辣椒种质资源形态学性状相关性、主成分与聚类分析

以全国各地搜集的205份辣椒种质为试材,观测28个形态性状,并对其进行相关性、主成分和聚类分析研究。结果表明:辣椒形态学性状间存在较高相关性,单株果数、叶形、株型、果形、茎绒毛、花梗着状、熟性、花柱色是最关键的性状。6个主成分的方差累积贡献率为50.653%,暗示这28个性状代表了更多的性状改良方向。主成分归纳为形态因子、产量因子、熟期因子、色彩因子,呼应聚类分析的主要区分依据果形、单株果数、熟期和果色,将205份种质分成7类,有效区分了不同的品种。说明在改良形态性状时,按育种目标的要求选取主要性状,同时也要注意与其它性状间的关联。     

MYB转录因子参与植物非生物胁迫响应与植物激素应答的研究进展

基因的时空表达受转录因子的精确调控。植物在面对不利环境因素比如高温、低温、干旱、盐碱等胁迫时其细胞生理生化会迅速地从“舒适”状态转变进入“胁迫响应”状态。这种快速响应的状态转变依赖于植物对胁迫信号的感知及传递、激素通路(脱落酸、茉莉酸等)的激发、转录因子的活化等复杂的过程;最终植物通过胁迫相关基因的表达、次生代谢转变、抗氧化物质的积累等实现胁迫条件下细胞内环境的再平衡从而获得生存。植物MYB(v-MYB avian myeloblastosis viral oncogene homolog)转录因子就是上述转变中的重要参与者。本文介绍了植物MYB转录因子的结构特征、分类,综述了近些年来MYB转录因子与非生物胁迫,以及植物激素应答过程相关的研究进展。     

水霉属菌(Saprolegnia)分离培养技术研究

 对水霉(Saprolegnia)的分离培养技术进行了探索,筛选出大麻籽、油菜籽、红花籽、苍蝇、蚜虫、小麦粒、玉米片、茶叶、葵花仁9种材料作为诱发水霉菌的诱饵。其中油菜籽能防止腐霉菌(Pythium)污染,是初步纯化菌种、排除杂菌的适宜饵料。同时发现控制温度能使水霉在最短时间内分别产生无性或有性繁殖。在水培条件下,25℃左右适合菌丝及无性器官的发育,有性器官却不能产生,而只有在15~17℃条件下才能使水霉很快进入有性生殖阶段;在加入200mg/L链霉素的CMA培养基上促发有性阶段则需要在25℃左右的温度下进行,方能缩短培养时间。     

黄皮的生物学特性研究

通过本试验观察表明:黄皮[Clausena Lansium (Lour.)Skeels]的开花与温度有密切关系,温度高,开花过程短;温度低,开花过程长。花穗中的花轴增长速度也随温度升高而加快,花轴增长快,则花轴长,花穗大;反之,花轴增长速度慢,花轴短,花穗小。黄皮开花的顺序是从花穗基部第1—4个分枝开始,每个分枝则先从基部1—8个二次分枝首先开放。31℃是黄皮花粉萌发最适宜温度。在培养基中加入15—20％蔗糖或2.4—D,三十烷醇等生长调节物质,明显可提高黄皮花粉的萌发力。本试验对黄皮的物候期及植物学特性同时进行了研究。     

Alfalfa Phytoestrogen Content: Impact of Plant Maturity and Herbage Components

Legumes contain a range of non‐nutritional phytochemicals that may have health‐promoting effects in humans. In this study, we determined the concentrations of four phytoestrogens (coumestrol, apigenin, luteolin and quercetin) in field‐grown alfalfa (Medicago sativa L.). Differences between plants of different stages of maturity, between plant parts, and different canopy segments were assessed. The concentration of individual phytoestrogen in whole herbage varied between 15 and 225 μg g^?1 dry matter (DM) and was strongly affected by stage of maturity. Coumestrol and apigenin concentrations were highest at early vegetative stages, luteolin and quercetin at early vegetative and late flowering stages. All phytoestrogens were found in lowest concentrations at the early flowering stage (average 68 μg g^?1 DM); stage at which alfalfa is usually harvested when used as a forage source for animals. At vegetative stages, apigenin was the predominant phytoestrogen in herbage followed by coumestrol, the reverse being observed upon initiation of flowering; luteolin and quercetin were found at all stages in similarly lower concentrations. Concentrations of luteolin, quercetin and apigenin were 225, 410 and 690 % greater, respectively, in flowers than in leaves or stems; coumestrol concentration was similar between plant parts. In flowers and stems the predominant phytoestrogens were apigenin and quercetin, followed by coumestrol and luteolin. Similar concentrations (average 26 μg g^?1 DM) of each of the four phytoestrogens were found in leaves. Concentrations through the herbage canopy varied and were greatest at >60 cm from the soil surface for apigenin and coumestrol, but greatest at >60 and 0–20 cm for quercetin and at 0–20 cm for luteolin. The results suggest that if alfalfa is to be used as a source of phytoestrogens and is harvested for the production of herbal supplements or nutraceuticals, management will need to be adapted.     

泡沫比例混合器在液下喷射灭火系统中的应用

提出了环泵泡沫比例混合器和泡沫压力比例混合器在相应灭火系统中的应用、安装和操作中应注意的问题，对两种泡沫比例混合器组成的系统进行了对比，认为环泵比例混合泡沫灭火系统采用正压进水，可以克服负压进水方式存在的缺陷，比较适合油库火灾的扑救；压力比例混合泡沫灭火系统灵活性、匹配性较差，适用于泡沫混合液流量相对不变的火灾扑救。     

我国农业区域开发简史及历史经验

本文讨论了中国农区开发之始、几个主要农区的深开发、黄淮江湖的连片开发、海河流域的开发、其它农区的开发和农区开发的历史经验与教训。完好的灌溉系统、导致深开发的人工运河和农业技术是开发成功的要素。     

Viral and bacterial agents associated with experimental transmission of infectious proventriculitis of broiler chickens.

Proventriculitis of broilers can be reproduced by oral inoculation of day-old chicks with a proventricular homogenate from affected 3-wk-old broilers. The objective of the following studies was to isolate from this homogenate viral and bacterial isolates that could produce proventriculitis. A monoclonal antibody to infectious bursal disease virus (IBDV) was used to precipitate virus from the homogenate. A primary chicken digestive tract cell culture system was also used to isolate virus from a 0.2-microm filtrate of the homogenate, and a bacterium was also isolated from the homogenate. In trial 1, day-old birds were orally inoculated with either proventriculus homogenate or monoclonal antibody immunoprecipitated IBDV (MAB-IBDV). At 4, 7, 14, and 21 days postinfection (PI), 12 birds from each treatment group were subjected to necropsy. In trial 2, day-old birds were orally inoculated with either infectious proventriculus homogenate, suspect virus isolated in cell culture and propagated in embryo livers and spleens, or a bacterial isolate. Twelve birds from each treatment were subjected to necropsy at days 7, 14, 21, and 28 PI. In trial 3, treatments were maintained in negative pressure isolation chambers, and an additional treatment included virus plus bacterial isolate. Twenty-four birds from each treatment were subjected to necropsy at day 21 PI. In trial 1, infectious homogenate decreased body weight and relative gizzard weights at 4, 7, 14, and 21 days PI. Proventriculus relative weight was increased at days 7, 14, and 21 PI, and proventriculus lesion scores were increased at days 14 and 21 PI. Bursa/spleen weight ratios were decreased at day 14, and feed conversion was increased at days 4 and 21. The MAB-IBDV treatment decreased proventriculus and gizzard relative weights at day 4 PI, increased proventriculus lesion scores and bursa/spleen weight ratios at day 14, and decreased heterophil/lymphocyte ratios at day 21. In trial 2, all infected birds had significantly higher mean relative proventriculus weights at 21 days PI and had higher 4-wk mean proventriculus scores as compared with both control groups. In trial 3, birds treated with homogenate and birds treated with both suspect virus and the bacterial isolate had significantly higher proventriculus lesion scores; higher relative weights of proventriculus, gizzard, liver, and heart; lower body weights; and lower relative bursa weights compared with the saline control group. These studies suggest that infectious proventriculitis has a complex etiology involving both viral and bacterial infection.     

鸡的微卫星DNA标记与胴体性状的相关分析

测定了青脚麻鸡与隐性白鸡杂交后自交的F2代个体的全净堂重、全净堂率、脂肪宽带、腹脂重和腹脂率6个胴体性状,检测10个微卫星DNA标记,对标记基因型胴体性状值进行方差分析和多重比较,结果表明:MCW328对于10周龄体重和全净膛重两性状各基因型均有显著的差异(P<0.05);ADL292对于腹脂重性状各基因型有极显著的差异(P<0.01),对于腹脂率有显著的差异(P<0.05)。MCW328标记基因与控制10周龄体重和全净膛重QTL连锁,ADL292标记基因与控制腹脂重和腹脂率QTL连锁。     

杨梅袋苗大棚嫁接及管理技术

杨梅是我国的特产水果，福建的“浮宫杨梅”以成熟期国内最早、色泽紫红、酸甜适口而受到广大消费者的青睐，果品销往国内各大城市和东南亚地区，2004年首次出口到欧盟，市场前景广阔。杨梅传统的繁殖采用大苗嫁接法，即先在定植穴种实生苗，2～3年或更长时间后再进行嫁接。