地熊蜂访花行为及对番茄营养品质的影响

为了深入分析熊蜂在新疆伊犁温室番茄上的授粉行为及对营养品质的影响,以地熊蜂为材料,观察地熊蜂日活动规律,测定其出巢温度、授粉温度、蜂群30 min内的出巢数及工作时间;分别对熊蜂授粉、座果灵蘸花授粉处理(对照)的番茄进行可溶性固形物、硬度、维生素C、还原糖、总酸及种子数等营养成分的测定,明确番茄储藏期间可溶性固形物、硬度的变化规律.结果表明,地熊蜂出巢、授粉温度分别为8℃和9℃,日工作时间为10h,在13:00左右熊蜂的出巢数达到最大值;熊蜂授粉处理的番茄,其维生素C、可溶性固形物含量、硬度和种子数显著高于对照,呈极显著性差异(P＜0.01);经回归方程预测,熊蜂授粉处理的果实储存时间比对照延长5.75 d,提高番茄的保质期和营养价值.     

Variation for aphid resistance and insecticidal acyl sugar expression among and within Lycopersicon pennellii-derived inbred backcross lines of tomato and their F1 progeny

Five inbred backcross lines (IBL) were selected for higher relative expression of insecticidal acyl sugars (rank average) from an inbred backcross population derived from the cross Lycopersicon esculentum cultivar ‘Peto 84’×Lycopersicon pennellii accession LA716. These five BC₂S₅ IBLs were crossed in a partial diallel design (Method II), and their self and F₁ progeny and three control cultivars were tested at two California field locations in 1996. Counts of potato aphids, Macrosiphum euphorbiae Thomas, on leaves, as a measure of plant infestation, revealed significant general combining ability (GCA) for lower aphid numbers with IBL44 and IBL59; the F₁ hybrid IBL44 × IBL59 had significantly fewer aphids per leaflet than the susceptible cultivar ‘Alta’. GCA for acyl sugars was associated with IBL59 only. Of all the IBL and IBL × IBL F₁ hybrids, only IBL59 produced significant levels of acyl sugars. Significant within IBL59 variation for acyl sugars was observed, but not for aphid resistance. Our results suggest that factors other than acyl sugars contributed to L. pennellii-derived aphid resistance in IBL × IBL F₁ hybrids and IBL that do not produce significant amounts of acyl sugars. IBL59 and IBL44 may be useful for breeding for aphid resistance in cultivated tomato.     

Spatial and volume patterns of an unmanaged submontane mixed forest in Central Europe: 160 years of spontaneous dynamics

The long-term development of stand characteristics and tree spatial patterns (TSP), their mutual relation, and linkage to site and tree species were studied in the Boubín primeval forest (protected since 1858). Surveys were carried out in 1851, 1961/1964, 1972, 1984/1989, 1996 and 2010 on one to six research plots sized 0.58-1.00 ha. To see how results from these surveys could be generalized, results were also compared with whole-area data sets (46 ha) from 1972 to 2010.The proportion of Abies alba continually decreased, from 20% in 1851 to 2-3% in 2010. This decrease started no later than at the beginning of the 20th century. In contrast, the proportion of Fagus sylvatica slightly increased. The sum of dead and living wood volume was stable during the 159 year period, with deviations of only up to 5%. From 1961/64 to 2010, the number of living trees continually decreased, but the mean-tree volume and volume of dead wood increased. The distribution of dead wood always differed from the distribution of living trees.A random TSP was always most common, which seems to be typical for this type of forest. This was true even when A. alba was gradually forced out from the stand structure. Nevertheless, the pronounced decrease of A. alba found during the 1961/64 survey compared with 1851 was reflected in a tendency towards clustering, as gaps from A. alba dieback gradually closed. In these gaps, competitive pressure was lower, resulting in more clustered distributions. Regular distribution was recorded only rarely. F. sylvatica maintained a random or clustered TSP over long periods, depending on site conditions. On water-affected plots, it had a consistently higher tendency towards clustering. The only step change in TSP occurred due to Hurricane Emma in 2008. Otherwise, the most marked TSP changes over time were found for Picea abies, in which there was a gradual trend from clustered to random, connected with a decreasing number of individuals.The main reason for the decline of A. alba and the decreased number of living trees from 1961/64-2010 was the on-going effect of a high stock of red deer at the turn of the 19th and 20th centuries. The decreasing trend in the number of living trees showed no marked change, even 60 years after the game pressure was strongly reduced. However, the vertical structure became increasingly homogenized due to the long-term absence of severe abiotic and/or biotic disturbances.     

冬枣种质资源调查和保护对策

冬枣是一优良的晚熟鲜食品种,栽培历史悠久,但其商品价值近几年才被引起重视。冬枣的栽培面积迅速扩大,造成冬枣品种混乱,给生产带来了不利。本文主要调查了现存冬枣资源、冬枣原产地的特征、冬枣名称的混乱状况、鲁北冬枣的种质特性并提出了相应的保护冬枣种质资源对策。     

苹果木材的超微构造及其皱缩

本文在观察苹果木材超微构造的基础上，分析了苹果木材在构造上容易发生皱缩的原因，同时观察了苹果木皱缩材组织结构的变化，验证了皱缩机理；分析了温度和含水率对苹果木材基本皱缩条件的影响。     

微波浸提法提取大枣多糖的工艺研究

[目的]优化微波浸提法提取大枣多糖的最佳工艺条件。[方法]采用微波浸提法提取大枣多糖,初步考察了料液比、微波功率、微波处理时间对大枣多糖提取率的影响。[结果]微波浸提法提取大枣多糖的最佳工艺条件为:料液比1∶50 g/ml、微波功率420 W、微波处理时间8 min,在此工艺条件下提取率达到7.99%。[结论]微波辅助工艺在一定程度上提高了大枣多糖的提取率,可为进一步开发利用大枣资源提供参考依据。     

大马士革有机玫瑰红茶的窨制研究

[目的]为了开发一种高效优质的大马士革玫瑰红茶的窨制工艺技术。[方法]采摘新鲜大马士革玫瑰花,利用玫瑰花对新制红茶进行窨制,通过对叶底、外形、汤色、香气、滋味等5个指标分别进行打分评价窨制后红茶的品质,主要研究了窨制时间和配花量2个因素对大马士革玫瑰红茶窨制效果的影响,筛选最佳窨制条件。[结果]研究表明,最适宜的玫瑰花窨制红茶技术条件为:窨制时间1天,配花量300%。[结论]本研究可为大马士革玫瑰红茶的生产加工提供参考依据。     

苹果属植物花器形态特征与分类学研究

文章研究了苹果属（ＭａｌｕｓＭｉｌ）４９个生物型的花器形态解剖学特征，对主要特征进行了主成份和性状相关分析。结果表明，苹果属植物花器形态特征质量性状变异很少，呈显著的数量变异特点，组系间无明显间断。花器各部份的颜色间，各部份被毛与花柱平均数间以及花丝、花柱和花瓣数等性状与萼片外被毛之间呈明显正相关。各主成份的贡献率分散，累计贡献率增长缓慢，说明苹果属植物花器形态变异的多方向性。文章还讨论了花器特征的分类意义及一些种间的亲缘关系。     

SA诱导对苹果叶片中PGIP基因表达的影响

以抗病性不同的两个苹果品种秦冠和礼泉短富为材料，研究在叶面喷施不同浓度的SA对苹果叶片中PGIP基因表达水平的影响。结果表明，0.1和0.01 mmol/L的SA叶面喷施处理对苹果叶片PGIP基因表达在0~96 h、0~129 d均有影响。在SA诱导处理后0~96 h内，两种浓度的SA处理均可以促进秦冠叶片PGIP基因的表达，低浓度处理后，PGIP基因表达上调达到峰值的时间较长，峰值较高；高浓度的SA处理能提高礼泉短富叶片PGIP基因的表达水平，低浓度的SA处理抑制其表达。在SA诱导处理后0~129 d内，前期（13~27 d）秦冠叶片PGIP基因的表达维持在较高水平且低浓度SA处理促进效应大，后期（27~129 d）表达量下降，促进效应不明显；高浓度的SA处理促进礼泉短富叶片PGIP基因表达，处理后第40天达到峰值，而低浓度的SA处理抑制其表达。