Seedling Peroxidase and IAA Oxidase Activities in Relation to Hybrid Vigour in Pearl Millet (Pennisetum americanum L. Leeke)

Seedlings of three hybrids and their parental lines were analyzed for growth, and peroxidase as well as IAA oxidase activities in cytoplasmic and salt-extracted ionically bound fractions with a view to evaluate heterosis in pearl millet. The hybrid vigour was manifested in roots and shoots of all the three hybrids clearly for growth and activities of peroxidase and IAA oxidase except the wall-bound IAA oxidase. Either better parental or mid-parental heterosis was discernible. The role of peroxidase and IAA oxidase systems in meristematic activity and removal of excessive auxin levels to bring about maximal growth response in the hybrids is discussed.     

Effects of nitrogen fertilizer and weed control on nutritive quality of carrots (Daucus carota L.)

The nutritive quality of carrots, obtained from different herbicide-treated plots and under different levels of nitrogen application ranging from zero to 80kg nitrogen/ha, was compared. There were significant differences in carotene content, T.S.S. (total soluble solids) and organolptic characteristics under the influence of different treatments. The maximum carotene content, T.S.S. and organoleptic characteristics were observed with the application of 80 kg. nitrogen/ha and fluchloralin herbicide at 0.90 and 1.20 kg/ha.     

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.     

DDT and HCH Residues in Basmati Rice (Oryza sativa) Cultivated in Dehradun (India)

Organochlorine pesticides were used earlier for agricultureproduction. Their residues may still be present in soil and mayaccumulate in food crops, posing potential health problems to consumers. DDT, HCH, their isomers and metabolites were analyzedin samples of soil and rice plants collected from ten differentvillages of a well-known Basmati rice growing area in Dehradun.Residues of both pesticides were found in all samples ofsoil and different parts of rice plants except for a few grainsamples. Maximum residue was observed in husk and minimum ingrains. The average concentration of DDT in soil ranged from0.013 to 0.238 ppm. p,p′-DDE was the major metabolite (>63%). Theaverage concentration of DDT in rice grain varied from 0.002 to 0.040 ppm. o,p′-DDT was the main isomer (>93%). Theaverage concentration of HCH in soil ranged from 0.122 to 0.638 ppm. β-HCH was the predominant (43%) isomerfollowed by α-HCH (21%). The average HCH concentrationin rice grain ranged between 0.013 and 0.113 ppm. All four isomers were present in grains. The levels of DDT and CHCin grains were similar in magnitude as those from differentIndian states, but well below the maximum residue limit of 0.1 ppm for DDT and 0.05 ppm for HCH prescribed by the Government ofIndia and WHO/FAO. As such, the pesticide residue levels in thisexport commodity are not of hazardous nature.     

Chemical Fractions of Mn in Acidic Soils and Selection of Suitable Soil Extractants for Assessing Mn Availability to Maize (Zea Mays L.)

Twenty surface (0–15 cm) samples of acidic soils were analyzed for water soluble (WS), exchangeable (EX), lead displaceable (Pb-disp.), acid soluble (AS), manganese (Mn) oxide occluded (MnOX), organically bound (OB), amorphous Fe oxide occluded (AFeOX), crystalline iron (Fe) oxide occluded (CFeOX) and residual (RES) fractions of Mn, and also for extractable Mn in some common soil extractants: (diethylenetriaminepentaacetic acid (DTPA) (pH 7.3), DTPA (pH 5.3), AB-DTPA (pH 7.6), Mehlich-3 (pH 2.0), Modified Olsen, 0.005 M calcium chloride (CaCl₂), 1 M magnesium chloride (MgCl₂) and ion exchange resins. The WS-Mn fraction showed a significant and positive correlation with Mn extractable in DTPA (pH 5.3) and AB-DTPA (pH 7.6), while both WS-Mn and EX-Mn fractions correlated significantly and positively with Mn concentration and uptake by maize plants grown in these soils. The AB-DTPA (pH 7.6) and DTPA (pH 5.3) appeared suitable to assess the availability of Mn in acidic soils.     

A Tale of Two Rivers: Can the Restoration Lessons of River Thames (Southern UK) Be Transferred to River Hindon (Northern India)?

Water, Air, & Soil Pollution - Feasibility of dechlorination using ultra-high lime with aluminum process (UHLA) has been demonstrated by previous studies. However, the negative influences of...     

Breast-feeding initiation and determinants of exclusive breast-feeding - a questionnaire survey in an urban population of western Nepal

OBJECTIVE: To assess rates of initiation of breast-feeding and exclusive breast-feeding within 2 months after delivery and to determine the factors influencing exclusive breast-feeding. DESIGN: A health worker-administered questionnaire survey was carried out during the time period 1 August-30 September 2005. SETTING: Immunisation clinics of Pokhara, a submetropolitan city in western Nepal. SUBJECTS: Three hundred and eighty-five mothers who had delivered a child within the previous 2 months. RESULTS: The rates of initiation within 1 h and within 24 h of delivery were 72.7 and 84.4%, respectively. Within 2 months after delivery, exclusive breast-feeding was practised by 82.3% of the mothers. Breast milk/colostrum was given as the first feed to 332 (86.2%) babies but 17.2% of them were either given expressed breast milk or were put to the breast of another lactating mother. Pre-lacteal feeds were given to 14% of the babies. The common pre-lacteal feeds given were formula feeds (6.2%), sugar water (5.9%) and cow's milk (2.8%). Complementary feeds were introduced by 12.7% of the mothers. By logistic regression analysis, friends' feeding practices, type of delivery and baby's first feed were the factors influencing exclusive breast-feeding practice of the mothers. CONCLUSIONS: Despite the higher rates of initiation and exclusive breast-feeding, practices such as pre-lacteal feeds and premature introduction of complementary feeds are of great concern in this urban population. There is a need for promotion of good breast-feeding practices among expectant mothers and also the community, especially the families, taking into account the local traditions and customs.     

Has the introduction of modern rice varieties changed rice genetic diversity in a high-altitude region of Nepal?

We surveyed the uptake of three modern rice varieties by farmers in high-altitude villages in the Kaski district of Nepal and found that their uptake had displaced some traditional landraces in the district. The three varieties, Machhapuchhre-3 (M-3), Machhapuchhre-9 (M-9) and Lumle 2, were developed using client-oriented, participatory plant breeding methods and the first was introduced to farmers in 1996. By 2004 up to 60% of the land area was used to grow these modern varieties. Molecular markers (SSR) were used to assay levels of genetic diversity to test if adoption of modern varieties in the place of landraces had changed genetic diversity. The modern varieties were found to contain diverse alleles with a high proportion from the local parent variety, Chhomrong Dhan. We found a high level of allelic richness in the landraces, and although seven had been dropped in favour of the modern varieties, other diverse landraces were still being cultivated by farmers in the study villages on up to 40% of the rice area. Genetic diversity may be maintained even when landraces are displaced by modern varieties. Using a model we found that the partial replacement of landraces increased genetic diversity if the modern varieties were adopted on up to 65% of the area. Only above these levels did overall diversity decline.     

Genomic characterization of drought tolerance-related traits in spring wheat

Drought tolerance was investigated in ‘C306’, one of the most drought tolerant wheat cultivars bred in India in the 1960’s. An intervarietal mapping population of recombinant inbred lines of the cross ‘C306’ × ‘HUW206’ was evaluated for drought tolerance components, namely potential quantum efficiency of photosystem (PS) II (F_v/F_m), chlorophyll content (Chl), flag leaf temperature (Lt), and grain yield per plant (Gyp) under stress. Three independent experiments were conducted under well-watered and water-stressed conditions in greenhouses and growth chambers at Kansas State University (USA). Five hundred and sixty microsatellite markers covering the entire genome were screened for polymorphism between the parents. A QTL (QLt.ksu-1D) for Lt (low flag leaf temperature under stress) on the short arm of chromosome 1D between markers Xbarc271 and Xgwm337 at LOD 3.5 explained 37% of the phenotypic variation. A QTL for F_v/F_m (QF _v /F _m .ksu-3B) and Chl (QChl.ksu-3B) controlling quantum efficiency of PS II and chlorophyll content under stress were co-localized on chromosome 3B in the marker interval Xbarc68–Xbarc101 and explained 35–40% of the phenotypic variation for each trait. A QTL (QGyp.ksu-4A) for Gyp on chromosome 4A at a LOD value of 3.2 explained 16.3% of the phenotypic variation. Inconsistent QTLs were observed for F_v/F_m on chromosomes 3A, 6A, 2B, 4B, and 4D; for Chl on 3A, 6A, 2B and 4B; and for Lt on 1A, 3A 6A, 3B and 5B. The identified QTLs give a first glimpse of the genetics of drought tolerance in C306 and need to be validated in field experiments using the marker-phenotype linkages reported here.     

Distribution and Biocontrol Potential of phlD(+) Pseudomonads in Corn and Soybean Fields

ABSTRACT The abundance and diversity of phlD(+) Pseudomonas spp. colonizing the rhizospheres of young, field-grown corn and soybean plants were assayed over a 3-year period. Populations of these bacteria were detected on the large majority of plants sampled in the state of Ohio, but colonization was greater on corn. Although significant variation in the incidence of rhizosphere colonization was observed from site to site and year to year on both crops, the magnitude of the variation was greatest for soybean. The D genotype was detected on plants collected from all 15 counties examined, and it represented the most abundant subpopulation on both crops. Additionally, six other genotypes (A, C, F, I, R, and S) were found to predominate in the rhizosphere of some plants. The most frequently observed of these were the A genotype and a newly discovered S genotype, both of which were found on corn and soybean roots obtained from multiple locations. Multiple isolates of the most abundant genotypes were recovered and characterized. The S genotype was found to be phylogenetically and phenotypically similar to the D genotype. In addition, the novel R genotype was found to be most similar to the A genotype. All of the isolates displayed significant capacities to inhibit the growth of an oomycete pathogen in vitro, but such phenotypes were highly dependent on media used. When tested against multiple oomycete pathogens isolated from soybean, the A genotype was significantly more inhibitory than the D genotype when incubated on 1/10x tryptic soy agar and 1/5x corn meal agar. Seed inoculation with different isolates of the A, D, and S genotypes indicated that significant root colonization, generally in excess of log 5 cells per gram of root, could be attained on both crops. Field trials of the A genotype isolate Wayne1R indicated the capacity of inoculant populations to supplement the activities of native populations so as to increase soybean stands and yields. The relevance of these findings to natural and augmentative biocontrol of root pathogens by these bacteria is discussed.