Effect of conservation tillage and rice-based cropping systems on soil aggregation characteristics and carbon dynamics in Eastern Indo-Gangetic Plain

Paddy and Water Environment - Traditional rice–wheat cropping system, which follows wet puddling in rice and conventional tillage in wheat, is deteriorating soil health resulting yield...     

Genomic resources for breeding crops with enhanced abiotic stress tolerance

To meet the challenges of climate change, exploring natural diversity in the existing plant genetic resource pool as well as creation of new mutants through chemical mutagenesis and molecular biology is needed for developing climate‐resilient elite genotypes. Ever‐increasing area under existing abiotic stresses as well as emerging abiotic stress factors and their combinations have further added to the problems of the current crop improvement programmes. However, with the advancement in modern techniques such as next‐generation sequencing technologies, it is now possible to generate on a whole‐genome scale, genomic resources for crop species at a much faster pace with considerably less efforts and money. The genomic resources thus generated will be useful for various plant breeding applications such as marker‐assisted breeding for gene introgression, mapping QTLs or identifying new or rare alleles associated with a particular trait. In this article, we discuss various aspects of generation of genomic resources and their utilization for developing abiotic stress‐tolerant crops to ensure sustainable agricultural production and food security in the backdrop of rapid climate change.     

Molecular diversity and association of SSR markers to rust and late leaf spot resistance in cultivated groundnut (Arachis hypogaea L.)

Molecular diversity and association of simple sequence repeat (SSR) markers with rust and late leaf spot (LLS) resistance were detected in a set of 20 cultivated groundnut genotypes differing in resistance against both diseases. Out of 136 bands amplified from 26 primers, 104 were found polymorphic (76.5%). Cluster analysis (UPGMA) revealed two main clusters separated at 52% Jaccard's similarity coefficient according to disease reaction to rust and LLS. Based on the Kruskal–Wallis one-way anova and simple regression analysis three and four SSR alleles were found associated with rust and LLS resistance, respectively.     

Nano zinc vis‐à‐vis inorganic Zinc as feed additives: Effects on growth,activity of hepatic enzymes and non‐specific immunity in rohu,Labeo rohita (Hamilton) fingerlings

The effects of dietary administration of inorganic zinc (zinc sulphate, ZnSO₄) and nano zinc (zinc oxide nanoparticles, ZnO‐NP) were evaluated in rohu, Labeo rohita fingerlings. Fish were fed with a basal diet (Control) supplemented with ZnSO₄ (T1, T2 and T3) and ZnO‐NP (T4, T5 and T6) at 10, 20 and 30 mg/kg, respectively, for a duration of 45 days. The results revealed that fish fed diet containing 20 mg ZnO‐NP per kg (T5) had the highest weight gain and specific growth rate (SGR, % per day), which was significantly different (p < .05) from the other experimental diets. Significantly (p < .05), higher activities of the digestive and metabolic enzymes were recorded in the fish fed ZnO‐NP containing diets as compared to the diets containing inorganic Zn or control diet. The maximum serum glucose and protein levels were noted in fish reared on diet T5. Both SGOT and SGPT activities were significantly increased in fish fed Zn‐supplemented diets (T1 to T6), as compared to the control group. Similarly, innate immune parameters were improved with feeding Zn incorporated diets. The highest phagocytic (40.74 ± 0.65%) and respiratory burst (0.33 ± 0.001, OD 630nm) activities were recorded in the fish fed diet containing ZnO‐NPs at 20 mg/kg (T5). The maximum superoxide production and serum peroxidase activity were detected in the fish fed T5 and T6 diets. Overall, results indicated that short‐duration feeding (≤45 days) of dietary ZnO‐NP (20 mg/kg) improved growth, enzyme activity, serum biochemical parameters and immune function in rohu fingerlings.     

Isolation, purification and some structural features of the mucilaginous exudate from Musa paradisiaca

The water-soluble polysaccharides isolated from the vascular gel of Musa paradisiaca, were fractionated via anion exchange chromatography into four fractions. Fractionated polymers contained arabinose, xylose and galacturonic acid as major sugars, together with traces of galactose, rhamnose, mannose and glucose residues. Methylation analysis revealed the presence of a highly branched arabinoxylan with a significant amount of terminal arabinopyranosyl units and an arabinogalactan type I pectin. Periodate oxidation studies supported the results of methylation analysis.     

Assessment of genetic diversity of tea (Camellia sinensis (L.) O. Kuntze) by inter-simple sequence repeat polymerase chain reaction

Twenty-five diverse tea (Camellia sinensis(L.) O. Kuntze) cultivars were analyzed using the simple sequence repeat anchored polymorearse chain reaction (SSR-anchored PCR) or Inter SSR-PCR (ISSR). Out of the 45 primers 12were chosen for final study. These amplified a total of 130 bands out of which108 (84%) were polymorphic. A dendrogram was constructed using UPGMA method revealed three distinct clusters of Cambod, Assamand China type, which concur with the known taxonomical classification of tea. These results suggest that the ISSR-PCR method is potentially useful for genetic fingerprinting and molecular taxonomic classification of tea genotypes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Haematology, blood biochemistry and tissue histopathology of lambs maintained on diets containing an insect controlling protein (Cry1Ac) in Bt-cottonseed

This experiment assessed the effect of feeding genetically modified cottonseed (Bt) containing an insect controlling protein (Cry1Ac) on haematology, blood biochemistry and histopathology of lambs. Haemato-biochemicals were estimated at periodic intervals, and histopathology at termination of experiment. Thirty three weaner lambs were fed a composite feed mixture (CFM) ad libitum individually, in three groups for 123 days. The isonitrogenous CFM had roughage (Perl Millet Stover) and concentrate ratio of 350:650. Diet fed to control lambs contained groundnut oil meal as protein source while other two groups received diet containing either whole cottonseed (N-Bt) or Bt-cottonseed (Bt-CS). Daily feed intake and average daily gain were similar among lambs of three groups. Lambs fed N-Bt diet had higher (p < 0.05) serum protein and globulin compared to control and Bt diets, while albumin content was higher (p = 0.018) in Bt diet fed lambs. Serum urea and creatinin content, alkaline phosphatase (ALP) and serum glutamate pyruvic transaminase (SGPT) activities were not different among lamb groups, while urea and creatinin content and ALP activities increased linearly (p < 0.001) with increased feeding period. Blood haemoglobin (Hb), haematocrit (Hc), white blood cells (WBC), mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC) ranged from 11.1% to 11.2%, 31.8% to 32.8%, 7.0 to 8.3 (× 10(3) /μl), 19.1 to 22.5 fl and 33.2% to 35.5%, respectively, were similar among lamb groups. Erythrocyte sedimentation rate (ESR) (p = 0.008) and red blood cell counts (p = 0.006) were higher in Bt diet fed lambs. Control and N-Bt diet fed lambs had mild fatty infiltration in liver and/or micro-calculi in renal cortex, and such lesions were not seen in Bt diet fed lambs. Growth, haemato-biochemical and histopathology did not change by Bt-CS feeding in growing lamb. However, before recommending the use of Bt-CS in routine feed formulations prolonged feeding experiments of Bt-cotton seed require.     

Application of biochar and vermicompost against the rice root-knot nematode (Meloidogyne graminicola): an eco-friendly approach in nematode management

Journal of Plant Diseases and Protection - The rice root-knot nematode (Meloidogyne graminicola) is one of the key pests of rice (Oryza sativa L.) in irrigated and upland rice ecosystems inflicting...     

Uptake of fluoride by two paddy (Oryza sativa L.) varieties treated with fluoride-contaminated water

The use of fluoride enriched groundwater for irrigating the paddy crops is prevalent in many parts of the world. The fluoride in the irrigated water not only affects the growth and productivity of the crops, but is also accumulated in the plant tissues. We studied the accumulation of fluoride in roots, leaves and seeds two paddy varieties (i.e. Oryza sativa L. var. IR-36 and Oryza sativa L. var. Swarno) when treated with different concentrations of fluoridated water. The translocation pattern of fluoride was also observed. The water soluble fluoride ( $ {\text{F}}_{{{\text{H}}_{ 2} {\text{O}}}} $ ) in the soil and plant parts increased substantially with increasing fluoride concentration in treated water. The Swarno variety showed a slight but consistent higher uptake of fluoride than the IR-36 variety. Fluoride uptake by the germinated seedlings was many folds higher than the uptake by mature plants. At 30 mg l^?1 fluoride exposure, the mean $ {\text{F}}_{{{\text{H}}_{ 2} {\text{O}}}} $ accumulation (mg kg^?1 dry weight) in root, leaves, and seeds of Swarno was 54.1, 51.4 and 42.3, whereas the corresponding values in IR-36 were 50.9, 48.5 and 39.2. For the same exposure, the fluoride accumulation in root and shoot of Swarno and IR-36 seedlings were 3,480, 3,463 and 3,386, 3,360 mg kg^?1, respectively. Normally, the fluoride accumulation follows the order of soil > root > shoot > grain. However, at early stage of fluoride contamination (5 mg l^?1 NaF) roots tended to hyper accumulate fluoride from the soil.