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1.
Eviatar Nevo Avigdor Beiles Yitzchak Gutterman Nurith Storch Diane Kaplan 《Euphytica》1984,33(3):717-735
Summary Populations of wild emmer wheat, Triticum dicoccoides, in Israel, originating from diverse habitats, and tested earlier for allozyme (Nevo et al., 1982) and disease resistance polymorphisms (Moseman et al., 1983a, 1983b; Nevo et al., 1984a, 1984b), were compared and contrasted for performance in agronomically important phenotypic traits. The traits compared involved 10 variables comparing germination, earliness, biomass and yield variables. The field experiments were conducted in 1980, 1981 and 1982 in two relatively standardized and contrasting environments: mesic (Mount Carmel, Haifa) and xeric (Acedat Farm, and Sede Boqer, in the northern Negev desert). The experimental design involved 12 population quadrangles at Avedat Farm in 1980, and rows of randomized genotypes of five populations in both Haifa and Sede Boqer in 1981 and 1982.The results indicate that the characters studied are partly genetically determined. Striking genetic variation was found between and, at least in some characters, also within populations in each site, whereas remarkable environmental variation including genetic-environmental interaction was found between the mesic and the xeric sites. We conclude that natural populations of wild emmer wheat in Israel vary not only in genetic polymorphisms of allozymes and disease resistance, but also in quantitative traits of agronomic importance. These traits are economically significant and should be conserved and utilized in wheat crop improvement. 相似文献
2.
An artificial capillary barrier to improve root zone conditions for horticultural crops: physical effects on water content 总被引:1,自引:1,他引:0
Eviatar Ityel Naftali Lazarovitch Moshe Silberbush Alon Ben-Gal 《Irrigation Science》2011,29(2):171-180
Capillary barriers (CBs) occur at the interface of two soil layers having distinct differences in textural and hydraulic characteristics.
The objective of this study was to introduce an artificial CB, created by a layer of gravel below the root zone substrate,
in order to optimize conditions for the cultivation of horticultural crops. Potential root zone formats were analyzed with
and without the gravel CBs for variables including the following: depth of CB; barrier separating the root zone from the surrounding
soil; and root zone soil texture. Field and simulated results revealed that artificial CBs increased root zone water content
and changed water flow dynamics. Volumetric soil water content was increased by 20–70%, depending on the soil texture and
depth of the barrier. Sandy soil texture and shallower placement resulted in relatively higher water content. For sandy soil
without plants, a shallow (0.2 m depth) CB increased water content of the overlaying soil by 50% compared to the control.
The introduction of a gravel CB below the root zone of pepper plants (Capsicum Annum L.) lead to 34% higher matric head, 50% lower diurnal fluctuations in matric head and 40% increase in pepper fruit yield.
Increasing water content by way of artificial CBs appeared to improve the water use efficiency of pepper plants. Such an improvement
could lead to reduced water and fertilizer application rates and subsequent reduction in contamination below the root zone.
This is especially relevant for substrates of low water-holding capacity typically used in horticulture crop production. 相似文献
3.
Alex Beharav Dalia Lewinsohn Aleš Lebeda Eviatar Nevo 《Genetic Resources and Crop Evolution》2006,53(3):467-474
A total of 1027 genotypes of wild Lactuca spp. (L. serriola, L. saligna, and L. aculeata), originating from Israel, Jordan, East Turkey, Armenia, Kazakhstan, China, and various other countries in Europe were screened
for resistance to the lettuce downy mildew (Bremia lactucae Regel). The genotypes of L. serriola (N = 962); L. saligna (N = 43); and L. aculeata (N = 22) were tested at the seedling stage with two isolates of B. lactucae (race Bl-21 and Isr-74) isolated from cultivated lettuce in Italy and Israel, respectively. Altogether, the isolates possess
virulence against 17 out of 20 Dm genes/R-factors composing the established differential set of lettuce lines/varieties. They could therefore be used for preliminary
detection of the presence of new resistance factors. A total of 83 and three genotypes of L. serriola and L. saligna, respectively, were resistant to infection by each of the two isolates alone as well as to the infection by a mix of the
two isolates. These genotypes probably carry previously unknown resistance, and therefore could be suitable for exploitation
by breeders and further detailed research. The wild progenitor of lettuce, L. serriola, and related species harbor significant untapped genetic resources for lettuce improvement. 相似文献
4.
Xiaoling Ji Chaojie Xie Zhongfu Ni Tsomin Yang Eviatar Nevo Tzion Fahima Zhiyong Liu Qixin Sun 《Euphytica》2008,159(3):385-390
Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a devastating disease of wheat (Triticum aestivum) in China and worldwide, causing severe yield losses annually. Wild emmer (T. dicoccoides) accession IW72 collected from Israel is resistant to powdery mildew at the seedling and adult stages. Genetic analysis indicated
that the resistance was controlled by a single dominant gene, temporarily designated MlIW72. The F2 population and F3 families derived from a hybrid between IW72 and susceptible durum wheat line Mo75 were used for molecular mapping of the
resistance gene. MlIW72 was linked with SSR loci Xgwm344, Xcfa2040, Xcfa2240, Xcfa2257 and Xwmc525 on the long arm of chromosome 7A. In addition, two STS markers, MAG2185 (derived from RFLP marker PSR680) and MAG1759 (developed
from EST CD452874), were mapped close to MlIW72. All these markers were physically located in the terminal bin 0.86–1.00 of 7AL. The chromosome location and genetic mapping
results suggested that the powdery mildew resistance gene identified in wild emmer accession IW72 might be a new allele at
the Pm1 locus or a new locus closely linked to Pm1. 相似文献
5.
Hermann Buerstmayr Michael Stierschneider Barbara Steiner Marc Lemmens Michaela Griesser Eviatar Nevo Tzion Fahima 《Euphytica》2003,130(1):17-23
Head blight of wheat (FHB, scab) caused by Fusarium spp. has been associated with yield and quality losses in many wheat-growing regions. In tetraploid wheat sources of resistance
are scarce. In the search for novel sources of resistance, 151 Triticum dicoccoides genotypes, originating from 16 habitats in Israel and one habitat in Turkey together with several control genotypes, were
evaluated for reaction to fungal spread (Type II resistance) in replicated greenhouse experiments. Significant genetic diversity
was found among the tested genotypes, the broad sense heritability for Type II FHB resistance was 0.71. Most of the tetraploid
accessions were highly susceptible, only a few showed moderate resistance. Among the eight T. dicoccoides lines with the lowest relative infection rates, five originated from the Mt. Gerizim population, and three from the Mt. Hermon
population. None of the
T. dicoccoides lines reached the level of resistance present in the common wheat cultivar Sumai3.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Belcher JW Bridge HS Bagenal F Coppi B Divers O Eviatar A Gordon GS Lazarus AJ McNutt RL Ogilvie KW Richardson JD Siscoe GL Sittler EC Steinberg JT Sullivan JD Szabo A Villanueva L Vasyliunas VM Zhang M 《Science (New York, N.Y.)》1989,246(4936):1478-1483
The plasma science experiment on Voyager 2 made observations of the plasma environment in Neptune's magnetosphere and in the surrounding solar wind. Because of the large tilt of the magnetic dipole and fortuitous timing, Voyager entered Neptune's magnetosphere through the cusp region, the first cusp observations at an outer planet. Thus the transition from the magnetosheath to the magnetosphere observed by Voyager 2 was not sharp but rather appeared as a gradual decrease in plasma density and temperature. The maximum plasma density observed in the magnetosphere is inferred to be 1.4 per cubic centimeter (the exact value depends on the composition), the smallest observed by Voyager in any magnetosphere. The plasma has at least two components; light ions (mass, 1 to 5) and heavy ions (mass, 10 to 40), but more precise species identification is not yet available. Most of the plasma is concentrated in a plasma sheet or plasma torus and near closest approach to the planet. A likely source of the heavy ions is Triton's atmosphere or ionosphere, whereas the light ions probably escape from Neptune. The large tilt of Neptune's magnetic dipole produces a dynamic magnetosphere that changes configuration every 16 hours as the planet rotates. 相似文献
7.
Lucia Liviero Elena Maestri Mariolina Gulli Eviatar Nevo Nelson Marmiroli 《Genetic Resources and Crop Evolution》2002,49(2):133-144
Long primer PCR (LP-PCR) markers specifically targeted to sequences involved in the response to abiotic stress were utilised to analyse genetic variation within and among wild barley populations from Israel.Populations were sampled in locations reflecting a wide range of habitats and the potential correlation between genetic variation and ecogeographic parameters was examined. A high level of polymorphism was observed. Most of the variability was due to differences within populations, however a substantial portion of genetic variation (36%) could be attributed to differences among populations, indicating local adaptation of genotypes to microclimatic conditions. Moreover, clustering and ordination techniques showed that genotypes grouped together according to their area of origin and were separated on thebasis of ecogeography, chiefly by a combination of temperature, altitude and rainfall variables. Finally, 28% of the polymorphic PCR fragments were significantly correlated with ecogeographic parameters. Our results demonstrate the effectiveness of PCR-based molecular markers targeted to environmentally regulated genes in detecting useful variation andthus in monitoring the impact exerted by adaptation to the environment ongenetic differentiation. 相似文献
8.
Isabella Grishkan Alexander Tsatskin Eviatar Nevo 《European Journal of Soil Biology》2009,45(4):341-350
Microfungal communities from two profiles of the neighboring pale rendzina and basaltic vertisoil in the Upper Galilee area, Israel, were analyzed and compared. The bedrock lithology determines the key differences in mineralogical composition of the contrasting soils on chalk and basaltic rocks. Pale rendzina on chalk is strongly calcareous while the basaltic soil profile is leached from carbonates below the 5–8 cm depth and is significantly magnetically enhanced. The soils also differ in CEC, exchangeable cations, and in microstructure. In parallel, mycobiota isolated by the soil dilution plate method (124 species) displays different patterns both in distribution along the contrasting profiles and in structure of the communities at definite depths. The basaltic mycobiota is significantly richer (87 vs. 69 species in the rendzina) being less heterogeneous and even at a 5–50 cm depth. According to all estimated mycobiotic characteristics, at 15–18 cm depth the differences between the basaltic and rendzina soils are mostly pronounced. Excellent aeration of the basaltic soil in contrast to the rendzina may account at least partly for the peak of mycobiotic differences at this depth. No single edaphic parameter is responsible for the greatest level of variations in the mycobiotic characteristics indicating that co-influence of soil biotic/abiotic factors determined distribution of microfungi throughout the profiles. 相似文献
9.
Bridge HS Belcher JW Coppi B Lazarus AJ McNutt RL Olbert S Richardson JD Sands MR Selesnick RS Sullivan JD Hartle RE Ogilvie KW Sittler EC Bagenal F Wolff RS Vasyliunas VM Siscoe GL Goertz CK Eviatar A 《Science (New York, N.Y.)》1986,233(4759):89-93
Extensive measurements of low-energy positive ions and electrons in the vicinity of Uranus have revealed a fully developed magnetosphere. The magnetospheric plasma has a warm component with a temperature of 4 to 50 electron volts and a peak density of roughly 2 protons per cubic centimeter, and a hot component, with a temperature of a few kiloelectron volts and a peak density of roughly 0.1 proton per cubic centimeter. The warm component is observed both inside and outside of L = 5, whereas the hot component is excluded from the region inside of that L shell. Possible sources of the plasma in the magnetosphere are the extended hydrogen corona, the solar wind, and the ionosphere. The Uranian moons do not appear to be a significant plasma source. The boundary of the hot plasma component at L = 5 may be associated either with Miranda or with the inner limit of a deeply penetrating, solar wind-driven magnetospheric convection system. The Voyager 2 spacecraft repeatedly encountered the plasma sheet in the magnetotail at locations that are consistent with a geometric model for the plasma sheet similar to that at Earth. 相似文献
10.
Alon Ben-Gal Eviatar Ityel Lynn Dudley Shabtai Cohen Uri Yermiyahu Eugene Presnov Leah Zigmond Uri Shani 《Agricultural Water Management》2008,95(5):587-597
Maximization of crop yields when the salinity of irrigation water is high depends on providing plant transpiration needs and evaporative losses, as well as on maintaining minimum soil solution salinity through leaching. The effect of the amount of applied irrigation water was studied regarding transpiration, yields, and leaching fractions as a function of irrigation water salinity. Bell pepper (Capsicum annum L. vars. Celica and 7187) in protected growing environments in the Arava Valley of Israel was used as a case study crop to analyze water quantity–salinity interactions in a series of lysimeter, field and model simulation experiments. Leaching fraction was found to be highly influenced by plant feedback, as transpiration depended on root zone salinity. Increased application of saline irrigation water led to increased transpiration and yields. The higher the salinity level, the greater the relative benefit from increased leaching. The extent of leaching needed to maximize yields when irrigating with saline water may make such practice highly unsustainable. 相似文献