蔬菜良种包衣技术应用研究

本文采用11种种衣剂对6种蔬菜作物进行种子包衣试验,研究了各处理对种子活力和幼苗素质等的影响。结果认为：1／10NAD或1／10～1／12菠菜专用种衣剂可用于菠菜种子包衣,1／12．5～1／15津蔬衣号可用于萝卜等十字花科蔬菜种子包衣,豇豆种子包衣效果十分显著,用1．0／100～1．2／100NAD等处理可达到成衣好,促萌发生长和提高幼苗素质的作用。试验还表明梨瓜种子对种衣剂敏感,可能易受毒害,辣椒种子成衣较难,有等进一步研究。     

8个紫花苜蓿品种种子产量和休眠特性研究

连续2年在甘肃定西对8个紫花苜蓿品种的种子生产性能和种子休眠特性进行研究,结果表明:品种间种子产量最高的是Vela,其次是Famous和Rest;种子产量与其构成因素的相关性在年度间及品种间的表现基本一致,相关性强弱依次为生殖枝数/m²>荚果数/生殖枝>粒数/荚>千粒重;在种子生活力无显著差异情况下,Vela、Famous和Rest新收获种子的硬实率显著低于其他品种;自然条件下贮藏1年,与贮前相比种子的生活力无显著变化,硬实率显著下降,发芽率显著提高,其中Vela、Famous和Rest的硬实下降率为44%～56%,最终发芽率达58%～71%,种用价值高于其他品种。     

膏桐叶浸提液对其种子萌发的影响

[目的]研究膏桐自毒化感作用对其种子萌发的影响。[方法]采用膏桐嫩叶和枯叶的水浸提液（1∶50 w/v）作床,分别浇灌清水和浸提液,测定膏桐种子发芽率和发芽势。[结果]1∶50浓度的膏桐嫩叶和枯叶水浸提液均可以促进膏桐种子的萌发,且嫩叶浸提液的效果优于枯叶浸提液,尤其以嫩叶浸提液作床后浇灌蒸馏水的处理方式最佳。[结论]在1∶50浓度时,膏桐嫩叶和枯叶水浸提液对其种子萌发具有促进作用。     

He-Ne激光辐射对糯玉米种子的生物学效应

种子活力是检验种子质量高低的一项最重要的指标。采用苏糯一号玉米种子为材料,研究了He-Ne激光不同剂量以及不同照射时间对糯玉米种子发芽率、发芽指数、活力指数、电导率、可溶性蛋白含量以及淀粉含量的影响。结果表明,采用13mA剂量的激光照射糯玉米种子50s能够明显的提高其种子活力,增加幼苗可溶性蛋白和淀粉的含量。     

闽江口琅岐岛朴树防护林种子雨时空分布特征1）

以闽江口琅岐岛天然朴树防护林林下、林隙2种生境为对象,采用离地收集种子的方法,连续定位观测了朴树种子雨的数量动态。结果表明：朴树种群种子雨是从9月下旬开始,一直到次年的1月结束;林下的种子雨总量和完好种子比例,均极显著高于林隙内（P＜0．01）;林隙内种子雨量具有时空异质性特征,这对林隙内朴树更新格局产生深刻影响。总体上,林隙内南北向的种子雨,高于东西向的。林下与林隙内,朴树种子雨高峰期有所不同,林隙内种子雨高峰期在9月下旬到10月中旬;而林下的是在11月下旬到12月中旬,林下的种子雨在9月下旬到10月中旬也有一个小高峰。林隙内种子雨主要受天气因素影响;而林下的种子雨既受朴树生物学特性影响,又受天气因素影响。朴树在林隙内主要采用实生更新,不是因为种子源比林下多,而是林隙内环境更适合其种子萌发和幼苗生长。     

Dispersal potentials determine responses of woody plant species richness to environmental factors in fragmented Mediterranean landscapes

While maximizing plant species richness continues to be central in the design, conservation and reforestation action plans, plant life histories are receiving increasing attention in assessments for the conservation of biodiversity in fragmented landscapes. We investigated the determinants of woody plant species (trees, shrubs and climbers) richness in the forest patches of the Guadalquivir river valley, a Mediterranean agricultural landscape with ∼1% forest cover. We analyzed three species richness variables, total, and those corresponding to species with short-distance (ballistic, barochorous, myrmecochorous and short-distance anemochorous) and long-distance (anemochorous, endozochorous, exozoochorous, hydrochorous and dyszoochorous) dispersal systems, which significantly characterize earlier and late successional stages, respectively. We selected eleven predictor variables related to habitat structure (patch area, shape, distances to the nearest patch and reserve, and general isolation), physical environment (temperature, precipitation, elevation, and lithological heterogeneity), and anthropogenic influences (disturbance and proportion of old-growth forest). We used ordinary-least-squares multiple regression (OLS) and the Akaike's information criterion (corrected for spatial autocorrelation) and derived indices to generate parsimonious models including multiple predictors. These analyses indicated that plant species richness increase primarily along with increasing patch area and decreasing disturbance, but also detected secondary effects of other factors when dispersal was considered. While the number of species with potential long-distance dispersal tended to increase in more isolated patches of areas with greater precipitation and lithological heterogeneity (e.g. highlands at the valley edges), the number of species with short-distance dispersal increased towards drier and less lithologically complex zones with shorter between-patch distances (e.g. central lowlands). Beyond emphasizing the need to consider dispersal in fragmentation studies, our results show that woody plant species richness would be favoured by actions that increase patch area and reduce anthropogenic disturbances particularly in lowland forests.     

中国苜蓿育成品种遗传多样性及亲缘关系研究

以苜蓿的种子贮藏蛋白的多态性为研究指标,对中国14个审定登记的苜蓿育成品种的遗传多样性及亲缘关系进行了研究。研究结果表明:蛋白单体的分子量介于21.2～85.1kD之间,蛋白单体电泳图谱多态性品种间无显著的特异性;在参试的14个育成品种中,品种内基因多样性平均值(HS)为0.3136,总基因多样度(HT)为0.3741,基因分化系数(GST)为0.162;以λ=3.700为标准划分,14个育成品种划分为六个组群,各组群划分结果主要与参试品种的亲本来源有关,而与其种植地、育种地关系不大。     

Does nectar reward affect rarity and extinction probabilities of orchid species? An assessment using historical records from Belgium and the Netherlands

The long-term persistence of plant populations may partly depend on pollination processes and seed production. The exact role of pollination in determining plant population viability still remains largely unclear. Orchid species have often been shown to be pollinator limited. Especially, non-rewarding species are characterized by infrequent pollinator visits and low seed set. Therefore, it can be hypothesized that, if overall population fitness of orchid species is influenced by seed production, non-rewarding species should be more prone to local extinction than rewarding species. To study the importance of nectar reward on orchid persistence, we collected historical records about the distribution of 32 orchid species in Flanders (Belgium) and 37 orchid species in the Netherlands. For both regions, present distribution patterns were compared with historical data. Between 1930 (Flanders) or 1950 (the Netherlands) and 2000, 26 (81%) species showed decreases in distribution range in Flanders, eight of which had gone extinct, whereas 29 (78%) species showed declines in distribution area in the Netherlands, five of which went extinct. Contrary to previously reported results, orchid distribution patterns were not related to nectar reward. There was also no significant relationship between nectar reward and extinction for both regions. Orchids typically occurring in wet grasslands and heathlands suffered greater losses than orchids typically confined to forest habitats or calcareous grasslands. We conclude that the production of nectar does not represent a safeguard for local extinction of orchid species. Habitat loss and other deterministic threats associated with habitat fragmentation and deterioration are more important determinants of orchid persistence.     

吉兰泰地区梭梭林天然更新规律研究

根据八年的观测资料分析得知梭梭林天然重新的关键所在是幼苗的产生和当年生幼苗的保存，幼苗的产生必须在有较多的种子为前提，当年春３～５月有一次较大降水的情况下完成，这一较大降水必须能将干沙层全部浸透与稳定湿沙层相接，种子吸水后迅速发芽生长，保证根系能顺利地保持在湿沙层内持续生长。因此，梭梭林的天然更新呈现周期性规律，平均每九年内有一更新年。