不同氮效率粳稻品种的冠层特征

探明氮高效水稻品种的冠层特征,对于培育和筛选氮高效品种具有重要意义。以2个氮高效品种武运粳30号和连粳7号及2个氮低效品种扬粳4038和宁粳1号作为材料进行大田试验,观察了两类水稻品种的冠层特征及其与产量和氮肥利用率间的关系。结果表明,与氮低效品种相比,氮高效品种总颖花量、结实率、产量和氮肥利用率较高;氮高效品种抽穗期具有较高的单茎茎鞘重、光合速率、光合氮素利用效率、剑叶厚度、比叶重、中上层冠层的光截获量及冠层顶部比叶氮含量、氮消减系数和光氮匹配度,上述主要冠层特征与产量及氮素籽粒生产效率呈显著或极显著正相关。这些冠层特征可作为筛选和培育氮高效水稻品种以及培育高产高效群体的重要指标。     

新老水稻品种植株干物质积累变化的比较分析

以吉林省8个具有代表性的新老粳稻品种为供试材料,对其单株质量、叶片质量、茎鞘质量和穗质量进行测量,分析不同生育时期单株各器官干物质的积累与产量的关系。研究结果表明:新老水稻品种的单株质量、叶片质量和茎鞘质量这3个指标的变化规律不同,在整个生育期内,叶片质量与产量一直保持显著正相关,在分蘖期和乳熟期达到极显著正相关。茎鞘质量与产量相关性波动较大,在拔节期茎鞘质量与产量达显著负相关,在抽穗期达极显著正相关,剩余生育期内则表现为显著正相关,穗质量与产量的相关性在整个生育期内几乎都为极显著正相关,是产量增加的反应。      

不同浓度多效唑对晋遗31大豆农艺性状和产量的影响

于2010和2011年采用0、50、100、150、200、250、300、350 mg.kg-18个多效唑浓度对6片复叶期的晋遗31大豆进行叶面喷施。结果表明,50～350 mg.kg-1多效唑处理均表现增产,增产幅度2.22%～21.97%。其中以200mg.kg-1产量最高(4 175.40 kg.hm-2)。喷施多效唑后大豆株高和结荚高度明显降低,分枝增多,节间距缩短,百粒重、总荚数、单株重和单株粒重明显增加。综合分析,6片复叶期叶片喷施200 mg.kg-1多效唑能够有效改善农艺性状并提高大豆产量。     

水稻叶片叶绿体发育分子机制的研究进展

概述了近年来国内外有关水稻叶片叶绿体发育分子机制的研究进展,通过试验说明了温度和光照对水稻叶片叶绿体发育相关基因表达的影响,并展望了水稻叶片叶绿体在分子水平上的研究前景。     

阿月浑子褐斑病病原菌生物学特性研究

[目的]研究阿月浑子褐斑病的发病规律及其病原菌的生物学特性。[方法]田间实地调查阿月浑子褐斑病的发病规律;从阿月浑子发病组织中分离纯化出一种真菌,室内观察其培养性状和形态特征,根据其形态鉴定其分类地位;研究了不同温度对病原菌菌丝生长的影响以及不同温、湿度对病原菌孢子萌发的影响。[结果]阿月浑子褐斑病是一种真菌性病害,主要侵染阿月浑子叶片和果实,造成叶斑和枯梢,在我国的阿月浑子引种地发病情况严重。该病原真菌经鉴定为链格孢（Alternaria alternaria）,其菌丝生长的最适温度为20～25℃;孢子萌发最适温度为25～30℃,最适相对湿度在95%以上。[结论]春夏之交和夏秋之交是病害发生的2个高峰期,夏季连续阴雨是阿月浑子叶片褐斑病侵染和爆发的决定性条件。     

刺五加不同叶位叶片光合特性及显微结构研究

研究了全光照和遮阳条件下刺五加5年生树不同叶位叶片光合特性及显微结构。结果表明,全光处理上部叶（1-3片）和下部叶（8～10片）的光饱和点均高于遮阳处理上部叶（1-3片）和下部叶（8～10片）,而光补偿点却均低于遮阳处理。不同处理和不同叶位叶片显微结构也存在区别,遮阳处理叶片厚度低于全光处理,上部叶的栅,海比高于下部叶的栅／海比。说明叶片结构的改变可能是光诱导的结果,并引起了光合特性的不同。     

大蒲葵叶斑病病原生物学特性研究

对引起大蒲葵叶斑病的拟盘多毛孢(Pestalotiopsis neglecta)进行了生物学特性和形态学研究,结果表明该菌在10～30℃范围内均可生长,最适生长温度为25℃;该茵适宜在偏酸性基质中生长,最适pH值为5;供试碳源对茵丝生长的影响不显著,供试氮源中磷酸二氢铵较有利于茵丝生长.     

Leaf litter ingestion and assimilation by two endemic pill millipedes (<Emphasis Type="Italic">Arthrosphaera</Emphasis>)

This study aims to determine leaf litter preference, consumption rate, growth rate, food conversion efficiency, and quality of fecal pellets of two endemic pill millipedes (Arthrosphaera dalyi and Arthrosphaera davisoni) of the Western Ghats of India by laboratory microcosm experiments. Among seven combinations of three plantation leaf litters offered in 4-day trial, top three preferred combinations were selected for 4-week trial. In 4-week trial, preference of mixed litter diet was higher than single litter diet, which resulted in enhanced growth as well as food conversion efficiency of millipedes. Among Hopea , Pongamia , and Areca litters, A. dalyi preferred Hopea + Pongamia, and its consumption was significantly correlated with contents of organic carbon (P < 0.05; r = –0.97) and nitrogen (P < 0.01; r = 0.99), while growth rate with phosphorus content (P < 0.05; r = 0.97) and food conversion efficiency with contents of organic carbon (P < 0.05; r = 0.98) and calcium (P < 0.01; r = –0.99). Among Areca , Elettaria , and Coffea litters, Areca + Elettaria  + Coffea was most preferred by A. davisoni, which was significantly correlated with organic carbon content (P < 0.05; r = 0.98) and food conversion efficiency with calcium content (P < 0.0001; r = 0.99). The food conversion efficiency, however, was the highest in millipedes fed with Areca  +  Elettaria. The present study demonstrated increased nitrogen and phosphorus contents and decreased phenolic content and C/N ratio in fecal pellets of pill millipedes fed with plantation litter, and thus, these millipedes play an important role in leaf litter mineralization and soil enrichment in plantations Western Ghats.     

Assessing the protective effect of vertically heterogeneous canopies against radiative frost: The case of quinoa on the Andean Altiplano

Night radiative frost is a highly limiting factor for agriculture in Andean highlands. Nevertheless, a diversity of crop species have been domesticated there, commonly showing high heterogeneity in plant growth at the field level. The possible protective effect of crop canopy heterogeneity against nocturnal radiative frost is examined using a dual approach, combining a field experiment and a simplified energy balance model at the leaf level. Leaf and air temperatures were registered over an entire quinoa crop cycle in the Andean highlands of Bolivia, comparing two cultivars: Blanca de Yanamuyu, a traditional landrace with high plant height heterogeneity, and Surumi, a more homogeneous selected variety. In both cultivars, inverted air density profiles during calm and clear nights result in air temperature changes up to 3 °C over 0.5 m height, with minimum air temperature concentrated at the upper part of the canopy. In these conditions, leaf temperature gradients of up to 2.6 °C m⁻¹ develop within the canopy of the traditional landrace, with minimum leaf temperature significantly higher (P < 0.001) in shaded plants of the landrace than in the selected cultivar. A dynamic model of leaf temperature based on canopy parameters and climatic records at screen level adequately simulates leaf temperature differences in the case of a vertically heterogeneous quinoa canopy. A sensitivity analysis of the model reveals that canopy height, leaf area index, and sky cloudiness have the most important influences on the development of the sheltering effect, while air temperature and air humidity play a minor role under typical radiative frost conditions. As for wind speed, its actual influence remains unclear due to experimental and modelling limitations at low wind speeds. The significance of these results is discussed in terms of the trade-off between stress adaptation and biomass productivity.     

Assessing effects of transgenic Cry1Ac cotton on the earthworm Eisenia fetida

Transgenic insect-resistant cotton containing a synthetic version of the insecticidal toxin gene from Bacillus thuringiensis subsp. kurstaki has been planted in China in a large scale and may have adverse impacts on soil organisms. The leaves of the transgenic cotton and the non-transgenic parental cotton were collected and their impacts on the earthworm, Eisenia fetida, were tested in laboratory studies. No significant acute toxicity on E. fetida from oral exposure to the transgenic cotton line, GK19, was detected. The average weight, numbers of cocoons and new offsprings of E. fetida in the GK19 groups were all higher than in the Simian3 groups, but the differences were not significant.