喜树叶、枝水溶性糖提取的研究

用正交实验结果作方差分析表明：溶剂用量对试验结果有较显著的影响（a=0.10)，提取温度对试验结果也有较大的影响，而提取时间对试验结果的影响不显著。喜树叶中水溶性糖的提取最优方案是A3C2B3，即溶剂用量为60ml，提取温度80℃，提取时间60min；喜树叶水溶性糖的提取最优方案是A2C2B1，即溶剂用量为40ml，提取温度80℃，提取时间20min。通过对喜树叶与枝的成对比较分析，叶与枝的水溶性糖含量无显著差异。     

10-nonacosanol,sitosterol and nonacosanediols in Juniperus pinchotii

GC of juniper leaf non-saponifiables gave three peaks of sterol-triterpenes which were identified as 10-nonacosanol, sitosterol and a mixture of nonacosanediols.     

Rehabilitation of Barbarine cull ewes using rosemary residues and linseed: effect on weight gain,carcass characteristics and meat quality

The cull ewes represent an important part of sheep flock. However, this category of animal is often submitted to under nutrition leading to poor BW and skeletal carcasses. Their rehabilitation using a high energy diet can be an alternative to improve their body condition. The objective of this experiment was to study the BW gain and carcass characteristics of Barbarine cull ewes using rosemary (Rosmarinus officinalis L.) distillation residues (RR) and extruded linseed. For this, 28 ewes above 6 years old and 33±0.5 kg of BW were divided into four groups: CCC was fed 500 g of barley-straw with concentrate, RCC received 300 g of straw and 200 g of RR as basal diet with concentrate; whereas two other groups received the experimental concentrate, containing 10% of linseed, with 500 g of straw for CLC and 300 g of straw plus 200 g of RR for RLC group. At the end of experiment (90 days), all animals were slaughtered. For all ewes, the daily concentrate intake averaged 700 g; the average daily gain was 131 g and the slaughter BW 43.4 kg without significant difference between groups. Neither basal diet nor concentrate type did affect the carcass’ weight, yield and composition. In addition, the organ’s proportions were similar for all groups. The RR intake slightly improved muscle’s protein content (P=0.03) and tended to decrease initial pH (P=0.06) and to increase meat redness (P=0.06), whereas linseed concentrate had no effect on meat color and its chemical composition. The subcutaneous fat color and firmness score relived a good quality trade for carcasses from all diets, in spite of higher yellowness and lower firmness recorded for linseed diet (P<0.05), which were moderately improved by rosemary combination with linseed. To conclude, the Barbarine cull ewes could gain up to 120 g/day in BW. The used diets permitted this BW gain without undesirable effects on carcass characteristics and meat quality. However, the study of meat fatty acid profile and antioxidant status should continue.     

Alkaloids of Dyera costulata

Six bisindole alkaloids have been isolated from the leaves of Dyera costulata (Apocynaceae). One is the known ochrolifuanine A and the others are the novel ochrolifuanines E and F, and the 18-dehydroochrolifuanines A, E and F.     

Epi- and intracuticular lipids and cuticular transpiration rates of primary leaves of eight barley (Hordeum vulgare) cultivars

The major constituents of the epi- and intracuticular lipids of primary leaves of 8 cultivars of barley ( Hordeum vulgare L.) have been studied together with cuticular transpiration rates. The total amount of analysed cuticular lipids ranged from 9.6 to 13.4 μg cm⁻² and was dominated by the epicuticular fraction, which made up 73–84% of the total. There were variations in the percentages of the analysed lipid classes, alkanes, esters, aldehydes, β-diketones and alcohols, between epi- and intracuticular lipids among individual cultivars, but no clear tendency in these variations, except for the aldehydes, was found. The epicuticular lipids were richer in aldehydes than the intracuticular lipids. The cuticular transpiration rates were poorly correlated with the levels or composition of epi-, intra- or total cuticular lipids. The cuticular transpiration rates were considerably altered as a response to a water stress treatment, but these changes could not be correlated with any changes in amount or composition of the cuticular lipids. From these results it is concluded that some property other than amount or composition of cuticular lipids is the most important in regulation of water diffusion through the cuticle.     

Cuticular morphology and aspects of the ecology and fossil history of North Queensland rainforest Proteaceae

Cuticles of North Queensland rainforest Proteaceae were examined using light and scanning electron microscopy. The genera of North Queensland rainforest Proteaceae are mostly endemic and composed of one or few species, with greatest diversity in the granitic uplands of the region. Knowledge of cuticular morphology may be an important tool in determining the true affinities of several undescribed taxa in the region and can be used to explore hypotheses relating to the history of the Proteaceae. Some species exhibit purported xeromorphic features of thick cuticles, sunken stomates and dense trichome cover on the abaxial surface. Grevillea , Banksieae and Stenocarpus are believed to have radiated into open, much less mesic environments. In the former two taxa this can be interpreted in terms of xeromorphic features expressed in their cuticular morphologies, whereas in Stenocarpus amphistomaty in species of open habitats suggests an alternative mode of evolution more related to physiological factors. Several Cainozoic proteaceous macrofossils temporally and spatially far removed from North Queensland possess cuticular morphologies very similar or identical to extant rainforest taxa in the region.     

Turonian Pinaceae of the Raritan Formation, New Jersey

 Fossil vegetative and reproductive structures from deposits of the Raritan Formation in New Jersey (Turonian, Upper Cretaceous, ∼90 MYBP) include ferns, gymnosperms, and angiosperms. Gymnosperms collected from this formation have been known since the beginning of the 20th century. Fossil leaves, wood and seed cones have been are identified as belonging to the Cupressaceae, Pinaceae, and Taxodiaceae. In the present contribution, we describe a series of fossil dwarf shoots, leaves and a pollen cone belonging to the family Pinaceae. Fossils are charcoalified with preserved three-dimensional structure and excellent cellular detail. The dwarf shoots are assigned to a new species Prepinus crossmanensis sp. nov. and to the previously described Pinus quinquefolia Jeffrey. The new species Prepinus crossmanensis differs in size, shape, presence of hypodermis, sclerenchyma and stomata in the cataphylls, and number and shape of needle leaves from previously known species. Also, isolated leaves were found that were assigned to the new species, Prepinus raritanensis sp. nov. The new species is differentiated by the size and shape of stomata, the presence of number of layers of the hypodermis; and the cell-shape and number of layers of the mesophyll and transfusion tissue. A previously undescribed male cone, Amboystrobus cretacicum gen. and sp. nov., has an axis with spirally attached microsporophylls, each bearing two abaxial ovoid microsporangia. The pollen grains are monosulcate and bisaccate (eusaccate), with an elliptical corpus, granulate exine sculpture, and honeycomb-like wall structure. Received March 21, 2000 Accepted November 13, 2000     

Quality of micropropagated plants—Vitrification

Summary Vitrification-Hyperhydrous shoot development, effects the survival and quality of several micropropagated plants ex-vitro. The leaves which are the immediate organ to be affected, exhibit abnormal morphology and physiology. Leaf malfunction is apparently a stress response to very rich media and high relative humidity. The understanding of the underlying mechanism of vitrification and its control in vitro can contribute to a more efficient micropropagation. Vitrification was found to be associated with elevated ethylene production which was related to hypolignification and poor cell wall development. Liquid and low agar media induced callose formation along with reduced and disoriented cellulose biosynthesis, manifested also in non-functioning guard cells. Malfunctioning stomata, in addition to defective cuticle contributed to increased transpiration and desiccation of in vitro formed leaves. The activity of various enzymes, associated with cell wall synthesis, was low and total proteins in normal leaves was higher than in vitreous ones. Various measures were found to reduce vitrification; lowered matrix and water potential in the medium, reduction in RH, low NH ₄ ⁺ , changes in Ca⁺⁺ levels and the removal of ethylene. These measures improved leaf morphogenesis, survival and the quality of several micropropagated plant species. Presented in the Session-in-Depth Transition of Plants From Culture to Establishment In Vivo,“ at the 41st Annual Meeting of the Tissue Culture Association, Houston, Texas, June 10–13, 1990.     

Determination of free amino acids in burley tobacco by high performance liquid chromatography

A reversed-phase high performance liquid chromatographic method was developed for determining free amino acids in burley tobacco. The test was done by OPA/3-mercaptopropionic acid as the pre-column derivatizing reagent. Chromatographic column was Elitte C¹⁸ column (4.6 mm × 250 mm i.d., 5 μm). Mobile phase A was 18 mol/l NaAc (pH7.2) including 0.002%(v/v) triethylamine and 0.3%(v/v) furanidine. Mobile phase B was 100 mol/l NaAc (pH7.2)–acetonitrile–methanol (v/v = 1:2:2). The column temperature was 40 °C and the flow rate was 1.0 ml/min. The fluorescence detector was used with 350 nm excitation wave length and 450 nm emission wave length. The average recoveries of the method ranged from 95.3–100.7% with the relative standard deviation of 2.32–9.24%. The method is simple, accurate and has good repeatability. The results of the determination of seventeen kinds of free amino acids in burley leaves were produced by the way of different ratios of cake fertilizer and inorganic fertilizer. The results show that Aspartic acid has the highest content however ratio of cake fertilizer and inorganic fertilizer. The contents of most of the free amino acids are increased and then gradually decreased with the increase in organic manure. The contents of most of the free amino acids are very close at 15:85% ratio and 30:70% ratio of cake fertilizer and inorganic fertilizer. The total amount of free amino acids is the highest at 30:70% ratio of cake fertilizer and inorganic fertilizer. Considering comprehensively, the quality of burley leaves is the best at 30:70% ratio of cake fertilizer and inorganic fertilizer.     

The rate of development of water deficits affects Saxifraga cernua leaf respiration

We allowed plant water deficits to develop at two different rates following the cessation of watering in order to investigate the effects of water stress on cytochrome pathway and alternative pathway respiration in the leaves of the arctic herb Saxifraga cernua. Plants were pretreated by growth in either a commercial organic (CO) mixture or a vermiculite-perlite (VP) mixture, which allowed the complete development of water deficits in 19 and 8 days, respectively. The rate of water potential reduction was approximately 0.11 MPa day⁻¹ in the leaves of CO plants, compared to a reduction of 0.21 MPa day⁻¹ in leaves of VP plants. Osmotic adjustment occurred to a greater extent in leaves of CO plants and corresponded with an increase in ethanol-soluble sugars. In leaves of CO plants, cytochrome pathway activity gradually declined from that of control rates until day 11, and then declined more rapidly. In contrast, cytochrome pathway activity significantly increased in response to water deficits in leaves of VP plants. In leaves of both CO and VP plants, alternative pathway activity declined as water stress progressed. Relatively severe water deficits reduced alternative pathway capacity in leaves of both CO and VP plants. We also investigated the effect of previous exposure to water deficits on leaf respiration. In plants that had previously experienced three cycles of water stress, the increase in cytochrome pathway activity during the fourth water stress cycle was small compared to the increase observed in leaves of plants experiencing water stress for the first time. These results suggest that cytochrome pathway activity is differentially sensitive to the rate of development of plant water deficits and that respiratory responses to acute water stress are not necessarily similar to the responses to chronic water stress.