南德温牛的种用特性研究

对纯种南德温牛的体尺、外貌、肉用指数、生产和繁殖性能、杂交效果及肉质等方面指标进行统计分析,这些特性的研究,对南德温牛种群的保种、扩繁、利用具有重要意义。

Varietal Characteristics and Nutrition Characteristics of Several New Varieties of High Biomass Sugarcanes for Sugar and Energy

[Objective] The aim was to study the varietal characteristics of six new varieties of high biomass sugarcanes for sugar and energy namely GT02-833,GT97-69,GT02-351,GT03-2287,B9 and GT02-770,as well as the nutrition characteristics of them under drip irrigation conditions. [Method] Industrial and agronomic characters,total N,total P,total K and chlorophyll content were determined. [Result] Cane yield,total biomass yield and sugar content of six varieties were more than 180,200 and 25 t/hm2 respectively,which were higher than that of the control Xintaitang 22. The total nitrogen and total phosphorus contents of six varieties were high and persistent from Jul to Nov,but they decreased sharply in Dec. Total potassium content of all varieties increased from Jul to Dec. Chlorophyll content of all varieties were high from Aug to Oct,but they decreased sharply in Nov. Total nitrogen,total phosphorus and total potassium content of GT02-833,GT97-69 and B9 were higher than that of CK. [Conclusion] GT02-833,GT97-69 and B9 had characteristic of efficient use of nutrients,thus should be extended as elite varieties.

提高羔羊成活率的措施

羔羊是指从出生到断奶这段时间的幼龄羊。羔羊出生后，因其各个器官发育尚不健全，调解机能差，适应能力弱。是比较难养的时期，如果管理不当，不仅影响其成活率，而且很难发挥其应有的种用特性，所以这个时期是养好羔羊的关键时期。

Interactions between Soil Characteristics, Environmental Factors, and Plant Species Abundance: A Case Study in the Karst Mountains of Longhushan Nature Reserve, Southwest China

The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables.Understanding this response requires examining factors or their interactions that have influence on plant and resource availability.Our objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological(rock type), and other environmental variables in the Longhushan karst mountains ecosystem.Species density and dominance were examined using ANOVA, ANCOVA,and Generalized Linear Models to establish the single or combined effects of these groups of factors.The results showed that trends in abundance were mainly affected by rock type(related to the percentage content of dolomite and calcite), soil characteristics in association with topography.Both plant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope degree.The results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, andenvironmental factors, suggesting their interaction influence on plants.We postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and temperature.The study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.

Methods of Testing Seed and Seedling Physiological Traits for the Improvement of Rapeseed Yield Stability

The presented work is based on laboratory testing of seed germination speed, emergence and seedling growth under different stress conditions simulated by subnormal water revel, extreme high and low temperatures. It allows one to eliminate the plant materials （initial breeding materials and cultivars） which do not tolerate extreme temperatures and temperature changes during germination, have low water use efficiency and is intolerant to abiotic stressors all right at the seed level. It was confirmed that these genotypes also have poor t^eld emergence and initial root growth implications for further vegetation periods, mainly for over wintering and spring regeneration which has significant influence on the yield. The method also represents the tool for screening genetic resources with the resistance to the abiotic stressors and this technology process is also acceptable for other crops. The results confirm the importance of the seed and root characteristics for crop production. The deteriorating quality of soil in recent years, increasing variability of weather and long periods of drought directly support the need to intensify activities in this research. Obtained results also show the influence of seed quality characteristics on roots and above ground parts of the plant. A relationship exists also vice versa.

Seasonal dynamic variation of pollination network is associated with the number of species in flower in an oceanic island community

Aims Plant-pollinator interaction networks are dynamic entities,and seasonal variation in plant phenology can reshape their structure on both short and long timescales.However,such seasonal dynamics are rarely considered,especially for oceanic island pollination networks.Here,we assess changes in the temporal dynamics of plant-pollinator interactions in response to seasonal variation in floral resource richness in oceanic island communities.Methods We evaluated seasonal variations of pollination networks in the Yongxing Island community.Four temporal qualitative pollination networks were analyzed using plant-pollinator interaction data of the four seasons.We collected data on plant-pollinator interactions during two consecutive months in each of the four seasons.Four network-level indices were calculated to characterize the overall structure of the networks.Statistical analyses of community dissimilarity were used to compare this community across four seasons to explore the underlying factors driving these patterns.We also evaluated the temporal variation in two species-level indices of plant and pollinator functional groups.Important Findings Both network-level specialization and modularity showed a significantly opposite trend compared with plant species richness across four seasons.Increased numbers of plant species might promote greater competition among pollinators,leading to increased niche overlap and causing decreased specialization and modularity and vice versa.Further analyses suggested that the season-to-season turnover of interactions was dominated by interaction rewiring.Thus,the seasonal changes in niche overlap among pollinators lead to interaction rewiring,which drives interaction turnover in this community.Hawkmoths had higher values of specialization and Apidae had higher values of species strength compared with other pollinator functional groups.These findings should be considered when exploring plant-pollinator interactions in ecosystems of isolated oceanic islands and in other ecosystems.