樱桃中苹果蠹蛾溴甲烷熏蒸试验研究

试验设11~15℃、16~20℃、21~26℃3个温度区间,试验用苹果蠹蛾幼虫人工接种到樱桃上,分别用4种不同溴甲烷剂量进行处理,每个处理设5个重复,1个对照,试验在温控室的熏蒸桶中进行。结果表明,在11~15℃,溴甲烷剂量48 g/m3,熏蒸2h;16~20℃,溴甲烷剂量40 g/m3,熏蒸2h;21~26℃,溴甲烷剂量32g/m3,熏蒸2h,均能够100%杀死樱桃中苹果蠹蛾幼虫。考虑温度对樱桃品质的影响,建议将11~15℃、溴甲烷剂量48g/m3,熏蒸2h,作为溴甲烷熏蒸樱桃中苹果蠹蛾的技术参数。     

2种不同熏蒸剂对舞毒蛾不同虫态的杀灭效果

为判断溴甲烷和硫酰氟对舞毒蛾不同虫态的杀灭效果,在25℃下,分别在经过气密性检测的熏蒸桶内投入16、20、24、32 g/m3的溴甲烷和40、56、72、88 g/m3的硫酰氟,熏蒸处理舞毒蛾卵、幼虫、蛹和成虫4.5h.结果表明,经过4.5h熏蒸,杀灭舞毒蛾卵、1龄幼虫、蛹和成虫的溴甲烷浓度分别为32、20、24和16 g/m3,杀灭上述虫态硫酰氟浓度分别为88、56、72和40 g/m3.本文结果表明,舞毒蛾卵为最耐受溴甲烷和硫酰氟熏蒸的虫态,在目前口岸实际熏蒸处理中应充分考虑熏蒸剂对舞毒蛾卵的杀灭效果.     

磷化氢和溴甲烷复合熏蒸红心火龙果携带番石榴实蝇技术研究

本文研究了磷化氢(PH₃)和溴甲烷(MB)复合熏蒸对番石榴实蝇的毒力以及对红心火龙果采后品质的影响。结果表明,复合熏蒸方式下,各个浓度的磷化氢和溴甲烷均存在增效,当溴甲烷浓度为4 g/m³时,复合熏蒸发挥最佳增效效果的磷化氢浓度为1.42 g/m³。复合熏蒸番石榴实蝇仅需13.19 g/m³的溴甲烷即可在95%置信区间下达到致死率99.996 8%。与对照相比,复合熏蒸对火龙果的外观和内部品质无显著影响,而与溴甲烷单独熏蒸相比,复合处理会显著降低呼吸强度并减少药害。因此,溴甲烷和磷化氢复合处理对番石榴实蝇具有协同效应,表明磷化氢和溴甲烷复合熏蒸有可能成为水果采后处理的一种新策略。     

溴甲烷对扶桑绵粉蚧的熏蒸处理研究

为建立扶桑绵粉蚧溴甲烷熏蒸处理方法,本文测定了溴甲烷熏蒸2h对扶桑绵粉蚧各虫龄的致死毒力。用机率值分析表明:各虫龄对溴甲烷敏感性不同,以1龄若虫对药剂最敏感,以3龄若虫耐药性最强;在20℃和29.5℃下3龄若虫达到99%死亡率所需CT值分别为44.09 g.h/m3和29.77 g.h/m3,其对应的LC99分别为28.09 g/m3和18.10 g/m3。验证实验表明在21～25℃下以剂量38g/m3,在26～30℃下以剂量25 g/m3熏蒸2h各供试虫龄死亡率均达到100%,该指标可为扶桑绵粉蚧安全检疫处理提供参考。     

溴甲烷对松木片中松材线虫的熏蒸作用

采用二次正交旋转组合设计,在室内条件下研究了溴甲烷剂量、熏蒸处理时间和处理温度对松木片中松材线虫熏蒸效果的影响。结果表明,溴甲烷剂量是影响熏蒸效果的最主要因子;14、18 ℃和22 ℃条件下处理24 h,松材线虫死亡率达99.9%时的溴甲烷浓度分别为17.92、16.07、14.87 g/m3; 14、18、22 ℃条件下,松材线虫死亡率达99.9%时,溴甲烷浓度和时间乘积,即CT（99.9）分别为192.52、174.705、166.229 g•h/m3。溴甲烷可用于口岸松木片中松材线虫的除害处理。     

溴甲烷熏蒸对桃蛀果蛾的毒力作用

对溴甲烷熏蒸处理桃蛀果蛾结果进行机率值法分析,推算出在25℃温度条件下溴甲烷熏蒸处理1.5h和2h,达到桃蛀果蛾Carposina sasakii Matsumura幼虫死亡率99%的浓度时间乘积(CT值)分别为43.79g·h/m3和46.77 g·h/m3;15℃和10℃温度条件下熏蒸处理3h,达到桃蛀果蛾幼虫死亡率99%的溴甲烷浓度分别为50.84 g·h/m3和118.55 g·h/m3.研究表明,溴甲烷熏蒸对桃蛀果蛾幼虫的毒性作用随着溴甲烷熏蒸浓度的增加而增加,相同熏蒸剂浓度条件下,随着温度升高,溴甲烷熏蒸效果明显增加.     

木质包装松材线虫溴甲烷熏蒸处理

为寻求一定温度下溴甲烷熏蒸处理杀灭木质包装中松材线虫的有效浓度和时间,给国际贸易中木质包装松材线虫的熏蒸处理提供科学依据,进行了木质包装松材线虫溴甲烷熏蒸处理研究.研究分实验室基础试验和集装箱应用试验两部分,先在实验室中筛选出熏蒸有效浓度和时间,再于集装箱中进行应用试验.结果表明:11～15、16～20、≥21℃时,溴甲烷剂量分别为64、56、48g/m3,熏蒸24h,24h时浓度分别不低于32、28、24g/m3,即CT值分别为1152、1008、864 gh/m3,能够100%杀灭木质包装中松材线虫的成虫、幼虫及卵.此外,证实了国际植物检疫措施标准ISPM NO.15<国际贸易中木质包装材料控制准则>中熏蒸处理的要求偏低,不能完全杀灭木质包装中松材线虫.     

低温条件下溴甲烷和硫酰氟对紫穗槐豆象的毒力

熏蒸环境温度为5℃、10℃的条件下,设计6～10个不同剂量分别开展溴甲烷和硫酰氟熏蒸杀灭紫穗槐种子携带紫穗槐豆象(Acanthoscelides pallidipennis)老熟幼虫的毒力试验,应用PoloPlus软件进行机率值分析的结果表明:在5℃条件下,预计紫穗槐豆象老熟幼虫达到99.9968%死亡率所要求的CT值(Lct_(99.9968))为溴甲烷2855.7g.h/m~3、硫酰氟3973.5g.h/m~3,熏蒸24h所需剂量为119.3g/m~3、158.7g/m~3;在10℃条件下,Lct_(99.9968)为溴甲烷2145.2g.h/m~3、硫酰氟1436.3g.h/m~3,熏蒸24h所需剂量为88.1g/m~3、59.0g/m~3。因此,随着熏蒸温度的提高,硫酰氟对紫穗槐豆象老熟幼虫的毒力作用增长明显,可作为进出口紫穗槐种子检疫处理的有效熏蒸剂,但熏蒸的环境温度须高于10℃。     

溴甲烷对松木木质包装穿透性研究

25℃、48g/m3起始剂量条件下,溴甲烷熏蒸12h,熏蒸箱内溴甲烷浓度衰减率超过40%,而12h后到48h熏蒸结束时,溴甲烷衰减率小于5%。箱内溴甲烷CT值在6h达到200g.h/m3。溴甲烷对松木的穿透是顺着木纹进行的。在熏蒸48h内,无虫害木块内部各采样孔的溴甲烷浓度与箱内浓度无法达到平衡,15cm处CT值不足200g.h/m3;有虫害木块内部各采样孔溴甲烷浓度在20h与箱内浓度基本平衡,15cm处的溴甲烷CT值达到200g.h/m3需13h。     

溴甲烷熏蒸对山楂叶螨和桃蛀果蛾的毒力研究

苹果是我国的重要出口水果,山楂叶螨(Tetranychus viennensis Zacher)和桃蛀果蛾(Carposinasasakii Matsumura)在苹果主产区广泛分布,严重威胁我国苹果出口。为确定溴甲烷检疫处理山楂叶螨和桃蛀果蛾的技术指标,本文系统测定了一系列温度条件下溴甲烷对山楂叶螨成螨和富士苹果中桃蛀果蛾老熟幼虫的毒力,确定在5℃、10℃、15℃、20℃和25℃下,溴甲烷熏蒸山楂叶螨死亡率达到机率值9所需浓度时间乘积(CT值)分别为126.66、84.35、59.15、45.23和40.33mg.h/L,溴甲烷熏蒸桃蛀果蛾死亡率达到机率值9所需CT值分别为128.05、81.80、52.91、41.56和36.43mg.h/L。根据上述结果,建议采用10.0～14.9℃40g/m3 2h、15.0～19.9℃32g/m3 2h、20.0～24.9℃24g/m3 2h和大于25.0℃20g/m3 2h作为出口苹果的溴甲烷熏蒸处理技术指标。     

减压条件下溴甲烷对松褐天牛熏蒸效果的研究

利用XMG-35真空熏蒸库在11～21℃和减压条件下,选择不同压力和浓度梯度,对含有松褐天牛(Monochamus alternatus Hope)幼虫的黑松(Pinus thunbergii)木段进行4h的溴甲烷熏蒸处理,投药后循环20min,将库内气压立即回升至95kPa。结果表明,松褐天牛幼虫的杀灭效果和环境温度、压力、投药剂量有关,在其他条件相同的情况下,压力越低,对松褐天牛的杀灭效果越好;在相同条件下,保持30kPa状态20min再将气压缓慢回升至95kPa,对松褐天牛的杀灭效果介于常压熏蒸与减压后快速回压熏蒸之间。     

Eco-physiological studies on desert plants: germination of Halothamnus iraqensis Botsch. seeds under different conditions

With the aim to investigate if the halophyte Halothamnus iraqensis Botsch. can be suitable for re-vegetation and remediation of salt-affected lands, this study evaluated(1) the effects of photoperiod, thermoperiod, storage period and wings' presence on its seed germination, and(2) the ability of its seeds to have successful germination recovery after salt stress. Germination tests in different photoperiods(12 h light/12 h darkness and total darkness) and thermoperiods(15℃/20℃ and 20℃/25℃) were conducted for seeds collected in 2012, 2013, 2014, 2015 and 2016. The seeds collected in 2016 were sown under different salinity levels(0, 100, 200, 400 and 600 m M Na Cl) to assess the salinity tolerance during the germination. Wings' presence highly inhibited seed germination of this species in both photoperiods and thermoperiods under all salinity level treatments. In addition, the germination recovery occurred well when seeds were deprived of their wings. The photoperiod of 12 h light/12 h darkness and the thermoperiod of 15℃/20℃ were the best conditions for seed germination. Germination percentages of H. iraqensis seeds decreased with the increasing storage duration, especially after three years of the collection. In addition, H. iraqensis seeds were able to germinate under different salinity levels, and their germination percentages decreased with increasing salinity levels. H. iraqensis seeds have the ability to recover their germination after alleviating the salt stress, irrespective of photoperiod, highlighting the halophilous character of this species.     

温周期、贮藏时间和盐分对短毛柽柳种子萌发的影响

短毛柽柳(Tamarix karelinii)是分布于盐渍化沙地和重盐碱地的灌木。为了阐明短毛柽柳种子的萌发特性,设置不同的温周期、储藏时间和盐分梯度,采用室内控制实验研究这些因子对种子萌发的影响。结果表明:1短毛柽柳种子在4个温周期中均具有高的萌发率,并且温周期温度越高,种子的萌发速率越快。2室温贮藏1个月显著提高种子的萌发速率,在贮藏6个月内,种子的最终萌发率都能达到100%。3≤0.8 mol·L~(-1)的Na Cl溶液对种子的最终萌发率无显著影响,而≥1.0 mol·L~(-1)的溶液则抑制种子的萌发,且随着浓度的增加,种子的最终萌发率呈下降趋势,直至为0。将1.0~4.0 mol·L~(-1)溶液中没有萌发的种子,转移至蒸馏水继续培养后,仍有71.67%~28.00%的种子恢复萌发率,表明种子具有较强的耐盐性。对短毛柽柳种子萌发特性的研究,为短毛柽柳的种苗培育提供基础资料。     

Effects of water stress and NaCl stress on different life cycle stages of the cold desert annual Lachnoloma lehmannii in China

For a plant species to complete its life cycle in arid and saline environments, each stage of the life cycle must be tolerant to the harsh environmental conditions. The aim of the study was to determine the effects of water stress (water potentials of -0.05, -0.16, -0.33, -0.56, -0.85 and -1.21 MPa) and NaCl stress (50, 100, 200, 300, 400, 500 and 600 mmol/L NaCl) on seed germination percentage, seedling survival and growth, juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge (Brassicaceae), an cold desert annual that grows in the Junggar Basin of Xinjiang, China in 2010. Results indicated that low water stress (-0.05 and -0.16 MPa) had no significant effect on seed germination percentage. With a decrease in water potential, germination percentage decreased, and no seeds germinated at -0.85 and -1.21 MPa water stresses. Germination percentage of seeds was significantly affected by NaCl stress, and higher germination percentages were observed under non-saline than saline conditions. An increase in NaCl concentrations progressively inhibited seed germination percentage, and no seeds germinated at ≥400 mmol/L NaCl concentration. Non-germinated seeds were transferred from both PEG (polyethylene glycol-6000) and NaCl solutions to distilled water for seed germination recovery. The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased. About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration. Thus, seed germination, seedling establishment and reproductive stage in the life cycle of L. lehmannii are water- and salt-tolerant, with seedlings being the least tolerant. These tolerances help explain why this species can survive and produce seeds in arid and saline habitats.     

两种雀麦种子萌发期耐热性比较研究

设置了八个变温梯度 ,三种播前预措方式及一个对照 ,分别对两种雀麦 (沙地雀麦Bromus ircutensis和无芒雀麦 Bromusinermis)种子进行萌发测试。测定了不同处理下的发芽率、发芽指数、休眠率和死亡率 ,并依此比较了这两种牧草种子在萌发期的耐热性能。结果表明 ,从发芽率和发芽指数看 ,二者并无明显的差异 ( P<0 .0 5) ,在较低的温度下二者都有较高的发芽率和发芽指数 ,当温度超过 45℃时二者都不萌发。从休眠和死亡状况可知 ,沙地雀麦种子比无芒雀麦种子有较强的耐高温性。三种预措方式中 ,三次回干效果较好     

Inter-population variabilities in seed mass and germination of Panicum turgidum and Pennisetum divisum in the desert of Kuwait

Understanding variability in seed germination among populations is essential for planning an effective germplasm collection for restoration and conservation purposes.The knowledge of germination and dormancy patterns among populations of desert grasses is crucial for determining the potential of the species and populations to be used for restoration and conservation as well as forage production.Variability in seed germination of Panicum turgidum Forssk and Pennisetum divisum(Gmel.)Henr.in the desert of Kuwait was evaluated in different populations in May 2017.Experiment of seed germination(25 seeds and 4 replicates)was conducted for each population at night/day temperatures of 15℃/20℃and 20℃/30℃under the following light condition:continuous darkness or 12 h/12 h light/dark.Results showed that seed masses of both species strongly varied according to their seed provenances,and both species produced heavier seeds in population with a higher soil electrical conductivity.Seed germination percentage considerably varied between two species,and the variation in P.turgidum was greater(17%–49%)than that of P.divisum(72%–93%).Germination percentage in P.turgidum was greater at high temperature(20℃/30℃)than at low temperature(15℃/20℃).However,temperature regimes had no effect on germination percentage of P.divisum seeds.Mean germination time of both species exhibited significant inter-population variability.This result is especially relevant to assure the selection of the best population of each species and the regeneration success of the species.Besides this,inter-population variability also provides valuable information for enhancing our understanding of the mechanisms that regulate seed germination and how they might be related to seed provenance.     

Germination strategies of annual and short-lived perennial species in the Arabian Desert

Germination timing is highly regulated in short-lived plant species since it strongly influences recruitment success of vegetation. In deserts, the spatiotemporal distribution of plant-available water is highly episodic and unpredictable, making winter months more favorable for seed germination when other abiotic conditions co-occur. We hypothesized that changes in photoperiod and thermoperiod would impact germination more in seeds that had undergone in situ storage. We assessed 21 annual and short-lived perennial species in the Arabian Desert to find (1) if seeds were dormant at maturity, (2) if in situ seed storage increased germination percentage compared with no storage, (3) if photoperiod and thermoperiod germination requirements were influenced by in situ storage, and (4) if a phylogenetic association in seed germination could be observed. Seeds of each species collected in early 2017 were divided into two batches. One was tested for germination within one week (fresh seeds). The other was stored in situ at the maternal location (stored seeds) until October 2017 and tested for seed germination in the first week of November. Seed germination was conducted in incubators at two thermoperiods (15°C/20°C and 20°C/30°C; 12 h/12 h), and two photoperiods (12 and 0 h light per day). Results indicated that seed germination percentages of 13 species were significantly enhanced by in situ storage. A thermoperiod response was exhibited by stored, but not fresh seeds. Light exposure increased germination of fresh seeds but had only a minimal effect on stored seeds. Germination traits exhibited no phylogenetic correlation. This result indicated that selection pressure for germination strategy was stronger than that for taxonomic traits of these desert species.