Investigation of Genomic Variability of Xanthomonas Arboricola Pv. juglandis by AFLP Analysis

Xanthomonas arboricola pv. juglandis is the causal agent of walnut blight, one of the most important and widespread diseases of Persian (English) walnut (Juglans regiaL.), causing severe damage to leaves, twigs and nuts. To investigate the genomic variability of X. arboricolapv. juglandis, 66 isolates obtained from different countries (England, France, Italy, The Netherlands, Romania, Spain, USA, and New Zealand) were analysed using the Amplified Fragment Length Polymorphism (AFLP) technique. EcoRI and MseI were used as restriction endonucleases. Primers with a core sequence including endonuclease recognition sites and a 3^prime-terminal cytosine selective base for MseI primer, or no selective base for EcoRI primer, were used. Data were analysed by means of a multiple correspondence analysis. A total of 76 amplified polymorphic DNA fragments were used to compute relationships among isolates. The AFLP profiles of X. arboricola pv. juglandis isolates appeared to be reliably distinguishable from X. arboricola pv. pruni and X. arboricola pv. corylina, and from other Xanthomonas species, i.e. X. campestris pv. campestris, X. fragariae, X. hortorum, X. axonopodis pv. vesicatoria. Though this pathogen is associated with one single host genus, a high level of genomic diversity was found. This diversity might be partly explained by the geographic origin. Nevertheless, isolates with different patterns were collected within one country, and similar molecular patterns were found in isolates collected at different sites. However, genetic diversity might be influenced by exchanging vegetative material from different countries. Mixing of X. arboricola pv. juglandis isolates might have partly concealed the influence of the geographic location from which the bacteria were isolated.     

核桃新品种‘中核短枝’

 ‘中核短枝’核桃是1965 年从新疆引入的早实核桃中通过种子实生选种，经40 多年选育出 来的新品种。树势中庸，枝条节间短而粗；果实生育期125 d，果实近圆柱形，平均坚果质量15.1 g，壳 厚0.9 mm，核仁乳黄色，味香，出仁率65.8%；优质高产，适应性广，在抗黑斑病和冬季冻害方面具有 较强的抗逆性。     

早熟薄皮核桃新品种‘双早’

 ‘双早’是以‘云新7926’为母本，四川乡土核桃‘夏早’为父本杂交育成的早实核桃新品种。坚果壳薄（0.69 mm），光滑。平均单果质量11.3 g，出仁率55.4%，粗脂肪含量68.84%，粗蛋白含量20.74%。4年生树冠投影面积坚果产量达465 g · m^-2。     

三个美国果用黑核桃品种在新疆喀什的引种研究

对3个美国果用黑核桃品种Emma K、Sauber、Football进行了为期3 a的引种观察试验。结果表明:3个品种在新疆喀什生长结果正常,且具有早果、大果、出仁率高的特点;3个品种中Emma K的出仁率最高(达38.7%)、果壳最薄、且最易取仁,综合性状最优;初步认为这3个美国果用黑核桃品种可以适应新疆喀什地区的气候条件。     

核桃树1年生幼苗的室内嫁接技术

详细介绍了核桃1年生幼苗室内嫁接技术,规范了该嫁接技术的时间、方法和接后管理要求。该技术为省内外核桃的优良品种繁育具有广泛的指导意义。     

An integrated spatial assessment of the investment potential of three species in southern Ontario, Canada inclusive of carbon benefits

This study explores the economic feasibility of several long-rotation afforestation scenarios for southern Ontario, Canada. Three species, red pine (Pinus resinosa Ait.), Norway spruce (Picea abies L.) and black walnut (Juglans nigra L.) are examined. We integrate growth and yield models, site suitability maps, and several management scenarios to investigate the investment attractiveness of these species inclusive and exclusive of carbon sequestration values. We report net present values (NPV), internal rates of return (IRR) and two break-even price metrics. For wood value only scenarios the IRRs range from 4.3 to 4.6% for red pine and 3.4–3.6% for Norway spruce (for the most attractive 10,000 ha, in a single rotation scenario). Black walnut had rates of return 3.5–3.7% for the most attractive 10,000 ha area. Adding carbon valued at Cdn $3.4 per metric ton CO_2 − e (roughly 2005 prices in the Chicago Climate Exchange) increases rates of return by about 0.6% for red pine and Norway spruce and 0.4% for black walnut scenarios. Perhaps surprisingly these returns are comparable and better than 20-year rotation hybrid poplar plantations. To achieve a 6% real rate of return break-even carbon prices were $10.7/t CO_2 − e for red pine, $12.6/t CO_2 − e for Norway spruce and $17.2/t CO_2 − e for black walnut (again for the “best” 10,000 ha). Although somewhat unremarkable, the results suggest that these longer-rotation species may be a better investment than perhaps previously expected if landowners have the appropriate site conditions.     

超临界流体萃取核桃油的研究进展

我国核桃产量居世界首位,以核桃为原料制油是深加工的主要方向之一,采用超临界CO2流体萃取技术可以生产出天然活性成分高、品质优良、具有保健功能的食用核桃油。阐述了超临界CO2流体萃取核桃油的基本原理、设备流程、技术特点和研究进展,并对应用前景进行了展望。     

Tree establishment and growth using forage ground covers in an alley-cropped system in Midwestern USA

The integration of forage crops in an alley-cropped system was examined as a method of encouraging tree planting to increase farm income, improve soil quality, and enhance biodiversity on Midwestern U.S. farms. Crop and tree performance were evaluated in an alley-cropped system using four forage intercrops grown in tree alleyways to simulate a potential hay crop – oat (Avena sativa L.) and red clover (Trifolium pratense L.); oat, red clover, and red fescue (Festuca rubra L.); oat, red clover, and orchardgrass (Dactylis glomerata L.); and oat and hairy vetch (Vicia villosa Roth) – compared to a herbicide, mowing and control (no management) treatment. Five tree species, divided into fast-growing hardwoods of two poplar (Populus spp.) clones [Crandon (P. alba L. × P. grandidentata Michx.) and Eugenei (P. deltoids Bartr. × P. nigra L.)], and silver maple (Acer saccharinum L.) were compared with two high-value, slow-growing hardwoods planted from seed and as seedlings: red oak (Quercus rubra L.) and black walnut (Juglans nigra L.). Tree survival in the first year was greater for the fast-growing species, and by the fourth year, tree height among the four forage treatments was equivalent for all upland locations. The oat/hairy vetch ground cover was associated with the shortest trees in the bottomland site. Herbicide-treated trees were taller than the average of the four forage treatments for all four planting conditions. Tree height in the mowing and the control treatments was not significantly different for all four planting conditions. The nutritive value of the forage crop was excellent in the second year of tree establishment, with crude protein content and digestibility at 17 and 71%, respectively, in the oat/red clover/red fescue treatment, suggesting the viability of forage crops as alternatives to herbicides in alley-cropped systems.     

不同提取条件对核桃叶中抗病毒物质活性的影响

植物病毒病给农业生产造成极大的损失.据统计,全世界每年仅烟草花叶病毒(tobacco moscaic virus,TMV)造成的损失就达1亿美元以上(吴云峰,1995).