Eucalyptus silver dollar (Eucalyptus cinerea) is cultivated under intensive agronomic practices for production of cut foliage branches for the floriculture industry. A range of damage symptoms, suspected to be related to unoptimized mineral nutrition, routinely occur in the leaves at the production plantations and reduce yield quality. No information is available about the nutritional requirements of Eucalyptus silver dollar, or of any other Eucalyptus species under intense cultivation for cut foliage branches production. In this study we evaluated the hypotheses that: (1) leaf damage symptoms in the Eucalyptus silver dollar plantations might be related to the nutritional status of the leaves; and (2) they are affected by environmental and growing conditions, and will therefore differ between seasons and location of the plantations. To test these hypotheses we studied the seasonal and location variations in the ionomics of damaged and healthy leaves, physiological parameters, and postharvest attributes of cut foliage branches during vase life in four plantations of Eucalyptus silver dollar in Israel. The observed leaf symptoms were also characterized anatomically. The range of concentrations for individual macronutrients in the leaves was (in g kg–1): N (18–40); P (1.2–3.0); K (5.5–17.0); Ca (3.5–14.0); Mg (1.1–2.8); S (1.3–2.6). The concentrations range for micronutrients was (in mg kg–1): B (10–100); Fe (30–170); Zn (14–27); Mn (38–190); Cu (3.5–5.9). None of the identified leaf symptoms correlated with a consistent increase or decrease of the content of a specific mineral nutrient or heavy metal compared to the healthy leaves, suggesting that they were not caused by mineral deficiency or toxicity. The leaf ionomics was affected by season and varied between locations. The main damage symptoms observed in the four examined plantations during the four harvests were red and purple spots, and oil stains. Postharvest experiments showed that the quality of branches was reduced during 7–15 days of vase life following transport simulation to the local market. The degree of reduced quality during vase life was also dependent on the location of the plantation and the season of harvest. The oil stains appeared in the two most southern locations during summer, suggesting that this symptom might be derived from the summer conditions such as the high temperatures and high light intensities occurring in the southern part of Israel.
Nirit Bernstein, Shani Shushan, Dorit Shargil, Yaakov Perzelan, Shoshana Salim, Tamar Zadka, Joseph Riov, Mollie Sacks, Eliezer Spiegel, Yair Tamari, Shosh Weizman, Shimon Meir, Sonia Philosoph-Hadas and Hanita Zemach
M. Edelstein, R. Cohen, F. Baumkoler and M. Ben-Hur
Semi-arid and arid regions are characterized by water scarcity and long dry summers. To ensure continued food supply and to combat desertification in these regions, marginal waters such as saline water and treated domestic sewage (effluent) are increasingly used for irrigation. These conditions may decrease plant growth and fruit yields of vegetables, which are relatively sensitive to environmental stress, and increase the accumulation in plant shoots of toxic elements which could enter the human food supply. In addition, the use of highly saline water for irrigation may increase the susceptibility of plants to soil and airborne pathogens. Experiments conducted in the field and in greenhouses show that grafting, a horticultural technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join, in general increases the tolerance of vegetable plants to salinity, high concentrations of toxic elements, and soilborne diseases. Moreover, the concentrations of toxic elements, such as B, Zn, Sr, Mn, Cu, Ti, Cr, Ni, Cd, and Na are lower in the tissues of grafted than in those of nongrafted plants. This difference is most likely a result of exclusion of toxic elements by the rootstock of the grafted plants. It is suggested that grafting could be a useful tool to increase the tolerance of vegetable plants to salt, toxic elements, and soilborne diseases, and to prevent the entry of contaminants and saline elements into the human food supply under arid and semi-arid conditions.
David. J. Bonfil
Phenomics is a relatively new approach by breeders, who use modern sensors for monitoring germplasm performance and as a selection tool. Plant physiologists can also make use of phenotyping in their studies, which usually focus on plant response to abiotic and biotic stresses. Simple active radiometer sensors such as RapidScan enable phenotyping within the framework of field experiments, and may open new horizons for breeders. The objectives of this study were to: (i) test the ability of vegetation indices (VIs) to distinguish between wheat cultivars during the entire growth period; and (ii) evaluate the accuracy of yield estimation based on only one or a few monitoring days. The following studies were conducted to test RapidScan as a tool for wheat phenotyping in the field: (i) response of 10 cultivars to water deficiency; (ii) response of 13 cultivars to late top N application. Plants were scanned weekly. The default VI parameters, NDVI and NDRE, could be used to show development during the growing season. However, due to low repeatability, it was almost impossible to use these indices for cultivar differentiation, unless there was wide variation in the cultivar phenotype. Nevertheless, combining the data from a few monitoring days improved cultivar classification and yield estimation. Although variation between fields and treatments affected the VI vs. crop parameter relationships more than the within-field variation, the results showed that the use of the proximal-sensing technique allows for rapid and quite accurate phenotyping. Thus, RapidScan can assist breeders during breeding programs for wide-scale in-field phenotyping.
Alvaro Israel and Rachel Einav
The link of the Mediterranean Sea to the Indian and Pacific Oceans was artificially created with the opening of the first Suez Canal in 1897, and the second in 2015, allowing the direct passage of marine organisms into the Eastern Mediterranean Sea. About 307 macroalgae (seaweeds) exist in the Israeli Mediterranean shores. The current study lists marine macroalgae within the Levant basin described after the year 1900, with special focus on species from Israeli shores. We identified 86 species for the whole Levant area regarded as exotic, namely, introduced by artificial vectors derived from human activities, including arrivals via the Suez Canal (Lessepsian invasion). Of those 86 species, 42 are Rhodophyta, 23 are Chlorophyta and 21 are Ochrophyta. Further, about 68% are of Indo-Pacific origin, 20% of Atlantic origin, with 12% of the species of uncertain origin. With precaution, we suggest that about 16% of the marine flora in the Israeli Mediterranean shores are of exotic nature. This survey also indicates that about half of the exotic Ochrophyta are of Atlantic origin, while there are no reports of Chlorophyta of Atlantic origin in the Levant basin. Key aspects when evaluating the exotic nature of marine macroalgae are the trustworthiness of past taxonomic identification and long-term records and description of seaweed collections, both particularly troublesome for the Levant basin.
Ori Fragman-Sapir and Nikolai Friesen
Allium palaestinum, a long-forgotten taxon of arid Israel and Jordan, is re-described here. The new description is based on Kolmann's work in 1971 and on living plants and fresh herbarium specimens. Independence of the species is confirmed not only by differing morphological and ecological features of the nearest related Allium species, but also by molecular methods. Hence, the species is no longer treated within Allium neapolitanum. Discussion on phylo-geography, distribution, conservation status and habitat is provided.
G. Caneva and F. Bartoli
A study was carried out on biodeterioration processes at six Jewish cemeteries in north-eastern Italy, which were generally subject to very poor maintenance. Several crustose lichens, as well as ruderal wooden plants, were found growing differentially on stone types in the various cemeteries. Lichens colonizing gravestones and woody plants were examined through field observations and several microscopic analyses. Evaluations were carried out on selected species and some damage risk indices were applied. The Index of Lichen Potential Biodeteriogenic Activity (LPBA) was calculated for Nanto stone, which suffered the highest degree of deterioration. The Hazard Index (HI), which is independent from the lithotype, was calculated for all the wooden plants. We also analyzed the ecological relationships of such colonization in order to evaluate indirect conservation treatments. The various lichen species were causing differential interactions with the stone, sometimes contributing in cracking and detachment of fragments. Their potential aggressiveness is mainly attributable to the different lithotypes, but also to changes in maintenance, tree canopy cover, and eutrophication. We have made suggestions for an appropriate plant management that considers their environmental, ornamental and symbolic importance in such context. For the stone conservative treatments against lichens, we also carried out tests on selected biocides.
Irene Blecher and Michael Blecher
Commicarpus grandiflorus is recorded for the first time in Israel. The new record in the En Gedi area extends the known range of this species conspicuously northeast, with a gap of more than 300 km from the southern Sinai Peninsula to the Dead Sea. Morphology, habitat and plant community data are presented and discussed. A description of this newly recorded perennial herb is given and drawings of the plant were made from freshly collected specimens. A revised identification key for the genus Commicarpus in the Flora Palaestina area is provided. An estimation of C. grandiflorus population size in the En Gedi area is made. The plant is recommended for inclusion in the national Red List of Threatened Species.
While plant mimicry by animals to make them cryptic from both prey and predators has received significant attention, the reverse situation, i.e. animal mimicry by plants as defense from herbivores, has been paid dramatically less. Here, in an essay intended to both stimulate and intrigue, I describe the various proposed types of defensive animal mimicry by plants, discuss the few published experimental tests of this hypothesis, and propose some future directions of research of defensive animal mimicry by plants. Animal mimicry by plants as defense from herbivores comprises two general types: direct animal mimicry, and mimicry of cues about animal action. The direct type includes bee, wasp, caterpillar, ant, aphid, beetle, butterfly, eye, and snake mimicry. The animal cue mimicry includes tunneling, chewing damage, spider web or arthropod silk, animal dung-shaped plants, and carrion and dung odors. These defenses include Batesian mimicry, masquerade, a mixture of Batesian mimicry and masquerade, and probably also perceptual exploitation. As an overlooked phenomenon, this area of evolutionary ecology has good potential for interesting finds.
Nils Bareither, André Scheffel and Johannes Metz
The ecological benefits of polyploidy are intensely debated. Some authors argue that plants with duplicated chromosome sets (polyploids) are more stress-resistant and superior colonizers and may thus outnumber their low ploidy conspecifics in more extreme habitats. Brachypodium distachyon (sensu lato), for example, a common annual grass in Israel and the entire Mediterranean basin, comprises three cytotypes of differing chromosome numbers that were recently proposed as distinct species. It was suggested that increased aridity increases the occurrence of its polyploid cytotype.
Here, we tested at two spatial scales whether polyploid plants of B. distachyon s.l. are more frequently found in drier habitats in Israel. We collected a total of 430 specimens (i) along a large-scale climatic gradient with 15 thoroughly selected sites (spanning 114–954 mm annual rainfall), and (ii) from corresponding Northern (more mesic) and Southern (more arid) hill slopes to assess the micro-climatic difference between contrasting exposures. Cytotypes were then determined via flow cytometry.
Polyploid plants comprised 90% of all specimens and their proportion ranged between 0% and 100% per site. However, this proportion was not correlated with aridity along the large-scale gradient, nor were polyploids more frequently found on Southern exposures.
Our results show for both spatial scales that increasing aridity is not the principal driver for the distribution of polyploids in B. distachyon s.l. in Israel. Notably, though, diploid plants were restricted essentially to four intermediate sites, while polyploids dominated the most arid and the most mesic sites. This, to some degree, clustered pattern suggests that the distribution of cytotypes is not entirely random and calls for future studies to assess further potential drivers.
John Richard Edmondson
In 1836 Col. Francis Rawson Chesney, a British army officer, led an expedition to test the proposition that large iron vessels could successfully navigate the river Euphrates from southern Turkey to the Persian Gulf. The naturalist Dr Johann Wilhelm Helfer, his wife Pauline (later Countess Nostitz), and the surgeon-geologist William Francis Ainsworth made field observations and gathered natural history collections from along the banks of the Euphrates. Botanical specimens were processed by John Lindley and made available to Antonio Bertoloni of Bologna, who described a number of new species from the material. A partial catalog of this material has been compiled, noting the location of type specimens, and the collections have been localized as far as possible given the scanty evidence from the labels. A bibliography of references relevant to natural history from the extensive literature on the expedition is provided.