Differential Response of Two Wheat Genotypes to Nitrogen Supply. I. Ontogenic Changes in Laminae Growth and Photosynthesis

Two wheat genotypes viz. Uniculm 'gigas' (VI) and Kalyansona (V2) were raised till maturity with low (N1) and adequate (N2) nitrogen levels supplied at 30 and 120kg ha⁻¹, respectively. Laminae, numbering 1–8 on the main shoot, were examined for various parameters at weekly intervals from emergence through senescence. N1 resulted in gradual reduction in laminae growth from 5th leaf onwards with maximum effect on flag and penultimate laminae of both the genotypes. Chlorophyll concentration, soluble protein, rubisco concentration and rubisco activity in response to low N supply was reduced in the top two laminae in V2. Pn rate varied little with leaf position in wheat at adequate N supply. In V2, low N supply resulted in the reduction of laminae N content by about 25% with corresponding reduction in Pn rates in the penultimate and flag laminae. VI, in contrast, exhibited no significant change in leaf N concentration and hence maintained similar Pn rates at both levels of N supply throughout the ontogeny.
It is concluded that the two genotypes responded differently to N supply in relation to laminae growth and photosynthesis. Uniculm 'Gigas' (VI) responded to low N with large reduction in laminae size, adequately maintaining the metabolic constituents such as chlorophyll, soluble protein, rubisco and laminae N concentration and Kalyansona (V2), in contrast, responded with small changes in laminae size and greater reduction in synthesis and maintenance of the metabolic constituents.     

Ovipositional responses of the pulse beetle, Bruchus chinensis (Coleoptera: Bruchidae) to extracts and compounds of Capparis decidua

Extracts of Capparis decidua stems and flowers showed insecticidal and oviposition inhibitory activities against Bruchus chinensis. The LC50 values of these extracts were found to increase with the increase in the polarity of the extract at different exposure periods. For instance, after 96 h, the LC50 values were found to be 3.619, 7.319, and 10.151 microg for CD1, CD2, and CD3, respectively. Extract CD7 was effective only at higher doses. The toxicity was found to be dose- and time-dependent. The females laid lesser number of eggs, when exposed to sublethal doses of different extracts and pure compounds, as compared to control. The maximum oviposition deterrence index was found for extract CD1 followed in decreasing order by CD2, CD3, and CD7. From extract CD1, two compounds were isolated and characterized as triacontanol (C1) and 2-carboxy-1,1-dimethylpyrrolidine (C2). When the females were exposed to sublethal doses of these compounds, they laid lesser number of eggs as compared to the control. C2 was found to have a slightly greater oviposition inhibition effect than C1. From fraction CD7, one novel compound labeled as CDF1 has been isolated and identified as 6-(1-hydroxy-non-3-enyl)tetrahydropyran-2-one. CDF1 has also shown insecticidal and oviposition inhibitory activities against B. chinensis at low concentrations.     

Molecular characterization and expression profile of ghrelin gene during different reproductive phases in buffalo (Bubalus bubalis)

Ghrelin, a novel motilin-related endogenous ligand for growth hormone secretagouge receptor, is implicated in various biological functions, including regulation of female reproduction. But the presence of ghrelin and its role in reproductive functions in buffalo, a species with poor reproductive efficiency, is not known. In the present study full-length ghrelin cDNA was isolated from bubaline abomasum, which encodes the entire prepropeptide of 116 amino acids. The deduced amino acid sequence of ghrelin of buffalo showed >95% and 31% identity with that of ruminants (cattle, sheep, and goat) and humans, respectively. Analysis of synonymous and nonsynonymous nucleotide substitutions in the coding region of ghrelin indicated that these sequences of different species have been under purifying selection. The 3995-bp amplicon of ghrelin gene consisting of 4 exons and 3 introns was cloned with genomic DNA from buffalo. Further, ghrelin expression was determined by quantitative real-time PCR, in situ hybridization, and immunohistochemistry in bubaline endometrial tissues at different stages of the estrous cycle and early pregnancy. Our results indicated the persistent expression of ghrelin mRNA and protein in the endometrium during stage I (day 3–5), stage II (day 6–15), and stage III (day 16–21) of the estrous cycle and also during early (∼day 30–40) pregnancy. Immunohistochemistry and quantitative real-time PCR experiments indicated the relatively higher expression of ghrelin in the endometrium during stage II (day 6–15) of the estrous cycle and early pregnancy than during stage I (day 3–5) and stage III (day 16–21) of the estrous cycle, but no statistically significant difference in ghrelin expression was observed among stages. To conclude, the results of the present study indicate the persistent expression of ghrelin in the uterine endometrium throughout the estrous cycle and in early pregnancy which might be helpful in determining its role in buffalo reproduction.     

Single strand conformation polymorphism detection in alpha-lactalbumin gene of Indian Jakhrana milk goats

Abstract

Alpha-lactalbumin (α-LA) (ALA), one of the two major whey proteins, is strongly correlated with the nutritional value and the functional properties of whey and whey products. The genetic variations of ALA gene in Jakhrana Goat breed (Capra hircus) were investigated using an optimized non-radioactive polymerase chain reaction–single strand conformation polymorphism (PCR–SSCP) analysis of four amplified fragments covering all four exons of the gene. A total of eight SSCPs patterns were detected in three of these exons in a sample of 50 Jakhrana goats, indicating that this breed has high genetic variability in the ALA gene. This result opens interesting prospects for future breeding programs and conservation strategies. These ALA gene variants can be sequenced and screened in the entire population to develop single nucleotide polymorphisms for association studies with different productive and reproductive performances and marker assisted selection. In addition, our data show that PCR–SSCP is an appropriate tool for evaluating genetic variability.     

Assessing forest fragmentation in north-western Himalaya: a case study from Ranikhet forest range,Uttarakhand, India

The northwestern Himalaya harbors high levels of biodiversity due to its unique topography, climatic conditions and heterogeneity. Forest fragmentation is one of the major threats causing a decline in biodiversity in the Himalayan region. We assesses forest fragmentation and changes in land use land cover(LULC) patterns using multi-temporal satellite data over a time span of four decades(1976–2013). Fragmentation analysis using the Landscape Fragmentation Tool(LFT) reveals a decrease in core and edge areas by 14 and 2.3 %, respectively; while an increase in non-forest, patch area and perforation area by 2.1, 0.4, and 14 %, respectively. The LULC dynamics show that the areas under dense forest and scrub forest have decreased by 2.8 % and 1.9 %, respectively; and there is an increase in open forest, crop land and fallow land area by 2.6, 1.7 and 2.1 %, respectively. The quantification of landscape heterogeneity is undertaken with the help of landscape metrics computed using FRAGSTATS at class and landscape level, showing signs of increased fragmentation. Our study provides baseline database that can support the future biodiversity conservation and sustainable forest management initiatives.     

Effect of alternate day feeding strategy of sub-optimal protein level on haemato-biochemical responses in Labeo rohita (Hamilton) juveniles

A feeding trial was conducted for 60 days to delineate the effect of alternate day feeding strategy of sub‐optimal protein level on haematological parameters, serum parameters and phagocyte respiratory burst activity (NBT) in Labeo rohita juveniles. One hundred and thirty‐five fingerlings (1.87 ± 0.01–2.26 ± 0.05 g) were distributed in triplicate groups of each treatment, and fish were fed at 5% body weight daily. Three experimental isocaloric (401.32–410.28 kcal/100 g) diets of 30%, 25%, and 20% crude protein designated as diet A, diet B, and diet C respectively, were prepared, using locally available feed ingredients. Three different feeding schedules of normal protein diet continuously (diet A‐30%), alternate feeding of 1‐day diet A followed by 1‐day diet B (1A/1B) and alternate feeding of 1‐day diet A followed by 1‐day diet C (1A/1C) were tested. The total erythrocyte count and haemoglobin content was significantly (p < 0.05) enhanced in the group T1 fed (1A/1B), and the lowest count was recorded in the group T2 fed (1A/1C). Total leucocyte counts, total serum protein, and serum globulin were higher in the group T1 fed (1A/1B) and lower in the group T2 fed (1A/1C) as compare to control. The respiratory burst activity (NBT) of blood phagocytes and serum A‐to‐G ratio was recorded significantly difference in among the treatment groups. Based on the results of the present study, it is concluded that alternate feeding of 1‐day diet A followed by 1‐day diet B (1A/1B) is equally effective and promote the immunity in Labeo rohita juveniles.     

QTL identification for molecular breeding of fibre yield and fibre quality traits in jute

In jute (Corchorus olitorius), quantitative trait loci (QTL) analysis was conducted to study the genetics of eight fibre yield traits and two fibre quality traits. For this purpose, we used a mapping population consisting of 120 recombinant inbred lines (RILs) and also used a linkage map consisting of 36 SSR markers that was developed by us earlier (Das et al. 2011). The RIL population was derived from the cross JRO 524 (coarse fibre) × PPO4 (fine fibre) following single seed descent. Using single-locus analysis involving composite interval mapping, a total of 21 QTLs were identified for eight fibre yield traits whereas for fibre quality (fibre fineness), only one QTL was detected. The QTL for fibre fineness explained 8.31–10.56% of the phenotypic variation and was detected in two out of three environments. Using two-locus analysis involving QTLNetwork, as many as 11 M-QTLs were identified for seven fibre yield traits (excluding top diameter) and one M-QTL was identified for fibre fineness which accounted for 4.57% of the phenotypic variation. For six fibre yield traits, we detected 16 E-QTLs involved in nine QQ epistatic interactions. For fibre fineness, four E-QTLs involved in two QQ epistatic interactions and for fibre strength, six E-QTLs involved in three QQ epistatic interactions were identified. Eight out of the 11 M-QTLs observed for the fibre yield traits were also involved in QE interactions; for fibre fineness and fibre strength, no QE interactions were observed.