Immature stages of some aphidophagous syrphid flies of India (Insecta, Diptera, Syrphidae)

Immature stages, viz. egg, larva and puparium, of six species of the economically most important syrphid flies, Scaeva latimaculata (Brunetti), Ischiodon scutellaris (Fabricius), Episyrphus altemans (Macquart), Sphaerophoria Indiana Bigot, Metasyrphus confrater (Wiedemann), and M. latilunulatus (Collin), have been studied. These species are voracious feeders on three aphid species, Lipaphis erysimi (Kaltenbach), Myzus persicae (Sulzer) and Brevicoryne brassicae (L.), which are serious pests of mustard, Brassica campestris L.     

Biology, immature stages and rearing of cocoa-capsids (Miridae: Heteroptera)

Some aspects of the biology of four West African capsid pests of Cocoa, Distantiella theobroma (Distant), Sahlbergella singularis Haglund, Bryocoropsis laticollis Schumacher and Helopeltis corbisieri Schmitz (Miridae: Heteroptera) are briefly summarized. Their immature stages are described and sketched in detail. Keys to distinguish all the larval stages are given and the techniques for rearing them reviewed. The systematics of Bryocorinae is discussed.     

Structure and function of the dorsal abdominal gland and defence mechanism in cocoa-capsids (Miridae: Heteroptera)

An account is given of the structure of the dorsal abdominal gland in Distantiella theobroma, Sahlbergella singularis, Bryocoropsis laticollis and Helopeltis corbisieri. The function is discussed, and defence mechanisms in the four species are described.     

Dynamic secretion changes in the salt glands of the mangrove tree species Avicennia officinalis in response to a changing saline environment

The specialized salt glands on the epidermis of halophytic plants secrete excess salts from tissues by a mechanism that is poorly understood. We examined the salt glands as putative salt and water bi‐regulatory units that can respond swiftly to altering environmental cues. The tropical mangrove tree species (Avicennia officinalis) is able to grow under fluctuating salinities (0.7–50.0 dS m^?1) at intertidal zones, and its salt glands offer an excellent platform to investigate their dynamic responses under rapidly changing salinities. Utilizing a novel epidermal peel system, secretion profiles of hundreds of individual salt glands examined revealed that these glands could secrete when exposed to varying salinities. Notably, rhythmic fluctuations observed in secretion rates were reversibly inhibited by water channel (aquaporin) blocker, and two aquaporin genes (PIP and TIP) preferentially expressed in the salt gland cells were rapidly induced in response to increasing salt concentration. We propose that aquaporins are involved and contribute to the re‐absorption of water during salt removal in Avicennia officinalis salt glands. This constitutes an adaptive feature that contributes to salt balance of trees growing in saline environments where freshwater availability is limited.     

<Emphasis Type="Italic">LIG1</Emphasis> polymorphisms: the Indian scenario

Elucidation of the genetic diversity and relatedness of the subpopulations of India may provide a unique resource for future analysis of genetic association of several critical community-specific complex diseases. We performed a comprehensive exploration of single nucleotide polymorphisms (SNPs) within the gene DNA ligase 1 (LIG1) among a multiethnic panel of Indian subpopulations representative of the ethnic, linguistic and geographical diversity of India using a two-stage design involving DNA resequencing-based SNP discovery followed by SNP validation using sequenom-based genotyping. Thirty SNPs were identified in LIG1 gene using DNA resequencing including three promoter SNPs and one coding SNP. Following SNP validation, the SNPs rs20580/C19008A and rs3730862/C8804T were found to have the most widespread prevalence with noticeable variations in minor allele frequencies both between the Indian subpopulation groups and also from those reported on other major world populations. Subsequently, SNPs found in Indian subpopulations were analysed using bioinformatics-based approaches and compared with SNP data available on major world populations. Further, we also performed genotype–phenotype association analysis of LIG1 SNPs with publicly available data on LIG1 mRNA expression in HapMap samples. Results showed polymorphisms in LIG1 affect its expression and may therefore change its function. Our results stress upon the uniqueness of the Indian population with respect to the worldwide scenario and suggest that any epidemiological study undertaken on the global population should take this distinctiveness in consideration and avoid making generalized conclusions.     

Association studies of dormancy and cooking quality traits in direct-seeded indica rice

Association analysis was applied to a panel of accessions of Assam rice (indica) using 98 SSR markers for dormancy-related traits and cooking quality. Analysis of population structure revealed 10 subgroups in the population. The mean r ² and D ^′ value for all intrachromosomal loci pairs was 0.24 and 0.51, respectively. Linkage disequilibrium between linked markers decreased with distance. Marker-trait associations were investigated using the unified mixed-model approach, considering both population structure (Q) and kinship (K). Genome-wide scanning, detected a total of seven significant marker-trait associations (P < 0.01), with the R ² values ranging from 12.0 to 18.0%. The significant marker associations were for grain dormancy (RM27 on chromosome 2), α-amylase activity (RM27 and RM234 on chromosomes 2 and 7, respectively), germination (RM27 and RM106 on chromosome 2), amylose (RM282 on chromosome 3) and grain length elongation ratio (RM142 on chromosome 4). The present study revealed the association of marker RM27 with traits like dormancy, α-amylase activity and germination. Simple correlation analysis of these traits revealed that these traits were positively correlated with each other and this marker may be useful for simultaneous improvement of these traits. The study indicates the presence of novel QTLs for a few traits under consideration. The study reveals association of traits like dormancy, α-amylase activity, germination, amylose content, grain length elongation ratio with SSR markers indicating the feasibility of undertaking association analysis in conjunction with germplasm characterization.