芦笋优良雄株无性系繁殖的研究

研究结果:①PP333诱导芦笋芽苗生根的效果与嘧啶醇近似,二者的生根率分别为85.0%和86.7%;PP333诱导芽苗生根的最佳浓度为1.0mg/l;②茎切段在含PP333的培养基上诱导生根后,及时转培于无激素培养基是培养易移栽试管苗的基本技术程序;③将芦笋试管苗置5～10klx光强下闭瓶炼苗7～10天后,直接移栽于含黄绵土和细沙各50%的苗床,上覆塑料薄膜拱棚,平均移栽成活率为85%.     

晋中盆地麦蚜发生为害程度及原因分析

晋中盆地麦蚜发生为害高峰常出现于小麦孕穗到灌浆期,大发生年发生高峰可提前至拔节期。从1998～2003年连续6年的系统观察调查得出,遇暖冬及早春温暖干旱气候,麦蚜呈现早发生或大发生;如遇冬春低温多雨,尤且是1～2月份极端温度低于-20℃,时间长达15d时,对麦蚜发生形成明显抑制。另外,蚜虫发生程度与天敌数量关系密切,小麦播种面积与蚜虫发生总量呈正相关关系。     

大麦黄矮病毒(BYDV-GPV)的循回传播机理

对植物组织中蚜虫口针分泌的胶状唾液染色观察发现，蚜虫刺探时口针穿行在细胞间隙，仅在吸食时下颚口针进入细胞内。禾谷缢蚜饲毒１２ｈ时ＲＴ－ＰＣＲ方法在后肠、血淋巴液和附唾液腺中检测到ＧＰＶ；而非介体麦长管蚜在ＧＰＶ毒源上吸食２４ｈ时，仅在后肠组织中检测到ＧＰＶ；当继续取食４８ｈ时，在后肠及血淋巴液中也发现了ＧＰＶ，但仍无能力进入附唾液腺，说明蚜虫后肠和附唾液腺对病毒均有专化选择作用，禾谷缢管蚜传播ＢＹＤＶ－ＧＰＶ时存在吸食、获毒和传毒三个阶段。     

柑桔蚜虫种类及其发生为害的考查(同翅目:蚜科)

1984～1986年的调查结果表明,为害我省柑桔的蚜虫有绣线菊蚜Aphis citricola van derGoot、棉蚜A.gossypli Glorer、豆蚜A.craccivora Koch、枯蚜Toxoptera citricidtt s(Kirkaldy)、枯二叉蚜T.aurantii(Boyer de Fonscolomhe)、桃蚜Myzus persicae(Sulzer)和樟修尾蚜Sinomegoura citricola(van der Goot)7个种。其中豆蚜为我国柑桔害虫新记录,绣线菊蚜是本省柑桔蚜虫的优势种,共次为棉蚜和枯蚜。柑桔新梢有蚜率可达80％以上。几种蚜虫常混合发生。夏秋梢受害比春梢重,幼年树,肥水条件好和靠近村庄的果园受害较重。文中还讨论了柑桔蚜虫优势种的演替问题。     

施氮量对棉花和棉蚜的影响

在田间和盆栽情况下,进行了施氮量对棉花和棉蚜(Aphis gossypii Glover)影响的研究。随着施氮量的增加,棉叶中可溶氮和蛋白质含量增加;棉花的产量相应提高;初生蚜到成蚜开始胎生的历期缩短,成蚜的个体增大,寿命延长,繁殖力增加;棉蚜的种群数量增加。通过对氮肥费用,化防费用及棉花产量3因素的综合分析,初步得出每亩施氮10kg,种植棉花的经济效益最佳。     

10个小麦品种（材料）对麦长管蚜的室内苗期抗蚜性*

［目的］ 明确不同小麦品种对麦长管蚜(Sitobion avenae)的室内苗期抗性。［方法］ 在温室内采用每株小麦接种1头蚜虫的方法,测定了麦长管蚜在来源于3个国家的10个小麦品种上的发育历期（DD）、相对日均体重增长量（MRGR）和成虫日均产仔数（Rm）,以此来确定不同小麦品种（材料）的抗蚜性。［结果］ 应用多元方差分析,多目标综合判别及聚类分析等方法分析表明,麦长管蚜在‘Ww2730’、‘98 10 30’、‘Astron’上的适应性最差,这几个品种对其抗性最好,是可以利用的抗性品种（材料）;‘98 10 35’、‘98 10 32’次之;‘Batis’对麦长管蚜的适应性最好,抗性最差;‘186Tm’,‘Xanthus’,‘Amigo’对麦长管蚜适应性较好,与作为对照的‘小偃 22’一样,抗性处在中间水平。［结论］ 研究结果可以为进一步的抗蚜育种提供依据。     

Soil quality variables in organically and conventionally cultivated field sites

This study aimed to answer the following questions (a) which of the soil variables (chemical, biological, enzyme activities and potential metabolic profile based on the Biolog method) could be used as indicators reflecting differences in soil quality between organically and conventionally managed asparagus fields, (b) how the duration of organic management affects these soil variables and (c) in what extent the soil quality in organic fields is comparable to that in hedgerows. The study included four organically cultivated fields which differed in the time they enter organic treatment: 6 years (O6), 5 years (O5), 3 years (O3) and 2 years (O2), the closest to them hedgerow (Ho), a conventionally managed field (CF) and its adjacent hedgerow (Hc). Among the chemical and biological variables, those contributing for most to the discrimination of the organic and conventional fields were mainly microbial biomass C (MBC) and N (MBN) and secondly variables related to N-cycle (NO₃, N organic, rate of N mineralization). MBC and MBN were higher in organic and conventional areas, respectively, reflecting differences in the structure of their microbial communities. The chemical and biological variables did not differ among O3, O5 and O6 fields, while low values of organic N, rate of N mineralization and extractable P was recorded in O2 area. The enzyme activities of amidohydrolases (l-asparaginase,l-glutaminase, urease) and phosphatases (alkaline and acid phosphatase) were by far higher in organic areas than in the conventional one. The activities of amidohydrolases and alkaline phosphatase changed in a similar way, exhibiting higher values in O3 and O5 areas while between the oldest (O6) and the newest (O2) area no differences were recorded. While the suppress of enzyme activities in O2 was related to low inputs due to transition, the negative feedback between supply of N and P and activities in O6 was a possible explanation. The activity of acid phosphatase increased from the newest to oldest organic areas. The potential functional diversity and substrate evenness did not differ among sampling areas. Differences between areas were recorded only in relation to the carbohydrates' consumption. The soil quality of hedgerows seems to be completely different than that of the arable land in terms of all studied variables. Also, significant differences were recorded between the two hedgerows, a fact that could be related to the different management practices applied in the neighboring fields.     

芦笋离体快速繁殖中嫩茎增殖培养对根分化的影响

本试验对芦笋组织培养中影响生根的培养基激素配比、嫩茎增殖培养中激素配比及嫩茎增殖次数等因素进行了研究。结果表明,嫩茎增殖培养基激素配比和嫩茎增殖次数等因素对后续的茎段生根有重要影响。芦笋组培再生完整植株优化培养过程为:芦笋外植体(茎段)在J2(MS NAA 0.2 mg/L BA 0.5 mg/L)培养中诱导出嫩茎后,再在嫩茎增殖培养基J3(MS NAA 0.2 mg/L BA 0.1 mg/L)或J9(MS NAA 0.05 mg/L BA 0.1 mg/L)增殖1次(嫩茎增殖次数对后续生根影响极大),然后取增殖1次后的茎段接种到生根培养基G4(MS IBA 0.5 mg/L BA 0.05 mg/L 2.0 mg/L PP333)中进行生根培养,最高生根率可达90%以上。芦笋组培苗移栽成活率主要受诱导出的根质量的影响。通过几个因素的优化,最终可使芦笋根诱导率达90%~100%,移植成活率达100%。     

高粱抗蚜基因的遗传分析和SSR标记定位

高粱蚜是高粱生产中的一种毁灭性害虫,利用植物的固有抗性是防治害虫的最有效途径。经多年杂交选育获得1个对高粱蚜免疫的高粱品种“河农16”,用其作亲本与感蚜品系“千三”进行杂交,对亲本、F1、F2抗蚜性鉴定表明,“河农16”和F1对蚜虫表现高抗,F2抗感分离符合3∶1,该抗蚜性受一对基因控制,表现出显性遗传。用已定位到连锁群上的微卫星标记和分离群体分析法,对抗蚜基因进行了连锁分析,发现1个与抗蚜基因连锁的微卫星标记(SSR标记),与抗蚜基因的遗传距离为8.7 cM。该标记位于第9连锁群上,因而将该基因初步定位于第9连锁群。     

Triterpene saponins of Quillaja saponaria show strong aphicidal and deterrent activity against the pea aphid Acyrthosiphon pisum

BACKGROUND: Saponins are a class of secondary plant metabolites consisting of a sugar moiety glycosidically linked to a hydrophobic aglycone (sapogenin) that often possess insecticidal activities. Four saponins were selected: two triterpene saponins, Q. saponaria saponins and aescin, and two steroidal saponins, digitonin and diosgenin. Their effects were investigated on an important pest species and a model piercing‐sucking insect, the pea aphid Acyrthosiphon pisum. The triterpene Q. saponaria saponins bark saponin received special attention because of its high activity. Aphids were challenged by oral and contact exposure to demonstrate aphicidal activities, and in choice experiments to support use as a natural deterrent. RESULTS: When aphids were exposed to supplemented artificial diet for 3 days, a strong aphicidal activity was recorded for three of the four saponins, with an LC₅₀ of 0.55 mg mL^?1 for Q. saponaria saponins, 0.62 mg mL^?1 for aescin and 0.45 mg mL^?1 for digitonin. The LT₅₀ values ranged between 1 and 4 days, depending on the dose. For diosgenin, only low toxicity (14%) was scored for concentrations up to 5 mg mL^?1. In choice experiments with treated diet, a deterrence index of 0.97 was scored for Q. saponaria saponins at 1 mg mL^?1. In contrast, direct contact showed no repellent effect. Spraying of faba bean plants with Q. saponaria saponins resulted in an LC₅₀ of 8.2 mg mL^?1. Finally, histological analysis in aphids fed with Q. saponaria saponins demonstrated strong aberrations of the aphid gut epithelium, and exposure of midgut CF‐203 cell lines to Q. saponaria saponins in vitro confirmed the cytotoxic effect. CONCLUSIONS: The present insect experiments provide strong evidence that saponins, as tested here with triterpene Q. saponaria saponins, can be useful as natural aphicides and deterrents. Furthermore, the insect midgut epithelium is suggested to be a primary target of saponin activity.Copyright © 2011 Society of Chemical Industry