中国蜘蛛抱蛋属一新记录种——博格纳蜘蛛抱蛋

报道了产自中国云南喀斯特地区的蜘蛛抱蛋属一新记录种——博格纳蜘蛛抱蛋（Aspidistra bogneri H.-J.Tillich）。该种以前报道仅产于越南宁平省菊芳国家公园（Ninh Binh,Cuc Phuong National Park）,本次是中国首次记录。对该种的特征进行了详细描述并提供了彩色图片,凭证标本存放于中国科学院昆明植物研究所标本馆（KUN）。     

Nitrogen fertilizers promote plant growth and assist in manganese (Mn) accumulation by Polygonum pubescens Blume cultured in Mn tailings soil

Abstract

This study examined how different nitrogen (N) forms and application levels promote plant growth and assist in manganese (Mn) remediation of Polygonum pubescens Blume (P. pubescens) cultured in soil with a high Mn level. The effects of ammonium chloride (a) and urea (u), at three application levels (10, 20, and 30?mg L^?1 N) and control (no N addition, CK) on the growth, Mn accumulation, and enzymatic anti-oxidative defenses of P. pubescens were examined. In general, both ammonium-N and urea-N promoted the plant mass and height of P. pubescens. The total Mn amount of roots, stems, and leaves in N treatments were higher (p?<?0.05) than that of CK. The ammonium-N treatments showed greater plant biomass and Mn accumulation compared to the urea-N ones. In general, the accumulations of Mn, Cr, Zn, and Cu were significantly lower (p?<?0.05) in the N fertilizer treatment than those in the control; while the accumulations of Pb were higher (p?<?0.05) in P. pubescens across all N fertilizer treatments than those in the control. The N addition decreased the contents of O₂^? and H₂O₂ in the leaves of P. pubescens, while increasing the activities of enzymatic anti-oxidative defenses.     

Stomatal closure induced by high vapor pressure deficit limited midday photosynthesis at the canopy top of <Emphasis Type="Italic">Fagus crenata</Emphasis> Blume on Naeba mountain in Japan

Diurnal changes in gas exchange, chlorophyll fluorescence and leaf water potential (_leaf) were measured to determine the environmental and physiological factors that limit carbon gain in the horizontal leaves of Fagus crenata Blume at the canopy top. Although midday depression of the net CO₂ assimilation rate (A_n) and stomatal conductance (gH₂O) were clearly evident on a fine day, the potential quantum yield of PS II (F_v/F_m) was fairly constant around 0.83 throughout the day. This result indicates that the leaves at the canopy top do not suffer from chronic photoinhibition, and the excess energy is dissipated safely. Large reversible increases in non-photochemical quenching (NPQ) were evident on fine days. Therefore, the non-radiative energy dissipation of excess light energy contributed to avoid chronic photoinhibition. The electron transfer rate (ETR) reached maximum during the midday depression, and thus there was no positive relation between ETR and A_n under high light conditions, indicating a high rate of photorespiration and the absence of non-stomatal effect during midday. The protective mechanisms such as non-radiative energy dissipation and photorespiration play an important role in preventing photoinhibitory damage, and stomatal limitation is the main factor of midday depression of A_n. To separate the effect of air to leaf vapor pressure deficit (ALVPD) and leaf temperature (T_leaf) on gas exchange, the dependencies of A_n and gH₂O on ALVPD and T_leaf were measured using detached branches under controlled conditions. A_n and gH₂O were insensitive to an increase in T_leaf. With the increase in ALVPD, A_n and gH₂O exhibited more than a 50% decrease even though water supply was optimum, suggesting the dominant role of high ALVPD in the midday depression of gH₂O. We conclude that midday depression of A_n results from the midday stomatal closure caused by high ALVPD.     

Size distribution,growth and inter-year variation in sex expression of Bischofia javanica,an invasive tree

Flowering activity and sex expression of Bischofia javanica Blume were investigated for 3 years. B. javanica is an invasive dioecious tree of subtropical forests on the Bonin Islands in the western Pacific of Japan. The sex ratio showed a significant male bias (1.25-2.33). Smaller trees were significantly male biased, whereas larger trees showed no significant difference in sex expression, suggesting that males tend to be more precocious in sexual reproduction. We found evidence for sex changes in B. javanica; these have not been reported previously. Most of the 1,653 census trees remained non-flowering (58.1 %); 3.7 % of them showed sex changes, and the percentage of trees repeatedly flowering as males and females was 10.5 and 3.4 %, respectively. Sex changes were observed in both directions but a larger percentage of male trees became female. Flowering frequency and sex expression were significantly related to tree size (i.e. diameter at breast height). Over the 3 years, trees that were consistent females were the largest; inconsistent trees (switching sex between years) were intermediate in size, whereas consistent males were the smallest. There were no significant differences in relative growth rate (RGR) among trees of different sex or flowering frequencies. These results suggest that the maintenance of female reproduction is not related to changes in RGR of diameter but to flowering frequency or the reversal to the male form, dependent upon the internal resource status of individual trees.     

中国蜘蛛抱蛋属一新记录种——合瓣蜘蛛抱蛋

首次报道中国蜘蛛抱蛋属一新记录种——合瓣蜘蛛抱蛋Aspidistra connata H.-J.Tillich,该种与辐花蜘蛛抱蛋A.subrotata Y.Wanet C.C.Huang相似,但叶片长椭圆形至长卵状椭圆形,花被顶端8～10裂,裂片线形,顶端联合不分开,形成一个笼状包围着雌蕊可与后者区别。凭证标本存放于广西植物标本馆(IBK)。     

蜘蛛抱蛋属植物叶表皮微形态的扫描电镜观察

在扫描电子显微镜下,观察9种蜘蛛抱蛋属植物的叶表皮微形态。结果表明,9种植物叶下表皮的细胞都为长方形,垂直壁为直的,垂周界限为凸的,外层周壁凹陷。气孔椭圆形至卵圆形,气孔外拱盖表面多平滑,其内缘近平滑、浅波状或锯齿波状;角质膜多为脊状条纹、有的外层周壁有横纹或颗粒。气孔大小与染色体的倍性有一定的正相关关系。不同种间叶表皮特征表现出一定差异,对种的划分有一定的分类鉴定意义。     

华北低丘山区栓皮栎生态系统氧同位素日变化及蒸散定量区分

利用稳定同位素技术对华北低丘山区栓皮栎生态系统氧同位素日变化及蒸散定量区分进行研究,为华北低丘山区森林生态系统水汽交换研究提供基础。试验采用离轴积分腔输出光谱技术(OA-ICOS)连续测定生态系统不同高度水汽浓度和δ18O值,同时采用真空提取和液态水同位素分析仪测定枝条和土壤的δ18O值。结果显示,4个晴天中大气水汽浓度日变化复杂,变化趋势差异大,而δ18O日变化均成高-低-高的"V"型变化,最小值出现在12:00—18:00。Keeling方程在10:00—12:00的相关系数R2均大于0.71,方程达到极显著水平,表明此时段蒸腾速率较高,满足植物蒸腾的同位素稳定态假设。利用Keeling方程估算的栓皮栎生态系统δET值有相似的低-高-低日变化,与大气的δv值变化趋势相反。同位素分割结果显示栓皮栎生态系统中蒸腾占蒸散比例日变化呈现低-高-低的趋势,10:00—14:00蒸腾占蒸散比例达到90%以上,尽管6:00—10:00和14:00—18:00的蒸腾占蒸散比例下降,但平均值仍高达69.38%,表明华北低丘山区栓皮栎生态系统的蒸散主要来源于植物蒸腾。     

天目山山胡椒不同部位内生真菌组成及多样性分析

采用表面消毒法,从浙江天目山野生山胡椒[ Lindera glauca( Sieb.et Zucc.) Blume]的茎、叶和树皮中分离出内生真菌,基于ITS序列分析进行分类鉴定;并以内生真菌的分离率、定殖率、分离频率、多样性指数(H')及相似性系数为指标,分析了山胡椒内生真菌的菌群组成及多样性.结果显示:在26株山胡椒样株的728块组织块中共分离得到328株内生真菌(茎、叶和树皮中分别有161、40和127株);共鉴定出44个分类单元(茎、叶和树皮中各有19、18和28个),其中25个分类单元鉴定到种、17个鉴定到属、2个鉴定到科,ITS序列的GenBank登录号从JF502420至JF502462.在44个分类单元中,有40个分类单元属于子囊菌(310株),存在于山胡椒的各个部位;仅有4个分类单元属于担子菌(18株),且仅存在于茎和树皮中.山胡椒茎、树皮和叶中内生真菌的定殖率分别为65％、60％和15％,分离率分别为0.77、0.61和0.19;叶和树皮中内生真菌的多样性指数均为2.63,远大于茎(H’=1.83).山胡椒内生真菌的优势属为Phomopsis、Paraconiothyrium、Phoma和Colletotrichum,大量存在于叶、茎和树皮中.山胡椒茎与树皮、茎与叶及叶与树皮间内生真菌的相似性系数分别为0.27、0.19和0.18,显示树皮和叶之间以及树皮和茎之间内生真菌的组成极不相似.研究结果表明:山胡椒体内存在大量的内生真菌,其茎、叶和树皮的内生真菌菌群组成具有一定程度的多样性和差异性,且内生真菌的分布具有组织特异性.     

中国蜘蛛抱蛋属植物营养器官的解剖学研究

首次对中国蜘蛛抱蛋属 9种植物的营养器官进行了解剖学研究。结果表明 :该属 9种植物的解剖结构基本相同。根和根状茎都由表皮、皮层和维管柱组成。根表皮下有单层薄壁细胞 ;内、外皮层均为一层五面加厚的厚壁细胞 ,内皮层外切向壁薄 ,呈马蹄形 ,外皮层内切向壁薄而外切向壁特别加厚 ,并栓质化 ,在横切面上形成一明显的厚壁组织环带 ;根为多原形。根状茎有明显的内皮层 ,周木维管束散生于维管柱的基本组织中 ;具有次生结构 ,次生保护组织为周皮。叶为等面叶 ,具有C4植物结构特征 ;气孔在上、下表皮均有分布 ,保卫细胞肾形 ,属四轮列型。该属植物的解剖结构与其生态环境相适应 ,体现了结构与功能的统一。     

蜘蛛抱蛋属植物花粉形态及系统学意义

用扫描电子显微镜对国产 1 4种蜘蛛抱蛋属植物的花粉形态进行了观察 ,该属植物的花粉形态有长球形和球形 2种 ;外壁纹饰可分为 3大类型 :( 1 )皱波状纹饰 ;( 2 )小芽孢状纹饰 ;( 3)瘤棒状纹饰。它们的演化趋势是 :皱波状纹饰→芽孢状纹饰→瘤棒状纹饰