scholarly journals Effect of Increasing Elevation of Lowland Coastal Saline Soils of Sundarbans (India) on Soil Salinity and Its Seasonal Variation

2019 ◽  
pp. 1-10
Author(s):  
Tonmoy Sengupta ◽  
B. K. Bandyopadhyay ◽  
Sudipta Tripathi
Keyword(s):  
Seasonal Variation ◽  
Soil Salinity ◽  
West Bengal ◽  
Rhizosphere Soil ◽  
Late Summer ◽  
Crop Productivity ◽  
Groundwater Table ◽  
Considerable Decrease ◽  
River Ganges ◽  
Drainage Congestion

The delta region of the river Ganges spreads over India (West Bengal) and Bangladesh is popularly known as Sundarbans. Crop productivity of the region is very poor. Agricultural lands of the region are mostly saline and low-lying with drainage congestion due to presence of brackish groundwater table at shallow depth and flat topography. In recent years, improvement in productivity of these lands was witnessed by farmers when the elevation of lowlands was increased through land shaping. In the present study changes in the salinity status of soil were due to raise of land elevation through land shaping was investigated for two years and 3 seasons (winter, summer and late summer). It was found that there was a considerable decrease in soil salinity due to increase in elevation of lowlands through land shaping. The salinity of original lowlands was about 200% higher than the raised lands or uplands made through land shaping. Salinity of rhizosphere soil decreased with depth and there was a strong seasonal variation of soil salinity. At all soil depths soil salinity increased as the dry season progressed from winter to late summer through summer and soil salinity was highest in the surface (0-10 cm). The depth to groundwater table and the groundwater salinity also showed strong seasonal variation and were maximum in late summer season. The drainage condition of soil improved with increasing in land elevation.

scholarly journals Effects of soil salinity on rhizosphere soil microbes in transgenic Bt cotton fields

2017 ◽  
Vol 16 (7) ◽  
pp. 1624-1633 ◽  
Author(s):  
Jun-yu LUO ◽  
Shuai ZHANG ◽  
Xiang-zhen ZHU ◽  
Li-min LU ◽  
Chun-yi WANG ◽  
...  
Keyword(s):  
Soil Salinity ◽  
Soil Microbes ◽  
Rhizosphere Soil ◽  
Bt Cotton ◽  
Transgenic Bt Cotton ◽  
Cotton Fields

scholarly journals Contrasting recruitment seasonality of sea urchin species in Gran Canaria, Canary Islands (eastern Atlantic)

2014 ◽  
Vol 15 (3) ◽  
pp. 475 ◽  
Author(s):  
S. GARCIA-SANZ ◽  
P. G. NAVARRO ◽  
F. TUYA
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Late Summer ◽  
Paracentrotus Lividus ◽  
Abundant Species ◽  
Late Winter ◽  
Gran Canaria ◽  
Arbacia Lixula

Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula) at Gran Canaria Island (eastern Atlantic) via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds) within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula) with the most conspicuous species (D. africanum) in the study area.

scholarly journals Phenotyping and molecular marker analysis of WH1105 and Kharchia 65 backcrosses and F4progenies for salinity tolerance

2019 ◽  
Author(s):  
Varsha ◽  
Shikha Yashveer ◽  
Vikram Singh ◽  
Swati Pratap
Keyword(s):  
Salinity Tolerance ◽  
Soil Salinity ◽  
Wheat Variety ◽  
Crop Productivity ◽  
Recurrent Parent ◽  
Salt Tolerant ◽  
Salt Stress Condition ◽  
Initial Salt ◽  
The Cross ◽  
Molecular Marker Analysis

ABSTRACTSoil salinity is a worldwide adverse environmental factor for crop productivity and quality in arid, semiarid and coastal areas. In India, approximately 8.5 million hectare of land area is affected by high salinity (EC ≥ 5 dS m−1). Development of salinity tolerant varieties through marker assisted breeding is most efficient and effective strategy for management of soil salinity. WH 1105 is widely cultivated wheat variety with many agronomically superior qualities but is affected by soil salinity. Two genes (Nax1andNax2) for salinity tolerance were introgressed from Kharchia 65 into the genetic background of WH 1105 through marker assisted backcross breeding. BC1F3, BC2F2and F4generations of the cross WH1105 x Kharchia 65 were evaluated for various morphological traits under initial salt stress condition. On the basis of phenotypic and genotypic variations 44 high yielding plants were selected from the cross. Out of 178 SSRs tested, 30 were found polymorphic for background selection of the foreground selected plants. Cluster tree analysis of parents and all the three generations showed that all the selected plants were inclined toward recurrent parent (WH 1105) indicating higher similarity with the recurrent parent. Four plants were selected as high grain yielding and salt tolerant. These plants could be further backcrossed with the recurrent parent to develop salt tolerant wheat lines.

scholarly journals Seasonal Patterns of Carbohydrates in Mandarin cvs. ‘Fremont’, ‘Nova’ and ‘Robinson’ on Different Rootstocks

2013 ◽  
Vol 41 (1) ◽  
pp. 255 ◽  
Author(s):  
Ercan YILDIZ ◽  
Mustafa KAPLANKIRAN ◽  
Turan Hakan DEMIRKESER ◽  
Celil TOPLU
Keyword(s):  
Seasonal Variation ◽  
Starch Content ◽  
Late Summer ◽  
Carbohydrate Content ◽  
Poncirus Trifoliata ◽  
Soluble Carbohydrate ◽  
Total Carbohydrate ◽  
Fertilization Program ◽  
Total Carbohydrate Content ◽  
Continuous Decrease

The study was conducted at the experimental farm of Mustafa Kemal University, Dörtyol, Turkey during the 2010 and 2011 growing seasons. The aim of this study was to investigate the effect of ‘Troyer’ and ‘Carrizo’ citranges (Poncirus trifoliata Raf. × Citrus sinensis Osb. var. ‘Troyer’ and ‘Carrizo’), and common sour orange (Citrus aurantium L. var. common), rootstocks on the seasonal variation of carbohydrate content in the leaves of cvs. ‘Fremont’, ‘Nova’, and ‘Robinson’ mandarin. The seasonal variation of carbohydrate content of the three cultivars budded on different rootstocks was nearly same. Soluble carbohydrate concentration showed a continuous decrease from January to mid or late-summer, and then slowly began to increase after early autumn till winter. The sucrose was the dominant soluble carbohydrate in leaves. The seasonal evolution of starch content in leaves increased initially during January to March, and then decreased in April. The starch concentration showed a continuous decrease slowly until the mid-autumn, and then accumulation began during late-autumn and winter. The total carbohydrate content differences among the rootstocks were significant, but the content was changed among the cultivars and according to the season. The change in the total carbohydrate content of leaf tissues showed a strong similarity in cultivars budded on different rootstocks throughout the year. The total carbohydrate content reached their lowest levels in July for cv. ‘Robinson’, in August for cv. ‘Fremont’ and cv. ‘Nova’. The total carbohydrate content in leaves increased from the mid- or late-summer to winter. It is suggested that the seasonal variation of carbohydrate content in plant tissues can be considered during fertilization program in mandarin trees.

A Chart-recording Weighing Machine for Beekeeping or other Research

1927 ◽  
Vol 18 (1) ◽  
pp. 63-65
Author(s):  
C. B. Williams
Keyword(s):  
Seasonal Variation ◽  
Late Summer ◽  
Chart Recording

In the course of the beekeeping work of this Department we have had a number of hives weighed at regular intervals of about a week by means of a steelyard and tripod, and two permanently standing on platform weighing machine and weighed every day. The information obtained from these has been of great value in showing the seasonal variation in activity, the periods of honey flow, and the effect on the hives of the presence of enormous numbers of hornets in the late summer.There were, however, many problems, such as the daily periods of activity and honey-collecting, the effect of high midday temperature, etc., that could only be dealt with by more frequent weighings, and it was felt that a machine to record continuously the weight of the hive by means of a rotating clock drum and pen would be a most valuable instrument of research.

Rhizosphere soil microorganism populations and community structures of different watermelon cultivars with differing resistance to Fusarium oxysporum f. sp. niveum

2011 ◽  
Vol 57 (5) ◽  
pp. 355-365 ◽  
Author(s):  
Meijun An ◽  
Xingang Zhou ◽  
Fengzhi Wu ◽  
Yafei Ma ◽  
Ping Yang
Keyword(s):  
Microbial Community ◽  
Fusarium Oxysporum ◽  
Rhizosphere Soil ◽  
Crop Productivity ◽  
Sequencing Analysis ◽  
Culturable Bacteria ◽  
Susceptible Cultivar ◽  
Community Structures ◽  
Opposite Pattern ◽  
Soil Microbial Community Structure

Fusarium wilt is an increasingly serious disease of watermelon that reduces crop productivity. Changes in microorganism populations and bacterial and fungal community structures in rhizosphere soil of watermelon cultivars resistant or susceptible to Fusarium oxysporum f. sp. niveum were investigated using a plate culture method and PCR–DGGE analysis. Plate culture showed that populations of culturable bacteria and actinomycetes were more abundant in the rhizosphere of the resistant watermelon cultivar than the susceptible cultivar, but the fungi population had the opposite pattern. Populations of Penicillium , Fusarium , and Aspergillus were significantly lower in the resistant cultivar than the susceptible cultivar at the fruiting and uprooting stages (p < 0.05). Pattern matching analysis generated the dendrogram of the DGGE results indicating the relatedness of the different resistant watermelon cultivars and their corresponding rhizosphere microbial communities. Further sequencing analysis of specific bands from DGGE profiles indicated that different groups of bacteria and fungi occurred in the rhizosphere of different watermelon cultivars. Our results demonstrated that plant genotype had a significant impact on soil microbial community structure, and the differences in the rhizosphere microbial community may contribute to the differences in resistance to F. oxysporum f. sp. niveum.

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