Effects of elimination of Wolbachia on oogenesis of the uzifly Exorista sorbillans,a parasitoid of the silkworm Bombyx mori

Maternally inherited bacteria of the genus Wolbachia are known to affect the physiology and reproduction of several arthropod and nematode hosts. This paper presents the effects of using tetracycline to eliminate Wolbachia on the oogenesis of its host uzifly Exorista sorbillans (Diptera: Tachinidae), a parasitoid of silkworm Bombyx mori L. Earlier we reported cytoplasmic incompatibility, nucleo‐cytoplasmic conflict, male biased sex ratio and reduction in fecundity upon curing of Wolbachia infection using an antibiotic. This paper presents the abnormal growth and proliferation of oocytes in the uninfected/cured uziflies. The anomalies include abnormal/arrested oocyte production with inhibition of normal functioning of nurse cell nuclei, malformation and agglutination in egg chambers, empty egg chambers due to arrested vitellogenesis and undeveloped ovarian tubules. These anomalies further lead to reduction in growth of the ovarian tubules, which resulted in a 20% reduction of fecundity. It is hypothesized that normal oocyte production in uzifly requires the infection of Wolbachia bacteria. Further, in the uzifly, infection is at transition stage from a facultative to an obligatory mode of symbiosis. In light of this, this paper discusses the relationship between Wolbachia and oocyte production.     

Role of root hydrophobic barriers in salt exclusion of a mangrove plant Avicennia officinalis

Salt exclusion at the roots and salt secretion in the leaves were examined in a mangrove, Avicennia officinalis. The non‐secretor mangrove Bruguiera cylindrica was used for comparative study of hydrophobic barrier formation in the roots. Bypass flow was reduced when seedlings were previously treated with high salt concentration. A biseriate exodermis was detected in the salt‐treated roots, along with an enhanced deposition of hydrophobic barriers in the endodermis. These barriers reduced Na⁺ loading into the xylem, accounting for a 90–95% salt exclusion in A. officinalis. Prominent barriers were found in the roots of B. cylindrica even in the absence of salt treatment. A cytochrome P450 gene that may regulate suberin biosynthesis was up‐regulated within hours of salt treatment in A. officinalis roots and leaves, corresponding with increased suberin deposition. X‐ray microanalysis showed preferential deposition of Na⁺ and Cl^? in the root cortex compared with the stele, suggesting that the endodermis is the primary site of salt exclusion. Enhanced salt secretion and increased suberin deposition surrounding the salt glands were seen in the leaves with salt treatment. Overall, these data show that the deposition of apoplastic barriers increases resistance to bypass flow leading to efficient salt exclusion at the roots in mangroves.     

Complete mitochondrial genome of threatened mahseer <Emphasis Type="Italic">Tor tor</Emphasis> (Hamilton 1822) and its phylogenetic relationship within Cyprinidae family

The mahseers (Tor, Neolissochilus and Naziritor) are an important group of fishes endemic to Asia with the conservation status of most species evaluated as threatened. Conservation plans to revive these declining wild populations are hindered by unstable taxonomy. Molecular phylogeny studies with mitochondrial genome have been successfully used to reconstruct the phylogenetic tree and to resolve taxonomic ambiguity. In the present study, complete mitochondrial genome of Tor tor has been sequenced using ion torrent next-generation sequencing platform with coverage of more than 1000 ×. Comparative mitogenome analysis shows higher divergence value at ND1 gene than COI gene. Further, occurrence of a distinct genetic lineage of T. tor is revealed. The phylogenetic relationship among mahseer group has been defined as Neolissochilus hexagonolepis ((T. sinensis (T. putitora, T. tor), (T. khudree, T. tambroides)).     

Sclerospora graminicola- and arachidonic acid-induced autofluorescence in downy mildew resistant and susceptible genotypes of pearl millet

Autofluorescence of downy mildew resistant and susceptible cells of pearl millet seedlings undergoing hypersensitive reaction (HR) upon Sclerospora graminicola-inoculation and arachidonic acid (AA)-treatment was studied. Two-day-old seedlings of a highly resistant (IP 18296) and a highly susceptible (23D₂B) genotype of pearl millet were either inoculated with zoospore suspension of S. graminicola or treated with AA for 24 h. The coleoptiles with hypersensitive necrotic spots were processed by the standard procedure, and the tissues were subjected to fluorescence microscopy. A differential accumulation of autofluor-escent compounds in resistant and susceptible pearl millet genotypes was observed with most accumulation occurring in resistant cells treated with AA. The variation in the degree of fluorescence and the spatial accumulation of autofluorescent compounds among the two inoculated/treated genotypes is discussed.     

SENSORY PROFILING AND PRODUCT POSITIONING OF ROASTED AND GROUND (BREW) COFFEE AND SOLUBLE (INSTANT) COFFEE WITH AND WITHOUT ADDED FLAVOR

Coffee powders available commercially are of different qualities. The quality variations may be due to inherent quality of coffee beans, storage time and packaging materials used. Sensory profiles of brewed and soluble coffees were studied through profiling. Canonical discriminant analysis (CDA) used for positioning the different coffee samples showed that freshly made coffee from plantation arabica (PA), Pea berry (PB), PA with chicory (PAC), PB with chicory (PBC) and their blends viz. PA + PB and PAC + PBC occupied the quadrant where coffee aroma and overall quality rated higher. Other roasted & ground (R&G) coffee (market) samples were positioned where oily, fermented, musty, stale and caramelized notes dominated. In case of soluble coffee, the flavored coffee procured from the western market (S3, S6, S9 and S8) dominated the quadrant where other added flavor and oily notes dominated. The typical soluble (instant) coffee without any added flavor S10, S12 and S13 occupied another quadrant. The soluble coffee powder with spice incorporation took a separate quadrant where other added flavor and bitter taste dominated. The dominant quality attributes for the groups are different and are discussed in relation to the directional vectors.     

Effects of changing temperature regimes on resistance to races of Melampsora medusae in a cultivar of poplar

Leaf discs of Populus deltoides cv. W-79/307 inoculated with race 4–C of Melampsora medusae, give a compatible reaction when incubated at 16°C (LT), but an incompatible reaction at 26°C (HT). When, over a 12–day period, sets of inoculated leaf discs were reciprocally transferred between the temperature regimes (LT to HT, or HT to LT), incubation for as short as 15 h at HT resulted in incompatibility which was not reversed by subsequent incubation at LT. In contrast, incubation of the inoculated discs at LT for at least 4 days was necessary for the development of a compatible reaction following transfer to HT. Further, incompatibility induced in discs by inoculation with race 4–C and incubation at HT is epistatic to expected compatibility following subsequent inoculation with race 4–M, a temperature non-sensitive biotype. The rapidity, irreversibility and epistatic nature of the temperature-induced incompatibility suggests that initial recognition in this pathosystem may be for incompatibility. The significance of these results in this host/pathogen system is discussed.     

Morphology of some polystichoid ferns

The morphology of the spores and prothalli of Arachniodes aristata, A. assamica, Cyrtomium caryotideum, C. falcatum and 10 species of Polystichum is described. The spores are bilateral with a smooth exine and the perine smooth in Cyrtomium and granulose to spinulose in the others. Spore germination is of the Vittaria type and prothallial development is of the Aspidium type. The adult prothallus of Arachniodes and Polystichum is cordate, with profuse papillate hairs. Sex organs are of the common leptosporangiate type. The antheridium dehisces by a pore-like opening in the cap cell in Polystichum , whereas the cap cell collapses at dehiscence in Arachniodes. Both species of Cyrtomium are apogamous; the thallus becomes irregular in shape in C. caryotideum but is cordate in C. falcatum.     

SENSORY OPTIMIZATION OF PROCESS VARIABLES FOR PREPARING ROASTED GRAIN POWDERS

The quality of roasted grain powders is greatly affected bythe roasting process variables; viz., initial moisture content (IMC), grain-to-sand ratio (GSR), sand temperature (ST) and roasting time (RT). The sensory optimization for these variables was done in two phases. The IMC (12 ± 0.2%) and GSR (1:4) were standardized in the first phase, whereas ST (215C) and RT (1.5–2.0 min), in the second. The overall quality of the roasted grain powders was found to be greatly affected by ST followed by RT.