Flat Leaf Research Articles

Subtle origin for complex shapes

Plant Science The cup-shaped leaves of carnivorous plants have evolved multiple times from ancestors with flat leaves. Studying development of the carnivorous trap in the humped bladderwort, Utricularia gibba , Whitewoods et al. identified genes similar to those expressed in surfaces of flat leaves (see the Perspective by Moulton and Goriely). Ectopic expression and computational modeling reveals how slight shifts in gene expression domains make the difference between a flat leaf and a convoluted trap structure. Flexibility in growth rates in orthogonal polarity fields allows for diversity in shapes formed through development. Science , this issue p. [91][1]; see also p. [24][2] [1]: /lookup/doi/10.1126/science.aay5433 [2]: /lookup/doi/10.1126/science.aba3797

Evolution of carnivorous traps from planar leaves through simple shifts in gene expression.

Leaves vary from planar sheets and needle-like structures to elaborate cup-shaped traps. Here, we show that in the carnivorous plant Utricularia gibba, the upper leaf (adaxial) domain is restricted to a small region of the primordium that gives rise to the trap's inner layer. This restriction is necessary for trap formation, because ectopic adaxial activity at early stages gives radialized leaves and no traps. We present a model that accounts for the formation of both planar and nonplanar leaves through adaxial-abaxial domains of gene activity establishing a polarity field that orients growth. In combination with an orthogonal proximodistal polarity field, this system can generate diverse leaf forms and account for the multiple evolutionary origins of cup-shaped leaves through simple shifts in gene expression.

Breeding of a Fragrant, Mini-multiflora <i>Phalaenopsis</i> Hybrid Orchid Cultivar, ‘Bravo Star’

Phalaenopsis ‘Bravo Star’, a new orchid cultivar, is both fragrant and has a multi-branch architecture with miniature, pink flowers. It was derived from a cross made by Gyeongnam Agricultural Research and Extension Service in 2016 of ‘Kung’s Red Coral’ (female) to ‘Tzu Chiang balm’ (male). To produce the hybrid, five F1 lines having strong fragrance and multiple flowering characters were selected from 2010 to 2012. A line then referred to as ‘08–VIO-16’ was finally selected after confirmation of stability and uniformity characteristics through evaluation and testing during 2013–2015. The selection ‘08-VIO-16’ was described as having a flat flower form and dark pink (RPN 57B) petal and sepal as well as a 29.1 cm flower stalk length. It had a flat and narrow obovate leaf form. The average leaf length and width were 18.2 and 6.5 cm, respectively. The average flower length and width were 5.7 and 5.2 cm, respectively. Although t his selection had a relatively low f lower number of 7.8 flowers per stalk, it was determined to be a good candidate cultivar for the potted plant market during evaluation and exhibition due to its multi-branching and inflorescence shape as well as its strong, sweet scent that is similar to cinnamon fragrance. Furthermore, it was found to be relatively easy to propagate in vitro and had a vigorous and fast growing habit. Following evaluation, this selection was registered as hybrid cultivar ‘Bravo Star’ on March 2017 (registration no. 6719) and protected by the seed industry act.

YIELD AND BIOMETRIC CHARACTERISTICS OF MAIZE SUBMITTED TO PLANT POPULATION AND TRINEXAPAC-ETHYL DOSES

ABSTRACT The use of plant growth regulators in agriculture can alter the morphology of corn plants, increasing crop yield due to the possibility of increasing the population. This study aimed to evaluate the effects of plant populations associated with trinexapac-ethyl (TE) doses on the biometric characteristics of shoot and grain yield of contrasting corn cultivars regarding plant architecture. Experiments were conducted in the field during two seasons with the hybrids 2B710 HX (flat leaf) and TL Status (erect leaf) in a randomized block design (four replications) and treatments in a 5 × 5 factorial scheme, with five plant populations (40, 60, 80, 100, and 120 thousand plants ha−1) and five TE doses (0, 100, 200, 300, and 400 g a.i. ha−1) applied by foliar spraying at the V6 stage. Plant height, ear insertion height, stem diameter, leaf area index, and grain yield were evaluated. An increment in population increases plant height, ear insertion height, and the leaf area index, but reduces stem diameter. The plant growth regulator TE reduces plant height and ear insertion height. The interaction between plant population and TE favors corn yield, with the highest values observed in combinations of 93.4 thousand plants ha−1 with a dose of 176 g ha−1 of TE for the hybrid 2B710 HX and 92.2 thousand plants ha−1 with a dose of 251 g ha−1 of TE for the hybrid Status TL.

SR micro-XRF to study Pb diffusion using a one-dimensional geometric model in leaves of Brassica napus for phytoremediation

The purpose of phytoremediation is the removal of contaminants by plants that grow in soils with high levels of specific contamination. The technological implementation of lead phytoremediation depends on the understanding of tolerance and growth phenomena of the plant in contaminated soil, uptake and translocation of this element and its accumulation in aerial foliage of the plant. This work provides results about diffusive transfer of lead across the xylem towards leaf blade (or lamina) of Brassica napus using a 1-dimension model that assumes Fick's Second Law. It uses mapping data of Pb concentrations measured by synchrotron radiation micro x-ray fluorescence in order to calculate the diffusion coefficient in soft tissue of leaves. The diffusion equation is solved for a flat leaf geometric model and the solution is fitted to experimental values of Pb concentrations of equivalent leaves, harvested from the same plant in progressive times of its growing cycle. The results of the diffusion coefficient were calculated in a zone (∼600 μm) outside the leaf xylem, where the Pb concentration profile determines a well-defined gradient. These results are original and provide a contribution to understand the dynamics of Pb retention in leaves.

Karakterisasi Morfologi dan Komponen Hasil Cabai Rawit (Capsicum frutescens L.) Asal Pulau Timor

Cabai rawit merupakan salah satu plasma nutfah asal pulau Timor dikenal dengan sebutan un makaos, un lili, un fua melu atau un ana. Cabai rawit Timor memiliki kekhasan bentuk yakni berukuran kecil dengan panjang berkisar 0,5-2 cm dan rasa yang sangat pedas. Tujuan dari penelitian ini untuk mengidentifikasi karakter morfologi dan komponen hasil un makaos. Metode penelitian dilakukan berdasarkan kerangka ketentuan UPOV (International Union for The Protection of New Varieties of Plants) dan standar yang ditetapkan oleh IPGRI (International Plant Genetic Resources Institute). Hasil penelitian menunjukkan bahwa karakterisasi morfologi cabai rawit pulau Timor teridentifikasi memiliki habitus tanaman dengan percabangan yang kompak, bentuk batang silindris, pemendekan ruas lebih dari tiga dan memiliki batang berwarna hijau. Daun cabai berbentuk ovate (bentuk bulat telur, bagian terlebar dekat pangkal daun) dan berwarna hijau dengan tepi daun rata dan ujung daun meruncing. Mahkota bunga berwana putih dengan anter bunga berwarna biru serta kedudukan bunga tegak pada pohon cabai rawit. Warna buah hijau pada saat sebelum matang dan berwarna merah pada saat masak. Memiliki bentuk buah hornshaped (berbentuk tanduk) dengan ujung buah yang tumpul serta memiliki bentuk kaliks enveloping (membungkus). Karakter komponen hasil diantaranya bobot buah per tanaman memiliki nilai rata-rata sebesar 9,47-15,08 g, rata-rata jumlah buah per tanaman sebanyak 125,67-169,67 buah, cabai rawit memiliki panjang buah 0,73-0,82 cm dan buah memiliki diameter 0,36-0,38 cm.

KARAKTERISASI DAN SKRINING FITOKIMIA SIMPLISIA DAUN SELUTUI PUKA (Tabernaemontana macracarpa Jack)

Selutui puka (Tabernaemontana macrocarpa Jack) is a plant that is efficacious for treating tumor diseases and blisters. Simplicia is said to be of high quality if it meets the simplicia requirements. The initial process to find out the quality of simplicia is characterization. The study aims to determine the specific, non-specific characteristics and content of chemical compounds.This research is non experimental. The research starts from sampling, determination, making simplicia, characterization which includes macroscopic test, microscopic test, determination of moisture content, soluble ethanol extract content, water soluble extract content, moisture content, ash content, acid insoluble ash content and phytochemical screening. Data were analyzed using descriptive methods.Specific characteristics in the macroscopic and organoleptic tests showed long round leaves, pinnate leaf bones, spiky rounded leaf tips, rounded base of leaves, flat leaf edges, thick leaf flesh, dark green color, leaf width of 4.5 cm long, 12.5 cm long. The powder is dark green, aromatic and has a bitter taste. Microscopic tests include cover hair, vessels, bundles of stairs, upper epidermis and lower epidermis with bidiastic type stomata, 12% soluble ethanol, 15% water soluble extract. Non-specific characteristics consisted of 8% moisture content, 6.51% ash content, acid insoluble ash content 0.246%. The results of phytochemical screening contain alkoloid, flavonoids, tannins, saponins and steroids.

Morphophysiological analyses on Teak (Tectona grandis Linn. f.) from three provenances

High genetic diversity in teak species causes problems in identifying the individuals. To identify the characteristics of the individuals, an identification system using morphophysiological analyses for Teak is needed. This study was aimed to identify the morphological and physiological differences between three different teak provenances, i.e., Cepu, Sidrap, and Bau-bau provenances. The research was carried out by observing morphological characteristics, i.e., leaf characteristics (color, shape, venation pattern, margin, base, tip, and surface texture) and tree characteristics (height and diameter), and physiological characteristics (leaf area, chlorophyll content, and leaf water content). There were five leaf colors observed in the analysis (green- brownish, green-yellowish, green, dark green, and green with yellow spots). Leaf shapes were divided into two shape types, i.e., widened ellipse and inverted oval. Flat leaf margin, tapered leaf tip, and base, rough surface texture, pinnate venation pattern were observed on all evaluated leaves. Height and diameter of trees were higher in Bau-bau provenance than other provenances. Leaf area was affected by provenance but not leaf position in provenance. Chlorophyll content was affected by both provenance and leaf position, whereas water content was only affected by leaf position in provenance.

Optimized angles of the swing hyperspectral imaging system for single corn plant

During recent years, hyperspectral imaging systems have been widely applied in the greenhouses for plant phenotyping purposes. Current systems are typically designed as either top view or side view imaging mode. Top view is an ideal imaging angle for top leaves with flat leaf surfaces. However, most bottom leaves are either blocked or shaded. From side view, the entire plant structure is viewable. However, most leaf surfaces are not facing the camera, which impacts measurement quality. Besides, there could be advantages with certain tilted angle(s) between top view and side view. It’s interesting to explore the impact of different imaging angles to the phenotyping quality. For this purpose, a swing hyperspectral imaging system capable of capturing images at any angle from side view (0°) to top view (90°) by rotating the camera and the lighting source was designed. Corn plants were grown and allocated into 3 different treatments: high nitrogen (N) and well-watered (control), high N and drought-stressed, and low N and well-watered. Each plant was imaged at 7 different angles from 0° to 90° with an interval of 15°. The soil plant analysis development (SPAD) values and relative water content (RWC) ground truth measurements were used to establish treatment effects. The results showed that averaged plant-level Normalized Difference Vegetation Index (NDVI) values of plants in different treatments changed at different imaging angles. The results also indicated that for pixel-level NDVI distributions, the titled imaging angle of 75° was optimal to distinguish different water treatments, whereas, the tilted imaging angle of 15° was optimal to distinguish different N treatments. For pixel-level RWC distributions, the distribution difference between different water treatments was larger at higher imaging angles.

First Report of Pythium Root Rot Caused by Pythium mastophorum on Parsley in the United States

In California, parsley (Petroselinum crispum [Mill.] Fuss) is a versatile leafy green commodity that is grown for fresh, frozen, dried, and processed products. In May 2017, parsley grown in a commercial field in Santa Barbara County, CA, showed symptoms of an unknown disease. Plants were stunted, wilted, and had chlorotic foliage. The large taproots were discolored, and small feeder roots were sparse and necrotic. Affected plants appeared in clusters, and disease incidence was approximately 5%. To recover possible pathogens, roots were surface sterilized in 0.01% bleach for 30 s and plated on corn meal agar amended with pimaricin, ampicillin, rifampicin, and pentachloronitrobenzene (PARP) (Kannwischer et al. 1978). After 3 days, rapidly growing, coenocytic mycelia typical of a Pythium species grew out from all roots. Older cultures showed globose sporangia and ornamented oogonia. Oogonia had an average diameter of 23 µm, and projections were conical, measuring an average length of 3 µm. Five isolates were tested using a recombinase polymerase amplification genus-specific Phytophthora assay (targeting the trnM-trnP-trnM region in the mitochondria) and were found to be negative (Miles et al. 2015). To determine the species, DNA was extracted from mycelial plugs using a QIAamp DNA Mini Kit (Qiagen, Hilden, Germany), and the internal transcribed spacer (ITS) regions 1 and 2 were amplified and sequenced using ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 primers (5′-TCCTCCGCTTATTGATATGC-3′) (GenBank accession no. MG593942). The sequences were 99% homologous to Pythium mastophorum strain CBS 375.72 (GenBank accession no. AY598661). To test for pathogenicity, 4-week-old plants of flat leaf (cv. Italian Dark Green Flat) and curly leaf (cv. Moss Curled) parsley were inoculated using a root-dip method for five isolates. Inoculum was made by blending five fully colonized V8 plates with 250 ml of sterile water. Parsley root balls were soaked for 10 to 15 min in the inoculum and then repotted in a 1:2 sand/soil mixture. In 2 to 3 weeks, inoculated plants became stunted and chlorotic and had symptoms that matched those seen in the field. Roots were severely decayed. Roots plated onto PARP resulted in colonies that morphologically and molecularly were identical to the original isolates. Control plants of both cultivars were inoculated with a mixture of sterile V8 media and water using the above protocol. These plants developed no foliar or root symptoms. This test was completed three times with consistent results. We believe this is the first report of P. mastophorum infecting parsley in California. P. mastophorum has been reported on parsley only in southeastern Australia (Petkowski et al. 2013). In California, this species has been reported on celery (Vazquez et al. 1996). Because affected parsley plants were completely unharvestable, this disease could be a significant concern for growers if inoculum spreads throughout this and other parsley growing regions in the state.

A genetic link between epigenetic repressor AS1–AS2 and DNA replication factors in establishment of adaxial–abaxial leaf polarity of <i>Arabidopsis</i>

Balanced development of adaxial and abaxial domains in leaf primordia is critical for the formation of flat symmetric leaf lamina. Arabidopsis ASYMMETRIC LEAVES1 (AS1) and AS2 proteins form a complex (AS1-AS2), which acts as key regulators for the adaxial development by the direct repression of expression of the abaxial gene ETTIN/AUXIN RESPONSE FACTOR3 (ETT/ARF3). Many modifier mutations have been identified, which enhance the defect of as1 and as2 mutations to generate abaxialized filamentous leaves without adaxial traits, suggesting that the development of the adaxial domain is achieved by cooperative repression by AS1-AS2 and the wild-type proteins corresponding to the modifiers. Mutations of several genes for DNA replication-related chromatin remodeling factors such as Chromatin Assembly Factor-1 (CAF-1) have been also identified as modifiers. It is still unknown, however, whether mutations in genes involved in DNA replication themselves might act as modifiers. Here we report that as1 and as2 mutants grown in the presence of hydroxyurea, a known inhibitor of DNA replication, form abaxialized filamentous leaves in a concentration-dependent manner. We further show that a mutation of the INCURVATA2 (ICU2) gene, which encodes the putative catalytic subunit of DNA polymerase α, and a mutation of the Replication Factor C Subunit3 (RFC3) gene, which encodes a protein used in replication as a clamp loader, act as modifiers. In addition, as2-1 icu2-1 double mutants showed increased mRNA levels of the genes for leaf abaxialization. These results suggest a tight link between DNA replication and the function of AS1-AS2 in the development of flat leaves.

YABBY3-Orthologous Genes in Wild Tomato Species: Structure, Variability, and Expression

Evolution of the genes encoding YABBY transcription factors is believed to be one of the key reasons for flat leaf emergence from the radially symmetrical stem and gynoecium diversity. YABBY genes determine the identity of the abaxial surface of all aboveground lateral organs in seed plants. In the present study, complete sequences of YABBY3-orthologous genes were identified and characterized in 13 accessions of cultivated and wild tomato species with diverse morphophysiology of leaves, flowers, and fruits. The obtained gene sequences showed high homology (95-99%) and an identical exon-intron structure with the known S. lycopersicum YABBY3 gene, and they contained sequences that encode the conserved HMG-like YABBY and Cys2Cys2-zinc-finger domains. In total, in the analyzed YABBY3 genes, 317 variable sites were found, wherein 8 of 24 exon-specific SNPs were nonsynonymous. In the vegetative and reproductive organs of red-fruited and green-fruited tomato species, YABBY3 gene expression was similar to that in S. pimpinellifolium described earlier, but it demonstrated interspecies differences at the leaf-, bud- and flower-specific expression levels.

YABBY3-ортологи дикорастущих видов томата: структура, полиморфизм и экспрессия

Evolution of the genes encoding YABBY transcription factors is believed to be one of the key reasons for flat leaf emergence from the radially symmetrical stem and gynoecium diversity. YABBY genes determine the identity of the abaxial surface of all aboveground lateral organs in seed plants. In the present study, complete sequences of YABBY3-orthologous genes were identified and characterized in 13 accessions of cultivated and wild tomato species with diverse morphophysiology of leaves, flowers, and fruits. The obtained gene sequences showed high homology (95-99%) and an identical exon-intron structure with the known S. lycopersicum YABBY3 gene, and they contained sequences that encode the conserved HMG-like YABBY and Cys2Cys2-zinc-finger domains. In total, in the analyzed YABBY3 genes, 317 variable sites were found, wherein 8 of 24 exon-specific SNPs were nonsynonymous. In the vegetative and reproductive organs of red-fruited and green-fruited tomato species, YABBY3 gene expression was similar to that in S. pimpinellifolium described earlier, but it demonstrated interspecies differences at the leaf-, bud- and flower-specific expression levels.

Investigation of Electromagnetic Drive of Vibratory Conveyor in Pre-resonant mode

The harmonic longitudinal oscillations and biharmonic normal oscillations with phase difference in vibratory conveying essentially increase the conveying velocity comparing with linear oscillations. But implementation of biharmonic oscillations requires the using of two vibratory drives with frequencies that differ in two times from each other. The electromagnetic drive may implement polyharmonic, in particular biharmonic oscillations in pre-resonant mode. The electromagnetic drive of vibratory conveyor in pre-resonant mode, when the frequency of natural oscillations is greater than the frequency of forced oscillations, is investigated. Formulas of amplitudes and phase difference of the first and the second harmonics of oscillation dependence on the frequency of natural oscillations are derived. Frequency and phase response of the electromagnetic vibratory drive are built. It is determined the natural frequency value at which optimal biharmonic oscillations are implemented.To testify theoretical results the experimental investigations were carried out on a special installation. The body of electromagnet was mounted on a massive plate. The anchor of electromagnetic drive was fastened with two flat leaf springs as well as the bracket with acceleration sensor. Exchange of frequency of natural oscillations was achieved by changing of springs’ length. The amplitudes of oscillations were regulated with aid of auto-transformers. The electromagnet was connected to the power supply using half-wave rectifier (diode), so the forced oscillations were implemented with frequency 50 Hz. Sensor readings were recorded on the wave-forms from which amplitudes and phase difference of harmonics were determined by equidistant ordinates method. The comparison of theoretical and experimental investigations shows the sufficient agreement.The using of biharmonic oscillations of the working track of vibratory conveyor in direction perpendicular to the conveying track is possible at a certain natural frequency without increasing of conveyor’s design complexity.

Experimental investigation of fiber reinforced composite leaf springs

Abstract The aim of this study is to experimentally investigate fiber reinforced polymeric composite leaf springs which could be used in a light commercial vehicle instead of a double steel leaf spring. E-glass/epoxy, carbon/epoxy and E-glass-carbon/epoxy flat leaf springs were produced by vacuum assisted resin transfer molding (VARTM) method with specially designed mold. Experimental results show that spring rates were 91.4, 98.4 and 97.1 N × mm−1 for carbon/epoxy, E-glass/epoxy and E-glass-carbon/epoxy leaf springs, respectively. Fatigue tests indicate that the carbon/epoxy leaf springs have the longest average usage life with approximately 89 % weight reduction, although E-glass/epoxy ones satisfy the minimum usage life requirements with higher load carrying capacity with 82 % weight reduction.

Optimization of Various Design Parameters for EN45A Flat Leaf Spring

Leaf springs are widely used as suspension system in automotive vehicles. In the present work, optimization of design parameters of flat leaf springs have been carried out: keeping into account the effect of shot peening intensity, reduction in the weight of components and increase in fatigue life at wide range of operating conditions. A computer program using Visual Basics has been prepared to predict the fatigue life, thickness and weight of shot peened EN45A spring steel leaf springs, based on stress approach. The results obtained from simulation are found in accordance with the experimental results. The developed program for flat leaf springs may be useful for fast and reliable optimization of various parameters of leaf springs in automotive vehicles.Consequently, there will be tremendous saving in material in leaf springs manufacturing industries as a result of optimization.

Regulation of MIR165/166 by class II and class III homeodomain leucine zipper proteins establishes leaf polarity

A defining feature of plant leaves is their flattened shape. This shape depends on an antagonism between the genes that specify adaxial (top) and abaxial (bottom) tissue identity; however, the molecular nature of this antagonism remains poorly understood. Class III homeodomain leucine zipper (HD-ZIP) transcription factors are key mediators in the regulation of adaxial-abaxial patterning. Their expression is restricted adaxially during early development by the abaxially expressed microRNA (MIR)165/166, yet the mechanism that restricts MIR165/166 expression to abaxial leaf tissues remains unknown. Here, we show that class III and class II HD-ZIP proteins act together to repress MIR165/166 via a conserved cis-element in their promoters. Organ morphology and tissue patterning in plants, therefore, depend on a bidirectional repressive circuit involving a set of miRNAs and its targets.

Flat leaf formation realized by cell-division control and mutual recessive gene regulation

Most of the land plants generally have dorsoventrally flat leaves, maximizing the surface area of both upper (adaxial) side and lower (abaxial) side. The former is specialized for light capturing for photosynthesis and the latter is specialized for gas exchange. From findings of molecular genetics, it has been considered that the coupled dynamics between tissue morphogenesis and gene regulation for cell identity is responsible for making flat leaves. The hypothesis claims that a flat leaf is generated under two assumptions, (i) two mutually recessive groups of genes specify adaxial and abaxial sides of a leaf, (ii) cell divisions are induced at the limited region in the leaf margin where both of two groups are expressed. We examined the plausibility and possibility of this hypothesis from the dynamical point of view. We studied a mathematical model where two processes are coupled, tissue morphogenesis induced by cell division and deformation, and dynamics of gene regulations. From the analysis of the model we found that the classically believed hypothesis is not sufficient to generate flat leaves with high probability. We examined several different modifications and revision of the model. Then we found that a simple additional rule of polarized cell division facilitates flat leaf formation. The result of our analysis gives prediction of possible mechanism, which can be easily verified in experiments.

Rhodoscirpus (Cyperaceae: Scirpeae), a new South American sedge genus supported by molecular, morphological, anatomical and embryological data

AbstractIn its broadest sense, Scirpus consists of a heterogeneous assemblage of up to 250 species, but modern circumscriptions suggest that only 40–50 species are part of the genus. Despite a narrower definition of the genus, atypical species continue to be segregated from Scirpus with a common pattern being the removal of Southern Hemisphere taxa to other genera and tribes. In South America, the morphology of remaining Scirpus species also suggests that they are not closely related to Scirpus s.str., but most of these taxa are only known from their types, making a detailed analysis of their generic affinities difficult. One notable exception is Scirpus asper, a species that is relatively common in the mountains and adjacent lowlands of Peru south to Argentina. Although this species possesses features used in the circumscription of Scirpus, such as cauline leaves, flat leaf blades and anthelate inflorescences, it is known to differ from Scirpus s.str. by its Schoenus‐type embryo, and most of its presumed allies are now placed in different genera (e.g., Scirpus analecti ≡ Cypringlea analecta; Scirpus giganteus ≡ Androtrichum giganteum). In this study, we use DNA sequence data from the plastid (matK, ndhF) and nuclear (ETS‐1f) genomes to demonstrate that Scirpus asper is not closely related to Scirpus s.str., but sister to Phylloscirpus within the predominantly South American Zameioscirpus clade (Amphiscirpus, Phylloscirpus, Zameioscirpus). When combined with morphological, anatomical and embryological data, results indicate that S. asper is best treated as the sole species of a new monotypic genus, Rhodoscirpus. The implications of these results on the taxonomy of tribe Scirpeae are discussed.

Minimization of residential microbial flora on spinach leaves using cobalt 60 to enhance its export potential

A leafy vegetable particularly spinach locally known as palak, has been part of human diet for many years. Pakistan stands among top ten spinach producing countries in the world and contributes considerably to the income. However, lack of proper storage facilities and microbial attack result in post-harvest losses. Food irradiation reduced storage losses, extended shelf life and improved microbiological and parasitological safety of foods. In present study, flat leaf variety of spinach was exposed to various gamma radiation doses (0.5, 0.75 and 1.0 kGy). The microbial flora of spinach before and after irradiation was analyzed to determine significant changes in the population of spoilage microorganisms. In the present study 0.75 kGy proved to be the most beneficial in reducing the microbial flora without affecting the sensory properties of flat leaf spinach and extended the shelf life up to 4days. So, this study can be useful in shelf life enhancement for export purpose.