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1.
The aim of this study was to reduce the length of the breeding cycle for faba bean by accelerating seed setting. We examined the mode and time of exogenous 6-benzylaminopurine (BAP) (cytokinin) application, and cold treatments and their combinations in two faba bean genotypes. Acropetal node number of pod and seed set and pollen viability were recorded during the experiments. Application of BAP improved pollen germination. The application of 10–5 M BAP 4 days after flowering increased seed set at the lower nodes. Cold treatment (8/4°C day/night for 2 days) after the onset of flowering induced the formation of more pods and faster pod set compared to the non-cold treatment. The time to first seed was significantly reduced, and pollen viability was increased in plants exposed to cold treatment. Increased pollen viability also showed a significant positive correlation with seed setting. The combinations of 10–5 BAP and cold treatment together had similar and independent effects. These results will accelerate plant breeding in faba bean by providing additional tools for reducing generation time.  相似文献   
2.
Trunk disease is a major problem on grapevine in Zanjan province, causing serious decline, despite which its aetiology remains unknown. The purpose of this study was to investigate factors involved in grapevine decline in vineyards of Zanjan province. Samples were collected from twigs and branches of grapevines in the region between October and November 2018. Fungal isolates were identified based on morphological characteristics and ITS-rDNA sequence data for selected isolates. The frequency and diversity of the fungal community recovered from grapevines in Darreh Sejin in Zanjan province were higher than in other regions. A total of 112 fungal isolates comprising 22 species were recovered. Phaeoacremonium minimum, Microsphaeropsis olivacea and Kalmusia variispora were identified as the dominant species in the region examined and could be considered the main trunk pathogens of grapevines in Zanjan region. In inoculation tests, M. olivacea was proved to be pathogenic on grapevine for the first time in this study.  相似文献   
3.
The parasite of genus Sarcocystis is one of the most commonly found parasite in domestic animals worldwide. Some species of Sarcocystis cause important economic loss when causing clinical and sub clinical disease. The aim of this study was to determine the prevalence of Sarcocystis in slaughtered Cattle in Kerman, Iran. The prevalence of Sarcocystis spp. infection was investigated in 480 cattle, slaughtered from May 2005 to February 2006 in the Kerman, Iran using naked eye examination for macroscopic Sarcocysts, and peptic digestion, muscle squash, squeezing methods for microscopic types. Muscles from heart, tongue, and esophagus, cervical and abdominal muscles of 480 slaughtered cattle were examined for Sarcocystis cysts. The prevalence of microscopic Sarcocystis cysts in cattle was detected in 100% and there was no macroscopic cyst in examined cattle.  相似文献   
4.
The accumulation of inbreeding and the loss of genetic diversity is a potential problem in Holstein dairy cattle. The goal of this study was to estimate inbreeding levels and other measures of genetic diversity, using pedigree information from Iranian Holstein cattle. Edited pedigree included 1 048 572 animals. The average number of discrete generation equivalents and pedigree completeness index reached 13.4 and 90%, respectively. The rate of inbreeding was 0.3% per year. Effective number of founders, founder genomes, non‐founders and ancestors of animals born between 2003 and 2011 were 503, 15.6, 16.1 and 25.7, respectively. It was proven that the unequal founder contributions as well as bottlenecks and genetic drift were important reasons for the loss of genetic diversity in the population. The top 10 ancestors with the highest marginal genetic contributions to animals born between 2003 and 2011 and with the highest contributions to inbreeding were 48.20% and 63.94%, respectively. Analyses revealed that the most important cause of genetic diversity loss was genetic drift accumulated over non‐founder generations, which occurred due to small effective population size. Therefore, it seems that managing selection and mating decisions are controlling future co‐ancestry and inbreeding, which would lead to better handling of the effective population size.  相似文献   
5.
Ranked set sampling is a sampling approach that could lead to improved statistical inference when the actual measurement of the variable of interest is difficult or expensive to obtain but sampling units can be easily ordered by some means without actual quantification. In this paper, we consider the problem of bootstrapping an unbalanced ranked set sample (URSS) where the number of observations from each artificially created stratum can be unequal. We discuss resampling a URSS through transforming it into a balanced RSS and extending the existing algorithms. We propose two methods that are designed to obtain resamples from the given URSS. Algorithms are provided and several properties, including asymptotic normality of estimates, are discussed. The proposed methods are compared with the parametric bootstrap using Monte Carlo simulations for the problem of testing a hypothesis about the population mean.  相似文献   
6.
BACKGROUND: The purpose of this study was to evaluate the efficiency of intracytoplasmic sperm injection (ICSI) and Piezo-assisted sperm injection after pretreatment with calcium ionophore (CaI) on the mouse embryo development. METHODS: In this study, the conventional ICSI and Piezo-ICSI procedures were used. The efficacy of the methods was examined after mouse matured oocytes were fertilized with or without CaI-treated sperms. RESULTS: Piezo-ICSI demonstrated significantly more favorable results, with a fertilization rate of 64% (conventional ICSI: 42%, P<0.001) and a cleavage rate of 73% (conventional ICSI: 58%, P<0.05). When the Piezo-ICSI procedure was performed with CaI-pretreated sperms, the cleavage rate significantly increased (92% vs. 73%, P<0.05). However, the fertilization rate did not change significantly (64% vs. 56%). CONCLUSION: The Piezo-ICSI accompanies with CaI-treated sperms is more efficient than the conventional ICSI method for fertilizing and thus obtaining more mouse embryos.  相似文献   
7.
BACKGROUND: The present study describes the quantitative changes in herbicide use during the specific observation periods in the Wheat Self-sufficiency Project in Iran from 1994 to 2004 and the associated changes in herbicide risk, area and yield in this context. A risk index, the environmental impact quotient (EIQ), was used to estimate the environmental impacts (EIs) of herbicides applied to wheat agroecosystems. RESULTS: The results suggest that, during this period, the overall risk posed by the herbicides applied to wheat agroecosystems increased substantially, as evidenced by a 71% increase in herbicide usage (weight of pesticide applied) and a 62.2% increase in EI rating, in spite of an 8.2% decrease in overall EIQ rating and an 89.2% decrease in mean application rate. Furthermore, a 0.57% increase in the area and a 23.6% and 22.7% increase in irrigated and rainfed yields, respectively, were observed. The results also indicate that the EIQ(FUR) of two herbicides, dichlorprop-P/mecoprop-P/MCPA and difenzoquat, is much higher than that of other herbicides, and they could be qualified as high-risk herbicides. CONCLUSION: As a whole, an increase in herbicide usage (weight of pesticide applied) was an important factor on herbicide environmental impact boost. However, this increase has not led to a similar increase in wheat yield, which could be attributed in part to the negative impact of high herbicide consumption in wheat fields and subsequent threat to the long-term sustainability of these agroecosystems.  相似文献   
8.
Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. Though many factors are involved in the evolution of resistance, the proportion of the parasite population under drug selection is believed to be the single most important factor influencing how rapidly resistance develops. Therefore, where prevention of resistance is an important parallel goal of worm control, it is recommended to leave a portion of the animals untreated. Recently, a novel system called FAMACHA was developed in South Africa, which enables clinical identification of anemic sheep and goats. When H. contortus is the primary parasitic pathogen, this system can be applied on the farm level to reduce the number of treatments administered, thereby increasing the proportion of the worm population in refugia. Since most studies validating the FAMACHA method have been performed in South Africa, it is important that the method be tested in other regions before its use is broadly recommended. We performed a validation study of FAMACHA by testing the system in sheep (n = 847) and goats (n = 537) of various breeds and ages from 39 farms located in Arkansas, Georgia, Louisiana, Florida, and the US Virgin Islands. The color of the ocular conjunctiva of all animals were scored on a 1-5 scale using the FAMACHA card, and blood samples were collected from each animal for determination of packed cell volume (PCV). Fecal samples were also collected from a majority of the animals tested for performance of fecal egg counts (FEC). Correlations between PCV and eye scores, PCV and FEC, and FEC and eye scores were all highly significant for both sheep and goats (P < 0.001). Data for both FAMACHA scores and PCV were evaluated using two separate criteria for anemia: eye score values of 3, 4 and 5 or 4 and 5, and PCV values of < or =19 or < or =15 were considered anemic. Specificity was maximized when eye score values of 4 and 5 were considered anemic and PCV cut off for anemia was < or =19, but sensitivity was low. In contrast, sensitivity was 100% for both sheep and goats when eye score values of 3, 4 and 5 were considered anemic and PCV cut off was < or =15, but specificity was low. In both sheep and goats, predictive value of a negative was greater than 92% for all anemia and eye score categories, and was greater than 99% for both eye score categories when an anemia cutoff of < or =15 was used. Predictive value of a positive test was low under all criteria indicating that many non-anemic animals would be treated using this system. However, compared to conventional dosing practices where all animals are treated, a large proportion of animals would still be left untreated. These data indicate that the FAMACHA method is an extremely useful tool for identifying anemic sheep and goats in the southern US and US Virgin Islands. However, further studies are required to determine optimal strategies for incorporating FAMACHA-based selective treatment protocols into integrated nematode control programs.  相似文献   
9.
Inappropriate crop management and long-term use of heavy agricultural equipment can lead to soil compaction. On the other hand, soil and water salinity causes reduction in the plant yield in addition to adverse effects on plants tolerance to the various stresses. The aim of this study was to investigate the interaction between soil compaction and salinity on the macronutrients uptake and wheat yield as well as its agronomic traits. The pot experiment was carried out on the loamy soil in a completely randomized block design with three replications. The treatments consisted of two salinity types (saline, EC = 6 dS/m and non-saline soil) and five levels of compaction; control, 5%, 10%, 15% and 20%. The results showed that soil compaction had significant effect on the amount of N, P and K in wheat grain, so that the uptake of N, P and K by grain has been decreased by increasing the compaction level of soil. Soil salinity had significant effect on N, P and K content in grain that the content of N, P and K has been diminished in the saline treatments compared to non-saline treatments. Results on the agronomic traits and yield of wheat also revealed that soil compaction and salinity had significant effect (p < 0.01) on straw weight, number of ears, number of grain, and thousand grain weight which caused reduction in these parameters. The interaction between compaction and salinity had only significant correlation (p < 0.01) with thousand grain weight leading to the decrement of thousand grain weight with increasing compaction levels, particularly in the saline treatment.  相似文献   
10.
In this study, interactions of nickel sulfate and urea sprays on vegetative growth, yield and leaf mineral contents in strawberry were investigated. Rooted Pajaro strawberry plants were potted in 3 liter pots filled with soil, leaf mold and sand (1:1:1, v/v/v). Established plants were foliar sprayed with nickel sulfate at 0, 150, 300 and 450 mg L?1 and urea 0 and 2 g L?1 concentrations. Results indicated that nickel (Ni; 300 mg L?1) plus urea (2 g L?1) significantly increased the yield and runner numbers. Nickel sulfate at the rate of 300 and 150 mg L?1and urea (2 g L?1) significantly increased the crown numbers. The greatest root fresh and dry weights were obtained from untreated plants. Urea at 2 g L?1 without nickel significantly increased shoot fresh and dry weights. Nickel at 450 mg L?1 without urea significantly increased Ni concentration in leaves. Overall, nickel sulfate at 150 and 300 mg L?1 along with urea at 2 g L?1 were the best treatments.  相似文献   
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