储藏小麦粉中害虫发生与温湿度变化的关系研究

研究了不同初始虫口密度(0、2、15头/kg小麦粉)的不同储粮害虫(锈赤扁谷盗成虫、赤拟谷盗成虫、赤拟谷盗成虫与锈赤扁谷盗成虫混合)发生对储藏小麦粉温度及环境湿度变化的影响.结果表明,在全部实验观察期间,随着实验时间延长,害虫为害引起小麦粉温度升高,初始感染害虫虫口密度越高小麦粉温度也越高;不同起始虫口密度的不同虫种害...     

锈赤扁谷盗侵染后小麦自身挥发性化合物动态变化研究

为探究不同储藏周期及不同虫口密度锈赤扁谷盗侵染后小麦自身挥发性化合物的动态变化,采用两种固相微萃取模式(顶空固相微萃取Headspace Solid-Phase Micro-extraction HS-SPME,浸入固相微萃取Direct Immersion Solid-phase Micro-extraction DI-SPME)结合气相色谱-质谱联用(Gas Chromatography Mass Spectrometry,GC-MS)技术进行定性定量测定。基于小麦挥发性化合物的相对含量,通过偏最小二乘法-判别分析(Partial Least Squares Discrimination Analysis, PLS-DA)建立模型,然后找到对分类起关键作用的差异挥发性化合物,最后通过绘制热图和层次聚类分析(Hierarchical Clustering Analysis, HCA)确定差异化合物在不同储藏周期及不同虫口密度锈赤扁谷盗侵染下的变化规律。结果表明：小麦中共定性检测出57种挥发性化合物,锈赤扁谷盗侵染后小麦中共定性检测出61种挥发性化合物,其中包括醛类、醇类、烃类、酸类、酮类、酯类等;锈赤扁谷盗侵染后小麦相比空白对照组,化合物含量均有变化,差异挥发性化合物为γ-亚麻酸、2-十九烷酮、γ-己内酯、十七烷酮、二十九烷、二十七烷、二十七烷醇、1-碘-2-甲基十一烷、壬醛;小麦挥发性化合物的种类及含量随储藏周期变化呈规律性变化。因此,锈赤扁谷盗侵染后小麦的酸类化合物显著增加,导致其霉变,品质下降。     

赤拟谷盗对小麦粉品质的影响

赤拟谷盗是小麦粉加工及储存过程中的重要害虫之一。选用普通小麦粉180g,向其中投入赤拟谷盗成虫,研究小麦粉在感染头数分别为0、10、30、60、100、200,感染时间为0、15、25、35、45d时的品质变化。实验表明:随着虫口密度的增大和感染时间的延长,小麦粉的水分稍有上升,灰分变化不大;粗淀粉含量降低,粗蛋白质含量升高,湿面筋含量和面筋指数则呈现不规律的波动;清蛋白、球蛋白、谷蛋白含量下降,醇溶蛋白的含量上升;降落数值下降明显。在较低虫口密度下时,小麦粉的峰值黏度、最低黏度、黏度破损值和最终黏度有升高趋势,但随着虫口密度的增大又逐步降低。     

鸡骨柴挥发油及其主要组分γ-萜品烯对赤拟谷盗成虫和幼虫的防治作用

本研究分析了鸡骨柴挥发油及其主要组分γ-萜品烯对赤拟谷盗成虫和幼虫的防治作用。通过触杀、熏蒸和驱避试验评价鸡骨柴挥发油及γ-萜品烯对赤拟谷盗成虫和幼虫的生物活性。结果显示，鸡骨柴挥发油及γ-萜品烯对赤拟谷盗成虫具有明显的触杀活性（LD50 = 26.64和33.04 μg/头）和熏蒸活性（LC50 = 32.16和16.94 mg/L-1）。鸡骨柴挥发油对赤拟谷盗幼虫触杀和熏蒸活性均弱于成虫（LD50和LC50分别为111.72 μg/头和78.25 mg/L-1）。驱避活性测试中，在5 mg/ml测试浓度下，鸡骨柴挥发油对赤拟谷盗成虫和幼虫驱避作用显著，驱避率值分别达到100%和90%以上。γ-萜品烯对赤拟谷盗成虫和幼虫未表现出驱避活性及对赤拟谷盗幼虫未表现出触杀和熏蒸活性。鸡骨柴挥发油及其主要组分γ-萜品烯对赤拟谷盗具有一定的防治作用。     

赤拟谷盗和玉米象的相互关系研究

在75%RH、30℃条件下通过相互选择性实验、单独饲养和混合饲养实验研究赤拟谷盗和玉米象在小麦中的相互关系。研究结果表明:在相同生态环境中,赤拟谷盗和玉米象间的相互选择行为不明显。在小麦中单独饲养情况下,赤拟谷盗种群中成虫数量随处理时间延长先减少后增加,且增长缓慢,在处理56 d后最大成虫数量增加为起始虫数的11.5倍;而玉米象种群中成虫数量随处理时间延长而显著增加,在处理56 d后最大种群中成虫数量增加为起始虫量的53.9倍。与单独饲养相比,在小麦中混合饲养时,赤拟谷盗和玉米象的繁殖速率和种群中成虫数量都显著增加,在处理56d后最大种群中成虫数量分别增加为起始虫量的20.3倍和93.4倍。因此,赤拟谷盗和玉米象均为小麦储藏过程中重要害虫,玉米象的危害对赤拟谷盗种群增长有促进作用。     

赤拟谷盗和玉米象的相互关系研究（网络首发、推荐阅读）

在75%RH、30 ℃条件下通过相互选择性实验、单独饲养和混合饲养实验研究赤拟谷盗和玉米象在小麦中的相互关系。研究结果表明：在相同生态环境中,赤拟谷盗和玉米象间的相互选择行为不明显。在小麦中单独饲养情况下,赤拟谷盗种群中成虫数量随处理时间延长先减少后增加,且增长缓慢,在处理56 d后最大成虫数量增加为起始虫数的11.5倍;而玉米象种群中成虫数量随处理时间延长而显著增加,在处理56 d后最大种群中成虫数量增加为起始虫量的53.9倍。与单独饲养相比,在小麦中混合饲养时,赤拟谷盗和玉米象的繁殖速率和种群中成虫数量都显著增加,在处理56 d后最大种群中成虫数量分别增加为起始虫量的20.3倍和93.4倍。因此,赤拟谷盗和玉米象均为小麦储藏过程中重要害虫,玉米象的危害对赤拟谷盗种群增长有促进作用。     

黄花蒿挥发油对赤拟谷盗成虫和幼虫的生物活性研究

本研究分析了黄花蒿挥发油的化学成分及其对赤拟谷盗成虫和幼虫两个阶段的防治作用。采用水蒸气蒸馏法提取挥发油,GC-MS分析挥发油的化学成分和相对含量。结果表明,黄花蒿挥发油的主要成分和含量为：蒿酮13.2%,β-芹子烯12.3%,樟脑12.2%,桉叶油醇10.3%等。生物活性测试结果显示,黄花蒿挥发油对赤拟谷盗成虫和幼虫的触杀活性LD50分别为37.32 μg/头和70.34 μg/头。同时,黄花蒿挥发油对赤拟谷盗成虫和幼虫均具有明显的驱避作用。因此,本研究能够为黄花蒿挥发油防治粮食仓储害虫提供参考。     

速溶豆粉、牛奶粉及羊奶粉挥发性成分的比较

对速溶豆粉、牛奶粉和羊奶粉的挥发性成分进行鉴定并比较,分析三者挥发性成分的差异。结果表明,速溶豆粉中共鉴定出42种挥发性物质,牛奶粉中共鉴定出48种挥发性物质,羊奶粉中共鉴定出47种挥发性物质,主要包括醇类、醛酮类、烃类、酸类、酯类和其他类等物质。三者中烃类、醛酮类和酯类物质的种类和含量均较高。速溶豆粉检出的醇类和酸类物质含量最高;牛奶粉中检出的烃类和酯类物质含量最高;羊奶粉中检测到的醛酮类和其他类物质含量最高。聚类分析和主成分分析结果表明,癸醛、(E,E)-3,5-辛二烯-2-酮、1-十二烯、正癸酸、丙位辛内酯、2-正戊基呋喃、2,6-二叔丁基对甲酚是速溶豆粉的关键挥发性物质;壬醛、δ-癸内酯、十二烷、丁位十二内酯、2,2,4,6,6-五甲基庚烷、1-十三烯是牛奶粉的关键挥发性物质;1-戊醇、庚醛、2-庚酮、二甲基砜、3-辛烯-2-酮、壬醛、γ-十二内酯等挥发性物质是羊奶粉的关键挥发性物质。这些物质是导致速溶豆粉、牛奶粉和羊奶粉风味差异的主要物质。     

S-烯虫酯防治拟谷盗持效性及解毒酶功能影响研究

在当前害虫抗药性强和社会安全健康意识增强的背景下，迫切需要开发生态友好的防治手段。因此，采用小麦入仓全仓拌和S-烯虫酯进行防治。通过分别扦取处理90天和365天后的小麦样品，在实验室内模拟了赤拟谷盗和杂拟谷盗的防治效果，并测定了S-烯虫酯对拟谷盗幼虫三种解毒酶的影响。研究结果表明，施药时间和虫态是影响S-烯虫酯杀虫效果的关键因素。在施用S-烯虫酯90天后的小麦样品中，武汉、成都和齐河3个品系的赤拟谷盗卵孵化率为0%，广东和北京2个品系的杂拟谷盗卵孵化率分别为1.67%±2.04%和0%。此外，施用S-烯虫酯90天后对赤拟谷盗和杂拟谷盗的杀蛹活性较好，羽化成虫无繁殖能力；施用365天后的杀蛹活性大大降低，羽化成虫有繁殖能力，而F1代蛹无法羽化。两处理组对两种成虫直接致死作用也有一定效果，但施用365天后的致死率大大降低，赤拟谷盗F1代仅有幼虫，而杂拟谷盗F1代有部分幼虫可化蛹但不能进一步转化为成虫。说明赤拟谷盗比杂拟谷盗更为敏感。S-烯虫酯胁迫之后，两种拟谷盗科幼虫体内的3种解毒酶活性受到了影响，且随着时间延长而增强。     

顶空固相微萃取-气质联用分析不同储藏条件下小麦粉挥发性成分变化

利用顶空固相微萃取和气相色谱-质谱(HS-SPME-GC/MS)对不同储藏条件下的小麦粉挥发性成分进行研究。对固相微萃取头、萃取温度、萃取时间和解析时间进行条件优化。实验结果表明:小麦粉挥发性成分的最佳分析条件为,萃取头DVB/CAR/PDMS;萃取温度80℃;萃取时间60 min;解析时间3 min。经鉴定分析小麦粉中挥发性成分主要有烃类、醛类、酮类、醇类、有机酸及杂环类等多种成分。原样和储后2个月样中最高的是烃类和醛类,其次为醇类、酮类。储藏2个月后,变化较明显的挥发性物质有己醛、苯甲醛、辛醛2、-壬醛、己醇、十二烷、十六烷和十八烷。     

储粮环境中米象发生与CO2含量变化的关系研究

为阐明储粮环境中害虫发生与CO_2气体含量变化的关系,研究不同含水量的小麦感染不同虫口密度(0、2、5、10、20、30头/kg)米象后储藏环境中CO_2气体体积分数变化的情况。结果表明:对于含水量相同的储藏小麦,储藏环境中CO_2气体体积分数随虫口密度的增加和储藏时间的延长而显著增加。对于含水量12%的小麦,初始感染虫口密度为30头/kg的储粮环境中CO_2气体体积分数最初为0.413%,在第30天达到最大值为14.777%。对于含水量14%的小麦,初始感染虫口密度为30头/kg的储粮环境中CO_2气体体积分数最初为0.720%,在第15天达到最大值为17.197%。本研究结果为今后通过检测CO_2体积分数变化来监测粮堆中虫害发生情况提供了可靠信息。     

The effects of population densities and diet on Tribolium castaneum (Herbst) life parameters

The effects of population densities (10, 25, 50 and 100 adults/50 g) and three diet types (protein-rich, carbohydrates-rich and compound feed) on life parameters (first emergence, development rate, number of progeny and body weight) of T. castaneum progeny were assessed. For each diet type and population density unsexed adults were allowed to feed and oviposit for 7 days before removal.No progeny developed on protein-rich diets (sunflower meal, soybean concentrate, and corn gluten). In carbohydrates-rich diets (corn feed flour, wheat bran, coarse wheat) and compound feed for pigs and laying hens, first adults required the least time to emerge in wheat bran and control diet (wheat flour + 5% yeast) (15.2–16.5 days), and the longest in corn feed flour (23.1–24.5 days). In wheat bran and control diets, the adult emergence period was the shortest (15.7 and 15.2 days) at the initial population densities of 100 and 50 adults/50 g, and significantly longest (16.5 and 16 days) at the lowest density. Conversely, adults fed on feed for hens diet emerged the latest, after 22.5 days, at the population density of 100 adults/50 g, and the earliest, after 18.6 days, at 25 adults/50 g. The shortest period of adult emergence at all population densities was found in the control (15.9–20.2 days) and wheat bran (18–29.7 days), and the longest in feed for hens (56.2 days) and pigs (59.5 days) at the highest population density. Considering all densities, number of progeny were the highest in control diet (498-1226 adults) and wheat bran (354-1344 adults), and lowest in coarse wheat (220-300 adults). With increasing population density, progeny body weight decreased, and the highest weight was found in control diet and wheat bran (1.7 and 1.6 mg) at the lowest population density, and the lowest weight (1.0 mg) in hen and pig feeds at the highest density.     

Development and progeny performance of Tribolium castaneum (Herbst) in brewer’s yeast and wheat (patent) flour at different population densities

The effects of brewer's yeast and wheat patent flour on Tribolium castaneum (Herbst) life parameters at different population densities (1, 2, 5 and 10 pairs) were examined. A standard diet (95% wheat flour + 5% brewer's yeast) was used as control. The effect was examined on the duration of egg, larval and pupal stages, total development cycle, first adult emergence, eclosion period, the total number of offspring, number of offspring per female and body weight of adult offspring. For each diet type and population density, adults were allowed to feed and oviposit for 7 days before removal from diets. A longer larval stage was recorded in brewer's yeast (between 23.88 and 26.25 days, depending on population density) and patent flour (17.63–23 days) compared to the standard diet (12.88 and 13.38 days). The longest eclosion period was recorded in patent flour (19–21.23 days), which was the only diet unaffected by population density. In the brewer's yeast and standard diet, the period of eclosion was prolonged with the increase in population density. The lowest number of progeny was recorded in patent flour (44.29–49.63 insects), followed by brewer's yeast (22.86–177 insects), while the highest number of progeny (107.25–313.38 insects) was recorded in the standard diet. Population density did not affect the total number of progeny in patent flour, which remained low at all densities, while in the brewer's yeast and standard diet the rise in population densities caused a rise in progeny numbers. The type of diet did not affect the body weight of adult progeny: the highest body mass of progeny was recorded at the lowest population density and the lowest mass at the highest. This study provides insight into poorly researched development cycle and reproductive strategies of T. castaneum on brewer's yeast and patent flour, which are important stored products.     

全麦粉添加量对干挂面挥发性成分的影响研究

采用顶空固相微萃取-气相色谱-质谱联用法研究3种不同全麦粉添加量(50%、75%和100%)干挂面和1种精白挂面样品的挥发性成分,共检测到85种挥发性成分,其中包括17种醛,34种烃,16种醇,7种酮,1种呋喃,7种酯,2种胺和1种酸。四种挂面均含有烃类、醛类、醇类、酮类、酯类和胺类化合物。精白挂面和三种全麦挂面中分别检测到44、53、52和50种挥发性成分,全麦挂面相比于精白挂面挥发性成分显著增加。在挥发性成分中醛类物质是最主要物质,相对含量达25%以上。己醛含量显著高于其他醛类物质。全麦粉添加量的增加对各种类挥发性成分构成影响不大,而对各挥发性成分的相对含量有较大影响。     

哈萨克斯坦小麦挂面的感虫性研究

使用两种哈萨克斯坦小麦制挂面与国产小麦制挂面这三种样品对次生性害虫中的赤拟谷盗、锯谷盗进行了诱捕以及自然感虫实验的观察,并利用GC-IMS(气相离子迁移谱)分析三种挂面中的挥发性物质。研究结果表明在自然条件下哈麦原味挂面更容易受锯谷盗的感染；同时在饥饿12 h、诱捕8 h的条件下,锯谷盗对哈麦原味挂面的选择性最为显著,为44.38%,而在饥饿16 h、诱捕10 h的条件下,赤拟谷盗则对其选择性最显著,为53.13%。分析三种挂面挥发性物质,结果发现,三种挂面挥发性物质种类和浓度具有差异,哈麦原味挂面中浓度较高的 1-辛烯-3-醇和戊醛两种化合物可能是哈麦原味挂面感染赤拟谷盗和锯谷盗的主要风味来源,哈麦玉米风味中由于有玉米特异的风味物质,降低了两种害虫对其的选择性。     

全麦速冻油条复热加工中风味与抗氧化特性

利用电子鼻和顶空固相微萃取气相色谱-质谱联用检测技术,分析不同复热加工过程中全麦粉和全麦速冻油条挥发性成分及指纹图谱变化,以及对其内部多酚类化合物含量和抗氧化特性的影响.结果表明不同加工阶段会产生不同的特征风味物质.在速冻油条预炸和复热的过程中,全麦粉中部分风味物质消失.预炸后全麦油条的醛类物质峰面积百分比高达50％以...     

Population dynamics of red flour beetle (Tribolium castaneum (Herbst)) under different temperatures and patch sizes

Population dynamics of red flour beetles, Tribolium castaneum (Herbst), was determined using three different sizes of grain patch (bulk) at different temperature profiles. Grain patches were 0.03 kg, 2 kg, and 14 kg of wheat with 14.5% moisture content (wb). The temperature profiles tested were constant temperatures of 21, 25, 30, 35 °C, and incrementally decreased or increased temperatures (T-decrease (Td) and T-increase (Ti)). Every 28 d up to 168 d, the live and dead adults were separated from the wheat and their numbers counted. At Td, adults were separated and counted every 28 d during the first 140 d, then one last time 70 d later. After separating and counting, these adults were discarded and the wheat, which contained immature stages, was incubated at 30 °C. Four weeks later the emerged adults (referred to as “offspring”) were counted. The number of both adults and offspring showed great variation among temperatures at the same storage time and the same patch size. The peak number and density of insects also showed variation among different temperatures and patch sizes. Peak live adult density was the highest in the small patches. The peak live adult densities were 300 ± 50 at 21 °C, 673 ± 118 at 25 °C, 689 ± 48 at 30 °C, 1100 ± 150 at 35 °C, 1150 ± 150 at Td, and 1133 ± 94 adults/kg at Ti. The offspring density at 35 °C was higher than that at other temperatures in the small patches. Even though many factors and their interaction influenced population dynamics of T. castaneum, the number of insects was mainly influenced by temperature at the same patch size, while large patch size could provide more room for insects to multiply.