胡桃长足象研究初报

胡桃长足象是核桃果实的大害虫,为害损失很大。1975年以来,我们在四川平武地区进行了生活习性观察和防治试验,初步明确了以下几个问题。1.胡桃长足象一年一代。11月份以成虫越冬,次年4月上旬开始活动,为害果、芽、嫩枝、叶柄,5月上旬交尾产卵于果中,一般一果一粒,8月中旬产卵结束,10月陆续死亡。当年成虫6月中旬羽化,进行为害。2.成虫有假死性和向阳性,飞翔力弱,具有与核桃树芽苞相似的保护色。3.防治胡桃长足象,应抓住越冬成虫大量出现和卵孵化盛期时进行。用每毫升含孢量二至五亿的白僵菌液或50%的三硫磷乳油、50%速灭松乳剂、82%磷胺乳剂加水一千倍喷雾,效果良好。     

小麦抗源武汉2号和品冬34的抗条锈性遗传分析

为明确小麦品种武汉2号和品冬34对小麦条锈菌流行小种的抗病性及抗病遗传规律,用小麦条锈菌生理小种CYR29、CYR31、CYR32、CYR33以及致病类型Su11-4、Su11-5、Su11-11、PST-Ch42在苗期接种小麦品种武汉2号和品冬34进行抗病性鉴定,并用武汉2号和品冬34分别与感病亲本铭贤169进行杂交,对F₂群体和F_2：3家系在温室进行苗期遗传分析。结果表明：武汉2号对CYR29和CYR32表现感病,对其它小种和致病型均表现抗病,且对CYR31的抗性由1对隐性基因控制;品冬34对所测试的小种和致病类型均表现高抗,且对CYR32的抗性由1对显性基因控制。     

Artificial Diet Influences Population Growth of the Root Maggot Bradysia impatiens (Diptera: Sciaridae)

In order to investigate the effects of artificial diets on the population growth of root maggot Bradysia impatiens, its population growth parameters were assayed on eight artificial diets (Diet 1, D2, D3, D4, D5, D6, D7, and D8). Results showed that developmental duration from egg to pupa was successfully completed on all eight artificial diets. However, the egg to pupal duration was shortest, while the survival rate of four insect stages was lowest when B. impatiens was reared on D1. When B. impatiens was reared on D7 and D8, the survival rate, female longevity, and female oviposition were higher than those reared on other diets. When B. impatiens was reared on D7, the intrinsic rate of increase (r_m = 0.19/d), net reproductive rate (R₀ = 39.88 offspring per individual), and finite rate of increase (λ = 1.21/d) were higher for its population growth with shorter generation time (T = 19.49 d) and doubling time (Dt = 3.67 d). The findings indicate that the D7 artificial diet is more appropriate for the biological parameters of B. impatiens and can be used an indoor breeding food for population expansion as well as further research. We propose that vitamin C supplement added to the D7 is critical for the improvement of the B. impatiens growth.     

重庆市农业生态系统能流研究

本文对1987年重庆市农业生态系统进行系统分析后得出:单位耕地面积能量输入和输出分别为94.1×10~9J/ha、252.5×10~9J/ha。在投能结构中,非工业能与工业能之比为3.40:1;单位播种面积的工业能投入居全国中等水平,化肥投能增产潜力大,畜禽粪尿能效果显著;能量投入少而复种指数高的县应适当降低复种指数,实行耕地重点投资,以提高单位播种面积产量;畜禽养殖亚系统的生产效率为21.2％;乡村居民在本系统内摄取的食物能为10856.4KJ/人、日,全年烧掉的秸秆相当于整个系统初级生产能量的1/4。     

一种适于PCR和LAMP检测的松木中松材线虫DNA快速提取方法

【目的】本研究旨在探索快速、简便地直接从病木中提取松材线虫 DNA 的方法。【方法】运用 Chelex-100结合异硫氰酸胍蛋白变性缓冲液建立新的高效快速提取微量木块中线虫 DNA 的方法,并通过普通 PCR 与环介导等温扩增( LAMP)对提取的 DNA进行检测验证。【结果】建立了提取线虫 DNA 的新方法 Chelex-100法,并对影响提取效率的Chelex-100浓度、冻融时间和煮沸时间进行了优化。Chelex-100法最适Chelex-100终浓度为1.5%( W/V),最适冻融时间为5 min,最适煮沸时间为8 min。与传统的 CTAB法和蛋白酶 K 法比较,Chelex-100法提取的 DNA得率高,相同条件下,该方法提取的 DNA浓度远远大于常规方法。3种方法的 OD260/280比值从大到小依次为CTAB法＞蛋白酶K法≥Chelex-100法,Chelex-100法的OD260/280值显著低于CTAB法,而略低于或等同于蛋白酶K法,但这并不影响对提取的 DNA 进行 PCR 扩增。采用 Chelex-100法提取松木中松材线虫的 DNA,结合常规的PCR和 LAMP检测,检测灵敏度高,特异性强,稳定性好;提取的松材线虫 DNA 的75倍稀释液再稀释32倍后进行PCR扩增,扩增产物电泳依然有清晰的条带。用新方法提取病木中线虫的 DNA 后进行检测,所有带病松木样品的检测结果均呈阳性,而健康黑松、马尾松、油松木屑及盘多毛孢样品的检测结果均呈阴性。此外,该提取方法简便快速,20 min内即可完成整个 DNA的提取;经济方便,试剂保藏无特殊要求,单个样品提取耗费低于3.5元。【结论】Chelex-100法是一种快速有效的提取松木中松材线虫DNA的方法,此方法结合PCR和LAMP检测技术将进一步提高松材线虫的检测效率、灵敏度和准确性,可为松材线虫的野外检测提供可靠的技术依据。     

机器视觉在木材缺陷检测领域应用研究进展

为了提高木材利用率,采用机器视觉来实现木材缺陷快速而稳定的检测,不仅可以克服人工检测效率低、劳动强度大、准确率低等弊端,而且对提高木材加工企业的智能化水平具有重要意义。文中概述了机器视觉检测技术及设备的国内外研究现状,介绍基于机器视觉检测木材缺陷所涉及的相关理论和算法研究,以及相关图像处理算法的优缺点;针对机器视觉应用在木材缺陷检测领域存在的不足,提出机器视觉木材表面检测应进一步向人工智能方向发展,以提高木材缺陷检测效率及准确性。     

冬小麦条锈病内外菌源的原理和效应研究

[研究目的]量化研究小麦条锈病菌源类别、作用和独特性,为防控提供依据.[方法]在易辨期(齐穗扬花期)将病田分类,病菌具潜伏性,在短时间内底叶未发病田和发病田的剑叶发病由外部和内外部菌源侵害引发的,用致控病两种方法研究.[结果]齐穗扬花期之前是以内部菌源作用为主,之后外部菌源作用开始大于内部菌源.齐穗扬花期底叶不发病田控效明显,之后晚发病田控效降低.高温有一定控病效果.发病越早.底部叶片发病越重,内部菌源越多,齐穗扬花期上部叶片发病越重,之后各类病田发病轻重差异减小.[结论]对病田要早期挑治和中期控制,阻止外部菌源的落户和本田菌源的形成,有效减轻后期发病程度,中度以上发病年份.齐穗扬花期普防病田.     

Rapid identification and differentiation of Theileria sergenti and Theileria sinensis using a loop-mediated isothermal amplification (LAMP) assay

The present study developed and validated a species-specific loop-mediated isothermal amplification (LAMP) assay for the rapid detection and discrimination of two benign bovine Theileria species – T. sergenti and T. sinensis. The LAMP assay is inexpensive and easy to perform and involves a rapid reaction-the amplification can be performed in 55 min or 50 min under isothermal conditions of 61 °C or 63 °C, respectively, by employing a set of four species-specific primer mixtures. The results can be checked using agarose gels. The optimal assay conditions, under which the assay exhibited with no cross-reaction with other closely related tick-borne parasites (T. annulata, Babesia bovis, B. bigemina, B. major, B. ovata, B. U. sp., Anaplasma marginale) or between the two Theileria species of interest, was established. The assay is approximately 10-fold more sensitive than the conventional specific PCR assay. The LAMP assay was validated using DNA from 6 standard stocks in the laboratory and was evaluated for its diagnostic utility using blood samples collected from experimentally and naturally infection cattle or yaks in China. These findings indicate that this Theileria species-specific LAMP assay may have potential clinical applications for the detection and differentiation of two benign bovine Theileria species – T. sergenti and T. sinensis, especially in endemic countries.