林木非同化器官树枝（干）光合功能研究进展

尽管多数林木非同化器官树干、树枝内都存在绿色组织（Chlorenchyma）,但是其生态学意义很少为人注意。综合前人研究结果,得出以下结论：（1）树枝的光合速率（暗呼吸与饱和光照下呼吸之差）的在0～10μmolm^-2s^-1之间,而大部分的结果认为光合速率在0．5～3．Oμmolm^-2s^-1之间。而且多数研究认为其是对自身呼吸的再固定,而不是对外界大气CO2的吸收,对再固定率（光合／呼吸比值）分析表明80％以上的研究结果认为树干光合作用能够固定40％～100％呼吸所释放的CO2。但其对个体乃至林分整体碳平衡的影响报道的较少。（2）不仅非同化器官光合作用直接影响其呼吸作用,冠层叶片光合产物对非同化器官的气体代谢也产生显著影响,但新形成光合产物和储藏碳水化合物是否存在功能上的差异不同学者意见不一。（3）尽管叶绿素含量多在80～450mgm^-2之间,低于相应叶片叶绿素含量340～620mgm^-2,但其叶绿素a／b平均值（2．5）显著低于叶片的平均值（3．6）（P〈0．0001）,说明更加适应于阴生环境。（4）有关类胡萝卜素在非同化器官的功能,比较传统的观点认为其单位质量或者单位面积含量远低于叶片,是一种适应于低光照环境的表现,但最近研究表明其单位叶绿素含量远高于叶片,可能是在高浓度CO2条件下、叶绿体片层结构酸性化导致光合过程中光化学淬灭能力低下,需要以叶黄素循环为主导能量淬灭过程保证其功能正常。（5）在树皮光学特性方面,大部分光照被吸收,而有少部分被反射和透射。在透光率方面,70％左右的结果认为树皮的透光率在5％～15％之间,而超过85％的结果认为透光率在0％～20％之间。而且光照可以在木质化树干导管、纤维及管胞有效进行轴向导光,树干内部的光以红外和远红外光为主,其它低波长光的透射能力远低于红外光。（6）尽管已有研究表明某些草本植物茎具有C4特征,但对于多数、特别是木本植物未见报道,特别是对于茎内高浓度CO2、高红／蓝光比、低氧特征对光合机构的影响尚需要深入研究。     

果树枝条栽培灵芝的品质特性分析

【目的】研究果树枝条作为栽培基质对赤灵芝(菌株:金地灵芝)子实体品质的影响。【方法】比较果树(苹果、桃树、梨树)枝条和常规杂木屑栽培灵芝的农艺性状、营养成分及活性成分含量的变化,进一步对其改善睡眠的功能进行评价。【结果】果树枝条栽培的灵芝品质具有较大的差异。3种果树枝条栽培的灵芝菌丝体生长速度显著低于常规组(P0.05),发菌时间延长7-13 d,同时产量有不同程度的下降。各组间的营养成分含量无明显差异,而果树枝条组的矿质元素含量均显著大于常规组。此外,虽然果树枝条组的灵芝多糖含量较常规组低,但是均能够有效延长小鼠注射戊巴比妥钠后的睡眠时间,并且梨树枝条组能够有效缩短睡眠潜伏期,增加小鼠的入睡率(P0.05),改善睡眠功能显著。【结论】利用果树枝条栽培灵芝对其产量和农艺性状指标有一定影响,但是具有较好的改善睡眠的功能。因此,通过果树枝条配方优化,栽培高品质灵芝是切实可行的。     

中国长蠕孢属的分类研究Ⅱ.四川省的两个新种

报道生于四川省枯树枝上的长蠕孢属两个新种,假喙长蠕孢Helminthosporium spurirostrum和四川长蠕孢Helminthosporium sichuanense。假喙长蠕孢的分生孢子可产生假喙,这是首次报道长蠕孢属的一个新的特征。四川长蠕孢与黄檀长蠕孢H.dalbergiae较相似,但是黄檀长蠕孢的分生孢子大(长58-125μm,宽12-14μm),分生孢子梗细(宽10-12μm)。研究标本保存在山东农业大学植物病理学标本室(HSAUP)。     

Gene tree quality affects empirical coalescent branch length estimation

Assessing effects of gene tree error in coalescent analyses have widely ignored coalescent branch lengths (CBLs) despite their potential utility in estimating ancestral population demographics and detecting species tree anomaly zones. However, the ability of coalescent methods to obtain accurate estimates remains largely unexplored. Errors in gene trees should lead to underestimates of the true CBL, and for a given set of comparisons, longer CBLs should be more accurate. Here, we furthered our empirical understanding of how error in gene tree quality (i.e., locus informativeness and gene tree resolution) affect CBLs using four datasets comprised of ultraconserved elements (UCE) or exons for clades that exhibit wide ranges of branch lengths. For each dataset, we compared the impact of locus informativeness (assessed using number of parsimony-informative sites) and gene tree resolution on CBL estimates. Our results, in general, showed that CBLs were drastically shorter when estimates included low informative loci. Gene tree resolution also had an impact on UCE datasets, with polytomous gene trees producing longer branches than randomly resolved gene trees. However, resolution did not appear to affect CBL estimates from the more informative exon datasets. Thus, as expected, gene tree quality affects CBL estimates, though this can generally be minimized by using moderate filtering to select more informative loci and/or by allowing polytomies in gene trees. These approaches, as well as additional contributions to improve CBL estimation, should lead to CBLs that are useful for addressing evolutionary and biological questions.     

Intra-specific hybridization: generator of genetic diversification and heterosis in Andrographis paniculata Nees. A bridge from extinction to survival

Andrographis paniculata (AP) has been stated as a low-diverse, endangered and red-listed plant species. Self-pollinated mating system, being an introduced species and experiencing a bottleneck as well as over exploitation cause such a consequence. Inter and intra-specific hybridizations have been suggested as essential techniques for generating genetic diversity. To test the effect of intra-specific hybridization on diversification and heterosis of AP, seven accessions were outcrossed manually in all 21 possible combinations. Three types of markers including morphological, phytochemical and RAPD markers were employed to evaluate the mentioned hypothesis. The results revealed that hybridization acted as a powerful engine for diversification of AP as it caused heterotic expression of the studied traits, simultaneously. Initially, it seems that additive and non-additive gene effects both can be considered as the genetic basis of heterosis in AP for the investigated traits. Agronomic and morphological traits were differentiated from each other, while positive heterosis was recorded mainly for agronomic traits but not for the morphological traits. Intra-specific hybridization increased the genetic diversity in AP population. Nevertheless, a part of this variation could also be attributed to the negative heterosis. The current exploration demonstrated the first ever conducted manual intra-specific hybridization among AP accessions in a mass scale. However, the 17 RAPD primers produced a monomorph pattern, but perhaps increasing the number of markers can feature a new genetic profile in this plant.     

藿香枝叶多糖的提取工艺及其清除羟基自由基作用研究

采用苯酚-硫酸,并以超声法辅助提取野生藿香枝叶中的多糖,设计L9(34)正交试验考察料液比、pH和超声提取时间对藿香枝叶中多糖提取的影响,并对藿香多糖进行清除.OH试验。结果表明,藿香多糖的最佳提取工艺为料液比1∶10,超声提取30min,pH值为6,可使藿香多糖的提取率高达7.50%。藿香多糖对羟基自由基有显著地清除效果,表明其有抗氧化作用。     

Volubolin,a 4-phenyl-2H-1-benzopyran-2-one from Dalbergia volubilis

From the ether soluble portion of a methanolic extract of young non-green branches of Dalbergia volubilis, sitosterol, 7-hydroxy-4-methyl-2H-1-benz     

Seasonal changes in the Modulus of Elasticity of living branches of three coniferous species

The seasonal changes in the Modulus of Elasticity (E) of living branches ofCryptomeria japonica, Chamaecyparis obtusa andLarix leptolepis were investigated over a period of 1 year by means of a quick and non-destructive method previously introduced by the authors. Two sample trees were used for each species and 12 branches were selected from each tree. Readings of the experiments began in summer 1992 and were successively conducted in autumn 1992, winter 1993, spring 1993 and finally in summer 1993. Our investigations revealed that meanE values increased in cold seasons and decreased in warm or hot seasons. Mean values ofE estimated in summer (1993) were relatively close to those estimated in summer 1992 indicating that any changes that occurred were the direct result of the environmental factors prevailing in the intervening seasons. Extremely high meanE values were measured when the branches were in a frozen state in winter; 69.4%, 29.9% and 24.6% higher than the previous summer for branches ofCryptomeria japonica, Chamaecyparis obtusa andLarix leptolepis, respectively. This sharp increase over the initialE values measured in summer 1992 was quite likely due to the freezing effect of rime on the branches.     

Comparative phenological and water potential patterns of three Calligonum species in the eastern great Erg of Tunisia

Calligonum azel, C. comosum and C. arich (Polygonaceae) are three dominant and economically important species widely distributed in active sand dunes in the southern desert of Tunisia, which differ in growth form and may co-occur under the same climatic constraints. The aims of this work were to compare their phenological and water potential patterns, as well as branch, flower and fruit production during three years at monthly intervals. Predawn (Ψ_pd) and midday (Ψ_md) water potentials followed similar trends with a few exceptions. For all species, Ψ_md reached values more negative than −2.5 MPa during the hot and dry summer, with extremes in July. Ψ_pd differed between the species, and C. comosum attained the most negative values (−1.71 MPa). Seasonal differences in Ψ_pd were less pronounced for Calligonum species established in dunes as compared to C. comosum from interdunes. Spatial and temporal variations in soil water content provoked changes in water potentials of these species. Diurnal amplitudes resulting from the difference between Ψ_md and Ψ_pd were more pronounced during the dry season compared to the wet months. The phenological pattern of the three species showed a similar sequence of phenophases with growth activity occurring mostly between spring and summer. We found a species-dependent response to summer drought, as C. comosum ended all phenophases in June, while C. azel and C. arich extended their vegetative growth into the summer period of low precipitation. Water availability for the plants was better on the dune slopes. Differences were statistically significant among species, concerning green branch production and numbers of initially formed flowers and mature fruits. Our data suggest that changes in the studied parameters may depend on the rooting depth of the species.