed seeds of each cultivar served as control. Both dressed and undressed seeds were used for dry-planting and wet-planting in early and late seasons. The results showed that seed dressing with the fungicides significantly (p ≤ 0.05) reduced the incidence and severity of downy mildew and increased grain yield. Dry-planting also significantly (p ≤ 0.01) increased grain yield irrespective of disease incidence. Delay in sowing led to a significant reduction in incidence and severity of downy mildew. Differences between the cultivars in relation to incidence and severity of downy mildew and grain yield were significant. SOSAT-C88 developed low or no downy mildew in both seasons. Sowing of dressed SOSAT-C88 as soon as rainfall established appeared most beneficial in the control of downy mildew. Dry- or wet-planting Ex-Borno dressed with any of the metalaxyl formulations proved to be effective for downy mildew management and for high yield.

Development and validation of an accurate and rapid LC-ESI-MS/MS method for the simultaneous quantification of aflatoxin B1, B2, G1 and G2 in lotus seeds

An accurate and rapid LC-ESI-MS/MS analytical method was developed and validated for the simultaneous determination of aflatoxin B1, B2, G1 and G2 in lotus seeds. The samples were firstly extracted with methanol-water solution (80:20, v/v), and then cleaned up by immunoaffinity columns. The mass spectrometer was operated in the positive ionization electrospray (ESI+) mode using multiple reaction monitoring (MRM) for analysis of four aflatoxins. The transitions of m/z 313 → 285 (AFB1, CE 33 eV), m/z 315 → 259 (AFB2, CE 37 eV), m/z 329 → 243 (AFG1, CE 37 eV) and m/z 331 → 257 (AFG2, CE 37 eV) were used to quantify these four aflatoxins, respectively. The limits of detection (LODs) of aflatoxin B1, B2, G1 and G2 were 0.007, 0.005, 0.003 and 0.005 μg kg−1 based on a signal-to-noise ratio of 3:1, respectively. The limits of quantification (LOQs) of aflatoxin B1, B2, G1 and G2 were 0.02, 0.015, 0.01 and 0.015 μg kg−1 based on a signal-to-noise ratio of 10:1, respectively. Recoveries for samples of spiked lotus seeds were all above 66% with relative standard deviation all below 15% for all compounds. Nineteen out of twenty batches of lotus seeds collected from different drug stores or markets in China were found to be contaminated with aflatoxins at different levels ranging from 0.02 to 688.4 μg kg−1.

Micropropagation and seed cryopreservation of the critically endangered species Tennessee yellow-eye grass, Xyris tennesseensis Kral

Xyris tennesseensis is a critically endangered species native to the southeastern USA. A micropropagation protocol was developed which may assist in the safeguarding and augmentation of dwindling natural populations of this ecologically and medically valuable plant. Four different batches of seeds were sterilized using hydrogen peroxide and germinated in vitro on modified one third-strength Murashige and Skoog medium. Shoot multiplication from seedling tissue was obtained using modified one third-strength Murashige and Skoog medium containing 1 mg/l kinetin and 0.1–0.5 mg/l α-naphthaleneacetic acid. Optimal shoot size and sustainable multiplication rates of three to five per 2-mo subculture occurred on medium containing 0.3–0.4 mg/l α-naphthaleneacetic acid. Shoots rooted successfully when placed on growth regulator-free medium for 10 d followed by transfer to greenhouse soil under high humidity. Use of seed cryopreservation resulted in significant increases in germination compared to control treatments with average germination rates of 97%. Shoot tip cultures from soil-grown plants of X. tennesseensis and Xyris spathifolia were also developed using the above protocols. Plant tissue culture tools will assist in the multiplication, long-term storage, and conservation of these rare and valuable plants as well as provide a template for the micropropagation of other Xyris species.