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排序方式: 共有618条查询结果,搜索用时 15 毫秒
101.
102.
Summary

When strawberries (Fragaria ananassa Duch.) are produced in a greenhouse, usually two crops a year are obtained; in the fall and in the spring. To increase productivity, new cultivation techniques are needed. The aim of this study was to examine the effect of daylength treatments on the performance of strawberry plants to improve plant production protocols. The possibility of obtaining two successive crops during forcing was explored by exposing plants of cultivar Korona to two successive short day (SD) treatments followed by cold storage. The following daylength treatments were studied: 3 wk SD + 2 wk long day (LD) + 3 wk SD (3SD2LD3SD), 3 wk SD + 4 wk LD + 3 wk SD (3SD4LD3SD), and 10 wk SD (10SD). In addition, crown branching was studied in plants subjected to SD treatments. Two successive SD treatments enabled two successive flowering and cropping periods during greenhouse forcing after eight weeks of cold storage.The first SD treatment caused crown branching and induced flowering in the apical meristem of the main-crown and in the oldest axillary meristem(s), whereas younger axillary meristems were induced during the second SD treatment. Marketable yield and the number of inflorescences were comparable in 3SD4LD3SD and 10SD, but considerably lower in 3SD2LD3SD. However, this study demonstrated the high cropping potential of artificially SD treated plants, which makes them a potential alternative for greenhouse strawberry cultivation. Multi-crowned plants of ‘Korona’ can be produced by subjecting young plants to a three week SD treatment, and crown branches can be induced to flowering by a new SD treatment resulting in a very high cropping potential. Induced plants can be stored at –1°C for later forcing.  相似文献   
103.
Summary

The characterisation of sweet cherry (Prunus avium L.) genetic resources in Turkey may help to increase their use in breeding programmes worldwide, as Turkey is the centre of origin of sweet cherry. Amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers were therefore used to analyse genetic diversity among a total of 78 local and introduced sweet cherry cultivars. Four AFLP primer combinations, and six SSR primer pairs for sweet cherry were used for genetic diversity analysis. A genetic similarity matrix was calculated using the combined data from AFLP and SSR analyses with simple matching coefficient. Genetic similarities among the sweet cherry genotypes studied were higher than 42%. No two accessions had an identical AFLP and SSR marker profile, indicating that all 78 genotypes were unique. An UPGMA dendrogram, based on the similarity matrix, revealed 18 separate Groups at or above the 70% similarity level. While some Groups consisted of both introduced and local genotypes, other Groups had only local genotypes. This result suggests that there was broad genetic diversity among the local Turkish sweet cherry genotypes, which was not present in the introduced sweet cherry accessions. The genetic variation present in local Turkish sweet cherry genotypes may be useful for future breeding programmes. We found that the use of both SSR and AFLP marker systems was effective for distinguishing between genetically-close sweet cherry genotypes. These marker systems can be used to complement pomological and morphological markers during the characterisation and identification of sweet cherry genotypes.  相似文献   
104.
The aim of this study was to determine the changes in diameter of corpus luteum (CL), maternal progesterone (P) concentration, lipid peroxidation and non‐enzymatic antioxidant levels along with enzymatic antioxidant activities in pregnant ewes bearing single and twin foetuses. The ewes were selected from healthy animals that were brought to the abattoir for slaughtering. The ewes were divided into three groups: Group 1 (non‐pregnant, non‐oestrous, n = 30), Group 2 (pregnant bearing a single foetus, n = 30) and Group 3 (pregnant bearing twin foetuses, n = 12) after they were slaughtered. Pregnant ewes were in the first half of the pregnancy. The diameter of CL and P concentration of pregnant ewes bearing a single foetus or twin foetuses were found higher than that found in non‐pregnant ewes. Similarly, the P concentration of pregnant ewes bearing twin foetuses was higher than that found in pregnant ewes bearing a single foetus. Malondialdehyde (MDA) level in pregnant ewes bearing twin foetuses was higher than that found in both non‐pregnant and pregnant ewes bearing a single foetus. The serum glutathione (GSH) level and glutathione‐peroxidase (GSH‐Px) activity of pregnant ewes bearing twin foetuses were found lower than that found in non‐pregnant ewes. Additionally, the GSH‐Px activity of pregnant ewes bearing twin foetuses was found lower than that found in pregnant ewes bearing a single foetus. No significant difference was found between pregnant ewes bearing female and male foetus with respect to diameter of CL, P concentration and oxidative stress parameters. There were significant positive correlations between foetal number (0, 1, 2) and diameter of CL, P concentration, MDA level, and between P concentration and diameter of CL, MDA level. However, significant negative correlations were found between foetal number (0, 1, 2) and GSH level, GSH‐Px activity, and between P concentration and GSH‐Px activity. In conclusion, the diameter of CL enlarges, P production increases and oxidant/antioxidant balance impairs because of the gestation stress in ewes during pregnancy.  相似文献   
105.
The aim of this study was to determine the fattening performance and the slaughter and carcass characteristics of Akkeçi (Saanen × Kilis (B1) crossbred) male kids raised in individual crates (IC) or in group pen housing (GP). In both GP and IC groups, total 13 heads of male kids, whose initial body weights were 21.43 ± 1.03 kg and 20.61 ± 0.98 kg, respectively, evaluated for their fattening performances. After 56 days of the fattening period, the final body weights and average daily weight gains of the GP and IC kids were recorded as 30.84 ± 0.82 kg and 25.84 ± 0.76 kg; 182.42 ± 14.77 g and 92.09 ± 13.76 g, respectively (P < 0.001). Adrenal gland weights of the GP and IC groups were similar as 1.66 ± 0.25 g and 1.77 ± 0.22 g, respectively. Although, the carcass conformation of kids was similar between groups, there were significant differences between GP and IC groups for some slaughter and carcass characteristics. In general, although housing kids reared in individual crates provides opportunity to individually feed and monitor a kid, the results obtained from the individual crates in the present study were not satisfactorily from the ethological and production points of view.  相似文献   
106.
The effects of vitamin E and vitamin E-selenium combination on seminal plasma arginase activity and nitric oxide level and some spermatological properties in rams were investigated in this study. For control group, animals were injected intramuscularly with physiological saline. For vitamin E group, rams were injected intramuscularly with 300 mg/ram vitamin E. For vitamin E + selenium group, animals were injected intramuscularly with 5 ml/ram vitamin E + selenium. The semen was collected by artificial vagina at 1st, 4th, 24th, 48th and 72nd hr after administration in each group. Significant decreases in seminal plasma arginase activity (at 1st, 24th and 48th hr), nitric oxide level (at 72nd hr) and abnormal sperm rate (at 1st, 24th and 72nd hr), and significant increases in semen volume (at 24th hr), semen mass activity (at 24th and 48th hr), sperm motility (at 24th, 48th and 72nd hr) and concentration (at 1st hr) were observed in vitamin E group compared with control group. Similarly, significant increase in semen volume (at 1st, 24th and 48th hr), mass activity, (at 48th hr), motility (at 48th and 72nd hr) and concentration (at 4th, 24th and 48th hr), and significant decrements in abnormal sperm rate (at 1st, 24th, 48th and 72nd hr), seminal plasma nitric oxide level (at 1st, 4th, 24th and 48th hr) and semen pH (at 24th and 48th hr) were detected in vitamin E + selenium group in comparison to the control group. As a result, it is suggested that vitamin E and/or vitamin E + selenium applications may improve reproductive performance.  相似文献   
107.
108.
Kosovo, one of the countries in the Balkan Peninsula, has a long tradition in sheep farming, and sheep breeds share triple purpose breed characteristics: milk, meat and wool. Bardhoka sheep, also with triple productive profile, is an important sheep breed because of its economic value with its milk production. In this study, 24 mandibles of adult Bardhoka sheep (12 male and 12 female) aged between 2 and 5 were used. The sheep were acquired from slaughterhouse around Kosovo, and the mandibles were selected without any deformities from healthy sheep. After cleaning the mandibles, a total of 12 morphometric measurements were taken from each sample using digital calliper. The difference between female and male was statistically significant (p < .05) for measurement 11 (height of mandible level of alveolar edge of 3rd molar tooth). The mean value of measurement 11 in male individuals was 42.26 ± 3.96, and it had a higher value than in female individuals (39.37 ± 2.57). In the literature, knowledge related to mandible morphometry of Bardhoka sheep was insufficient. The aim of this study was to determine mean values from osteometric measurements of Bardhoka sheep mandible and obtain references with the values acquired.  相似文献   
109.
Abstract

It has been proposed that salicylic acid (SA) acts as an endogenous signal molecule responsible for inducing environmental stress tolerance in plants. In this study, the effects of seed soaked (1.0 mM for 24 h) and soil incorporated (0.1 mM and 0.5 mM) salicylic acid (SA) supply on growth and mineral concentrations of maize (Zea mays L., Hamidiye F1) grown under either salt, boron toxicity or drought-stressed conditions were investigated. Exogenously applied SA either with seed soaked (SS) or soil incorporated (SI) increased plant growth significantly in all the stresses conditions. Salicylic acid inhibited Na and Cl accumulation in saline conditions, and 0.5 mM of soil incorporated SA decreased B significantly in boron toxicity treatment. Except in drought condition, SA treatments stimulated N accumulation in plants. And P, K, Mg and Mn concentrations of SA received plants were increased in the stress conditions. These results suggest that SA regulates the response of plants to the environmental stresses and could be used as a plant growth regulator to improve plant growth and stimulate mineral nutrient concentrations under stress conditions.  相似文献   
110.
Cultivated wheat, (Triticum aestivum L.), is one of the most important food crops in the world. The Aegilops L. genus is frequently utilized by plant breeders for improving the current wheat cultivars due to their close relationships. Therefore, understanding the phylogenetic relationships among the species of these genera is not only valuable for plant taxonomy, but also for plant breeding efforts. The presented phylogenetic analysis was based on the sequences of trnT-F chloroplast DNA containing three non-coding sub-regions. Twelve genotypes belonging to four species of Triticum L. genus and twenty-four genotypes belonging to eight species of Aegilops genus were used in the current study. The results postulated a close genetic relationship between diploid Aegilops species containing the BB genome and polyploid Triticum species. With the exception of Aegilops cylindrica Host (CCDD), all other Aegilops species having the CC genome were alienated from Aegilops speltoides Tausch (BB) and clustered together. These two clusters joined by a third cluster including the AA genome containing diploid Triticum species.  相似文献   
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