安徽短萼黄连种群特性及其濒危机制探讨

对安徽省境内短萼黄连的地理分布、分布地自然概况及种群大小、分布格局、年龄结构等种群特性进行研究.结果表明,短萼黄连在安徽省主要分布于九华山、黄山、清凉峰和牯牛降等山区.其生境涉及林冠下和水沟边两种类型,均表现为阴湿、土壤疏松、呈酸性而富含有机质,要求光照荫蔽度平均达到70%以上,空气相对湿度70%～90%,土壤含水量在30%以上.现有短萼黄连种群均为高群集分布,年龄结构不合理,且多为小种群,表明种群已处于相对不稳定阶段.自然生境的严重破坏、成年植株的过度采挖对短萼黄连种群的生存构成严重威胁,是造成部分野生种群个体数量急剧减少的主要原因.     

南方红豆杉响应不同传粉式样的结实表现

采用开花前雌株短枝套袋隔离传粉、花期人工授粉、风媒传粉 对照 及其传粉障碍等几种传粉式样 ,比较不同传粉 授粉 方式对南方红豆杉 Taxus chinensis var.mairei 结实的影响 ;在风媒传粉条件下 ,研究了南方红豆杉不同种植行向、树冠不同方位、上下内外不同层面的结实表现 .结果表明 :南方红豆杉存在孤雌生殖现象 ,平均单枝结实率为 2 8.7% ,与风媒传粉相比较 ,存在极显著差异 P<0 .0 1 ;人工授粉能显著提高结实率 P<0 .0 5 2 0 .7% ;2～ 3月份开花期 ,江汉平原盛行东北风 ,在风媒传粉条件下 ,东西向种植的南方红豆杉有更多的授粉机会 ,其结实情况极显著优于南北向种植的 P<0 .0 1 ;东西向种植的南方红豆杉树冠果实的空间分布 ,受传粉条件包括风向、冠层方位及距传粉源的距离、冠层内外上下层次等因素的影响 ,方位间的结实量按东南西北方位依次为 :2 30 .375粒、185 .6 2 5粒、12 8.813粒、10 5 .4 38粒 ,呈递减趋势 ,冠外层结实量普通高于冠内层 ,树冠东向下外层结实量最高 4 16 .75粒 ,北向下内层最低 2 2 .0 0粒 .     

硬毛地笋化学成分研究

采用各种色谱对硬毛地笋(Lycopus lucidus Turcz.var.hirtus Regel)的化学成分进行分离,通过理化性质和波谱分析进行结构鉴定。从硬毛地笋全草甲醇提取物中分离鉴定了9个化合物:β-胡萝卜素(1),7,3’,4’-三羟基黄酮(2),β-谷甾醇(3),3’,4’,5-三羟基-3,7-二甲氧基黄酮(4),α-香树脂醇(5),β-香树脂醇(6),24-羟基-乌苏-12-烯-28-酸(7),β-胡萝卜苷(8),24-甲基-5α-胆甾-7,22-二烯-6α-醇-3β-O-葡萄糖苷(9)。化合物4,7和9为首次从该科植物中分离得到,化合物1～9均为首次从硬毛地笋中分离得到。     

升温突变对川西不同坡向和海拔岷江冷杉径向生长的影响

坡向和海拔作为重要的地形因子决定着林木立地条件的水热分配,为揭示川西地区升温突变前后制约岷江冷杉(Abies fargesii var.faxoniana)径向生长的气候因子变化及其在坡向和海拔上的响应格局,通过树木年轮学方法构建了4个坡向(NE、N、NW和W)的3个海拔梯度(≥3650 m)共12个岷江冷杉的标准年表,采用皮尔逊相关分析和回归分析的方法分析了升温突变前后(1980年)限制岷江冷杉径向生长主要气候因子的变化及径向生长的变化趋势。结果表明：升温前,生长季(7月)低温和降水、前一年冬季(10—11月)最高温和平均温制约岷江冷杉的生长,而当年春季(3月)温度的升高和生长季前(5月)较多的降水不利于其生长。升温后,4个坡向的林线、东北坡中海拔,西坡中、低海拔岷江冷杉的径向生长与大部分月温度表现为正相关关系,且上述样点树木径向生长明显加速。1980年升温前,制约不同样点岷江冷杉径向生长的气候因子具有一致性——坡向和海拔对其径向生长与温度相关关系的干扰和影响较小。增温促进了各坡向林线岷江冷杉的径向生长,且偏阳坡在更大的海拔范围内对增温表现出正反馈。研究对未来气候变化背景下川西不同坡...     

Use of the additive main effects and multiplicative interaction model in QTL mapping for adaptation in barley

The additive main effects and multiplicative interaction (AMMI) model has emerged as a powerful analytical tool for genotype x environment studies. The objective of the present study was to assess its value in quantitative trait locus (QTL) mapping. This was done through the analysis of a large two-way table of genotype-by-environment data of barley (Hordeum vulgare L.) grain yields, where the genotypes constituted a genetic population suitable for mapping studies. Grain yield data of 150 doubled haploid lines derived from the Steptoe x Morex cross, and the two parental lines, were taken by the North American Barley Genome Mapping Project (NABGMP) at 16 environments throughout the barley production areas of the USA and Canada. Four regions of the genome were responsible for most of the differential genotypic expression across environments. They accounted for approximately 50% of the genotypic main effect and 30% of the genotype x environment interaction (GE) sums of squares. The magnitude and sign of AMMI scores for genotypes and sites facilitate inferences about specific interactions. The parallel use of classification (cluster analysis of environments) and ordination (principal component analysis of GE matrix) techniques allowed most of the variation present in the genotype x environment matrix to be summarized in just a few dimensions, specifically four QTLs showing differential adaptation to four clusters of environments. Thus, AMMI genotypic scores, when the genotypes constituted a population suitable for QTL mapping, could provide an adequate way of resolving the magnitude and nature of QTL x environment interactions.Ignacio Romagosa was on sabbatical leave from the University of Lleida and the Institut de Recerca i Tecnologia Agroalimentàries, Lleida, Spain, when this study was conducted     

Subgroups in theHordeum patagonicum complex (Poaceae)

Seeds of theHordeum patagonicum complex were collected from the field and grown in the greenhouse. The aim was to take a sample of members of the complex, and on the basis of the phenotypic similarities in some morphological and physiological characters, determine whether distinct groups exist. When cluster analyses, to generate hypotheses, and orthodox statistical procedures, for hypotheses obtained a priori, were applied to the reproductive morphology, germination and flowering patterns, onlyH. patagonicum subsp.magellanicum, out of the five recognized taxa, could be distinguished consistently. The remaining four taxa, which overlapped considerably, could be re-formed into three groups whose centroids were different but whose ranges of variation were not distinct from each other. We conclude that the highly cross-compatible members of theH. patagonicum complex, first defined as species and later redefined as subspecies are probably no more than biotypes.     

The Effects of Root Treatment with Various Stress Agents on Plant Cold- and Heat-Tolerance

The root systems of cucumber (Cucumis sativus L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.) plants were subjected to a short-term (6–7-h-long) treatment with low and high temperatures, sodium chloride, and lead nitrate, and the effect of these treatments on the changes in the cold- and heat-tolerance of leaf cells was determined. It was established that chilling of cucumber and wheat seedling roots at 10 and 2°C, respectively, or their heating at 38°C and 40°C, respectively, induced an increase in both cold- and heat-tolerance of leaf cells. An increase in the cold- and heat-tolerance was also observed in roots treated with sodium chloride at concentrations of 0.15 M (cucumber) and 0.2 M (wheat), as well as with lead nitrate at a concentration of 0.1 mM (barley, wheat). The tolerance increase induced by these stress agents was accompanied by a considerable increase in the ABA concentration in leaves. The effect of physical and chemical stress agents is suggested to induce the same nonspecific changes in the aboveground organs. These changes bring about, directly or indirectly, an increase in the cold- and heat-tolerance and are related to an increase in the ABA content.     

Evaluation of DNA damage and mutagenicity induced by lead in tobacco plants

Tobacco (Nicotiana tabacum L. var. xanthi) seedlings were treated with aqueous solutions of lead nitrate (Pb²⁺) at concentrations ranging from 0.4 mM to 2.4 mM for 24 h and from 25 μM to 200 μM for 7 days. The DNA damage measured by the comet assay was high in the root nuclei, but in the leaf nuclei a slight but significant increase in DNA damage could be demonstrated only after a 7-day treatment with 200 μM Pb²⁺. In tobacco plants growing for 6 weeks in soil polluted with Pb²⁺ severe toxic effects, expressed by the decrease in leaf area, and a slight but significant increase in DNA damage were observed. The tobacco plants with increased levels of DNA damage were severely injured and showed stunted growth, distorted leaves and brown root tips. The frequency of somatic mutations in tobacco plants growing in the Pb²⁺-polluted soil did not significantly increase. Analytical studies by inductively coupled plasma optical emission spectrometry demonstrate that after a 24-h treatment of tobacco with 2.4 mM Pb²⁺, the accumulation of the heavy metal is 40-fold higher in the roots than in the above-ground biomass. Low Pb²⁺ accumulation in the above-ground parts may explain the lower levels or the absence of Pb²⁺-induced DNA damage in leaves.     

桂林小花苣苔离体快速繁殖技术

对抗结核植物桂林小花苣苔(Chiritopsis repanda var. guilinensis)进行离体培养与快速繁殖技术研究。结果表明: 桂林小花苣苔叶片外植体的最适初代诱导培养基为MS+0.5 mg·L^–16-BA+0.05 mg·L^–1IBA, pH8.0; 最适继代增殖培养基为 MS+0.1 mg·L^–16-BA+0.05 mg·L^–1IBA, pH6.0, 繁殖系数7.0/35天; 最适生根培养基为1/2MS+0.2 mg·L^–1NAA, pH6.0, 生根率为93.6%。模拟桂林小花苣苔自然生境, 在春季对生根试管苗进行大棚移栽, 成活率达90%。根据上述快繁技术, 理论上每株试管苗每年可繁殖桂林小花苣苔种苗46万株。     

梅州沙田柚结果树中矿质元素的季节性变化

研究了梅州沙田柚 (Citrusgrandisvar shatinyuHout )叶片、果实在各时期的矿质元素含量变化。结果表明 ,沙田柚在年周期中 ,树体的营养元素含量随着物候期表现出明显的季节性变化 ,说明沙田柚的栽培必须按各物候期、迎合沙田柚对营养要求 ,适时地、适量地供给各种养料 ;根据成熟果实中N、P的吸收量可推算出其全年所需的施氮、磷施肥量。