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161.
Temperature plays a crucial role in plants development whereas a sudden rise may cause severe consequences. Heat stress impairs plant growth, photosynthesis, pollen development and reproduction. The plant photosynthetic efficiency is mainly reduced by the over production of reactive oxygen species, denaturation of heat shock proteins and alteration in many enzymes activities. Unlike drought stress, plants have developed a very few mechanisms to encounter heat stress problem. Recently, the use of nutrients such as sulphur has emerged as one of the efficient methods to enhance plant tolerance against high temperature stress. The mechanistic understanding of sulphur-based strategies could be very helpful to sustain plant development and global food supplies in future hotter climates. The present review mainly focuses on (1) high temperature induced changes in plant functions, (2) possible roles of sulphur metabolites in heat stress tolerance and (3) possibilities of using sulphur as a management strategy. Moreover, the review consolidates the future research needs that must focus on (i) heat tolerant germplasm screening; (ii) sulphur dose optimisation, application method and crop growth stages response; (iii) finding of sulphur induced heat tolerance mechanisms and (iv) the use of omic approaches to discover sulphur metabolites role in heat stress tolerance.  相似文献   
162.
The aim of this study was to evaluate the effectiveness of some natural safe essential oils in control of cumin root rot disease to reduce the pollution of environment as a result of wide distribution of synthetic chemicals which are employed as fungicides.  相似文献   
163.
Degree of milling (DOM) of rice plays a key role in determining rice quality and value. Therefore, accurate, nondestructive, quick, and automated surface lipid content (SLC) measurement would be useful in a commercial milling environment. This study was undertaken to provide calibration models for commercial use to provide quick and accurate evaluation of milled rice SLC and Hunterlab color parameters (L,a,b) as indications of rice DOM. In all, 960 samples, including seven cultivars from seven southern United States locations, stored for 0, 1, 2, 3, and 6 months, were milled for four durations to obtain samples of varying DOM. The samples were used to develop calibration models of milled rice SLC and L,a,b values. Another sample set (n = 58) was commercially milled and used to validate the developed models. A DA 7200 diode array analyzer was used to scan milled rice samples in wavelength spectra of 950–1,650 nm. SLC and color parameters were measured using a Soxtec system and a HunterLab colorimeter, respectively. The partial least squares regression (PLS) method using the full near‐infrared spectra was used to develop prediction models for rice SLC and color parameters. Milled rice SLC was well fitted with a correlation of determination of predicted and measured values of (R2 = 0.934). Color parameters were also successfully fitted for L (R2 = 0.943), a (R2 = 0.870), and b (R2 = 0.855). Performance of the developed models to predict rice DOM was superior in predicting SLC and L,a,b values with R2 predicted and measured values of 0.958, 0.836, 0.924, and 0.661, respectively.  相似文献   
164.
165.
Three olive (Olea europaea L.) cultivars Nabali Baladi (NB), Nabali Muhassan (NM), and Grossi Di'Espagna (GE) were evaluated under salt stress. Seedlings were treated with salinity induced by a 3:1 ratio of calcium chloride and sodium chloride to four concentration levels measured as electrical conductivity (EC) [1.2, 4.1, 7.0, and 14.0 dS/m] for 122 days. Olive seedlings varied in their response to salinity. In all treatments, NB had the highest root; stem and leaf dry weights had among the highest total plant dry weights, specific stem length (SSL) and relative water content (RWC). NB seedlings maintained the highest stomatal conductance at 7.0 dS/m and highest chlorophyll index at 14.0 dS/m. Olive seedlings that tolerated salt tolerance developed mechanisms of nutrient acquisition and distribution in the organs, by storing minimal amounts of sodium (Na+) and chloride (Cl?) in the stems and loading the most in the leaves and roots.  相似文献   
166.
Sugar beet, Beta vulgaris L. is a strategic crop of sugar industry in Egypt. It is threatened by several insect pests among most important of them is the beet beetle Cassida vittata. This work deals with the biological control of this insect using four Egyptian and imported entomopathogenic nematodes (EPNs). The nematodes included Steinernema carpocapsae S2, Heterorhabditis bacteriophora S1, S. feltiae and H. bacteriophora (1-3). Daily mortality of larvae, pupae and adults of C. vittata were recorded after treatment with serial concentrations (from 500 to 4,000 infective juveniles/ml) of each of four studied EPNs. Development of nematodes in insect bodies was followed up. S. carpocapsae S2 was chosen for the application against different stages of the pest in a sugar beet field. In the field, single application of S. carpocapsae S2 killed 65% of the larvae, 92% of the pupae and 57.3% of the adults of C. vittata within a week. This work is the first report on using the EPNs to control sugar beet beetle.  相似文献   
167.
The present work aimed to study the effects of high constant and alternating temperatures on the development and prey consumption by Dicyphus tamaninii Wagner (Het., Miridae) with Aphis gossypii Glover (Hom., Aphididae) as prey.Results showed that the predator was able to successfully develop and reach the adult stage, on average, after 20.1 () and 20.6 () days at a temperature of 30 ± 1 °C with A. gossypii as prey. On the other hand, it was not able to develop at 35 ± 1 °C, here all N1 instars used at the beginning of the experiments had died even before moulting to N2 instar. At alternating temperatures of 25/15 ± 1 °C, the predator reached the adult stage 23.7 () and 23.5 () days after egg hatching, whereas when the temperatures were increased to 35/22 ± 1 °C, it took a significantly shorter period: 20.6 () and 20.9 () days. In general, the highest mortality occurred during the first two nymphal instars. The total percentage mortality during development from N1 to adult stage was 30 % and 100 % at the constant temperatures 30 ± 1 °C and 35 ± 1 °C, respectively. At the alternating temperatures of 25/15 ± 1 °C, it was lowest with 16.5 %, while at 35/22 ± 1 °C, it was 20 %.The results of the experiments on prey consumption showed that an individual D. tamaninii consumed during its development to adult stage at 30 ± 1 °C an average of 442.2 (), 433.6 () aphids. At the constant temperature of 35 ± 1 °C, the average daily prey consumption started with 4 aphids and decreased continuously till it approached nil on the 9th day, where all predatory nymphs died. At the alternating temperatures of 25/15 ± 1 °C, the total prey consumption during development was, on average, 359.3 () and 297.0 () aphids, while at 35/22 ± 1 °C it was 348.5 () and 334.0 () aphids. The effect of the four temperatures on the prey consumption by D. tamaninii during the first 10 days after emergence was also studied. At a constant temperature of 30 ± 1 °C, a total of 446.4 () and 372.0 () aphids were consumed, compared to 40.6 () and 39.0 () at 35 ± 1 °C. At alternating temperatures of 25/15 ± 1 °C, the predatory adult consumed, on average, a total of 267.0 () and 207.0 () aphids. Increasing the temperature to 35/22 ± 1 °C resulted in a higher prey consumption by the adult predator, reaching 351.5 () and 267.7 () aphids over the same period.In conclusion, results indicated that D. tamaninii is a promising predator of the melon aphid at a temperature spectrum ranging from 15 ± 1 °C up to 35 ± 1 °C.  相似文献   
168.
Bacteria in the air of animal housing is assumed to have an impact on the health of the humans and the animals in them and on the environment. The bacterial count in poultry housing systems is particularly high in comparison to those of pigs and cattle. Little is known about the bacteria in the air of new laying hen housing systems. We therefore made simple, simultaneous measurements in the air of three different systems (enriched cages, AK; conventional battery cages, BK; aviary, VOL), in the unheated scratching area of the VOL, and in the outside air over a period of one year (24-h samples were taken about once a month using polycarbonate filters) in order to determine the general bacterial count (using blood agar). The highest concentrations of bacteria were found all year long in the VOL, followed by the BK and the AK. In the VOL, there were on average 2.16 and 0.56 x 10(6) colony forming units (cfu)/m3 in the winter and summer, respectively; 0.25 and 0.38 in the BK; and 0.39 and 0.12 in the AK. These preliminary results show that air quality considerations should be included in the development and implementation of new housing systems, as should the impact on the respiratory system of the humans and animals in them and on the environment, because high concentrations of air contamination in the housing generally also lead to high emissions into the vicinity of the facility, the significance of which cannot always be estimated, as has recently been shown for antibiotics in the exhaust air from animal housing.  相似文献   
169.
Using ELISA to determine whether cowpea mild mottle virus (CMMV) was present in soybean and groundnut seeds, the virus was not detected in 4144 seeds harvested from seven CMMV-infected soybean genotypes and in 214 seeds collected from CMMV-infected groundnut plants (cv. Gajah). These results, together with those of other researchers, suggest that, under the conditions tested, CMMV is not transmitted by seed. This in contrast to what is generally accepted and published in reviews.  相似文献   
170.
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