Int. J. Plant Biol., Volume 1, Issue 1 (January 2010) – 10 articles

Post-harvest protection of white variety sweet potato (Ipomoea batatas) has been dealt with rarely in the past, although it is comparatively easy to grow and has high consumer acceptability in Ghana. Microbial deterioration of sweet potato roots stored in three different storage structures was studied. The sweet potato roots initially cured for 7 and 14 days were stored in traditional, pit, and clamp storage structures for a maximum of 28 days. For the 7 days-cured sweet potato roots, the bac­teria population in the three different storage structures increased by 1.2–2.3 log cfu/g whereas for the 14 days-cured roots, the bacteria population was 0.1–1.0 log cfu/g within 28 days of storage. The fungal population in the 14 days-cured sweet potato roots was higher than in the 7 days-cured sweet potato roots by 0.6–1.6 log cfu/g for 28 days of storage. For both the 7 and 14 days-cured sweet potato roots, the sweet potato roots stored for 28 days in the three different storage structures had a higher microbial count compared to the sweet potato roots stored for 14 days. Aspergillus flavus was the most dominant fungal species occurring in all of the three different storage structures followed by A. niger, Rhizopus stolonifer, Tricho-derma viride, Fusarium oxysporum, Penicillium digitatum, Cladosporium herbarum,and Aspergillus ochraceus, in that order. Full article

Tapping panel dryness (TPD) syndrome is one of the latex yield affecting factors in the rubber tree (Hevea brasiliensis Mull. Arg.). Therefore, identification of a DNA marker will be highly useful for screening progenies in breeding programs. The major goal of this study was to detect genetic variations and/or identification of gene fragments among 37 Hevea clones by the random amplified polymorphic DNA “fingerprinting” technique. Different levels of DNA polymorphism were detected with various primers and a distinct polymorphic band (2.0 kb) was obtained with OPA-17 primer. It was cloned into a plasmid vector for further sequence characterization and the nucleotide sequence shows homology with a novel putative plant thymidine kinase (TK) gene, designated as HbTK (Hevea brasiliensis thymidine kinase; GenBank accession number AY130829). The protein HbTK has 67%, 65%, 64%, and 63% similarity to TK genes of Medicago, Oryza, Arabidopsis, and Lyco-persicon, respectively, and it was highly conserved in all species analyzed. The predicted amino acid sequence contained conserved domains of TK proteins in the C-terminal half. Southern blot analysis indicated that HbTK is one of the members of a small gene family. Northern blot results revealed that the expression of the HbTK gene was up-regulated in mature bark tissues of the healthy tree while it was down-regulated in the TPD-affected one. These results suggest that this gene may play important roles in maintaining active nucleotide metabolism during cell division at the tapped site of bark tissues in the healthy tree under stress (tapping) conditions for normal latex biosynthesis. Full article

In spite of the high economic value of the Saussurea species in the Indian Himalayan Region (IHR), the potential of most of the species is yet to be investigated. Therefore, an attempt has been made to study the diversity, distribution, habitat preference, nativity, endemism, status and indigenous uses of Saussurea species in the IHR. A total of 62 species were recorded from the IHR; of these, 37 species were native to the Himalayan region, 8 were endemic and 21 were near endemic to the IHR. Twenty-seven of the 28 species that were known to have indigenous uses also had medicinal value and are used for the treatment of various diseases/ailments. Many species, e.g., S. affinis (Ganga Mula*), S. auriculata (Pachak Kut), S. bracteata (Prerak Mul), S. costus (Kuth), S. gossypiphora (Kasturi Kamal) and S. obvallata (Brahm Kamal), have multiple uses. The genus showed high habitat specificity in that 16 species were recorded to be restricted to one or two habitats only. As many as 44 species were identified as rare in the study region. Considering the high industrial demand for raw materials and the endangered status of S. costus, S. gossypiphora, S. obvallata and S. simpsoniana (Fen Kamal), these species should be prioritized for conservation (in situ and ex situ) throughout the IHR. Population assessment of the rare-endangered, native, endemic and economically important species using standard ecological methods has been suggested for the quantification of the existing stock of these species in their natural habitats. Further, phyto-chemical investigations for the identification of active ingredients are suggested. Propagation and cultivation techniques are lacking for most of the species of Saussurea except for S. costus, S. obvallata and S. medusa (Snow Lotus). Furthermore, the native communities need to be sensitized to the sustainable use and conservation value of the species in this genus. * Local names given in parentheses throughout are in the Pahari language, spoken by native communities in the Himalayan region. Full article

Compared to animal cells, plant cells are typically non-spherical, which may bias morphometric and fluorimetric analyses, including flow cytometry and other approaches used in the study of cellular biodiversity. The morphometric study of cotyledonary cells may serve to distinguish between genotypes, as cell shape is clearly an important issue when assessing flour quality and seed digestibility by animals, being affected by the surface and volume of particles. We devised a shape coefficient that resolves these difficulties with pea (Pisum sativum L.), and may find general applicability in cytological studies and for the characterization of biodiversity patterns. Full article

Background: Anthocephalus cadamba (Rebox) Miq. (Rubiaceae) is widely distributed throughout the greater part of India, especially at low levels in wet place. Traditionally the bark is used as tonic, febrifuge and to reduce the pain and inflammation. The anti-inflammatory effect of methanol extract obtained from Anthocephalus cadamba aerial parts, MEAC, were investigated in this study. Design and methods: The effects of MEAC on the acute and chronic phases of inflammation were studied in carrageenan, dextran and mediators (histamine and serotonin) induced paw edema and cotton pallet-induced granuloma, respectively. The anti-edema effect of MEAC was compared with 10 mg/kg of indomethacin orally. Results: The results suggested that MEAC possess potent anti-inflammatory activity. The acute inflammatory model showed that all the doses of MEAC effectively suppressed the edema produced by histamine, so it may be suggested that its anti-inflammatory activity is possibly backed by its antihistaminic activity. In chronic inflammatory model the effect may be due to the cellular migration to injured sites and accumulation of collagen and mucopolysaccharide. Conclusions: On the basis of these findings, it may be inferred that Anthocephalus cadamba is an anti-inflammatory agent and the results are in agreement with its traditional use. Full article

Characterization of populations by means of DNA techniques provides a tool for precise identification and a quantitative estimate of genetic diversity, crucial in evaluation of genetic fragmentation within and among populations. NBS profiling are PCR-based approaches that sample genetic variation in resistance genes (R-gene), and R gene analogs (RGA). To date, myb patterns have not been used for evaluating genetic diversity in other species. NBS primers are homologous to the conserved sequences in the Nucleotide-Binding-Site of the NBS-LRR class of R-genes. A total of 12 populations from five Campanula species (C. barbata L., C. latifolia L., C. rapunculoides L., C. spicata L. and C. trachelium L.), autochthonous of the West Italian Alps, were genotyped via nucleotide-binding site (NBS) and myb gene profiling. The selected markers produced a total of 361 bands, showing high levels of polymorphism. Genetic diversity among and within species and population structure was evaluated by different statistical analyses performed using TREECON software, Mantel Nonparametric Test, NTSYS package, AMOVA and STRUCTURE. The correlation between genetic variability and geographical location suggests that the five Campanula species have been subjected to long-term evolutionary processes consistent with the natural fragmentation of continuous mountains areas. Full article

The flavor of sh2 super-sweet corn is preferred by consumers. Unfortunately, sh2 sweet corn has little genetic variation for insect resistance. In this paper we review the functions of two loci, p1 and a1. The P1 allele has a major role in sh2 sweet corn resistance to corn earworm, an allele that was lost in historical selection because of its pleiotropic effect on undesirable cob color and silk browning. The P1 allele has significant effects on biosyntheses of silk antibiotic compounds, maysin, apimaysin, methoxymaysin, and chlorogenic acid. The effect of a1 shows gene action for lowered maysin and significant epistatic action with p1. The dominant functional allele A1 causes anthocyanin pigments in aleurone, plant, and pericarp tissues; the recessive a1 allele causes absence of pigment in these tissues. If silk browning and cob color are critical factors for maysin production but lack the customer’s preference, then separating red cob and browning silk, which are controlled by the P1 allele, may be difficult if not impossible. One high silk maysin sh2 sweet corn germ­plasm, shrunken Zapalote Chico, has been released. There is some field corn germplasm with p1-wwr alleles, but the amount of antibiotic flavones and their potential as a donor need further investigation. Full article

Orange (pulp) and pineapple wastes were used as substrates for citric acid production by two strains of Aspergillus niger. A. niger strains NRRL 567 and 328 produced the maximum amount of citric acid (57.6% and 55.4%, respectively) at a moisture content of 38.9% in orange waste and the highest yields of 46.4% and 45.4% citric acid in pineapple waste at moisture contents of 54.4% and 63.4 %, respectively. The addition of 1–3% methanol to the substrates resulted in reduction in yield in both cases. Full article

We investigated effects of sodium nitroprusside (SNP) on sucrose metabolizing enzymes, acid, and alkaline invertase and alkaline phosphatase in lemongrass (Cymbopogon flexuosus Steud) Wats varieties i.e. Krishna, Cauveri, Nima and Cheerharit. Fifteen day old lemongrass tillers were treated with SNP (1 and 2 mM) under sunlight for four hours. Our results clearly indicated that SNP (2 mM) substantially decreased the amount of proteins in all varieties studied, with maximum values of 40% and 33% in Nima and Krishna, respectively. SNP (1 mM) significantly increased the amount of proteins 43% and 31% in Krishna and Cauveri, respectively. SNP (2 mM) rapidly and severely reduced the activity of acid and alkaline invertases in all varieties, except Krishna and Cauveri. However, the effect of SNP was more pronounced on acid invertase causing at 2 mM an inhibition of 37%, 35% and 28% in Cheerharit, Nima and Cauveri, respectively, whereas it showed relatively less inhibition in alkaline invertase activity 27%, 24% and 21%, respectively, in Nima, Krishna and Cheerharit. Alkaline phosphatase activity was only considerably decreased following SNP (2 mM) treatment in all lemongrass varieties studied with the exception of Nima, where a sharp decrease of 50% was observed. SNP (1 mM) also demonstrated similar effects on acid and alkaline invertases and alkaline phosphatase. These results clearly suggest that SNP affects acid and alkaline phosphatase activity and, therefore, has a role in sucrose metabolism in lemongrass. Alterations in alkaline phosphatase activity upon SNP treatment have several consequences. Full article

Salicylic acid (SA), a naturally occurring plant hormone, is an important signal molecule known to have diverse effects on biotic and abiotic stress tolerance. Its growth-promoting effect on various plants has been shown, but the information on the response of mungbean, an important leguminous plant, to SA application under salt stress is limited. Mungbean (Vigna radiata L.) cultivar Pusa Vishal plants grown with 50 mM NaCl were sprayed with 0.1, 0.5, or 1.0 mM SA and basic physiological processes were studied to substantiate our understanding of their role in tolerance to salinity-induced oxidative stress and how much such processes are induced by SA application. Treatment of plants with 0.5 mM SA resulted in a maximum decrease in the content of Na⁺, Cl⁻, H₂O₂, and thiobarbituric acid reactive substances (TBARS), and electrolyte leakage under saline conditions compared to the control. In contrast, this treatment increased N, P, K, and Ca content, activity of antioxidant enzymes, glutathione content, photosynthesis, and yield maximally under nonsaline and saline conditions. The application of higher concentration of SA (1.0 mM) either proved inhibitory or was of no additional benefit. It was concluded that 0.5 mM SA alleviates salinity-inhibited photosynthesis and yield through a decrease in Na⁺, Cl⁻, H₂O₂, and TBARS content, and electrolyte leakage, and an increase in N, P, K, and Ca content, activity of antioxidant enzymes, and glutathione content. Full article