角茴香根水浸液对生菜的化感潜力及机理初探

以生菜为受体植物,使用培养皿法研究了角茴香根水浸液的化感潜力,并对其可能的机理进行了初步探讨.结果表明:不同浓度角茴香根水浸液对生菜种子的萌发、幼苗的根和下胚轴的生长以及植株鲜重均有显著抑制作用,而凡处理液浓度越高,生菜生长所受到的抑制程度越深;随着角茴香根水浸液处理浓度的增大,生菜幼苗中超氧阴离子自由基的含量逐渐升高,其抗氧化酶如SOD、POD和CAT活性比对照显著增强.研究发现,角茴香根水浸液中可能含有较强活性的化感物质,使生菜幼苗受到了明显的活性氧伤害,也因此而表现出较强的化感潜力,但生菜通过上调体内抗氧化酶活性来应对这种伤害.     

Two ecologically distinct subspecies ofHypochaeris radicata L.

Summary Two subspecies ofHypochaeris radicata were compared with respect to differences in drought tolerance. The soil water content of the sites ofH. radicata ssp. ericetorum Van Soest was always lower than that ofH. radicata L. ssp.radicata throughout a great part of the growing season. Two water culture experiments were conducted at different light intensities. Water stress was induced by addition of NaCl to the culture solution. Both subspecies accumulated free proline andmyo-inositol during water stress. The results are compared with those of field observations. In all experiments with stress application ssp.radicata showed heavier wilting symptoms than ssp.ericetorum, concomittantly with a lower osmotic potential of the cell sap, a higher percentage of dry-weight and irreversible desiccation of older leaves in some experiments after stress application. The observed effects are attributed to the higher transpiration rate maintained by ssp.radicata during stress. Free proline accumulation depended on the severity of the internal stress rather than on the applied level of external stress. At low light intensity the stress resulted in a significantly higher proline accumulation in ssp.ericetorum than in ssp.radicata whereas at high light intensity this was the reverse. No differences inmyo-inositol accumulation were observed in the water culture experiments. Since ssp.ericetorum occurs in a nitrogen poor environment, the effect of nitrogen deprivation on accumulation of free proline andmyo-inositol was investigated. Both subspecies tended to accumulate less proline under such conditions especially ssp.radicata. Accumulation ofmyo-inositol was not favoured by nitrogen deprivation in the water culture experiments. Neither of the subspecies accumulated proline during the sampling period in the field presumably as a result of the wet summer. Leaves of whole plants collected in the field and subsequently subjected to water deprivation showed a high capacity to accumulate free proline. The level ofmyo-inositol in the field was higher in ssp.ericetorum than in either ssp.radicata or control plants in the water culture experiments. When the cytoplasmic volume is estimated as 10% of the total cell volume, free proline andmyo-inositol account for 44–69% of the osmotic potential. It is concluded that ssp.ericetorum is better adapted to the drier environment by its higher capacity to accumulate proline and reduce transpiration during stress. Grassland species research group, publication no41.     

Two ecologically distinct subspecies ofHypochaeris radicatal L.

Summary The present paper is part of a series of papers comparing two ecologically distinct subspecies ofHypochaeris radicata L.Hypochaeris radicata ssp.radicata grows in more fertile soils thanH. radicata ssp.ericetorum.The dry-weight yield of plants grown from seeds was measured after a 25 days culture period on varying levels of nitrate. Roots and shoots were analyzed for total organic nitrogen and free nitrate. Dry-weight yield showed an almost identical response over the whole range of nitrate concentrations used. The chemical analysis did not reveal differences between the subspecies that could explain the distribution in the field. In a second experiment the growth rate of the two subspecies was measured under optimal nitrate supply during a two month period. Both subspecies exhibited initially the same relative growth rate but one month after sowing the growth rate of both subspecies declined, with a sharper decline in ssp.ericetorum resulting in an 82 per cent difference in dry-weight between both subspecies two months after sowing. Some pronounced formative differences became evident. Shoot to root ratio of ssp.ericetorum showed little response to increasing nitrate concentrations whereas ssp.radicata was clearly responsive in this respect.The contribution of the tap root in total plant dry-weight was relatively higher in ssp.Ericetorum. The decline in growth rate and the formative differences can explain the absence of ssp.ericetorum from nutrient rich soils. when grown on ammonium ssp.radicata had a slightly but not significantly higher yield than ssp.ericetorum. The difference was even greater at low pH. It is concluded that both subspecies are adapted to ammonium nutrition at pH 4.5 as well as at pH 6 and that the absence of ssp.radicata from acidic soils cannot be explained by the low pH. The possibility that both subspecies have different abilities to reduce their growth when nitrate resources become limiting, and yet remain capable for further growth and reproduction is discussed.Grassland species research group, publ. no.16.     

Two ecologically distinct subspecies ofHypochaeris radicata L.

Summary Uptake and assimilation of nitrate by two subspecies ofHypochaeris radicata L. were investigated under laboratory conditions as well as in the field.H. radicata ssp.radicata grows on relatively nitrogen-richer soils thanH. radicata ssp.ericetorum. Attempts were made to relate nitrate uptake and nitrate assimilation in the two subspecies to their different distribution in the field.No differences between the two subspecies with respect to nitrate uptake and nitrate assimilation were observed under laboratory conditions. In plants from the field intact tissue nitrate reductase was higher in ssp.radicata than in ssp.ericetorum. The nitrate reductase activity of both subspecies responded positively to nitrate addition.The significance of nitrate uptake capacity and the level of nitrate reductase for the distribution of plants in the field is here discussed.Grassland species research group, publ. no.15.     

New taxa ofRubiaceae-Rubieae from Iran

Asperula sect.Oppositifoliae is validated. 2 new species ofAsperula and 7 new species and 1 variety ofGalium from Iran are described, discussed in respect to their affinities and illustrated. 2 subspecies are raised to species rank.     

苦橙叶精油化学成分及抗炎作用研究

为探究苦橙叶精油的抗炎作用。实验采用气相-质谱联用法(GC-MS)分析精油成分,并建立脂多糖(LPS)诱导RAW 264.7细胞炎症模型,用Griess法检测一氧化氮(NO)含量评价其体外抗炎作用,随后进一步通过巴豆油致小鼠耳肿胀模型和鸡蛋清致小鼠足肿胀模型评价其体内抗炎作用。结果表明苦橙叶精油成分以酯类、醇类物质为主;25μg/mL浓度能显著抑制RAW 264.7细胞NO的释放;中浓度苦橙叶精油能明显减轻小鼠耳肿胀程度;低、中、高浓度苦橙叶精油均对小鼠足肿胀模型有炎症缓解作用,并于肿胀前期呈浓度依赖性。以上实验证明苦橙叶精油在体外和体内具有一定抗炎作用。     

New bivalves from the Jurassic of Iran

Three new subgenera, Gervillaria (Platygervillaria), Isognomon (Iranognomon), and Mytilaster (Persiaster), and seven new species, Gervillaria (Platygervillaria) alifera, Isognomon (Iranognomon) arkelli, Inoperna (Inoperna) striata, Mytilaster (Persiaster) ancestralis, Astarte persipulla, Orthotrigonia fazli, and Gissaromya abramovi, from the Jurassic of Iran are described.     

New or rare chromosome counts in the genus Artemisia L. (Asteraceae, Anthemideae) from Armenia and Iran

Nineteen chromosome counts of 12 Artemisia species are reported from Armenia and Iran. Three of them are new reports, sewn are not consistent with previous counts and the remaining are confirmations of very scarce (one to three) previous data. Two basic chromosome numbers (x = 8 and 9) were found, each with several ploidy levels. Chromosome number reduction arising from fusion homozygosity was noted, confirming earlier studies.     

Gene transferability from transgenic Brassica napus L. to various subspecies and varieties of Brassica rapa

Gene transferability from transgenic rapeseed to various subspecies and varieties of Brassica rapa was assessed in this study. Artificial crossability was studied in 118 cultivars of 7 B. rapa subspecies and varieties with the transgenic rapeseed GT73 (Brassica napus) as the pollen donor. On average 5.7 seeds were obtained per pollination, with a range from 0.05 to 19.4. The heading type of B. rapa L. showed significantly higher crossability than non-heading types of B. rapa. The spontaneous outcrossing rate between B. rapa (female) and the transgenic rapeseed Ms8 × Rf3 (B. napus) (male) ranged from 0.039 to 0.406%, with an average of 0.19%. The fertilization process and the development of the hybrid seeds as shown by fluorescent staining techniques indicated that the number of adhered pollens on the stigma was reduced by 80%, the number of pollen tubes in the style was reduced by 2/3 and the fertilization time was delayed by over 20 h when pollinated with the transgenic rapeseed Ms8 × Rf3 in comparison with the bud self-pollination of B. rapa as control. About 10–70% of the interspecific hybrid embryos were aborted in the course of development. Some seeds looked cracked in mature pods, which showed germination abilities lower than 10%. The spontaneous outcrossing rates were much lower than the artificial crossability, and their survival fitness of the interspecific hybrid was very low, indicating that it should be possible to keep the adventitious presence of the off-plants under the allowed threshold, if proper measures are taken.     

中国蝴蝶新种, 新亚种及新记录种（Ⅲ）（鳞翅目）

记述中国粉蝶科1新种,4新亚种,1新型,1中国新记录种及6个《中国蝶类志》未记述的已知种,所有模式标本保存在西北农林科技大学昆虫博物馆。     

Volatile oil composition of the aerial parts of Ajuga orientalis L. from Iran

The volatile oil content and composition of the aerial parts of Ajuga orientalis L. (Lamiaceae) grown in northern parts of Iran have been analyzed by GC/MS. Thirty compounds were identified, representing 97.9% of the total oil. The main compounds were germacrene-D (24.2%), beta-cubebene (18.3%), beta-caryophyllene (16.9%) and alpha-cubebene (5.3%).     

Molecular analysis of species of Tulipa L. from Iran based on ISSR markers

Molecular characterization of Tulipa L. species can elucidate the relationships among the species and provide more information about the taxonomy of this valuable genus. In this study, the genetic relationship among 39 Tulipa accessions from Khorassan and Yazd Provinces, located in east and northeast Iran, were analyzed using inter-simple sequence repeat (ISSR) primers. Ten selected ISSR primers from 20 screened primers generated a total of 97 polymorphic DNA bands. Unweighted pair-group method of cluster analysis based on Dice similarity values separated the accessions into nine groups. Seven species were recognized within these groups, and T.?micheliana Hoog was the most frequently encountered species. The subgroups formed within both T.?micheliana and T.?lehmanniana Merckl. revealed a low level of diversity within these species. T.?biebersteiniana Schultes & Schultes fil. and T.?biflora Pallas accessions made a separate clusters. The grouping of accessions was generally consistent with principal coordinate analysis (PCA) and clearly showed the position of species in the subgenera and sections of Tulipa. These results clearly showed the usefulness of DNA fingerprinting for identification of Tulipa accessions, and it is imperative to collect and characterize more genetic variability from the other distribution areas of this genus.     

New taxa of Jurassic bivalve mollusks from Iran

A new subgenus, Isognomon (Semignomon), and eight new species Isognomon (Semignomon) tabasicum, Arcomytilus nudus, Plagiostoma immensum, Pinna Alborzica, Trigonia plana, Protocardia razavii, Corbula jurassica, and Ceratomya persica are described from the Jurassic of Iran.