Micromorphology, Ultrastructure and Histochemistry of Commelina benghalensis L. Leaves and Stems

Commelina benghalensis L. is used as a traditional medicine in treating numerous ailments and diseases such as infertility in women, conjunctivitis, gonorrhea, and jaundice. This study used light and electron microscopy coupled with histochemistry to investigate the micromorphology, ultrastructure and histochemical properties of C. benghalensis leaves and stems. Stereo and scanning electron microscopy revealed dense non-glandular trichomes on the leaves and stems and trichome density was greater in emergent leaves than in the young and mature. Three morphologically different non-glandular trichomes were observed including simple multicellular, simple bicellular and simple multicellular hooked. The simple bicellular trichomes were less common than the multicellular and hooked. Transmission electron micrographs showed mitochondria, vesicles and vacuoles in the trichome. The leaf section contained chloroplasts with plastoglobuli and starch grains. Histochemical analysis revealed various pharmacologically important compounds such as phenols, alkaloids, proteins and polysaccharides. The micromorphological and ultrastructural investigations suggest that Commelina benghalensis L. is an economically important medicinal plant due to bioactive compounds present in the leaves and stems.

Root Uptake and Distribution of Radionuclides 134Cs and 60Co in Sunflower Plants (Helianthus annuus. L)

Phytoremediation is the most common method to recover polluted environment caused by radionuclides. This study aims to determine the distribution of 134Cs and 60Co radionuclides in sunflower plants (Helianthus annuus. L). The sunflower plants were cultivated in soil media for 50 days, then transferred into a tube containing hydroponic solution contaminated by 134Cs and 60Co with variation of concentration of 134Cs (0.85 Bq/ml, 1.31 Bq/ml, 1.74 Bq/ml, 2.24 Bq/ml, 2.67 Bq/ml) and 60Co (4,213 Bq/ml, 8,537 Bq/ml, 12,187 Bq/ml). The distribution of radionuclides in roots, stems, leaves were observed using a gamma spectrometer to determine the accumulation of contaminants in plants. Samples were taken at varying intervals (0-720 hours) to determine the increased accumulation of contaminants in plants. The results showed that 134Cs and 60Co accumulated mostly in the leaf section. and the highest accumulation of 60Co was observed in the root section.

Oryzalin and Gamma Radiation Induced Polyploidization in Garden Balsam Plants (Impatiens balsamina L.) In Vitro

The aim of the research was to create genetic variation on garden balsam using oryzalin and Gamma radiation. Mutagenic agent may improve plant variation. Garden balsam seeds were treated by oryzalin (0%, 0.01%, 0.02%) then the seedlings were planted in the field four times to gain seeds generation M4. Seedlings of M4 (7 days of age) were radiated by gamma ray 60Co (0, 5, 10, 15 Gy) and planted in the field to collect seeds for in vitro study to induce a new type of mutant plant. In vitro methods was conducted to achieved rapid micropropagation of Impatiens balsamina L. mutant plants. Growth percentage of seedlings reached 90% by gibberellin 0.01 ppm. Leaf section used for explant and cultured in MS media enriched by 0.5 ppm NAA and 0.5 ppm BAP aseptically. Shoots were regenerated on 6 weeks after cultured however some shoots become vitrification. Number of chromosome varied (mixoploid) on treated plants (M5). Form of secondary metabolites ( alkaloids and terpenoids ) in the roots extract was not changed by oryzalin and gamma radiation. Mixoploid explants showed variation in morphology and some treatments only had little shoots and a treatment has vigorous roots. Control plants have shoot and callus.

STUDI ANATOMI DAUN CANTIGI (Vaccinium korinchense Ridl.) PADA ALTITUD BERBEDA DI GUNUNG TALANG

The study about leaf anatomy of Bilberry (Vaccinium korinchense RILD.) at altitude gradient on the Talang Mountain has been carried out in October to December 2015. The goal research is to compared that leaf thick tissues Bilbellry at altitude gradient. The sample were collected at Talang Mountain. The research used survey method and purpossive sampling with five altitude gradient (2200-2529 meter above sea level). Leaf section was maked at the Plant Structures developments Laboratory, Department Biology, Faculty of Mathematics and Natural Sciences, Andalas University. Data analysis used Kruskal-Wallis test. The results showed that leaf thickness, palisade and spongy thickness various between altitudes is sequentially 434-685 ?m, 183-322 ?m and 175-283 ?m . While epidermis thickness and cuticle thickness did not differ significantly between altitudes.

First Report of Target Spot of Flue-cured Tobacco Caused by Rhizoctonia solani AG-3 in China

In early August 2006, a disease caused severe losses in a 1,400-ha field of 5-month-old tobacco plants in Kuandian and Fengcheng Counties, Dandong City of Liaoning in northeast China. Symptoms were observed on almost every plant. Disease symptoms were subsequently observed at nearly 100% incidence in 2,000 ha of fields from three towns in Kaiyuan County and two towns in Xifeng County, Tieling City, Liaoning Province in the second half of August 2006. Symptoms first appeared on leaves as small (2 mm) water soaked spots, and developed into expanded, dark brown lesions (2 cm) on the middle to lower leaves. Each lesion exhibited concentric rings, a necrotic center, and a tear in the center and margin that often resulted in a shot-hole appearance. Fungal isolates were obtained from the margins of lesions that were surface-sterilized by dipping each leaf section into 75% ethyl alcohol for 3 sec, then in 0.1% HgCl2 for 15 sec, rinsing in sterilized distilled water three times, and plating the leaf section onto half-strength potato dextrose agar (PDA). Six isolates were identified as Rhizoctonia solani Kühn on the basis of mycelial characteristics: multinucleate cells, septate hyphae constricted at the junction of hyphae, and hyphal branching at approximately right angles (3). The sequence of the internal transcribed spacer (ITS) 1-5.8S-ITS2 region of rDNA from each of six isolates was amplified by PCR assay using universal primers ITS1 and ITS4. The sequences (GenBank Accession Nos. JQ219152 to JQ219157) matched 100% with the ITS sequence of an isolate of R. solani AG-3 (GQ885147). Koch's postulates were conducted for each of the six isolates by wound-inoculating six tobacco leaves (cv. NC89) detached from a total of three 8-week-old plants. Each tobacco leaf was first surface-sterilized in 0.5% NaOCl for 30 sec, rinsed in sterilized distilled water, and wounded at each of four locations by inserting a needle into the leaf. Each leaf was inoculated by depositing a PDA plug (0.5 cm diameter) colonized with R. solani onto each of the four wounds; wounded control leaves (six tobacco leaves from a total of three plants) were inoculated similarly with non-colonized PDA plugs. Inoculated leaves were incubated at 28°C in natural light within a plastic container covered with a hyaline cap to maintain high relative humidity. Symptoms similar to those observed on the original plants developed on inoculated leaves within 3 days, but not on the control leaves. The pathogen was reisolated from symptomatic leaves but not from control leaves and showed morphological characteristics consistent with those of R. solani. Tobacco target spot has been recorded in South America (1), South Africa (4), Argentina, and the USA (2). However, to our knowledge, this is the first report of target spot caused by R. solani AG-3 on flue-cured tobacco in China. References: (2) J. S. Johnk et al. Phytopathology 83:854, 1993. (4) H. D. Shew et al. Plant Dis. 69:901, 1985. (1) B. Sneh et al. Identification of Rhizoctonia Species. The American Phytopathological Society, St. Paul, MN, 1991. (3) E. Vargas. Turrialba 23:357, 1973.

A Quantitative Assay Using Mycelial Fragments to Assess Virulence of Mycosphaerella fijiensis

We describe a method to evaluate the virulence of Mycosphaerella fijiensis, the causal agent of black leaf streak disease (BLSD) of banana and plantain. The method is based on the delivery of weighed slurries of fragmented mycelia by camel's hair brush to 5-by-5-cm areas on the abaxial surface of banana leaf blades. Reliable BLSD development was attained in an environmental growth chamber with stringent lighting and humidity controls. By localizing inoculum onto small areas of large leaves, we achieved a dramatic increase in the number of strains that can be tested on each leaf and plant, which is critical for comparing the virulence of numerous strains concurrently. Image analysis software was used to measure the percentage of each inoculated leaf section showing BLSD symptoms over time. We demonstrated that the level of disease of four isolates was correlated with the weight of the mycelium applied and relatively insensitive to the degree of fragmentation of hyphae. This is the first report demonstrating that weighed mycelial inoculum, combined with image analysis software to measure disease severity, can be used to quantitatively assess the virulence of M. fijiensis under rigorously controlled environmental conditions.

First Report of the White Pine Blister Rust Fungus, Cronartium ribicola, on Pedicularis bracteosa

Until recently, Cronartium ribicola J.C. Fisch. was thought to utilize only Ribes spp. (Grossulariaceae) as telial hosts in North America. During 2004, Pedicularis racemosa Dougl. ex Benth. and Castilleja miniata Dougl. (Orobanchaceae) were proven as natural telial hosts at a subalpine site (48.634109°N, 116.570817°W, elevation 1,800 m) near Roman Nose Lake, ID, where whitebark pine (Pinus albicaulis Engelm.) and western white pine (Pinus monticola Dougl. ex D. Don) are aecial hosts, and Pedicularis, Castilleja, and Ribes spp. are common herbs/shrubs (2). During August 2006, teliospore columns typical of C. ribicola or the morphologically indistinguishable (2) C. coleosporioides J.C. Arthur were found on two Pedicularis bracteosa Benth. plants at this site, within 3 m of a large, sporulating canker on whitebark pine. ITS/5.8S rDNA regions were sequenced using detached teliospore column samples from the two plants, ITS1F and ITS4 primers (3), and standard PCR protocols (2). One sample sequence was identified as C. ribicola and the other as C. coleosporioides (GenBank Accession Nos. EF185857 and EF185858, respectively), by exact matches in comparisons with published sequences (2). Artificial inoculation confirmed P. bracteosa's ability to host C. ribicola. Sections of leaves collected near Freezeout Saddle, ID (47.00885°N, 116.00846°W, elev. 1,600 m) were rinsed in water, placed abaxial side up on moistened filter paper in 150-mm petri plates, inoculated with seven diverse sources of urediniospores/aeciospores, misted with distilled water, and incubated at 18°C with 12 h of light. A single leaf section produced urediniospores 17 days and teliospores 26 days after inoculation with one of two Roman Nose aeciospore sources. Urediniospores from this leaf section caused infections on Ribes nigrum L., and teliospore columns yielded a DNA sequence that matched C. ribicola. Though P. bracteosa is confirmed as yet another natural host of C. ribicola in North America, it may be producing less C. ribicola inoculum for pine infection than do the P. racemosa and Ribes spp. telial hosts at the collection site. Uredinia and telia of C. ribicola on P. bracteosa were much less frequent and smaller than those on P. racemosa and Ribes spp. and those of C. coleosporioides on this same host (2). Pedicularis (but not Castilleja) spp. are significant telial hosts of C. ribicola strains at some high elevation sites in eastern Asia (1). Discovery of multiple North American telial hosts in the Orobanchaceae suggests unrecognized complexity in C. ribicola's ability to exploit ecological niches in recently established pathosystems of North America (2). References: (1) G. I. McDonald et al. Pages 41–57 in: Forest Pathology: From Genes to Landscapes. J. Lundquist and R. Hamelin, eds. The American Phytopathological Society. St. Paul, MN, 2005. (2) G. I. McDonald et al. For. Pathol. 36:73, 2006. (3) T. J. White et al. Pages 315–322 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al. eds. Academic Press, San Diego, CA, 1990.