印度中央邦马尔瓦地区利用人工神经网络和回归模型预测蒸腾量的比较（摘选）

蒸发是水循环的一个重要组成部分,对蒸发量的估算是对水资源和灌溉水量有效利用的一个重要手段。该研究旨在利用多元线性回归模型、多层感知器（MLP）和人工神经网络（ANN）模型模拟印度中央邦马尔瓦地区周蒸发量。利用4种不同天气变量组合训练神经网络模型。多元线性回归模型只将最高温和相对湿度作为输入值,但是模拟结果不令人满意。MLP模型采用的数据集包括最高和最低温度、风速和相对湿度,在训练和验证中都取得了比较好的结果。MLP模型可以用来模拟周开放式蒸发皿蒸发量,估算缺失数据,并可以作为替代模型以验证蒸发量测定值。降雨量数据并不能改善模型性能。      

New subspecies-specific polymerase chain reaction-based assay for the detection of Acidovorax avenae subsp. citrulli

New subspecies-specific primers for the detection of Acidovorax avenae subsp. citrulli ( Aac ), the seedborne bacterium which causes bacterial fruit blotch of cucurbits, were designed based on PCR fragments obtained in ERIC- and BOX-PCR profiles of Aac strains. PCR with both primer sets identified 30 strains from different locations and hosts, but did not amplify DNA from other closely related species and subspecies assessed, with the exception of DNA of one strain of A. avenae subsp. avenae , which was amplified by one of the primer sets, named BX-S. This primer set, based on a BOX-PCR fragment, performed under high-stringency conditions without losing its detection sensitivity. The primers were also evaluated for their ability to detect the pathogen in contaminated watermelon and melon seed samples. The BX-S primers facilitated the detection of the pathogen from washings of 5000-seed samples with 0·02% infestation. This primer set was also assessed for detection using immunomagnetic separation polymerase chain reaction (IMS-PCR) and was shown to be as sensitive as a previously described primer set (AACF2/R3), detecting 0·02% infestation in seed samples. This highly specific and sensitive primer set could be used to improve PCR-based detection of this important pathogen.     

Assessment of surface and sub-surface waterlogged areas in irrigation command areas of Bihar state using remote sensing and GIS

Satellite remote sensing coupled with Geographical Information Systems (GIS) offers an excellent alternative to conventional mapping techniques in monitoring and mapping of surface and sub-surface waterlogged areas. In the present study, pre-monsoon and post-monsoon surface waterlogged areas were delineated in all the 132 irrigation command areas of the Bihar State, India using Indian Remote Sensing (IRS-1D) Linear Imaging Self Scanning Sensor (LISS-III) data acquired during the period 2002–2003. Normalized Difference Water Index (NDWI) was used primarily to delineate surface waterlogged areas. Perennial waterlogged and seasonal waterlogged areas were identified for the study area by integrating the waterlogged areas derived for both the pre- and post-monsoon seasons under GIS environment. Results show that the total surface waterlogged area in Bihar is 628 × 10³ ha, which is 10.57% of command area (5939 × 10³ ha) and spread over 132 command areas. Perennial surface inundation covers 2.95% of the waterlogged area in all the command areas. Maximum waterlogged area is observed in Gandak command (212 × 10³ ha) followed by Eastern Kosi irrigation scheme (116 × 10³ ha) and Sone modernization scheme (82 × 10³ ha), respectively. Further, waterlogged areas induced by rise in groundwater level were also assessed spatially under GIS environment using the ground water level data pertaining to pre- and post-monsoon seasons of the year 2002–2003 which were spread all over the study area. The analysis of pre- and post-monsoon groundwater levels indicates that the area under non-critical category during pre-monsoon period was reduced from 4287 × 10³ ha (72.72% of command) to 1391 × 10³ ha (23.42%) in the post-monsoon. Area under most critical category during post-monsoon period increased from 0.083 × 10³ ha of command area in pre-monsoon period to 50 × 10³ ha. The study demonstrates utility of integration of remote sensing and GIS techniques for assessment of waterlogged areas particularly in regions where waterlogging conditions occur both due to excessive irrigation and accumulation of rain and floodwaters.     

Comparison of Activated Carbon and Physic Seed Hull for the Removal of Malachite Green Dye from Aqueous Solution

In the present work, the effectiveness of physic seed hull, PSH (Jatropha curcas L.), as an alternative low-cost adsorbent for the removal of malachite green (MG) dye from simulated wastewater has been studied. It has been observed that PSH has remarkable adsorption capacity compared to granular activated carbon. The PSH adsorbent was characterized by SEM-EDX, BET, CHNS, zeta potential, and FTIR techniques. The adsorption behaviors such as adsorption kinetics, adsorption dynamics, and adsorption isotherms of PSH for the removal of MG dye from aqueous solution were studied in detail. The kinetic data fitted well with the pseudo second-order kinetic model for MG adsorption. Langmuir isotherm was found to be the model best fitted to describe the adsorption process.     

Investigation of phytosociological parameters and physico-chemical properties of soil in tropical semi-evergreen forests of Eastern Himalaya

The study of floral diversity in forest and its development are incomplete without taking consideration of plant-soil interactions. So with this view in mind, the present study was conducted in tropical semi-evergreen forests of the Mokukchung district, Nagaland, in eastern Himalaya. The aim of the study was to investigate the phytosociological parameters in relation to soil properties.Seven sites were randomly selected to study the soil properties at up to one meter in depth and a phytosociological study was carried out in nearby areas via the quadrate method. In the studied sites, the richness of tree species varied from 4 to 15 ha~(-1), with Gmelina arborea and Duabanga grandifloras being the common species.The highest total basal area was recorded in 10 mile village(47,998.16 cm~2ha~-1)) followed by Minkong village site(32,704.66 cm~2ha~(-1)). Soil physical and chemical properties—i.e. bulk density(BD), soil p H, organic carbon(OC),available nitrogen(N), available phosphorus(P), and available potassium(K) were analyzed using standard procedures. Significant differences were observed in the soil properties. The basal area of species showed significant positive correlation in terms of available K(0.754) and OM(0.302) content in soil, and the Shannon–Wiener diversity index(H) is also positively correlated with the available N content(0.402). The undisturbed nature of the sites played an important role in maintaining the soil fertility and floral diversity of the sites. Moreover, sites with maximum productivity and soil fertility are considered as potential carbon sequestration areas in the region while sites with the low soil fertility need restoration.     

Diversity analysis and evaluation of wild <Emphasis Type="Italic">Abelmoschus</Emphasis> species for agro-morphological traits and major biotic stresses under the north western agro-climatic condition of India

The wild species in general is considered to be the reservoir of genes especially for biotic and abiotic stresses. In okra, the predominant biotic stresses are yellow vein mosaic disease (YVMD), shoot and fruit borer and leaf hopper. Sixty eight (68) accessions belonging to four wild Abelmoschus species [Abelmoschus caillei (A. Chev.) Stevels, Abelmoschus manihot (L.) Medik., Abelmoschus moschatus (L.) Medik. and Abelmoschus tuberculatus Pal et Singh] and eight okra varieties were characterized and evaluated for phenological characters including biotic stresses under natural epiphytotic condition. The wild species examined consisted of 18 accessions (16 exotic and 2 indigenous) of A. caillei, 29 accessions of A. manihot, 16 accessions of A. moschatus and 5 accessions of A. tuberculatus. All the wild Abelmoschus species exhibited high diversity (as measured by Shannon Diversity Index) for 3 qualitative characters viz. intensity of stem colour, leaf shape, epicalyx shape, 13 quantitative characters and 3 biotic stress parameters. Among the wild species, A. caillei and A. tuberculatus showed maximum and minimum diversity for qualitative characters, respectively. There was significant variation for 19 out of 24 quantitative characters studied. Inter-species diversity pattern as estimated through Ward’s Minimum Variance Dendrogram and Principal Component Analysis revealed clear differentiation among the species with minimum overlapping indicating close association between geographical origins and clustering pattern. Intra-species diversity indicated role of specific adaptation in sub-clustering. Resistance to YVMD was found in accessions belonging to three wild species viz. A. caillei, A. manihot and A. moschatus while resistance to shoot and fruit borer and leaf hopper was found in accessions of all the four wild species. The resistant accessions can further be used for introgressing biotic stress resistance through pre-breeding into cultivated okra species.     

Phenotypic assessment of genetic gain from selection for improved drought tolerance in semi-tropical maize populations

Most maize production across the globe is rain-fed, and production is set to be negatively impacted as duration and occurrence of droughts increases due to climate change. Development of water-deficit tolerant maize germplasm has been a major focus for most breeding programmes. Here, we sought to assess the genetic gain for grain yield in two maize populations developed for drought tolerance at CIMMYT by evaluating their cycle progeny through hybrid performance. Inbreds derived from different cycles of the Drought Tolerant Population (DTP) and La Posta Sequia (LPS) were mated to a tester (CML550), and resulting hybrids were evaluated under managed water-deficit stress and well-watered conditions. The difference in yield between water-deficit and well-watered treatments was 27% and 36% for the DTP and LPS, respectively. Genetic gain for grain yield across cycles for the two populations was confirmed in the study. Genetic gain was observed for both treatments indicating that selection for water-deficit stress tolerance simultaneously improves grain yield in well-watered conditions. The DTP population had a genetic gain of 0.07 t ha⁻¹ cycle⁻¹, while the LPS had 0.16 t ha⁻¹ cycle⁻¹ under water-deficit conditions. Significant genetic gain was also observed in the well-watered treatments for both populations. Anthesis to silking interval was significantly reduced under water-deficit stress conditions in both populations. Plant and ear height were reduced in the LPS population in both treatments, while no reductions were observed for the trait in the DTP population. Potential water-deficit stress tolerance donor lines with yields comparable to commercial check varieties were identified.     

Modelling regional level spatial distribution of aphid (Lipaphis erysimi) growth in Indian mustard using satellite-based remote sensing data

Abstract

We developed a procedure for preparing a model for mapping spatially distributed zones of aphid pest (Lipaphis erysimi) outbreaks at a regional level. This study employed near-surface meteorological parameters derived from National Oceanic and Atmospheric Administration (NOAA) Television and Infra-Red Operational Satellites (TIROS) Operational Vertical Sounder (TOVS) data and field observations of disease infestation. The study area comprised three sites representing semi-arid and sub-humid regions of dominant Indian mustard (Brassica juncea L.)-growing regions of India. A model based on TOVS-derived cumulative surface air temperature and minimum specific humidity (SpH) was developed to estimate the date of ‘aphid onset’ (first appearance), date of peak infestation and location of severity with respect to aphid population density. Aphid population growth rate during the linear growth phase between aphid onset to peak was computed using SpH-weighted temperature and dates of sowing of the crop (crop age). Sowing dates of mustard crop, of northwest India, were obtained from spectral growth profiles derived from time series remote sensing (RS) products of the SPOT-4 VEGETATION sensor. Estimated dates of peak aphid infestation and peak population showed a strong match with the observed data. The location of peak aphid population density was depicted in each spatial grid of 25×25 km² for parts of northwest India. The simulated aphid population build-up and date of peak population density was validated with observed data for an unknown site in the Sriganganager district, Rajasthan state, India. Comparison of predicted dates of attaining peak aphid population with observations showed a deviation of ±7 days. After validation, the regional level model was applied over a large area of a mustard-growing region for varying dates of sowing, surface air temperature and specific humidity, to show the spatial distribution of aphid growing severity zones (population density) and to predict dates of severe aphid infestation (peak population) at each grid level in the region.     

Comparative analysis of multi-criteria probabilistic FR and AHP models for forest fire risk(FFR) mapping in Melghat Tiger Reserve(MTR) forest

A comparative study of Frequency Ratio(FR)and Analytic Hierarchy Process(AHP)models are performed for forest fire risk(FFR)mapping in Melghat Tiger Reserve forest,central India.Identification of FFR depends on various hydrometeorological parameters altitude,slope,aspect,topographic position index,normalized differential vegetation index,rainfall,air temperature,land surface temperature,wind speed,distance to settlements,and distance by road are integrated using a GIS platform.The results from FR and AHP show similar trends.The FR model was significantly higher accurate(overall accuracy of 81.3%,kappa statistic 0.78)than the AHP model(overall accuracy 79.3%,kappa statistic 0.75).The FR model total forest fire risk areas were classified into five classes:very low(7.1%),low(22.2%),moderate(32.3%),high(26.9%),and very high(11.5%).The AHP fire risk classes were very low(6.7%),low(21.7%),moderate(34.0%),high(26.7%),and very high(10.9%).Sensitivity analyses were performed for AHP and FR models.The results of the two different models are compared and justified concerning the forest fire sample points(Forest Survey of India)and burn images(2010-2016).These results help in designing more effective fire management plans to improve the allocation of resources across a landscape framework.