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331.
A collection of wild artichokes (Cynara cardunculus L. var. sylvestris (Lam.) Fiori) was conducted in south Italy. The distribution of the wild populations was not even all over the explored territory, from the coastline to the inner mountains, and in some areas wild artichokes were completely absent. A certain level of morphological variation for height and habit of plants, size and shape of capitula, length, shape, and position of bracteal spines, was observed. It has been noticed that picking capitula from the wild for human consumption is a common habit in southern Italy and Sicily. Historical data and etnobotanic inference suggest the idea that the artichoke could have been domesticated in south Italy, and Sicily in particular, and was spread by the Arabs to other regions of the Mediterranean Basin. 相似文献
332.
Tolson RH Duxbury TC Born GH Christensen EJ Diehl RE Farless D Hildebrand CE Mitchell RT Molko PM Morabito LA Palluconi FD Reichert RJ Taraji H Veverka J Neugebauer G Findlay JT 《Science (New York, N.Y.)》1978,199(4324):61-64
During the last 2 weeks of February 1977, an intensive scientific investigation of the martian satellite Phobos was conducted by the Viking Orbiter-1 (VO-1) spacecraft. More than 125 television pictures were obtained during this period and infrared observations were made. About 80 percent of the illuminated hemisphere was imaged at a resolution of about 30 meters. Higher resolution images of limited areas were also obtained. Flyby distances within 80 kilometers of the surface were achieved. An estimate of the mass of Phobos (GM) was obtained by observing the effect of Phobos's gravity on the orbit of VO-1 as sensed by Earth-based radiometric tracking. Preliminary results indicate a value of GM of 0.00066 +/- 0.00012 cubic kilometer per second squared (standard deviation of 3) and a mean density of about 1.9 +/- 0.6 gram per cubic centimeter (standard deviation of 3). This low density, together with the low albedo and the recently determined spectral reflectance, suggest that Phobos is compositionally similar to type I carbonaceous chondrites. Thus, either this object formed in the outer part of the asteroid belt or Lewis's theory that such material cannot condense at 1.5 astronomical units is incorrect. The data on Phobos obtained during this first encounter period are comparable in quantity to all of the data on Mars returned by Mariner flights 4, 6, and 7. 相似文献
333.
Domenico Carputo Luigi Frusciante Luigi Monti Mario Parisi Amalia Barone 《American Journal of Potato Research》2002,79(5):345-352
Tetraploid BC3 hybrids between sexually incompatible speciesSolanum commersonii andS. tuberosum were characterized for tuber quality (stolon length, tuber eye depth, chipping color from 3-month storage at 5 C, and specific gravity) and soft rot resistance traits. For all analysed morphological traits, except stolon length, genotypes resembled theS. tuberosum phenotype. On average, the specific gravity of selected genotypes was quite high (1.087), and 12 of them had a value >1.090. As for chipprocessing ability, 4.8% of genotypes chipped well directly from cold storage, and 14.3% after reconditioning. All but one of these genotypes also possessed a high specific gravity of tubers. Variability was found for resistance toErwinia carotovora subsp.carotovora. In particular, 24% of hybrids had a rotted area diameter ≤ 4 mm and were classified as resistant. The average percentage ofcommersonii-specific markers still present in the BC3 hybrids was 22%, ranging from 9% to 37%. Genotypes combining good qualitative tuber traits with a wild genome content lower than the average value of the population were selected for further breeding efforts. The importance of molecular-assisted selection is discussed. 相似文献
334.
The eleven most known landraces from central and southern Italy were analysed using ISSR markers on 15 randomly chosen individuals
for each landrace, with the aim of assessing genetic variation within and among landraces and possibly ascertaining their
origin and genetic relationships. A total of 164 loci were observed, 128 of which (78.05%) were polymorphic. Gene diversity
over all landraces was I = 0.3759. The highest within-landrace diversity was observed in samples from the Apennine ridge and for one Sicilian landrace;
on the other hand, samples from the small Sicily islands were less variable. Principal Component Analysis and AMOVA allowed
the discrimination of groups of landraces with higher similarity. Analyses indicate that the small Sicily islands landraces
are very closely related to one another and seem to be derived from the peninsular material; moreover, they help disclose
relationships among geographically close landraces. The knowledge so acquired can, therefore, contribute to elaborate strategies
for increasing the economical value of élite landraces and to protect producers from frauds. 相似文献