In this study six Pinus L. taxa from Canada （P. strobus L., P. parviflora Siebold ＆ Zucc., P. mugo Turra subsp, mugo, P. resinosa Sol. ex Alton, P. flexilis E. James and P. nigra J. F. Arnold） were studied to deter...In this study six Pinus L. taxa from Canada （P. strobus L., P. parviflora Siebold ＆ Zucc., P. mugo Turra subsp, mugo, P. resinosa Sol. ex Alton, P. flexilis E. James and P. nigra J. F. Arnold） were studied to determine on chemical characters of studied taxa. For this purpose, essential oil from needles of the six Pinus taxa were investigated by HS-SPME/GC-MS. 38, 33, 39, 28, 31 and 46 compounds were respectively identified from each species representing 95.90%, 95.07%, 95.79%, 96.20%, 93.05% and 96.25% of the oil. The results have given some clues on the chemotaxonomy of this genus and are of usable potentials of the plants as renewable resources. Although the essential oil composition of studied taxa showed chemical divergences because of climatical, seasonal, geographical and geological factors, but the major compounds of plant derivatives are generally similar and the major compounds are chemotaxonomical markers for studied taxa.展开更多
Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, i...Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, in some orchards and nurseries in the Southern part of Bulgaria. The following Phytophthora species were identified based on morphological and cultural characteristics, and temperature requirements： Phytophthora cactorum, Phytophthora citrophthora, Phytophthora drechsleri, Phytophthora cryptogea, Phytophthora hybrid specie and Pythium. Prevailing specie was P. cactorum. P. cryptogea and P. cactorum were confirmed by application of molecular methods. Nutritional requirements of P. cactorum and P. citrophthora were studied. Most Nitrogen sources stimulated the mycelial growth of P. cactorum to a higher extend, and reduced the colony size ofP. citrophthora. Different Carbon sources were utilized well by P. cactorum, and only saccharose and maltose had a stimulating effect on the mycelial growth of P. citrophthora. MgSO4.7H20 was the preferred sulfur source for both fungi, as L-cysteine and L-methionine only for P. cactorum. Phytophthora infection leads to physiological changes in the.host plant tissues. The tendency traced out is： about disorders in the amino acid metabolism, increase in the total sugars and slight reduction of the cellulose content. The total nitrogen, phosphorus and potassium content are reduced and the calcium and magnesium are increased. Photosynthesis of inoculated plants was suppressed and transpiration was increased.展开更多
The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of ...The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of uncertain relationships. In commonly accepted global regionalization schemata, Madagascar is treated together with Africa for animals, and with Africa, tropical Asia and the Pacific islands in the case of plants. Here we examine the similarities between the biotic assemblages of （i） tropical Africa, （ii） Madagascar, and （iii） the rest of the world, on a basic taxonomic level, considering the families of vascular plants and vertebrates as analysis units. The percentages of endemic families, families shared pair-wise between regions, or pre- sent in all three, are roughly similar between the two broad groups, though plant families with ranges limited to one region are proportionally fewer. In dendrograms and multidimensional scaling plots for different groups, Madagascar clusters together with Africa, Asia or both, and sometimes with smaller Indian Ocean Islands, but quite often （though not in plants） as a convincingly separate cluster. Our results for vertebrates justify the status of full zoogeographic region for Madagascar, though an equally high rank in geobotanical regionalization would mean also treating Africa and Tropical Asia as separate units, which would be debata- ble given the overall greater uniformity of plant assemblages. Beyond the Madagascan focus of this paper, the differences be- tween plant and vertebrate clusters shown here suggest different levels of ecological plasticity at the same taxonomic level, with plant families being much more environmentally-bound, and thus clustering along biome lines rather than regional lines [Current Zoology 58 （3）： 363-374, 2012].展开更多
文摘In this study six Pinus L. taxa from Canada （P. strobus L., P. parviflora Siebold ＆ Zucc., P. mugo Turra subsp, mugo, P. resinosa Sol. ex Alton, P. flexilis E. James and P. nigra J. F. Arnold） were studied to determine on chemical characters of studied taxa. For this purpose, essential oil from needles of the six Pinus taxa were investigated by HS-SPME/GC-MS. 38, 33, 39, 28, 31 and 46 compounds were respectively identified from each species representing 95.90%, 95.07%, 95.79%, 96.20%, 93.05% and 96.25% of the oil. The results have given some clues on the chemotaxonomy of this genus and are of usable potentials of the plants as renewable resources. Although the essential oil composition of studied taxa showed chemical divergences because of climatical, seasonal, geographical and geological factors, but the major compounds of plant derivatives are generally similar and the major compounds are chemotaxonomical markers for studied taxa.
文摘Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, in some orchards and nurseries in the Southern part of Bulgaria. The following Phytophthora species were identified based on morphological and cultural characteristics, and temperature requirements： Phytophthora cactorum, Phytophthora citrophthora, Phytophthora drechsleri, Phytophthora cryptogea, Phytophthora hybrid specie and Pythium. Prevailing specie was P. cactorum. P. cryptogea and P. cactorum were confirmed by application of molecular methods. Nutritional requirements of P. cactorum and P. citrophthora were studied. Most Nitrogen sources stimulated the mycelial growth of P. cactorum to a higher extend, and reduced the colony size ofP. citrophthora. Different Carbon sources were utilized well by P. cactorum, and only saccharose and maltose had a stimulating effect on the mycelial growth of P. citrophthora. MgSO4.7H20 was the preferred sulfur source for both fungi, as L-cysteine and L-methionine only for P. cactorum. Phytophthora infection leads to physiological changes in the.host plant tissues. The tendency traced out is： about disorders in the amino acid metabolism, increase in the total sugars and slight reduction of the cellulose content. The total nitrogen, phosphorus and potassium content are reduced and the calcium and magnesium are increased. Photosynthesis of inoculated plants was suppressed and transpiration was increased.
文摘The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of uncertain relationships. In commonly accepted global regionalization schemata, Madagascar is treated together with Africa for animals, and with Africa, tropical Asia and the Pacific islands in the case of plants. Here we examine the similarities between the biotic assemblages of （i） tropical Africa, （ii） Madagascar, and （iii） the rest of the world, on a basic taxonomic level, considering the families of vascular plants and vertebrates as analysis units. The percentages of endemic families, families shared pair-wise between regions, or pre- sent in all three, are roughly similar between the two broad groups, though plant families with ranges limited to one region are proportionally fewer. In dendrograms and multidimensional scaling plots for different groups, Madagascar clusters together with Africa, Asia or both, and sometimes with smaller Indian Ocean Islands, but quite often （though not in plants） as a convincingly separate cluster. Our results for vertebrates justify the status of full zoogeographic region for Madagascar, though an equally high rank in geobotanical regionalization would mean also treating Africa and Tropical Asia as separate units, which would be debata- ble given the overall greater uniformity of plant assemblages. Beyond the Madagascan focus of this paper, the differences be- tween plant and vertebrate clusters shown here suggest different levels of ecological plasticity at the same taxonomic level, with plant families being much more environmentally-bound, and thus clustering along biome lines rather than regional lines [Current Zoology 58 （3）： 363-374, 2012].
