温度对铁皮石斛组培苗质量的影响

目的: 考察温度对铁皮石斛组培苗质量的影响,为该药材的人工栽培提供参考。方法: 将增殖阶段和生根阶段的铁皮石斛组培苗在湿度、光照强度、光照时间可控的环境条件下,设置温度分别为15,20,25,30,35 ℃共5个梯度进行实验,观察组培苗生长状况,利用Pearson相关性分析增殖阶段温度与苗株数、株高,生根阶段温度与株高、茎粗、叶片数、根数、根长的相关性,并对每个温度间生长指标差异性进行方差分析。结果: 25~30 ℃的组培苗质量较好,表现出良好的生长和繁殖能力;Pearson相关性分析显示在增殖阶段温度跟苗株数和株高在0.01水平上显著相关;在生根阶段温度跟株高、叶片数、根数在0.01水平上显著相关。LSD多重比较显示在增殖阶段苗株数、株高的差异性明显;生根阶段叶片数、根数、株高差异性明显。结论: 温度是影响铁皮石斛组培苗质量的关键因子,最适温度25 ℃。     

知母种苗质量分级标准研究

目的:研究制定符合生产实际的知母种苗质量分级标准,为知母药材规范化生产提供依据。方法:对知母主产区基地以及药材市场销售的种苗进行质量指标调查,通过相关分析、主成分分析,并结合生产实践确定知母种苗的质量分级指标,通过K-均值聚类分析将知母种苗分为3个等级,并以不同等级种苗为处理材料进行田间试验,连续2年观测植株生长、药材产量及质量指标。结果:确定种球直径和百株质量作为知母种苗的质量分级指标,将种苗分为3个质量等级,Ⅰ级种苗:种球直径≥1.2 cm,百株质量≤2.0 kg;Ⅱ级种苗:种球直径≥0.8 cm,百株质量≤1.5 kg;Ⅲ级种苗:种球直径≥0.5 cm,百株质量≤1.0 kg且≥0.5 kg。不同等级种苗对植株根系生长、药材产量有显著影响,均表现为:Ⅰ级>Ⅱ级>Ⅲ级。不同等级种苗种植后药材的有效成分含量差异不显著,但均高于《中华人民共和国药典》的标准。结论:本研究制定的知母种苗质量标准即具科学性,也更符合生产实际,可为知母药材的规范化栽培提供理论依据。     

氮素水平对喜树幼苗喜树碱含量的影响

目的:探讨氮素营养水平对喜树幼苗喜树碱含量的影响。方法:在温室中对砂培喜树幼苗进行5种氮素水平处理,用HPLC测定了喜树幼苗各器官中喜树碱含量,观察了幼叶中喜树碱含量的动态变化过程。结果:不同氮素水平下喜树幼苗幼叶中喜树碱含量均明显高于其他器官的(P<0.01)。喜树幼苗幼叶中的喜树碱含量在不同氮素水平下随时间进程均呈明显的单峰曲线,处理的第50天达到高峰;幼叶的喜树碱含量随氮素水平的增加而明显减小,氮素水平为4 mmol.L^-1时幼叶的喜树碱含量最高(6.72‰),是16 mmol.L^-1的1.1倍。结论:适宜的供氮水平对于喜树幼苗幼叶中的喜树碱含量极为重要,适当的低氮胁迫能够显著地增加喜树幼苗幼叶的喜树碱含量。     

柴胡大棚育苗移栽技术研究

目的研究柴胡大棚育苗移栽的技术。方法在种植区选地建造冬暖式大棚,将柴胡种子处理后进行棚内育苗,待苗高10～15cm时进行移栽。结果柴胡大棚育苗与露地直播比较出苗整齐,病虫害减少,移栽的成活率达95%以上;药材的生长周期缩短,产量提高近50%,质量达到GAP生产要求。结论柴胡可利用大棚进行大面积育苗移栽,适宜规范化种植推广。     

Consequences of clonality for sexual fitness: Clonal expansion enhances fitness under spatially restricted dispersal

Clonality is a pervasive feature of sessile organisms, but this form of asexual reproduction is thought to interfere with sexual fitness via the movement of gametes among the modules that comprise the clone. This within-clone movement of gametes is expected to reduce sexual fitness via mate limitation of male reproductive success and, in some cases, via the production of highly inbred (i.e., self-fertilized) offspring. However, clonality also results in the spatial expansion of the genetic individual (i.e., genet), and this should decrease distances gametes and sexually produced offspring must travel to avoid competing with other gametes and offspring from the same clone. The extent to which any negative effects of clonality on mating success might be offset by the positive effects of spatial expansion is poorly understood. Here, we develop spatially explicit models in which fitness was determined by the success of genets through their male and female sex functions. Our results indicate that clonality serves to increase sexual fitness when it is associated with the outward expansion of the genet. Our models further reveal that the main fitness benefit of clonal expansion might occur through the dispersal of offspring over a wider area compared with nonclonal phenotypes. We conclude that, instead of interfering with sexual reproduction, clonal expansion should often serve to enhance sexual fitness.     

A root drench in unsaturated hydrogel solution reduced stress in transplanted Eucalyptus pilularis cuttings but was ineffective for seedlings: a glasshouse experiment

Available soil moisture and quality of planting material are two important criteria affecting survival during plantation establishment. It has been observed that in northern NSW most seedling deaths occur within the first four weeks of planting. Reducing the rate that plants become stressed is important as less-stressed plants are more capable of exploiting available soil moisture required for survival beyond this four-week period. The health (leaf gas exchange, visual symptoms of leaf and stem wilt) and survival of Eucalyptus pilularis Smith seedlings and cuttings were examined following the application of water in the form of either a hydrogel solution or as irrigation. The main findings were that the rate at which stress developed was slower for cuttings than for seedlings; and that supplying more water, either as hydrogel or irrigation, reduced transplant stress and prolonged survival. Differences in morphology between seedlings and cuttings may explain why cuttings developed stress more slowly than did seedlings. Compared with seedlings, cuttings had reduced leaf area, an increased root: shoot ratio and lower leaf area: root dry mass ratio, all of which are traits that enhance water uptake and reduce water loss. The most effective treatments for reducing stress of seedlings and cuttings were either removing individual seedlings or cuttings from nursery trays and dipping the root ball into a 100% saturated hydrogel solution which coated it with a layer of saturated hydrogel, or supplying the equivalent volume of water as irrigation when transplanting the plants. Drenching nursery trays in 25% and 50% unsaturated hydrogel solutions prior to the removal of the plants delayed stress of transplanted cuttings to a similar extent as the 100% saturated hydrogel solution, but these solutions were ineffective in delaying stress in seedlings. It is thought the more open structure of the soil medium used for cuttings allowed the unsaturated hydrogel solutions to enter the root-ball during root drenching, and because the hydrogel solutions are more viscous than water the drainage of the solutions after removing the nursery trays from the root drench was reduced.     

野生与组培金线莲有效成分的比较及RAPD分析

目的 研究人工栽培金线莲替代金线莲野生资源的可行性.方法 比较金线莲组培苗与野生金线莲药材中多糖、氨基酸及总黄酮的量,采用随机扩增多态性DNA (RAPD)技术对金线莲组培苗及野生药材进行了基因组DNA多态性分析.结果 多糖和总黄酮的比较表明,金线莲组培苗与野生品(台湾)的多糖和总酮量相近;总氨基酸比较表明,金线莲组培苗中总氨基酸达9.17％,高于野生品的总氨基酸量;通过随机扩增多态性DNA (RAPD)技术,从中筛选出了能用于鉴别金线莲组培苗的特异性引物.结论 初步证明通过组织培养获得的金线莲组培苗可以代替其野生品,它是解决金线莲资源紧缺的有效途径之一.     

铝毒胁迫对黄芩生理生化的影响

目的 探讨铝胁迫对黄芩幼苗生理生化的影响,为揭示铝毒害植物机理提供依据.方法 黄芩为研究材料,采用盆栽方式,待幼苗长至6片真叶时,用0.1、0.5、2.0、5.0 mmol·L-1浓度的铝溶液处理黄芩幼苗,在处理15d后,进行各项指标测定.结果 随着铝胁迫浓度升高,黄芩游离脯氨酸和丙二醛(MDA)含量逐渐增加,过氧化物...     

中性盐和碱性盐胁迫对黑果枸杞种子萌发及幼苗生长的影响

在中性盐(NaCl)和碱性盐(Na₂CO₃)胁迫下,对采自河西走廊黑河中游的黑果枸杞进行种子萌发及幼苗生长试验,测定了发芽率(G_r)、发芽势(G_v)、发芽指数(G_I)、活力指数(V_I)和相对盐害率及幼苗的组织含水量、可溶性蛋白质含量、叶绿素含量、电导率、丙二醛含量和POD含量等指标。结果表明,黑果枸杞种子萌发的NaCl、Na₂CO₃浓度的临界值分别是50 mmol·L^-1和2.5 mmol·L^-1,极限值分别是300 mmol·L^-1和100 mmol·L^-1;在NaCl和Na₂CO₃胁迫下,发芽率分别为69.17%和71.67%;幼苗组织含水量分别由对照的88.97%降低到56.17%、70.27%;可溶性蛋白质含量最大值分别为7.09%、7.73%;叶绿素含量分别由对照的1.27 mg·g^-1降到0.78 mg·g^-1、0.92 mg·g^-1;电导率分别由对照的25.63%增加到64.77%、74.8%;丙二醛含量分别由对照的1.5 μmol·g^-1增加到6.9、6.5 μmol·g^-1;POD活性分别由对照的380.4 U·g^-1·min^-1降低到139.2 U·g^-1·min^-1、192.7 U·g^-1·min^-1。黑果枸杞是盐生植物,低浓度的盐促进萌发,高浓度的抑制萌发;碱性盐更适合其生长;黑果枸杞幼苗在盐胁迫下的生理响应及生态适应综合表现出黑果枸杞更适于碱性盐生长。