Phenolic glycosides from Dodecadenia grandiflora and their glucose-6-phosphatase inhibitory activity

Phytochemical investigation of Dodecadenia grandiflora leaves led to the isolation and identification of three phenolic glycosides, designated 1-[(4′-O-(E)-p-coumaroyl)-β-d-glucopyranosyl]-oxy-2-phenol (1), 1-[(6′-O-(E)-p-coumaroyl)-β-d-glucopyranosyl]-oxy-2-phenol (2) and 1-[O-β-d-glucopyranosyl(1→2)-β-d-glucopyranosyl]-oxy-2-phenol (3), along with nine known compounds. Compounds 1, 2, 5 and 9 exhibited significant glucose-6-phosphatase inhibitory activity (63.7, 66.9, 82.9 and 85.4%) with IC₅₀ values of 88.5, 81.0, 51 and 50 μM respectively. On the basis of biological results, a structure–activity relationship has been discussed.     

Suppression of Reproduction in Poekilocerus pictus (F.) using Penfluron and Diflubenzuron

Abstract

Penfluron and diflubenzuron, both chitin synthesis inhibitors known to be highly effective against nymphs of Poekilocerus pictus (F.), were tested against the adult for their possible effects upon reproduction. These compounds were found to have the maximum effect, when no eggs were laid, if both sexes were treated. The eggs of treated males × untreated females did not hatch and those of treated females × untreated males gave rise to nymphs which died before reaching maturity.     

Resistance to blast (Magnaporthe grisea) in a mini-core collection of finger millet germplasm

Blast caused by Pyricularia grisea [teleomorph: Magnaporthe grisea] is an economically important and widespread disease of finger millet in the world. Host resistance is the most economical and effective means of combating this disease as finger millet is predominantly grown by resource-poor and marginal farmers. At the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), we evaluated a finger millet mini-core collection of 80 germplasm accessions (about 1 % of the total germplasm collection representing major trait variability) for blast resistance both in the field and greenhouse. Field evaluation was done using a refined screening technique that included new improved rating scales for leaf, neck and finger infection. Sixty six of the 80 accessions showed combined resistance to leaf, neck and finger blast in two seasons (2009 and 2010) of field screening. A highly significant and positive correlation was found between neck and finger blast ratings (r?=?0.92), whereas small but significant correlations were found between leaf blast and neck blast (r?=?0.25) and between leaf blast and finger blast (r?=?0.30). These accessions were also screened for leaf blast resistance in the greenhouse by artificial inoculation of seedlings to confirm field observations. Fifty-eight of the 80 accessions were resistant to leaf blast in the greenhouse screen as well. These resistant accessions represented one wild (africana) and four cultivated races (vulgaris, plana, elongate and compacta) of finger millet that originated from 13 countries in Asia and Africa and exhibited considerable diversity for agronomic traits, such as maturity period, plant height and panicle type. These blast resistant accessions from the mini-core collection would be useful in finger millet disease resistance breeding programs.     

Physiological Studies During the Growth and Development of Different Varieties of Guavas (Psidium Guajava L.)

In a study of three seed-bearing varieties of guava and one seedless variety changes in size and specific gravity and in the content of water, titratable acid, reducing and non-reducing sugars, tannins, pectin, and ascorbic acid were recorded at intervals from fruit-set to harvest. Respiration rates were also determined during this period.

Patterns of change were generally similar in seeded and unseeded varieties, though the sugars and ascorbic acid contents rose earlier and to higher levels in the seedless than in the seeded, and the fruits matured and fell from the trees earlier.

Increasing ascorbic acid content, concurrent with declining pectin content in the seeded varieties, is consistent with the hypothesis that pectin degradation and ascorbic acid are linked, but in the seedless variety a rapid rise in the ascorbic acid content occurred during a period of pectin accumulation. The end of the initial rapid decline in respiration rate generally coincided with the beginning of reducing-sugar accumulation.     

Response of cornmint (Mentha arvensis L. f. piperascens Malinv. ex Holmes) to micronutrients

Summary

A field experiment was carried over two years (1999 and 2000) in the subtropical climate of north India in a mollisol, to study the response of cornmint (Mentha arvensis L. f. piperascens Malinv. ex Holmes, Lamiaceae) ‘Himalaya ’ to application of six micronutrients, namely, iron (Fe: 15, 30, 45 kg ha^–1) manganese (Mn: 10, 20, 30 kg ha^–1), zinc (5, 10, 15 kg ha^–1), copper (Cu: 2, 4, 6 kg ha^–1), boron (B: 1, 2, 3 kg ha^–1) and molybdenum (Mo: 0.05, 0.10, 0.20 kg ha^–1). Application of micronutrients significantly increased the essential oil yield of cornmint in comparison with the control. However, the response to individual applications of micronutrients was observed up to 15 kg Fe, 10 kg Mn, 10 kg Zn, 2 kg Cu, 2 kg B or 0.05 kg Mo ha^–1. Beyond these levels, the essential oil yield variations among the doses within each trace element were not statistically significant. Of these rates of application, 2 kg B produced the maximum essential oil yield (116.5 kg ha^–1). The percentage increases in the essential oil yield over the control were: 36.2 for 15 kg Fe, 47.3 for 10 kg Mn, 35.7 for 10 kg Zn, 23.9 for 2 kg Cu, 62.9 for 2 kg B and 33.4 for 0.05 kg Mo.     

A PCR-based assessment of genetic diversity,and parentage analysis among commercial mango cultivars and hybrids

Summary

Three different PCR methods [Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeats (ISSR), and Directed Amplification of Minisatellite DNA (DAMD)] were used to analyse genetic diversity and parentage among 20 mango cultivars, including 18 landraces and two hybrids (‘Amrapali’ and ‘Mallika’). These hybrids together with a third hybrid (‘Ratna’), and an out-group species (Mangifera sylvatica) were also analysed for parentage. Fifteen, seven and four primers were used to amplify a total of 158, 69 and 59 distinct DNA fragments by RAPD, ISSR and DAMD, respectively. Of these, approx. 85%, 64% and 90% were polymorphic, respectively. Genetic distances between pairs of mango cultivars were measured separately by each method and depicted graphically as a Neighbor Joining (NJ) tree. The three methods revealed different groupings of cultivars and hybrids. A NJ tree based on the cumulative data from all methods correlated well with the parentage of the mango hybrids, and the grouping of cultivars on a regional basis. Genetic markers likely to be associated with important agronomic traits were identified by further analysing the hybrids, with their respective parents, using all three methods. On the basis of the highest number of polymorphic bands observed (90%), DAMD was judged to be the best method with which to analyse mango germplasm.     

Influence of Vermicompost on Dry Matter Yield and Uptake of Ni and Cd by Chamomile (Matricaria chamomilla) in Ni- and Cd-Polluted Soil

An experiment was conducted under simulated condition to study the influence of vermicompost on growth, yield and heavy metal accumulation by chamomile (Matricaria chamomilla), an important essential oil bearing crop grown under simulated condition. Nickel and Cadmium applied at 20?mg?kg^?1 soil significantly enhanced the dry matter yield of the crop as compared to the control (no heavy metal). The results also revealed that addition of vermicompost (at 2.5?g?kg^?1 soil) enhanced the heavy metal accumulation by chamomile in metal-treated soil. Although a sizeable amount of metals were being translocated to flowers, the essential oil extracted by hydrodistillation of flowers did not contain any heavy metal. Similarly, chemical constituents of the oil of chamomile were within the range of those obtained from chamomile grown under normal soil condition.     

Improvement in the diagnosis of <Emphasis Type="Italic">Brucella abortus</Emphasis> infections in naturally infected water buffaloes (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>) using an ELISA with a Protein-G-based indicator system

Brucellosis caused by Brucella abortus in domestic water buffaloes (Bubalus bubalis) raised under the traditional system of husbandry in northern India was diagnosed using an enzyme-linked immunosorbent assays (ELISA) with a Protein-G-based indicator system (Protein-G ELISA). A total of 1,551 animals that are positive (N = 61), negative (N = 243), and suspected (N = 1,247) for brucellosis were examined. Rose bengal test (RBT) was used to predict the disease, and accordingly, animals were dichotomized in positive and negative population for receiver operating characteristic (ROC) curve analysis to determine the sensitivity, the specificity, and the performance index of Protein-G ELISA. Taking all animals (N=1551) into account, the ROC curve analysis revealed cut off value of 29.6% positivity (%P) with 98.40% and 94.94%, sensitivity and specificity, respectively. The results were compared with ELISA in which anti-bovine conjugate was used. The cut off in ELISA was 37.9%P and sensitivity and specificity were 96.26% and 97.07%, respectively. The performance indexes of both the assays were almost equal and were 193.34 for Protein-G ELISA and 193.33 for ELISA. The cut off values of both the tests changed, if only known positive (N = 61) and known negative (N=243) animals were used for ROC curve analysis, and accordingly, changes in sensitivity and specificity were observed with significant decrease of performance indexes of both the tests. The high optical density (P<0.0001) background signal with negative serum control and high %P (P<0.0001) in sera from negative population were noticed in ELISA in comparison to Protein-G ELISA.     

Identification of unique DNA sequences present in highly virulent 2009 Alabama isolates of Aeromonas hydrophila

In 2009, a disease outbreak caused by Aeromonas hydrophila occurred in 48 catfish farms in West Alabama, causing an estimated loss of more than 3 million pounds of food size channel catfish. Virulence studies have revealed that the 2009 isolates of A. hydrophila are at least 200-fold more virulent than a 1998 Alabama isolate AL98-C1B. However, up to now, no molecular markers have been identified to differentiate the highly virulent 2009 isolates from other isolates of A. hydrophila. To understand the genetic differences between the highly virulent 2009 isolates and the less virulent AL98-C1B at molecular level, PCR-select bacterial genome subtractive hybridization was used in this study. A total of 96 clones were selected from the subtractive genomic DNA library. Sequencing results revealed that the 96 clones represented 64 unique A. hydrophila sequences. Of the 64 sequences, three (hypothetical protein XAUC_13870, structural toxin protein RtxA, and putative methyltransferase) were confirmed to be present in the three virulent 2009 Alabama isolates but absent in the less virulent AL98-C1B. Using genomic DNAs from nine field isolates of A. hydrophila with different virulence as templates, two sequences (hypothetical protein XAUC_13870 and putative methyltransferase) were found to be only present in highly virulent A. hydrophila isolates, but absent in avirulent isolates.