Seasonal Dynamics of Photosynthetic Response for Young Tree of B. macrostachya in Seasonal Rain Forest

[Objective] The aim was to study on biological characteristics of photosynthetic response for young trees of B. macrostachya in seasonal rain forest, providing scientific reference for protection of tropical rain forest under change of global climate. [Method] Young trees of B. macrostachya in Xishuangbanna tropical forest were chosen to research in foggy season, dry and hot season, and rainy season to measure dynamics of season changes. [Result] For young trees of B. macrostachya in Yunnan Province, Pn max was the biggest in rainy season, followed by dry and hot season and foggy season at 4.08, 2.89 and 1.81 μmol/（m·s） respectively; Gs and Tr in rainy season were the highest and WUE in dry season was the highest; Gi achieved peak in foggy season, of which the highest values were 0.18 and 1.59 mmol/（m 2 ·s）, and 7.35 μmol/mmol and 455 mmol/（m 2 ·s）; Ci showed an opposite trend with that of WUE, and Gs and Tr changed similarly. [Conclusion] Young trees of B. macrostachya in seasonal rain forest are of significant seasonal change in photosynthetic response, and young trees are shade tolerant.

Morphological characteristics of leaf epidermis and size variation of leaf,flower and fruit in different ploidy levels in Buddleja macrostachya (Buddlejaceae)

Buddleja macrostachya （Buddlejaceae） is a widespread shrub native to the Sino-Himalayan mountains and beyond. It has been found to occur at two ploidy levels, hexaploid, 2n=6x=114 and dodecaploid, 2n= 12x=228. To determine if morphological characters might be used as indicators of ploidy levels, we measured floral and fruit length, relative and absolute leaf size, trichome density on both leaf surfaces, and stomatal density and length in different populations orB. macrostachya. In general, flower and fruit length, absolute leaf size, and stomatal length in,eased with an increase at ploidy level （P〈0.01）, whereas adaxial cell and stomatal density decreased with an increase at ploidy level （P〈0.01）. We found no conspicuous differences in relative leaf size （P〉0.05） in different populations. Other characters studied such as trichome type, cuticular membrane and ornamentation of stomata, cell and stomatal shape, and anticlinal wall pattern were quite constant in this species. Thus it appears that flower and fruit length, absolute leaf size, and stomatal frequency and length can be used to distinguish hexaptoid from dodecaploid cytotypes either in the field or in herbarium specimens.

An assessment of factors leading to the decline of Beclardia macrostachya (orchidaceae) population in Mauritius

Clearing of forest land for agriculture and urbanization following colonization have reduced the forest cover in Mauritius to 3% of total land cover. Today exotic species such as Psidium cattleianum (wild guava), Araucaria columnaris, and Ravenala madagascarensis dominate at Pigeon Wood, the only site in Mauritius where Beclardia can be found, leaving little space for very few indigenous tree species like Labourdonnaisia glauca, Apholoia theiformis and Foetida mauritiana. Beclardia macrostachya is an orchid endemic to Mauritius, Madagascar andReunion. Though it is abundant in the latter countries, it is one of the rarest orchids in Mauritius. An assessment of the factors associated with the stability of this orchid was carried out in forests of these three countries to understand the drastic decline of this orchid in Mauritius. Morphometric and fertility counts carried out at different forests revealed differences in fitness and fertility rates among forests of the same countries and between different countries. Stability of the different Beclardia populations was carried out based on counts of juveniles and adults. Higher fertility rates and most stable populations were observed in the forests of Reunion Island (Bebours) and Madagascar (Ambohitanteley), whereas very low fruit set were observed in Mauritius, unless manual pollination was carried out. Microscopic analysis revealed the presence of pelotons of endomycorrhiza during the early development of the seedlings, in vivo. Based on comparative studies among the different sites, pollinator limitation and absence of suitable hosts were the primary factors that led to the present decline in Mauritius. The high density of wild guava, Psidium cattleianum, which has slowly taken up most of the forest areas inMauritiushas affected the regenerating capacity of Beclardia macrostachya and the density of putative hosts of this orchid. GC-MS/MS analysis of nectar revealed α-D- glucopyranose to be the primary reward of the pollinators and benzyl alcohol, methoxybenzyl alcohol and methoxy methyl phenol to be components floral fragrance.

Effectiveness of Hermetic Storage Using PICS Bags and Plastic Jars for Post-Harvest Preservation of <i>Acacia macrostachya</i>Seeds

In Burkina Faso, the availability of Acacia macrostachya “Zamnè” seeds throughout the year is threatened by the attacks of pests. So, the effectiveness of airtight (hermetic) storage for the preservation of these seeds was evaluated using 20-litre plastic jars and 50 kg PICS bags as hermetic containers with 50 kg polypropylene bags as controls. Seeds of Acacia macrostachya (17.5 kg) were stored in each of these storage devices for six months under ambient conditions in the laboratory. The number of storage pest Bruchidius silaceus increased significantly in polypropylene bags from 235 to 715 individuals on average/500 g of seeds. But in PICS bags and plastic drums, the number of this pest did not vary significantly (191 and 239 individuals on average/500 g of seeds for plastic jars and PICS bags respectively). In both hermetic devices, we found few individuals of another major storage pest Caryedon furcatus. However, polypropylene bags, haboured more pests’ in addition high numbers of C. furcatus and Oryzaephilus mercator which were not found in the hermetic devices. Seeds damage and weight loss increased significantly in polypropylene bags from 7.40% to 20.23% and 0.50% to 3% respectively compared to PICS bags and plastic jars. The germination rate of A. macrostachya seeds decreased significantly in PICS bags, plastic jars and polypropylene bags with average percentages of 14%;11% and 15% respectively compared to the initial average of 27%. PICS bags and plastic jars are therefore effective in preserving the quality of A. macrostachya seeds, but the effects of these hermetic devices on seed viability need to be explored further.

Fermentation Effect on the Nutrient and Antinutrient Composition of <i>Senegalia macrostachya</i>and <i>Parkia biglobosa</i>Seeds: A Comparative Study

This study aimed to evaluate the effect of the fermentation on the nutrient and antinutrient composition of Senegalia macrostachya and Parkia biglobosa seeds. For condiments production, the raw seeds were cleaned, cooked, drained, washed, cooked, drained and fermented. Results show that the pH increased (from 6.09 to 7.76 and from 6.99 to 7.92) from the onset of the fermentation till 48 h during fermentation of Senegalia macrostachya and Parkia biglobosa seeds respectively. Biochemical analyses revealed a slight increase in water content, ashes, lipids, minerals and a decrease in total carbohydrate for the two products. The fermentation of Senegalia macrostachya and Parkia biglobosa seeds reduced the initial phytates content by 38.21% and 41.37% respectively. Fermented seeds of Senegalia macrostachya are rich in protein (59.59 ± 0.74 g/100g DM), potassium and magnesium (1076.74 ± 37.49 mg/100g DM and 111.63 ± 06 mg/100g DM respectively) with an appreciable iron content (26.27 ± 0.06 mg/100g DM). Given its nutritional composition, fermented seeds of Senegalia macrostachya could be used as an alternative to soumbala in areas where it is not available.

大穗和中华结缕草的群落特征及种内分异研究

大穗结缕草为盐生植物 ,主要生长在沿海潮沟两侧的滨海盐土地带上 ,其区系组成绝大多数种类属于盐生植物 ,为海滩原生植物群落。中华结缕草为耐盐的优良草坪植物 ,其野生群落主要分布在沿海 2～ 40m的滨海阶地上。其生态幅较宽 ,土壤 pH在 7.2～ 9.2之间。中华结缕草群落为单优群落 ,盖度多在 60 %～ 90 %。中华结缕草种内存在十分丰富的变异 ,采用模糊聚类的方法将 1 7份草样划分为 6类 ,各类间差异很大。主分量分析表明有性繁殖器官如果穗高度和营养器官特征如叶长和匍匐茎扩展速度是研究中华结缕草种内分异的重要指标。这 2种植物可作为沿海城市建植草坪的优良植物。

光温对3种醉鱼草属植物种子萌发的影响

密蒙花、七里香和大序醉鱼草3种醉鱼草的种子细小,千粒重仅12￣58mg,但形态有差异,可以进行种类区分。种子充分吸水后,在20￣25℃条件下于5￣10d内就能迅速萌发,15d时发芽率达到75%以上。光照强度21.6￣32.4μmol·m-2·s-1和光照时间12￣16h·d-1均可显著提高七里香种子的发芽率,但光照抑制密蒙花种子萌发,而对大序醉鱼草种子萌发没有明显影响。种子苗移栽后3￣5d,真叶转绿,90%的幼苗可形成健壮植株。

大穗结缕草幼苗耐盐生理机制及耐盐能力研究

以大穗结缕草为实验材料,采用不同质量分数的NaCl处理后,观察盐胁迫对其生长及生理生化指标的影响。结果表明:随着盐胁迫浓度增大,大穗结缕草幼苗株高、鲜重、干重都逐渐下降,而根容量和根冠比却逐渐上升;随盐胁迫浓度的增大,大穗结缕草幼苗叶片细胞质膜透性和MDA含量逐渐增加,脯氨酸含量持续升高;其多数生长和生理指标在≥2.0%NaCl盐胁迫浓度下与对照差异显著,且此时的脯氨酸含量是对照的10倍以上。研究发现,大穗结缕草幼苗地上部分对盐胁迫更敏感、受害更严重;通过体内脯氨酸积累来减轻渗透胁迫是其可能的耐盐生理机制;2.0%盐胁迫可能是大穗结缕草的最高耐盐浓度。

西双版纳热带季节雨林4种树种幼苗生长死亡对海拔变化的反应

在西双版纳山地选取3个海拔梯度,对热带季节雨林4种主要树种进行幼苗移栽试验,观测幼树生长、死亡沿海拔梯度的变化,目的在于明确海拔变化对热带季节雨林主要树种幼苗生长、死亡的影响,热带季节雨林主要树种幼苗的生长是否在低海拔地区优于在高海拔地区。结果表明,4种幼苗对海拔变化的反应并不相同。绒毛番龙眼和云南玉蕊幼苗的生长和存活主要是受到温度的限制,随海拔的变化表现出显著的差异,这两种幼苗在低海拔上的生长显著优于在中、高海拔上,而云南肉豆蔻和小叶红光树没有表现出在低海拔上优于中、高海拔的特征,这可能是由于它们不适应强光照的生活环境而造成的。

大穗结缕草种子打破休眠的处理技术研究

[目的]探索既能有效地提高大穗结缕草种子发芽率又便于在生产中推广应用的种子处理方法。[方法]在综合考查各种可能影响大穗结缕草萌发和休眠因素的基础上,针对大穗结缕草种子深休眠的特性,研究了不同化学处理方法(H2O2、H2SO4、NaOH、丙酮和GA3)对大穗结缕草种子解除休眠的作用。[结果]在5种化学处理中,用浓度20%NaOH溶液处理大穗结缕草种子25min,再用清水清洗,对解除种子休眠效果最佳,10d发芽势达83.5%,比对照高出58.2百分点,15d发芽率达85%,比对照高出55.0百分点,已接近大穗结缕草种子的潜在发芽率,发芽历时比对照明显缩短。[结论]NaOH溶液处理大穗结缕草种子,既简便可行,种子发芽率又最高。在大穗结缕草种子工厂化处理中可采用此方法作为打破大穗结缕草种子休眠的措施。

大穗结缕草对盐胁迫响应及临界盐浓度的研究

以生长在盐城滩涂的大穗结缕草为试材,研究了不同浓度NaCl胁迫对其坪用质量、叶片相对生长率、叶片含水量、叶片丙二醛含量和相对电导率的影响。结果表明:大穗结缕草在1.0%盐浓度胁迫下不受盐胁迫的影响,在1.5%盐浓度胁迫下开始时略受盐胁迫影响,并逐渐适应。在2.0%、2.5%、3.0%、3.5%和4.0%盐浓度胁迫下,随着胁迫时间的延长,坪用质量、叶片相对生长率和相对含水量率逐渐下降,叶片丙二醛含量和相对电导率逐渐上升。通过建立回归方程,以坪用质量为6和叶片相对生长量下降50%作为确定具有景观价值和存活的临界值指标,求得大穗结缕草具有景观价值和致死临界盐浓度分别为2.08%和2.66%。

大穗结缕草萌发期耐盐能力试验

大穗结缕草属耐盐性草坪草之一,但其种子发芽时的耐盐性较差。试验研究了经20%氢氧化钠处理后的大穗结缕草种子在不同盐度下的发芽率及其对幼苗的影响。结果表明,随着盐度的增高,种子的发芽率逐渐降低,幼根和幼苗的生长受到抑制。当盐度达到1.0%时,大穗结缕草种子的发芽率仅为8.0%。因此,当土壤盐度达到1.0%时,大穗结缕草用种子进行繁殖的效率较低。

大穗结缕草对盐胁迫的响应

研究了大穗结缕草Zoysia macrostachya在1.5%NaCl胁迫过程中叶片形态、相对含水量、可溶性总糖及游离脯氨酸含量的变化对盐胁迫的响应,其结果发现,随着盐胁迫时间的延长,叶片受害程度先增加,后保持稳定,胁迫到15 d时外观又略有恢复;叶片的相对含水量表现为先下降,后保持稳定,最后又缓慢上升的趋势;叶片可溶性总糖含量和脯氨酸含量表现为逐渐增加到一个峰值后又下降的趋势。在盐分胁迫下叶片可溶性总糖和脯氨酸的积累可能是大穗结缕草抗盐的生理机理之一。

大穗结缕草对盐胁迫的生理适应性研究

[目的] 探讨盐胁迫对大穗结缕草生长和生理的影响。[方法] 用NaCl处理大穗结缕草，观测盐胁迫下不同时期其叶片形态特征、叶片相对含水量、可溶性总糖含量、游离脯氨酸含量、POD活性的变化。[结果] 卷曲叶片在盐胁迫0～9 d中由1/3增加至1/2。叶片相对含水量在盐胁迫3～6 d中一直下降，9～12 d基本保持平稳，12～15 d上升。可溶性总糖含量在盐胁迫3～9 d中平稳增加，9～12 d迅速增加，在第12天出现一个峰值，12～15 d下降。脯氨酸含量在盐胁迫3～9 d中缓慢增加，9～12 d迅速增加，在第12天出现一个峰值，12～15 d下降。POD活性在盐胁迫初期缓慢增加，6 d后大幅度增加，12 d后缓慢增加。[结论] 该研究为盐碱地区大穗结缕草的开发、种植与管理提供了理论依据。

石参根中总黄酮含量的测定

用乙醇为提取剂,在乙醇浓度80%、温度70℃、料液比1:20、提取时间90 m in条件下回流提取石参根中的总黄酮。以芦丁为标样,NaNO2-A l(NO3)3-NaOH显色体系进行显色,选择波长510 nm,分光光度法测定石参中总黄酮的含量。实验结果表明:石参根中总黄酮含量为1.10 mg/g,加标回收率为99.3%,RSD为2.0%。方法简便、重现性好,准确。

黄河三角洲大穗结缕草解剖结构的研究

目前对于草坪草的抗性研究多数集中在其生理方面的变化,而结合各抗性品种营养器官结构进行比较研究却报道较少。从采集自山东省无棣县沿海滩涂的大穗结缕草的营养器官解剖结构和微形态特征的研究中分析它的耐盐、耐寒、耐旱、耐践踏和弹性好的原因,从形态解剖的角度来认识大穗结缕草的优良特性。

季节雨林云南玉蕊幼树光合光响应的季节动态

[目的]了解热带季节雨林幼树个体光合光响应的生物学特性,为全球气候变化下热带雨林保护提供科学依据。[方法]在西双版纳热带季节雨林中选择林下云南玉蕊幼树,分别于雾凉季、干热季、雨季,测定其光合光响应特征的季节变化动态。[结果]云南玉蕊幼树林下Pnmax为雨季最大,干热季和雾凉季次之,分别为4.08、2.89和1.81μmol/(m2.s),季节间具显著差异;Gs和Tr以雨季相对最高,WUE以干热季为最高,Ci以雾凉季为最高,它们在人工光源下的最大值分别为0.18 mmol/(m2.s)、1.59 mmol/(m2.s)、7.35μmol/mmol和455μmol/(m2.s);Ci随光强及季节的变化与WUE呈相反趋势,而Gs与Tr变化趋势基本一致。[结论]热带季节雨林云南玉蕊幼树林下光合光响应特征具明显季节性,雨季中有比其他季节更为旺盛的光合特征,且幼树具有耐荫的特性。

盐生植物大穗结缕草种子萌发特性及其对盐旱胁迫的响应

以大穗结缕草为试材,研究了光照/黑暗、温度、盐胁迫和干旱胁迫对大穗结缕草种子萌发特性的影响。结果表明:种子萌发为非需光种子,种子萌发最适温度范围为25~30℃;当NaCl浓度为100mmol·L^(-1)时,大穗结缕草种子最终萌发率与对照无显著差异,但种子发芽势和活力指数与对照有明显差异。当浓度为150~200mmol·L^(-1)时,显著抑制大穗结缕草种子的萌发。种子耐盐临界浓度和极限浓度分别为144.12、244.12mmol·L^(-1);随着干旱胁迫程度的增加,萌发进程所用时间增长,最终萌发率也显著下降,50g·L^(-1) PEG模拟干旱胁迫对种子萌发无显著影响,种子的耐旱临界浓度和极限浓度分别为90.95、155.05g·L^(-1)。综上所述,大穗结缕草种子在萌发期表现出一定的抗盐性和抗旱性。

大穗结缕草愈伤组织诱导及植株再生研究

为获得大穗结缕草离体繁殖的最佳条件，以大穗结缕草不同器官作为外植体，MS为基本培养基，研究了不同消毒方法对外植体除菌效果的影响，不同外植体以及不同激素组合对愈伤组织诱导及分化的影响。结果表明：在光强1500～2000 lx ，16 h光照／8 h黑暗，（23±2）℃培养条件下，大穗结缕草外植体，经70％酒精浸泡45 s ，0．1％ HgCl2浸泡8 min ，污染率低，易于愈伤组织的诱导。以种子胚作为外植体最有利于愈伤组织的培养，愈伤组织诱导的最佳培养基是 MS ＋2，4‐D（2．0 mg·L‐1）＋6‐BA（0．2 mg·L‐1）＋TDZ（1．0 mg·L‐1）。

大穗崖豆一新变种

大穗崖豆一新变种钱义咏（云南省思茅行署林业局，思茅县６６５０００）关键词多小叶大穗崖豆ＡＮＥＷＶＡＲＩＥＴＹＯＦＭＩＬＬＥＴＴＩＡＭＡＣＲＯＳＴＡＣＨＹＡ￥ＱｉａｎＹｉｙｏｎｇ（ＦｏｒｅｓｔｒｙＢｕｒｅａｕｏｆＳｉｍａｏＡｄｍｉｎｉｓｔｒａｔｉｖｅＯ...