130 research outputs found
Storage stability of potato variety Lady Rosetta under comparative temperature regimes
Potatoes are usually stored under low temperatures for sprout prevention and to ensure their continuous supply. Low temperature sweetening in potato is the major temperature related disorder being faced by the growers and is also known to be associated with variety specific storage temperature. The present study aimed at identifying the appropriate storage temperature for the premium potato variety Lady Rosetta with special reference to the changes in its quality attributes, that is weight loss, total sugars, starch, ascorbic acids, total phenolic contents, radical scavenging activity, enzymatic activities and potato chip color. The selected potato variety was stored under different temperature (5, 15 and 25oC) regimes to identify appropriate storage temperature. Our results showed significant variations in the tested quality attributes in response to different storage temperatures. Storage at 5oC maintained tuber dormancy up to 126 days, however, found associated with increased sugar accumulation (2.32 g/100 g), rapid starch depletion (13.25 g/100 g) and poor post processing performance (L-value, 52.00). In contrast, potato storage at 15oC retained lower sugar contents (1.33 g/100g) and superior chip color (L-value, 59.33) till the end of storage. However, they were found associated with the increased polyphenol oxidase (38.47 U/g f.w) and peroxidase (15.25 U/100 g f.w) activities as compare to those potatoes stored at 5oC during the same storage period. Storage life of potato tubers at 25oC was significantly reduced due to dormancy break on 84th day and subsequent starch degradation (15.29 g/100 g) increased sugar accumulation (1.32 g/100 g) and increased polyphenol oxidase (79.89 U/g f.w) and peroxidase activities (40.69 U/100 g f.w). Our results showed that potato variety Lady Rosetta is cold sensitive and requires specific temperature for prolonged storage and best post processing performance
Transition in Tuber Quality Attributes of Potato (Solanum tuberosum L.) Under Different Packaging Systems During Storage
The suitability of different packaging materials i.e. jute, nylon, polypropylene, cotton, low density polyethylene, medium density polyethylene, and high density polyethylene were studied for tubers of the premium potato (Solanum tuberosum L.) variety âLady Rosettaâ. After harvest, potato tubers were washed, sorted, graded, cured, and subsequently stored in different packaging materials at ambient temperature (25±2 °C). Changes in quality attributes of potato tubers under different packaging materials were studied on the basis of their physico-chemical and functional parameters. Overall results revealed that packaging materials had a significant (p †0.05) effect on many important quality attributes. Generally, weight loss, glucose and glycoalkaloid amounts, and polyphenol oxidase and peroxidase activities increased, while ascorbic acid contents decreased with increasing storage time. Total phenolic contents and radical scavenging activity showed a nearly parabolic trend during the storage period. Amongst the different packaging materials employed, potatoes stored in polypropylene and low-density polyethylene presented the best overall retention of vital quality attributes during 63 days storage. However, the higher tensile strength of polypropylene packaging made it a more durable and thus more effective material for prolonged potato tuber storage, a characteristic having clear advantages when used in typical marketing supply chains
Are Land-use Changes Reflected in Diets of Mourning Doves (Zenaida macroura) in Eastern South Dakota
Food habits of the mourning dove (Zenaida macroura) have been extensively studied in the southern United States (McClure 1943, Korschgen 1958, Carpenter 1971) and consist primarily of vegetable matter throughout their range (Beckwith 1959). Diet studies in several states have indicated agricultural crops, specifically corn and wheat, were the most readily consumed plant seeds (Korshgen 1958, Carpenter 1971). Similarities observed in diets of doves were dependent on the agricultural crops available within the area. For example, in Missouri, some seasonal variability was documented suggesting doves forage based on food availability as much as by food preference (Korschgen 1958). However, in the agriculturally dominated landscape of east central South Dakota (SD), the two most important food items for doves were green (Setaria viridis) and yellow foxtail (S. glauca; Vanât Hul and Jenks 1992)
Crystalline surface structures induced by ion sputtering of Al-rich icosahedral quasicrystals
Low-energy electron diffraction patterns, produced from quasicrystal surfaces by ion sputtering and annealing to temperatures below âŒ700 K, can be assigned to various terminations of the cubic CsCl structure. The assignments are based upon ratios of spot spacings, estimates of surface lattice constants, bulk phase diagrams vs surface compositions, and comparisons with previous work. The CsCl overlayers are deeper than about five atomic layers, because they obscure the diffraction spots from the underlying quasicrystalline substrate. These patterns transform irreversibly to quasicrystalline(like) patterns upon annealing to higher temperatures, indicating that the cubic overlayers are metastable. Based upon the data for three chemically identical, but symmetrically inequivalent surfaces, a model is developed for the relation between the cubic overlayers and the quasicrystalline substrate. The model is based upon the related symmetries of cubic close-packed and icosahedral-packed materials. The model explains not only the symmetries of the cubic surface terminations, but also the number and orientation of domains
NOTES: ARE LAND-USE CHANGES REFLECTED IN DIETS OF MOURNING DOVES (ZENAIDA MACROURA) IN EASTERN SOUTH DAKOTA
Food habits of the mourning dove (Zenaida macroura) have been extensively studied in the southern United States (McClure 1943, Korschgen 1958, Carpenter 1971) and consist primarily of vegetable matter throughout their range (Beckwith 1959). Diet studies in several states have indicated agricultural crops, specifically corn and wheat, were the most readily consumed plant seeds (Korshgen 1958, Carpenter 1971). Similarities observed in diets of doves were dependent on the agricultural crops available within the area. For example, in Missouri, some seasonal variability was documented suggesting doves forage based on food availability as much as by food preference (Korschgen 1958). However, in the agriculturally- dominated landscape of east central South Dakota (SD), the two most important food items for doves were green (Setaria viridis) and yellow foxtail (S. glauca; Vanât Hul and Jenks 1992).
Large-scale land use changes have occurred in eastern South Dakota in the past few decades and several factors have contributed to increased grassland to cropland conversion (Wright and Wimberly 2013). Conversion of grasslands to agricultural crops has increased as demand for biofuels and commodity prices increased (Secchi and Babcock 2007, Searchinger et al. 2008, Fargione et al. 2009, Wright and Wimberly 2013). In east central South Dakota, corn and soybean plantings have increased from 2,400,000 ha in 1991 to 4,400,000 ha in 2013 (United States Department of Agriculture 2014). These significant land-use changes that have occurred in the intervening 20 years may influence mourning dove feeding habits. We compared mourning dove diet composition in Minnehaha County, South Dakota, USA, to those published 20 years earlier from a study conducted approximately 60 km north (Vanât Hul and Jenks 1992)
Heat tolerance indicators in Pakistani wheat (Triticum aestivum L.) genotypes
The effect of high temperature stress on six wheat cultivars exposed to 35â40 °C for 3 h each day for five consecutive days was examined. High temperature significantly affected total proline, soluble protein content, membrane stability index (MSI), yield, and various yield components, and had a direct effect on growth and other physiological attributes of wheat at anthesis and the milky seed stages. The wheat cultivar AS- 2002 achieved better osmotic adjustment by accumulating more leaf proline. Higher MSI was also observed in AS-2002, as well as Inqalab-91. The anthesis growth stage was found to be more sensitive to heat stress than seed development at the milky stage. Overall heat stress reduced yield 75% at anthesis and 40% at the milky stage. AS-2002 performed better on the basis of yield and yield components. Seed weight per spike was highest in AS- 2002, and lowest in SH-2002. The cumulative response of AS-2002 was better on the basis of physiological and yield attributes. In addition to yield, plant breeders should also include proline and MSI as selection parameter in the breeding program for development of heat tolerant wheat cultivars. Most of the evaluated wheat cultivars/lines were developed for cultivation in the rainfed areas of Pakista
Population Genomic Analysis Reveals Differential Evolutionary Histories and Patterns of Diversity across Subgenomes and Subpopulations of Brassica napus L.
The allotetraploid species Brassica napus L. is a global crop of major economic importance, providing canola oil (seed) and vegetables for human consumption and fodder and meal for livestock feed. Characterizing the genetic diversity present in the extant germplasm pool of B. napus is fundamental to better conserve, manage and utilize the genetic resources of this species. We used sequence-based genotyping to identify and genotype 30,881 SNPs in a diversity panel of 782 B. napus accessions, representing samples of winter and spring growth habits originating from 33 countries across Europe, Asia and America. We detected strong population structure broadly concordant with growth habit and geography, and identified three major genetic groups: spring (SP), winter Europe (WE), and winter Asia (WA). Subpopulation-specific polymorphism patterns suggest enriched genetic diversity within the WA group and a smaller effective breeding population for the SP group compared to WE. Interestingly, the two subgenomes of B. napus appear to have different geographic origins, with phylogenetic analysis placing WE and WA as basal clades for the other subpopulations in the C and A subgenomes, respectively. Finally, we identified 16 genomic regions where the patterns of diversity differed markedly from the genome-wide average, several of which are suggestive of genomic inversions. The results obtained in this study constitute a valuable resource for worldwide breeding efforts and the genetic dissection and prediction of complex B. napus traits
Large-Scale Spray Releases: Additional Aerosol Test Results
One of the events postulated in the hazard analysis for the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak event involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids that behave as a Newtonian fluid. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and in processing facilities across the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNLâs test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are mostly absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale testing. The small-scale testing and resultant data are described in Mahoney et al. (2012b), and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used to mimic the relevant physical properties projected for actual WTP process streams
Genome-wide analysis of the omega-3 fatty acid desaturase gene family in Gossypium
Background
The majority of commercial cotton varieties planted worldwide are derived from Gossypium hirsutum, which is a naturally occurring allotetraploid produced by interspecific hybridization of A- and D-genome diploid progenitor species. While most cotton species are adapted to warm, semi-arid tropical and subtropical regions, and thus perform well in these geographical areas, cotton seedlings are sensitive to cold temperature, which can significantly reduce crop yields. One of the common biochemical responses of plants to cold temperatures is an increase in omega-3 fatty acids, which protects cellular function by maintaining membrane integrity. The purpose of our study was to identify and characterize the omega-3 fatty acid desaturase (FAD) gene family in G. hirsutum, with an emphasis on identifying omega-3 FADs involved in cold temperature adaptation. Results
Eleven omega-3 FAD genes were identified in G. hirsutum, and characterization of the gene family in extant A and D diploid species (G. herbaceum and G. raimondii, respectively) allowed for unambiguous genome assignment of all homoeologs in tetraploid G. hirsutum. The omega-3 FAD family of cotton includes five distinct genes, two of which encode endoplasmic reticulum-type enzymes (FAD3-1 and FAD3-2) and three that encode chloroplast-type enzymes (FAD7/8-1, FAD7/8-2, and FAD7/8-3). The FAD3-2 gene was duplicated in the A genome progenitor species after the evolutionary split from the D progenitor, but before the interspecific hybridization event that gave rise to modern tetraploid cotton. RNA-seq analysis revealed conserved, gene-specific expression patterns in various organs and cell types and semi-quantitative RT-PCR further revealed that FAD7/8-1 was specifically induced during cold temperature treatment of G. hirsutum seedlings. Conclusions
The omega-3 FAD gene family in cotton was characterized at the genome-wide level in three species, showing relatively ancient establishment of the gene family prior to the split of A and D diploid progenitor species. The FAD genes are differentially expressed in various organs and cell types, including fiber, and expression of the FAD7/8-1 gene was induced by cold temperature. Collectively, these data define the genetic and functional genomic properties of this important gene family in cotton and provide a foundation for future efforts to improve cotton abiotic stress tolerance through molecular breeding approaches
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