Tillage Effects on Crop Yield and Physicochemical Properties of Sodic Soils

Tillage modifies soil structure and has been suggested as a practice to improve physical, hydrological and chemical properties of compacted soils. But little is known about effect of long‐term tillage on physicochemical soil properties and crop yield on sodic soils in India. Our objective was to investigate the effect of different tillage regimes on crop yield (wheat and paddy rice) and physicochemical properties of sodic soils. Two sodic sites under conventional tillage for 5 (5‐YT; 5‐year tillage) and 9 (9‐YT; 9‐year tillage) years were selected for this study. Changes in crop yield and physicochemical soil properties were compared with a control, sodic land without any till history, that is, 0‐year tillage/untilled (0‐YT). Five replicated samples at 0‐ to 10‐cm and 10‐ to 20‐cm soils depths were analysed from each site. In the top, 0‐ to 10‐cm soil depth 5‐YT and 9‐YT sites had higher particle density (Pd), porosity, water holding capacity, hydraulic conductivity, organic carbon, total nitrogen (N_t), available nitrogen (N_avail), phosphorus (P_avail) and exchangeable calcium (Exch. Ca⁺⁺) than 0‐YT, whereas bulk density (Bd), C : N ratio and CaCO₃ were significantly lower. Bd, pH, EC and CaCO₃ increased significantly with depth in all the lands, whereas Pd, porosity, water holding capacity, hydraulic conductivity, organic carbon, N_t, N_avail, P_avail and Exch. Ca⁺⁺ decreased. We conclude that continuous tillage and cropping can be useful for physical and chemical restoration of sodic soils. Copyright © 2014 John Wiley & Sons, Ltd.     

Genetic analysis of a CSR10 (indica) × Taraori Basmati F3 population segregating for salt tolerance using ISSR markers

Segregation for salinity tolerance and ISSR markers based molecular polymorphism were investigated in a F₃ plant population raised via single-seed descent method from a cross between salt-tolerant indica rice variety CSR10 and salt-susceptible premium traditional Basmati rice variety Taraori Basmati HBC19. A total of 130 F₃plants were evaluated individually for salinity tolerance on 1–9 scale on the basis of seedling growth parameters; the average score ranged between 1.7 to 8.3. Frequency distribution curve obtained using the salinity tolerance data of F₃ population and a chi-square analysis, showed a good fit to a normal distribution. Eleven plants each in the category of salt-tolerant and salt-susceptible were selected from the segregating F₃ population for ISSR marker analysis. A total of 149 bands (4–11 bands per primer) ranging from 200 to 3530 bp were scored for the two rice varieties and the selected CSR10 × HBC19 segregating F₃ plants using 26 ISSR primers. Of these, 89 were monomorphic and 60 were polymorphic. Of the 60 polymorphic bands,36 and 20 bands were specific to CSR10 andHBC19 respectively. The remaining four bands were amplified using UBC primers 810,848, 853 and 886 and present in only some of the CSR10 × HBC19 F₃ plants. Notably, ISSR primers with dinucleotide repeat motif and 5'-anchored end amplified more number of bands (7.0 bands/primer) compared to3'-anchored dinucleotide primers (5.4bands/primer), but 3'-anchored dinucleotide primers revealed higher level of polymorphism (2.6 polymorphic bands/primer) compared to 5'-anchoreddinucleotide primers (1.43 polymorphic bands/ primer). While distribution of majority of the polymorphic bands were more or less in the expected ratios in salt-tolerant and/or salt-sensitive F₃segregating plants, but some of the bands amplified using UBC ISSR primers 823, 825,826, 849, 853, 864, 866 and 884 showed highly skewed distribution. Such polymorphic bands stand greater chances of having a linkage with the genes/ QTLs for salinity tolerance and shall be the target for further studies. This revised version was published online in July 2006 with corrections to the Cover Date.     

Nitrate assimilation in pea leaves in the presence of cadmium

Supply of 0.01 to 1.0 mM Cd acetates either to the intact seedlings or to the excised leaves of 15 dPisum sativum L. Cv. Bonvilla seedlings inhibitedin vivo nitrate reductase activity (NRA), total soluble protein, chlorophyll, and carotenoids. The inhibition was independent of metal concentrations. In excised leaf tissues, higher concentrations (0.5 to 1.0 mM) of Cd had no conspicuous effect on nitrate assimilation. When NRA was assayed byin vitro method, an increase of 12 to 45% was obtained with Cd in intact and excised leaves. It appears that NRA is more sensitive to Cd concentration than any other parameter examined.     

Characterizing Groundwater Dynamics Based on Impact of Pulp and Paper Mill Effluent Irrigation and Climate Variability

Automated synoptic weather typing and robust orthogonal stepwise regression analysis (via principal components analysis) were applied together to develop within-weather-type air pollution prediction models for a variety of pollutants (specifically, carbon monoxide – CO, nitrogen dioxide – NO₂, ozone – O₃, sulphur dioxide – SO₂, and suspended particles – SP) for the period 1974–2000 in south-central Canada. The SAS robust regression procedure was used to limit the influence of outliers on air pollution prediction algorithms. Six-hourly Environment Canada surface observed meteorological data and 6-hourly US National Centers for Environmental Prediction (NCEP) reanalysis data of various weather elements were used in the analysis. The models were developed using two-thirds of the total years for meteorological and air pollution data; the remaining one-third (randomly selected) was used for model validation. Robust stepwise regression analysis was performed to analytically determine the meteorological variables that might be used to predict air pollution concentrations. There was a significant correlation between observed daily mean air pollution concentrations and model predictions. About 20, 50, and 80% of the 80 prediction models across the study area possessed R ² values ≥ 0.7, 0.6, and 0.5, respectively. The results of model validation were similar to those of model development, with slightly smaller model R ² values.     

Core subsets of base collections and priorities of national programmes: Indian perspective

Summary The establishment of representative core collections and back-up reserve collections was proposed to facilitate effective management and to promote utilization of large base collections. The priorities of the developing national PGR programmes, in the organization of components of their base collections, are different from those of IARCs since the strengths as well as limitations of the two systems vary. Unlike most IARCs, national programmes have the option of networking their active collections, maintained at several eco-sites, and linking this network to the base collection kept under long-term storage. This keeps open the option to develop situation-specific subsets for an effective germplasm utilization. There is a pressing need for a scientific re-examination of the concept of germplasm core in order better to apply it in developing core subsets in the national PGR programmes. The formulation of situation-specific subsets is advocated, as the system would be directed to users' requirements or addressed to gene bank managers' resource constraints. Arguments given in favour of developing core subsets, rather than a single core are: (i) logical; (ii) population genetic; and (iii) germplasm usage considerations. The Indian PGR programme and the emerging core context are briefly discussed, along with features of a programme designed to develop such core subsets.Abbreviations IARCs = International Agriculture Research Centers - NBPGR = National Bureau of Plant Genetic Resources - NAGS = National Active Germplasm Collection Site - NGSNs = National Germplasm Screening Nurseries - GACs = Germplasm Advisory Committees     

Preference and performance of <Emphasis Type="Italic">Plutella xylostella</Emphasis> (L.) (Lepidoptera: Plutellidae) on canola cultivars

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important insect pest of canola, Brassica napus L., in Ardabil, Iran. Host plant resistance is an essential component of integrated management of P. xylostella. We investigated the preferences and performance of P. xylostella on nine commercial cultivars of canola, namely Zarfam, RGS003, Adder, Okapi, Opera, Hyola401, Ebonite Option500 and Elite under greenhouse conditions at 23 ± 1°C, 50 ± 5% RH and 14L:10D. In free-choice situation, oviposition was lowest on Opera (23.5) and highest on Zarfam (44.7). In the life table study, fecundity of new generation female moths was lowest on Opera (95.4) and highest on Adder (145.7). Survival from egg to adult was significantly lower on Opera, Option500 and Hyola401 than on other tested cultivars. The intrinsic rate of natural increase (r _m) and population growth rate (λ) were lowest on Opera and highest on Zarfam. The generation time (T) was shortest on Zarfam (17.2 days) and longest on Hyola401 (19.9 days) whereas doubling time (DT) was longest on Opera (3.9 days) and shortest on Zarfam (3.0 days). Our results clearly suggest that Opera was the most resistant host among the tested cultivars and has the potential to be used in the integrated management of P. xylostella.     

Stomatal and tree growth characteristics of some crab apples

Fifteen crab-apple species were classified on the basis of their stomatal apparatus (density, length and width) and tree growth (trunk cross-sectional area, height and spread) characteristics. None of the stomatal parameters were correlated with tree vigour.     

A quantitative study of seminiferous tubular cells in the developing Murrah buffalo testis

We report here a systematic quantitative study of the seminiferous tubular cells of Murrah buffaloes. The most advanced germ cell types in the different age groups (months) were A(0) spermatogonia (SG) (1 and 3), early pachytene (6 and 9), late pachytene (12), secondary spermatocytes (15 and 18), elongating spermatids (21 and 24), elongated spermatids attached to Sertoli cells (30), elongated spermatids detached from Sertoli cells (36) and spermatozoa (42 and 48). Central primitive Sertoli cells (CPSC) and basal primitive Sertoli cells (BPSC) were present in the sex cord of one-month-old calves, while Sertoli cells (SC) were first seen in nine-month-old calves. The number of gonocytes were maximal at six months but they were not seen after this time. Prespermatogonia (PSG) and SG were at a maximum at nine months of age but PSG were not seen after 36 months. The number of SG decreased significantly after nine months up to 36 months of age.Although spermatocytes and spermatids appeared in earlier developmental stages, a rapid increase in their number was recorded after 36 months. The number of SC was maximal in 18-month-old animals. BPSC predominated in the sex cord of animals aged one to six months, SG at 9-12 months of age, primary spermatocytes from 15-30 months and spermatids from 36 to 72 months and in older animals. We concluded that a decrease in the number of SG in buffalo calves after nine months of age might be responsible for a delay in sexual maturity. Moreover, the small number of spermatocytes and spermatids present before 36 months of age may be associated with the low yield of different germ cell divisions and with the cellular degeneration. A rapid increase in the number of spermatocytes and spermatids after 36 months resulted in sexual maturity between 42 and 48 months.     

Analysis of volatile compounds as spoilage indicators in fresh king salmon (Oncorhynchus tshawytscha) during storage using SPME-GC-MS

A method was developed for the analysis of salmon volatiles using solid-phase microextraction and gas chromatography-mass spectrometry. This method was used to monitor the volatiles of fresh king salmon (Oncorhynchus tshawytscha) stored in ambient air or in a 40:60 (v/v) mixture of CO2:N2 over time. The levels of several of the volatile compounds were found to change during storage, with some showing a clear difference between storage in air and storage in CO2:N2. Of these, several alcohols (cyclopentanol, Z-2-penten-1-ol, 1-penten-3-ol, and 1-octen-3-ol) and aldehydes (hexanal, octanal, E-2-pentenal, and E-2-hexenal) were identified as potential markers for salmon freshness. Several other volatiles (acetoin, ethyl benzene, propyl benzene, styrene, 3-methyl butanoic acid, and acetic acid) were identified as potential markers for salmon spoilage. A comparison of salmon harvested with and without the "rested harvesting" technique showed that E- and Z-isoeugenol levels were increased by the use of the isoeugenol based anesthetic. The use of the anesthetic did not affect the levels of any of the other compounds identified.     

Morphological, anatomical and molecular investigation into witches’ broom disease of mamejvo (Enicostemma axillare)

Mamejvo (Enicostemma axillare Raynal) is a perennial herb with diversified health benefits. It was found to be affected by a witches?? broom disease under the field conditions at Anand, Gujarat, India. Affected plants were 53.33% reduced in height due to shortened internodes, leading to typical witches?? broom symptoms. Flower size was reduced significantly in the affected plants compared with the healthy ones and their petal color gradually turned green (virescence). Affected plants produced 2.5 times more dry herbage than the normal plants but with less active ingredient (swertiamarin). Symptomatic plants died early while root suckers from such plants failed to establish after transplanting. DAPI stained transverse sections of affected shoot tips showed the presence of discrete greenish fluorescence in the phloem cells under UV light. Amplification of 1.2?kb phytoplasma specific rDNA fragment from diseased tissue confirmed the presence of the pathogen. Further characterization of the pathogen through virtual rDNA?CRFLP pattern and rDNA sequence based phylogeny suggested that the pathogen, Enicostemma witches?? broom phytoplasma, belonged to 16SrII?CC group of ??Ca Phytoplasma aurantifolia??.