我国“海上丝绸之路”考察纪要

由广东省政府参事室、广东省政府文史研究馆、广东珠江文化研究会共同组织,广东省丝绸(集团)公司协办,以省政府参事室副主任周义为团长的“海上丝绸之路”专家考察团一行19人于今年3月5日至11日先后到湛江市、徐闻县、雷州市和阳江市进行实地考察,现将考察的主要情况纪要如下:     

Factors influencing female home range sizes in elk (<Emphasis Type="Italic">Cervus elaphus</Emphasis>) in North American landscapes

Home range size is a result of individual movements and the spatial distribution of a population. While body size, sex, and age are known to influence the area over which an animal ranges, it remains uncertain how landscape heterogeneity influences home range size. We examined elk (Cervus elaphus) seasonal home range sizes in relation to the quantity and spatial heterogeneity of forage biomass, forest cover, topography, snow–water equivalents, and landscape structure in three study landscapes: Yellowstone National Park, Wyoming, USA; eastern slopes of the Canadian Rockies, Alberta; and northern Wisconsin, USA. We used a 95% fixed kernel estimator to measure the home range size and location of all elk. To identify the scales at which important factors influenced home range sizes, we quantified environmental variables within the estimated home range polygon and within concentric circles with radii of 1000, 2000, 3000, 4000, and 5000 m from the home range center. Results indicate that there was an inverse relationship between forage biomass and summer and winter home range sizes in Alberta and Wisconsin, however the relationship was positive in Yellowstone. The size of summer and winter home ranges was positively related to percent forest cover; however this relationship was significant only when forest cover was quantified within the home range polygon or radii that were greater than or equal to 3000 m. Winter home ranges also had a positive relationship with snow–water equivalents. The predictive strength of summer home range models was greatest when landscape variables were quantified within the concentric circles with a radius of 3000 m or more, whereas the predictive strength of the winter models was greatest within the estimated home range polygon. Results suggest that elk ranging patterns reflected complex trade-offs that affect foraging, group dynamics, movement energetics, predation avoidance and thermal regulation. The multi-scale analysis indicates that elk based home ranging decisions on an area equal to their home range, but areas outside of the estimated home range were also important.     

被子植物二倍体孢子生殖在杂种优势固定中的实用价值探讨

根据大孢子母细胞的发育特性,将被子植物的二倍体孢子生殖分为８种类型,不同类型的胚胎学机制各不相同,从固定生物杂种优势的角度来看,只有薄公英型、苦荚菜型、委陵苹型和蝶须型这４种二倍体孢子生殖类型能保持亲子代之间的遗传稳定性,因而具有实用价值。     

河北省N38°滨海冲积海积平原水域空间差异

对河北省N38°冲积海积平原内地下水水位、水质及贮存条件,河流、水库水质的空间变异以及这些变异给生态环境造成的影响等进行了调查研究.结果表明,河北省N38°滨海冲积海积平原距海岸线30km范围内淡水资源缺乏,区内浅层地下水、河流、水库水质均受海水的不同程度侵染,其中氯离子浓度严重超标.深层地下淡水和天然降水是该区主要淡水资源.     

穗肥施用时期对水稻产量及群体质量的影响

采用迟熟中粳稻品种和杂交中籼稻汕优组合 ,进行穗肥施用时期试验。结果表明 :合理施用穗肥 ,利于控制抽穗期群体干物质适宜值、提高抽穗至成熟期的干物质生产量 ,利于提高有效、高效叶面积率 ,增加根系活力 ,提高颖花根活量 ,最终提高结实率和实粒数 ,获得高产。在当前推广品种中 ,在取得适宜穗数条件下 ,迟熟中粳稻在倒 3叶 1次施肥或倒 4倒 3叶分次施肥 ,确保提高群体质量而获得高产。     

施氮肥时期对土壤供氮、稻株吸氮及产量的影响

不同施氮肥时期对土壤供氮、稻株吸氮及产量的影响研究结果表明 :基肥对土壤供氮影响持续期长 ,一直持续到成熟期。蘖肥对土壤供氮仅影响到有效分蘖临界叶龄期。穗肥对土壤供氮影响到抽穗至成熟期。不施基肥与施基肥相比 ,植株各生育期的吸氮量少 ;不施蘖肥与施蘖肥差异较小 ,仅影响有效分蘖临界叶龄期到拔节期的吸氮量 ;不施穗肥的植株拔节到成熟期吸氮量下降 ,而不施粒肥仅影响抽穗至成熟期的吸氮量。基肥施用量在保证 N-n叶龄期达到够穗苗数的情况下 ,不施或少施蘖肥 ,增施粒肥量 ,有利于提高茎蘖成穗率 ,促进穗大粒多而高产。     

籼粳交恢复系D091的选育及应用

D0 91是四川省原子核应用技术研究所用广亲和中粳株系 0 2 42 8作母本 ,含育性恢复基因的籼型中间材料作父本杂交而成的籼粳交恢复系。该恢复系株型好 ,穗大 ,杂种优势强 ,米质优 ,花粉量足 ,与不育系N2 A配组育成的糯优 2号于 1999年通过四川省品种审定     

大赖草DNA导入小麦获得大穗品系的农艺性状和贮藏蛋白研究

应用花粉管通道法将大赖草ＤＮＡ导入小麦,已从受体７６１转化后代中选育出稳定遗传的大穗变异系。主要特征为：⑴大穗变异系生育期晚,株型高大,叶片宽大,穗长、穗粒数和单株粒重显著增加,同时籽粒长、宽和千粒重明显提高;⑵大穗变异系除蛋白质含量有显著变化外,其胚乳谷蛋白和醇溶蛋白电泳图谱发生了明显变化,出现了新的蛋白组分和受体一些带的消失。由此可见,大赖草ＤＮＡ导入小麦后发生广泛变异,可能是外源ＤＮＡ片段重     

毛竹锈褐斑病的初步研究

近年来,浙江毛竹山区发生了一种毛竹锈褐斑病,经初步鉴定,该病由竹裂爪螨（Ｓｃｈｉｚｏｔｅ－ｔｒａｎｙｃｈｕｓ ｂａｍｂｕｓａｅ Ｒｅｃｋ）引起的,主要为害毛竹,但也能为害早竹,雷竹,哺鸡竹,淡竹,石竹,刚竹、苦竹等竹种。目前危害毛竹特别严重,株发病率５０％￣１００％,感病指数２６．２￣７８．８,引起大量落叶,造成竹子生长迟缓,竹材质量,出笋量和毛竹的立竹量大大下降,严重的导致竹林全部枯死,竹山荒芜     

矮壮素和多效唑对草地早熟禾草坪质量的影响

探讨了矮壮素和多效唑对草地早熟禾草坪质量的影响。结果表明,施用矮壮素延缓了草地早熟禾的生长速度,并且随着浓度的增加延缓作用随之加强。矮壮素减弱了草坪的抗病性,提高了整齐度,但对颜色有伤害作用。低浓度矮壮素能促进分蘖和地下生物量的积累。340mg/kg的多效唑延缓了草地早熟禾的生长速度,抑制分蘖和地下生物量积累,损伤其颜色、整齐度,减弱抗病性。综合考虑,草地早熟禾以施用100mg/kg浓度的矮壮素较合适。