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1.
Accurate hybrid prediction and knowledge about the relative contribution of general (GCA) and specific combining ability (SCA) are of utmost importance for efficient hybrid breeding. We therefore evaluated 91 triticale single-cross hybrids in field trials at seven environments for plant height, heading time, fresh biomass, dry matter content and dry biomass. Fresh and dry biomass showed the highest proportion (23%) of variance due to SCA. Prediction accuracies based on GCA were slightly higher than based on mid-parent values. Utilizing parental kinship information yielded the highest prediction accuracies when both parental lines have been tested in other hybrid combinations, but still moderate-to-low prediction accuracies for two untested parents. Thus, hybrid prediction for biomass traits in triticale is currently promising based on mid-parent values as emphasized by our simulation study, but can be expected to shift to GCA-based prediction with an increasing importance of GCA due to selection in hybrid breeding. Moreover, the performance of potential hybrids between newly developed lines can be predicted with moderate accuracy using genomic relationship information.  相似文献   
2.
Environmental conditions influence phenology and physiological processes of plants. It is common for maize and sorghum to be sown at two different periods: the first cropping (spring/summer) and the second cropping (autumn/winter). The phenological cycle of these crops varies greatly according to the planting season, and it is necessary to characterize the growth and development to facilitate the selection of the species best adapted to the environment. The aim of this study was to characterize phenological phases and physiological parameters in sorghum and maize plants as a function of environmental conditions from the first cropping and second cropping periods. Two parallel experiments were conducted with both crops. The phenological characterization was based on growth analyses (plant height, leaf area and photoassimilate partitioning) and gas exchange evaluations (net assimilation rate, stomatal conductance, transpiration and water-use efficiency). It was found that the vegetative stage (VS) for sorghum and maize plants was 7 and 21 days, respectively, longer when cultivated during the second cropping. In the first cropping, the plants were taller than in the second cropping, regardless of the crop. The stomatal conductance of sorghum plants fluctuated in the second cropping during the development period, while maize plants showed decreasing linear behaviour. Water-use efficiency in sorghum plants was higher during the second cropping compared with the first cropping. In maize plants, in the second cropping, the water-use efficiency showed a slight variation in relation to the first cropping. It was concluded that the environmental conditions as degree-days, temperature, photoperiod and pluvial precipitation influence the phenology and physiology of both crops during the first and the second cropping periods, specifically cycle duration, plant height, leaf area, net assimilation rate, stomatal conductance and water-use efficiency, indicating that both crops respond differentially to environmental changes during the growing season.  相似文献   
3.
Journal of Crop Science and Biotechnology - The cultivation of sweet corn is expanding in Brazil, but there are serious constraints about the availability of commercial cultivars. The selection of...  相似文献   
4.
New Forests - Adventitious rooting (AR) is an obligatory step for vegetative propagation of commercial woody species. Paper industries have interest in Eucalyptus globulus Labill and its hybrids...  相似文献   
5.
山羊肺淋巴系的研究   总被引:2,自引:0,他引:2  
24例山羊肺经肺实质和肺胸膜下注射30%普鲁士蓝氯仿溶液,剖查其器官内淋巴管及淋巴流向。结果表明,山羊肺的器官内淋巴管有浅淋巴管和深淋巴管2种。左肺尖叶淋巴管注入左支气管肺淋巴结和气管支气管左淋巴结,左肺心叶淋巴管注入左支气管肺淋巴结、气管支气管左淋巴结和气管支气管中淋巴结,左肺膈叶淋巴管注入气管支气管左淋巴结、气管支气管中淋巴结和纵隔后淋巴结;右肺尖叶淋巴管注入右支气管肺淋巴结和气管支气管前淋巴结,右肺心叶淋巴管注入右支气管肺淋巴结和气管支气管右淋巴结,右肺膈叶淋巴管注入气管支气管右淋巴结、气管支气管中淋巴结和纵隔后淋巴结,右肺副叶淋巴管注入右支气管肺淋巴结、气管支气管中淋巴结和纵隔后淋巴结。  相似文献   
6.
To determine whether turkey herpesvirus (HVT) impairs the aspecific and specific defense against an avian pneumovirus (APV) infection, specific-pathogen-free turkeys were inoculated at 7 days of age with HVT and 1, 5, or 7 wk later with APV. Clinical signs, APV replication, and development of antibodies against APV were evaluated. No differences were found between the birds that received both HVT and APV and those that received only APV.  相似文献   
7.
8.
Summary Acute febrile diseases are characterized by specific and non-specific symptoms. The non-specific responses are presented under the headings: fever, inflammation and pain, experimental models for investigating febrile reactions, haematologic changes, blood biochemical changes, cardiovascular effects, changes in gastric function, and the effects of fever upon pharmacokinetics of drugs. It was the purpose of this review to describe present concepts of thermoregulation and fever, the associated reactions produced by bacterial pyrogens and the mechanisms of these reactions. The available data illustrate, that many questions have not yet been clearly answered. However, the entire field of research involving endogenous substances, such as interleukin-1, is now moving ahead with great speed. Furthermore, there is some evidence which suggests that fever and the associated lower plasma zinc and iron levels act together as a co-ordinated non-specific host defence mechanism. Since experimental fever has a distinct effect upon the pharmacokinetics of drugs, more attention should be given to this aspect.  相似文献   
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10.
A survey on coccidial infections in goats from central Spain was carried out. Fifty-five goat farms from 28 localities belonging to the three bioclimatic subregions of the area were visited. Individual samples (702) were obtained from the rectum of 130 young (under 1 year of age) and adult (572 over 1 year of age) goats. Coproscopical analyses showed a 100% prevalence and a moderate average intensity (7606.48 +/- 17918.78 Eimeria oocysts per gram of faeces), although wide variations were seen among herds and among individuals within each goat flock. Statistical analysis showed a strong age-related reduction in oocysts output in goats up to 4 years of age. The intensity of coccidial infections (young and adult goats, herds) was independent of the prevailing bioclimatic conditions. Heavier infections in young goats were found in bigger herds, whereas adult goats from these same big flocks (over 300 animals) showed the lowest oocyst output. Under our conditions, neither the female restocking rate nor the age structure seemed to play a significant role in the intensity of the Eimeria infections.  相似文献   
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