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ABSTRACT

This contribution presents descriptions of 14 fossil woods from the Piedra Chamana Fossil Forest in Peru, an assemblage of fossil woods and leaves dated at 39 Ma (late Middle Eocene). It is part two of the descriptions of the non-monocot angiosperm fossils from the site (see Woodcock et al. 2017). The woods are assigned to the subfamilies Bombacoideae, Bombacoideae/Malvoideae, Byttneroideae, Grewioideae, and Sterculioideae of Malvaceae and the families Melastomataceae, Muntingiaceae, Rubiaceae, Rutaceae, and Sapindaceae. Malvalean taxa make up around one-third of the wood types. Many of the woods are identifiable to modern-day genera or groups, including genera with species counted among the hyperdominant trees of the New World forests. Represented vegetation types include mixed freshwater swamp with Avicennia, seasonally flooded forest, and lowland tropical forest with a dry aspect. The assemblage shows floristic similarities to extant South American lowland tropical forest, particularly the seasonally flooded forests growing along white water rivers (várzea); however, the dry forest association has a less clear analog in the present-day tropics.

In: IAWA Journal

ABSTRACT

The Battery Point Formation of eastern Canada hosts an Emsian (c. 400–395 Ma) flora that marks one of the rare occurrences of anatomically-preserved Early Devonian plants. We describe four new euphyllophytes from small permineralized axes in this unit. Leptocentroxyla tetrarcha gen. et sp. nov. has a four-ribbed mesarch actinostele with Psilophyton-type (P-type) tracheids and a central area of scalariform tracheids. Stenoloboxyla ambigua gen. et sp. nov. has a bar-shaped to three-ribbed mesarch stele lacking central protoxylem, with one of the ribs less pronounced, P-type tracheids, and sclerenchyma forming a discontinuous layer in the cortex. Jowingera triloba gen. et sp. nov. has a three-ribbed mesarch actinostele with central protoxylem and P-type tracheids. Tainioxyla quebecana gen. et sp. nov. has bar-shaped xylem with mesarch protoxylem strands, P-type tracheids, and anatomy typical of cambial growth initiation. These new species raise the diversity of Battery Point Formation permineralized plants to nine genera, adding significantly to the diversity of Early Devonian plants characterized anatomically. The four species encompass structural diversity of unexpected breadth and novelty for their age. They are different from both older and coeval euphyllophytes and from younger euphyllophytes, exhibiting combinations of derived and plesiomorphic characters. Their mesarch actinosteles and barshaped protosteles, histological differentiation within metaxylem and cortex, and secondary growth, represent aspects of structural complexity common in more derived Middle-Late Devonian euphyllophytes. Concurrently, the four species share P-type tracheids typical of Early Devonian basal euphyllophytes with simpler anatomies. These new fossils offer a first glimpse of a plexus of plants representing a previously unsuspected stage of euphyllophyte morphoanatomical evolution. They demonstrate significant euphyllophyte diversification and exploration of structural complexity under way during the Early Devonian, against a background of plesiomorphic-type tracheids. When more completely characterized, these Emsian plants will provide links for resolving phylogenetic relationships at the base of the euphyllophyte clade.

In: IAWA Journal

Pumpkins and squash, Cucurbita species, are valued horticultural products almost everywhere. They have been cultivated and subjected to consumer-oriented selection for thousands of years. Under this consumer orientation, they have been improved culinarily and diversified into the wonderful array of fruit sizes, shapes, and colors that are seen today. Besides their value as food items, pumpkins and squash are associated by people with abundance, warmth, sexuality, and life itself. My current objective is to provide a succinct perspective on the process of consumer-oriented exploitation of pumpkin and squash genetic resources. I briefly review the etymology, taxonomy and gross morphology of Cucurbita plants. A view is presented of how gathering, nurturing, domestication and cultivation of Cucurbita, species-specific and consumer-driven, maintained some of the parallels among species but also magnified the phenotypic differences among them. At greater length are considered the differences in resource allocation required for the preferential consumer-driven production of mature versus young fruits. Environmental effects, abiotic and biotic, are briefly mentioned, as are some of the potential benefits of biotechnology, genetic engineering, mapping, genomics, and gene editing as cognates for breeding. Finally, I consider the processes and needs for collection, maintenance, characterization, and availability of Cucurbita genetic resources and the dangers imposed by under-informed administrators in academia and cavalier governmental regulatory statutes toward future consumer-oriented improvement of pumpkins and squash.

In: Israel Journal of Plant Sciences

Israel is a geographically small and relatively new state (founded in 1948) with high population density, industrial development and economic growth, all of which negatively affect the environment, particularly biodiversity. There is, however, a growing awareness in the country of the need for environmental and biodiversity protection. The Israel Nature and Parks Authority (INPA), the official body legally responsible for protecting natural habitats, biodiversity and ecosystems in Israel, established a program to protect and conserve the endangered, near-threatened and very rare (ENtR) plants listed in the Israel Red Data Book of flora at risk. In this communication, we describe the ex-situ conservation strategies of the Israel Gene Bank (IGB) within this program. The IGB has expanded its role in the conservation of ENtR species from only ex-situ seed conservation to active involvement in whole-plant conservation and reintroducing ENtR species back into nature. In the past 10 years, 1289 accessions belonging to 68% of the species in the Red List were collected to form the IGB core collection of endangered and rare species. The germination unit of the IGB developed 198 new protocols and propagated 87 different ENtR species.

In: Israel Journal of Plant Sciences

The winter annuals Brassica tournefortii and Raphanus raphanistrum (Brassicaceae) share similar habitats and life-history traits, but differ in their reproduction system (self-compatibility vs. self-incompatibility, respectively). The two phylogenetically close species offer means to assess the effect of reproductive biology on genetic diversity between and within populations. In general, genetic diversity between populations of B. tournefortii was higher than that found between populations of R. raphanistrum, while higher genetic diversity indices were evident within populations of R. raphanistrum. In addition, the results of pairwise genetic distances indicated that the genetic distances between populations can be associated to the species’ reproductive biology and not to the population’s distribution pattern. We discuss whether knowledge of reproductive and habitat characteristics can be used to predict genetic diversity when planning sampling scheme for ex situ conservation.

In: Israel Journal of Plant Sciences

Israel is rich in wheat wild relatives. Some of the species have a restricted geographic distribution, grow in small populations, and are subjected to habitat fragmentation. To better conserve and exploit these species there is a need to characterize the genetic structure of ex situ collections. The population structure and genetic diversity of three wheat wild relatives from the genus Aegilops were studied. Collections of the species Ae. longissima (23 accessions), Ae. sharonensis (105 accessions) and Ae. speltoides (157 accessions) from the Institute for Cereal Crops Improvement (ICCI), Tel-Aviv University were genotyped using genotyping by sequencing (GBS) technique. Principal Component Analysis (PCA) revealed different and similar diversity patterns among the species. All species had differences between northern and southern populations, however, in Ae. sharonensis there was a more significant component differentiating western and eastern populations. Some of the southeast accessions of Ae. sharonensis clustered together with the northern - coastal Ae. longissima accessions away from the rest of the Ae. longissima and Ae. sharonensis accessions. Ae. sharonensis collection has shown much more population differentiation than Ae. speltoides collection while in Ae. speltoides the total genetic diversity within populations diversity was higher. Ae. sharonensis population structure was more correlated with geographic distance while Ae. speltoides population structure has shown less structured populations and less correlation with geographic distance. Ae. sharonensis population structure was also correlated with soil type and humidity while in Ae. speltoides northern collection no correlation with the environment was found. The evolutionary and conservation perspectives of these finding are discussed.

In: Israel Journal of Plant Sciences
In: Israel Journal of Plant Sciences

Chickpea (Cicer arietinum L.) is an ancient crop, mentioned in the Bible and in the Jerusalem Talmud. In the last 60 years, chickpea cultivation and breeding have undergone great advances. Those in cultivation have involved mainly changing the sowing dates and developing disease management for Ascochyta blight. In the last 10 years, to increase sowing areas, effort has been invested in developing agrotechniques for immature green chickpea harvesting. Today, breeding efforts are focused mainly on producing erect and high-yielding cultivars that are resistant to Ascochyta blight and Fusarium wilt. Moreover, in the last decade, breeding programs for early flowering have been initiated in the south of Israel, in areas with terminal drought, as well as for resistance to herbicides and the broomrape Phelipanche aegyptiaca. Thanks to all of these efforts, today chickpea is the major pulse crop in Israel.

In: Israel Journal of Plant Sciences

The Institute of Evolution Wild Cereal Gene Bank (ICGB) at the University of Haifa, Israel, harbors extensive collections of wild emmer wheat (WEW), Triticum dicoccoides, and wild barley (WB), Hordeum spontaneum, the primary progenitors of wheat and barley, respectively. The ICGB also includes minor collections of 10 species of Aegilops, wild oat (Avena barbata), and Brachypodium stacei and B. hybridum (previously distachyon). Here, we describe the WEW and WB collections, explain sampling strategies, and introduce related studies. Natural populations were sampled across Israel along aridity gradients, occurring from north to south and from west to east, and in local microsites with variable (or contrasting) ecological factors. The collection sites varied greatly in terms of climatic (rainfall, temperature and humidity), edaphic (soil types), and topography (altitude, slope) variables. Thus, the ICGB collections represent wild cereals adapted to a wide range of habitats and eco-geographical conditions. We have collected and preserved these unique gene pools since mid-70th, and further used them for theoretical and applied studies in population genetics, evolution, domestication, adaptation to local and regional habitats, and coping mechanisms for a plethora of biotic and abiotic stresses. Our studies revealed that WEW and WB populations from Israel harbor high adaptive genetic diversity that can serve as a reservoir of beneficial alleles to improve important agronomic traits such as disease resistance, drought tolerance and improved grain protein content. These mostly untapped genetic resources could contribute to increasing world food production for the constantly rising human population.

In: Israel Journal of Plant Sciences

In recent years we initiated extensive studies on the characterization of the population structure of wild Lactuca relatives (WLRs) originating from their center of origin and diversity in Southwest Asia. The objectives of our research program are related to the identification, collection, distribution, conservation and sustainable use of these unique plant genetic resources (PGR) for breeding. Natural populations of Lactuca aculeata Boiss., a wild lettuce, closely related and fully inter-fertile with cultivated lettuce, sativa L., were identified throughout northeastern Israel. The collection includes 485 seed samples, which is likely the largest and most diverse collection of this important WLR. Seeds were collected from 46 locations, representing its ecogeographic distribution in northeastern Israel. Together with 14 additional observed localities, we recorded our observations from a total of 60 native locations of L. aculeata. Thus, we assume that northeastern Israel is an ecological domain where natural L. aculeata populations can be found. The analyzed data allowed us to specify the borders of the growing area in the region, as well as to describe the ecological features of the habitats and altitude distribution of natural L. aculeata within the studied area. Notably, our data included new findings of native locations of L. aculeata on the western side of the watershed in Israel. Selected morphological characteristics, from the regeneration of 185 samples, verified the identity of all except one as L. aculeata. Some progenies (0.27%) of the original collected plants were identified as hybrids of L. aculeata x L. serriola.

In: Israel Journal of Plant Sciences