成熟度与贮藏期对野生葎草种子发芽力的影响

[目的]探讨成熟度与贮藏期对野生葎草种子发芽力的影响。[方法]随机采种后,测定不同成熟度葎草种子生活力,比较完熟种子发芽力,比较纸床与土床种子发芽力的差异。[结果]葎草灌浆期、第2类乳熟期、第3类蜡熟期、第4类成熟期4种成熟度的种子含水量、千粒重、生活力差异很大的延长,变异系数分别为25.75%、56.22%和77.84%;种子在试验条件下7d左右开始发芽;发芽势随贮藏时间规律较差,发芽率随贮藏时间的延长逐渐下降;种子贮藏1年后发芽力降低为成熟初期的30%,畸化率随贮藏时间的延长逐渐下降;种子在纸床上13d开始发芽,土床上第31天才开始发芽,发芽持续时间分别为33和23d,发芽率相近。[结论]葎草种子成熟期的不一致性保证了该种群的延续性与自我更新能力;贮藏时间对其发芽力的影响有助于葎草的防除。     

Population development of Phorodon humuli and predators (Orius spp.) within hop cones: Influence of aphid density on hop quality

The price of hops in Spain is given per kilogram of dry product and according to their content of alpha-acids. If any aphids are noted inside cones there is a penalty of up to 10% of the dry weight. Experiments were performed in a hop garden in 2002, 2003 and 2004 to investigate population development of the damson-hop aphid, Phorodon humuli, and its natural enemies in hop (Humulus lupulus) cones. Furthermore, we investigated if the alpha-acid content was affected by aphid populations. Aphids were first observed within hop cones at the beginning of August and numbers rose sharply from mid- to late August onwards. Aphid infestation of cones reflected the numbers observed on foliage in July, with a greater population halfway up the bines (3 m height) than at the top (6 m height). The alpha-acid content of dried hops was unaffected by the aphid population on leaves, but aphid contamination reduced the economic value of the crop because of arbitrary commercial criteria related to the presence of aphids in cones. The hop aphid’s main natural enemies within cones were anthocorids, all belonging to the genus Orius. The anthocorid population in cones grew in tandem with the aphid population, suggesting that these predators are worthy of consideration in an integrated management approach.     

葎草不同器官化感活性的研究

以生菜、反枝苋、苘麻、小麦和稗草为指示植物,采用琼脂混粉法对葎草不同器官的化感活性进行了测定。研究表明,葎草的不同器官粉末在10 g/L的添加浓度下对各指示植物幼苗的生长均具有不同程度的抑制作用,且对生菜、反枝苋和苘麻3种双子叶植物的抑制效果高于对小麦和稗草2种单子叶植物的抑制效果,其中以叶器官的抑制活性最高。     

葎草水提液多酚的含量测定与抗氧化性研究

[目的]对葎草风干样水提液中多酚类物质含量和体外抗氧化性进行测定,以期对合理开发利用葎草资源价值,提供科学依据。[方法]采用酒石酸铁法测定葎草中多酚,利用改进的水杨酸法和邻苯三酚自氧化法对葎草各部位的多酚提取液进行抗氧化性测定。[结果]10月份采集的鲜叶中多酚含量最高,达到0.371±0.006 mg/g。提取的多酚抑制超氧阴离子自由基能力最高达到69.750%,清除羟自由基能力最高达65.790%。[结论]葎草地上部各部位多酚提取液都具有一定的抗氧化作用,其中以叶含量最高,茎含量最低。     

绿盲蝽对花期葎草的产卵选择性

前期研究发现,葎草进入盛花期后对绿盲蝽Apolygus lucorum成虫吸引力明显增强,植株上绿盲蝽成虫种群密度快速上升。2011年和2016年,研究了绿盲蝽成虫对初花期与盛花期葎草的产卵选择性。结果发现:盛花期葎草植株上的绿盲蝽成虫密度和卵密度显著高于初花期。绿盲蝽卵主要集中产在花上,而幼芽、嫩茎和叶柄上落卵量较低。同时,在盛花期葎草上,绿盲蝽若虫种群密度以及高龄若虫比例显著偏高。本研究进一步证实了绿盲蝽成虫对盛花期葎草的产卵偏好习性。     

葎草水分和光合特征及抗性物质含量响应冬季降温的性别差异

以野生雌雄异株攀援草本植物葎草为材料,12月自然降温为冬季降温梯度,于1日(T₁)、10日(T₂)、20日(T₃)和30日(T₄)通过测定雌雄株的水势、含水量、叶绿素含量、光合参数和代谢指标,分析降温对葎草新成熟茎叶生理代谢的影响,研究降温对雌雄葎草水分含量和光合作用及代谢系统影响的性别差异。结果表明:1)冬季♂株叶片水势和幼嫩叶含水量高于♀株(P<0.05),茎含水量低于♀株,降温对♂株叶片水势、茎叶含水量影响大于♀株(P<0.05);2)冬季♀株叶片的Chla、Chla/Chlb和Chl(a+b)大于♂株(P<0.05),降温显著降低了叶绿素含量(P<0.05),♂株下降快于♀株,成熟叶下降先于幼嫩叶;3)♂株的成熟和幼嫩叶的C_i(细胞间隙CO₂)大于♀株,G_s(气孔导度)和P_n(净光合速率)小于♀株(P<0.05),降温梯度对C_i、G_s和P_n影响大于性别间(P<0.05),降温使♂株C_i增大、G_s和P_n下降幅度大于♀株,T₃时♂株P_n为负值而♀株为正值,T₄时♀、♂株实际P_n均为负值,但♀株潜在P_n大于♂株;4)♂株叶片和幼茎的SS含量大于♀株,茎叶的Pro含量和成熟茎的SS含量小于♀株(P<0.05),降温下成熟和幼嫩茎叶抗逆性物质含量有显著的性别差异,T₂时♀、♂株的成熟和幼嫩茎叶中SS(可溶性糖)和Pro(脯氨酸)含量均增加(P<0.05),T₃时♂株成熟叶、幼嫩茎叶SS和Pro含量下降幅度大于♀株,T₄时♂株的成熟茎SS和Pro含量下降而♀株增加。降温对葎草叶片水势、茎叶含水量、光合参数和抗性物质含量影响有显著的性别差异,♀株具有比♂株更强应对冬季降温胁迫的生理基础。     

植物生长调节物质对龙利微体快繁影响的研究

研究了植物生长调节物质BA和NAA对龙利微体快繁的影响及2者的综合效应。结果表明：BA和NAA对龙利繁殖系数的影响极大。经比较,适宜的BA和NAA的浓度分别为1．0mg／L和0．1mg／L。对龙利根的诱导以IBA为好,适宜浓度为0．1～1．0mg／L。     

千里光(菊科:千里光族)的核形态及其系统学意义

研究了千里光的核形态：染色体问期为简单型与复杂型的过渡型，前期染色体为中问型。染色体长度从2．96μm到5．36μm，平均长度为4．03μm，核型公式为：2n=20=12m 8sm(2SAT)，为2A类型。从核形态分析，千里光处于进化中较稳定和较原始类型。     

Flow cytometric identification of sexually derived polyploids in hop (Humulus lupulus L.) and their use in hop breeding

The New Zealand hop breeding programme is based solely on the development of seedless triploid cultivars. This relies on the use of tetraploid parents. While a sexually derived tetraploid parents have been used successfully, sexually derived tetraploids offer a useful alternative. They may have a higher level of heterozygosity and are easier to obtain. Methods for the identification of tetraploids from seedling populations by flow cytometry are described. Two studies were conducted; one on field-grown plants, the other on plants grown in a glasshouse. Approximately 15%of seedlings in the two studies were identified as tetraploids (2n = 4x = 40). Between 70 and 80% were identified as either diploid (2n =2x = 20) or triploid (2n = 3x = 30). Remaining plants were haploid, pentaploid or probably aneuploid. Within triploid and tetraploid populations from 40to 50% of seedlings were female, 30 to40% were monoecious, with the remainder being males and non-flowering plants. Sexually derived tetraploid parents have been used successfully in the breeding programme, from which several promising triploid selections have subsequently been made. This revised version was published online in July 2006 with corrections to the Cover Date.     

不同光照及采食条件对薇甘菊和鸡屎藤叶片形态可塑性的影响

为探讨薇甘菊在生物控制的情况下对不同光照环境的入侵能力,本研究比较了不同光照强度(相对光强100%,14.72%)和模拟采食(每片叶片剪掉50%的叶面积,不剪叶)条件下薇甘菊叶片形态可塑性的变化,并将其与本地形态相似的藤本植物鸡屎藤进行对比。结果表明：遮阴显著增加了薇甘菊和鸡屎藤的叶面积,而模拟采食降低了薇甘菊的叶片面积和重量,却没有降低鸡屎藤的叶片面积和重量。遮阴显著增加了薇甘菊和鸡屎藤的比叶面积,增幅达近一倍,说明薇甘菊和鸡屎藤对光照条件的变化都有较强的可塑性反应。模拟采食并没有降低薇甘菊和鸡屎藤的这