Parasitoid attack of the seed-feeding beetle Bruchus loti enhances the germination success of Lathyrus japonicus seeds

Hard seeds of some legume species can germinate after seed-feeding insects bore through the seed coat and consequently break seed dormancy. Larvae of bruchine beetles are the main seed feeders attacking many legume species. Boring of the hard seed coat by bruchine beetle larvae enhances the germination percentage of legume species, but consuming too much of a single seed may reduce the chances the seed will survive. We hypothesise that the early mortality of bruchine larvae due to parasitism contributes positively to seed germination because larvae are killed before consuming too large a quantity of the seed. Here, we tested this hypothesis using Lathyrus japonicus seeds and Bruchus loti, the main seed feeder attacking this plant. B. loti larvae were mainly parasitised by two species of idiobiont parasitoids—Pteromalus sp. and Dinarmus sp. The seeds from which Pteromalus wasps emerged germinated more successfully than did the seeds from which B. loti adults emerged. B. loti larvae parasitised by the two wasp species consumed the seeds less intensively than did unparasitised larvae. Thus, the results of experiments supported our hypothesis. However, the germination success varied significantly between the seeds from which Pteromalus and Dinarmus wasps emerged. The difference in the size of seeds the two wasp species chose for parasitism may have influenced the germination percentage.     

New evidence for the use of root foods in pre-agrarian subsistence recovered from the late Mesolithic site at Halsskov, Denmark

Roots and tubers, together with other plant storage organs such as rhizomes, bulbs, corms, etc. are known to be a source of human food. Until very recently, however, remains of root foods were rarely identified from archaeological contexts in temperate Europe. New evidence for the use of root foods has been recently recovered from the early Erteb?lle settlement at Halsskov in Denmark. Remains included charred bulbs of Allium cf. ursinum and tubers of Conopodium majus. They were accompanied by charred remains of parenchymatous tissues derived from underground parts of other plants. All parenchymatous remains were recovered from features that could be interpreted as pit-cooking depressions. A minimum of two periods of root food gathering can be assumed, spring to early summer and autumn. The presence of charred seeds of Nuphar pumilum suggests that either the seeds or rhizomes (or both) were use as food. Received September 4, 2001 / Accepted February 27, 2002     

Charred plant remains from a 10th millennium B.P. kitchen at Jerf el Ahmar (Syria)

The Pre-potteryNeolithic A (PPNA) site of Jerf el Ahmar, Syria, dated to the 10th millennium uncal B.P., has produced over 657 flotation samples which are now under study. The results described in this article were obtained from the analysis of 32 samples of charred plant remains taken from a room of 2.5 × 3 m, which had been destroyed by fire. The room contained three saddle querns, two flat polished stone plates (each of 60 cm in diameter), one hearth, and three limestone "basins". These objects were in situ and the room appeared to represent a food preparation area (kitchen). On one of the querns two charred seed cakes were found. The finely ground seeds have been identified as Brassica/Sinapis, a rare taxon for this period. The major taxa, which are morphologically wild, have distinct spatial distributions, which provide evidence for plant processing activities. Hordeum spontaneum and Triticum/Secale were processed separately. The association of H. spontaneum with stone basins suggests soaking of this grain. Received August 10, 2001 / Accepted January 7, 2002     

Evidence for possible use of plant foods in Palaeolithic and Mesolithic diet from the site of Całowanie in the central part of the Polish Plain

Całowanie site, which supported hunter-gatherer populations from ca. 11 380±95 until 8270±100 B.P., is the major terminal Palaeolithic and early Mesolithic occupation complex of the North European Plain. The archaeological layers are intercalated with biogenic sediments. The remains of plants that probably served as food were recovered from terminal Palaeolithic and early Mesolithic layers. Most of the charred plant remains, apart from wood charcoal, derives from vegetative parenchyma which forms a major part of organs such as root and tuber. Two taxa have been identified on the basis of the anatomy of parenchymatous tissue, namely Sagittaria cf. sagittifolia and Polygonum sp. In addition, several charred seeds and fruits were recovered. This is the first evidence for the probable use of plant foods, other than hazel nuts or water-chestnuts, in the diet of hunter-gatherers in the North European Plain during the Palaeolithic and Mesolithic.     

Informal intercropping of legumes with cereals? A re-assessment of clover abundance in ancient Egyptian cereal processing by-product assemblages: archaeobotanical investigations at Khentkawes town,Giza (2300–2100 <Emphasis Type="SmallCaps">bc</Emphasis>)

The possibility that legumes were specifically cultivated as a separate fodder crop in ancient Egypt has been inferred, usually on the basis of abundance of both legume seeds and or dung in charred macro-botanical samples, combined with a lack of wood charcoal; the implication being that a scarcity of wood led to the use of dung as fuel, and that the legumes in the assemblage derive from livestock which had been fed with cultivated fodder. The archaeobotanical remains from excavations at the Old Kingdom ‘Khentkawes town’ (2300–2100 bc) on the Giza plateau in Egypt contained an abundance of legumes, but also much wood charcoal, and preservation of many fragile and ‘green’ seeds and plant parts. This assemblage has led to questioning of the theory of specific fodder cultivation in Pharaonic Egypt. In this article, alternative interpretations of legume-rich assemblages of cereal processing by-products are investigated. Intercropping of legumes with cereals is one of the most widespread and effective methods of improving crop value and security, and fodder/forage quality. Analysis of this assemblage has led to a hypothesis that Trifolium sp. and other ‘weeds’ may well have been viewed as integral plants within ancient Egyptian cereal fields, due to an awareness of the benefits of intercropping legumes with cereals—as opposed to having been specifically cultivated as a monocrop.     

Cotton seeds from the Neolithic in Egyptian Nubia and the origin of Old World cotton

During an excavation at Afyeh, Egyptian Nubia, in 1962, the Archaeological Survey of India recovered some plant remains. These contained, in addition to charred cereals, a few cotton seeds and dung of small animals. An anatomical study of the seed coat and hairs has revealed that this ancient Nubian cotton is similar, in the characters examined, to Gossypium arboreum var. soudanense and G. herbaceum var. africanum. Some hairs recovered from the dung indicate that the animals were fed with this cotton. The significance of this find is that the Nubians did not know at that time the potentiality of cotton hairs for making textile, but they apparently recognized the nutritive value of cotton seeds for animal feed. The hairs show an early stage of evolution from the wild to the cultivated cotton, having convolutions in the middle and no convolution towards the ends.     

A straight-forward seed production technology system for foxtail millet (Setaria italica)

For autogamous crops, a precondition for using heterosis is to produce sufficient pure male-sterile female parents that can be used to produce hybrid seeds. To date, cytoplasmic male sterility(CMS)and environment-sensitive genic male sterility(EGMS) have been used commercially to exploit heterosis for autogamous species. However, neither CMS nor EGMS has been established for foxtail millet(Setaria italica). Here, we report on the establishment and application of a seed production technology(SPT)...     

Improving success of rare plant seed reintroductions: a case study of Dalea carthagenensis var. floridana,a rare legume with dormant seeds

Recent reviews of rare plant reintroduction success indicate that far fewer studies have been conducted with seeds than whole plants, and of these, less than 10% have established or had long‐term population persistence reported. Because seed reintroductions are relatively less expensive than plant reintroductions, determining ways to increase efficacy of using seeds to establish rare populations has conservation benefits. In laboratory trials, we examined seed germination of an endangered legume, Dalea carthagenensis var. floridana, endemic in South Florida, U.S.A. Laboratory treatments confirmed that seeds are hard seeded, remaining viable for 1,452 days even when moist; nicking, heat, and freezing triggered higher and more rapid germination than controls. Field trials begun in 2009, using pretreated (frozen) and untreated seeds within two habitats (natural and novel) revealed that freezing pretreatment increased germination in both habitats. However, plants matured, reproduced, and established seedlings only in natural habitat, not in novel habitat. By 2012, seed treatment plots in natural pine rockland had significantly greater numbers of reproductive plants and seedlings than controls. In a restoration context, using seed pretreatments to stimulate germination can improve establishment success in suitable habitats. When paired with essential vegetation management and a controlled burn, seed augmentation helped rescue the population from the brink of extinction.     

Signs from a green desert: a preliminary examination of the archaeobotanical remains from a Byzantine dovecote near Shivta, Israel

This paper presents a preliminary examination of archaeobotanical material from pigeon dung samples obtained from Byzantine period destruction levels of a dovecote near the site of Shivta, Israel. Such pigeon dung was a valuable fertilizer in antiquity and would not have been abandoned without a reason. The plant remains from the dung provide direct evidence of pigeon diet and the local environment during the Byzantine period. Eleven plant taxa, represented by either seeds and/or plant parts (cereal chaff material), including five wild taxa, one legume, four fruit/nut taxa and several unidentified seed fragments were recovered. The most common seeds found were from weeds of the genus Thymelaea sp., and Ficus (fig). The finds indicate that the birds in the dovecote consumed a mixed diet of wild seeds including Thymelaea sp. and Fumaria sp. (fumitory), and small fruits of Vitis (grape), Ficus (fig), Olea (olive) and Phoenix (date). The sample analyzed also included Rumex (dock), Carex (sedge) and Androsace which may not have come from the feed. Apparently the pigeons were free to forage in the desert, the fallowed fields and refuse piles or/and were intentionally fed agricultural by-products including wild plants.     

The plant food component of the diet at the late Mesolithic (Ertebolle) settlement at Tybrind Vig, Denmark

Tybrind Vig is a late Mesolithic (Ertebølle) coastal settlement, dated to the period 5600–4000 BC. The site has yielded some very important finds associated with fishing activity, probably the best preserved example from the Mesolithic in Europe. Recently analysed botanical samples from submerged cultural deposits have provided evidence for the contribution of plants to the subsistence diet of the inhabitants of Tybrind Vig. The food plant remains are represented by the charred fragments of parenchymatous tissue from roots ofBeta vulgaris ssp.maritima (sea beet), fragments ofQuercus sp. parenchyma (acorn), and shell fragments ofCorylus avellana (hazelnut). The possibility that the grains ofGlyceria fluitans (floating sweet grass) and stems ofPhragmites australis (reed) were collected for food should not be excluded. In addition to the species identified in the charred remains, an abundance of edible plant seeds and fruits were represented in the waterlogged remains, suggesting that a much broader range of food plants was available in the area. These additional foods could have included a large variety of wild berries and other fruits, such asRubus idaeus, R. caesius, Fragaria vesca, Malus sylvestris, Cornus sanguinea, Crataegus monogyna/laevigata, Sorbus aucuparia, Viburnum opulus andRosa spp. Several other plants could have been gathered as green vegetables (Rumex crispus, Urtica dioica andCakile maritima), or could have been utilized for both their greens and seeds (Chenopodium album, Atriplex andScirpus maritimus).     

Intensity of pre‐dispersal seed predation in the invasive legume Leucaena leucocephala is limited by the duration of pod retention

Abstract The intensity of seed predation the invasive tropical legume Leucaena leucocephala by the bruchid Acanthoscelides macropthalmus was investigated in south‐eastern Queensland, Australia. The number of seeds damaged by A. macropthalmus as a proportion of total seeds available was found to increase the longer the pods remained on the tree. Seed predation ranged from a mean of 10.75% of seeds on pods that remained on the plant for 1 month and increased to 53.54% for pods that remained of the plant for 4 months. The low bruchid populations at high pod densities results in ‘predator satiation’. However, pods dehisce over time and the proportion of pods available over time to the bruchid correspondingly declines. By the time bruchid densities build up, most pods have dehisced and the seeds consequently escape predation. As a result the number of seeds lost to bruchid damage increases only marginally over time. Despite the levels of seed predation observed over the course of the study, the number of seeds in the soil seedbank almost doubled over time increasing from 8.5 seeds m^?3 to 15.5 seeds m^?3 over a 4‐month period. Levels of seed predation and addition of seeds to the soil seedbank were not correlated. The taxonomic (subspecies) status and apparency of host plants as measured by plant and patch traits (average plant height, density of podding plants and patch size) did not influence levels of seed predation. Pre‐dispersal seed predation studies need to take into account the pod/seed retention behaviour of the plant. The ability of the bruchid to regulate the invasiveness of Leucaena through influencing its demography is likely to be diminished if the insect populations cannot increase rapidly enough to use the seeds before pod dehiscence.     

Seed growth rate in grain legumes I. Effect of photoassimilate availability on seed growth rate

The dry weight of harvested grain legume seeds is strongly related to their growth rate during the period of storage accumulation in the cotyledons, which begins approximately at the end of embryo cell division. Depodding, defoliation, shading or changes in air CO2 concentration were applied during seed filling (i.e. during the decrease in seed water concentration) to field and glasshouse-grown plants, in order to affect the source-sink ratio. The experiments involved three legume species, namely pea (Pisum sativum L.), soybean (Glycine max L. Merr.) and white lupin (Lupinus albus L.). Some treatments affected the number of abortions of less developed seeds from younger pods, but they did not significantly affect the number or the growth rate of filling seeds, demonstrating the priority of carbohydrate partitioning to filling seeds. The maximum growth rate of seeds was achieved regardless of the intra-plant competition level, and the duration of seed growth was shortened if the photosynthetic activity was not sufficient to fulfil the assimilate demand of filling seeds.     

Impacts of fire cues on germination of Brassica napus L. seeds with high and low secondary dormancy

• Agricultural burning is used in farm management operations; however, information about the impact of fire cues on the release and/or induction of secondary dormancy in crop seeds is scarce.
• Seeds from two oilseed rape cultivars were induced for high (HD) or low (LD) secondary dormancy using polyethyleneglycol (PEG) pre‐treatment, and their germination after exposure to various fire cues was compared to control PEG pre‐treated and non‐dormant seeds.
• Non‐dormant seed germination was unaffected by various fire cues. Low doses of aerosol smoke released secondary dormancy in HD seeds, while higher doses increased dormancy of LD seeds. Dilute smoke water also released HD seed secondary dormancy, but concentrated smke water enhanced dormancy in both LD and HD seeds. The concentrated aqueous extracts from charred oilseed rape straw only promoted germination of HD seeds, while dilution inhibited LD seed germination. Heat shock (80 °C, 5 min) released secondary dormancy in HD seeds; however, higher temperatures and/or increased exposure time was associated with seed death. GC‐MS analyses of smoke water revealed two butenolides and an array of monoaromatic hydroxybenzene compounds with potential germination inhibitor or promoter activity.
• The extent of secondary dormancy induction in seeds affects their subsequent responses to fire cues. Both aerosol smoke and smoke water have both germination promoter and inhibitor activity. Lacking any butenolides, aqueous extracts of charred straw contain a potential germination stimulating steroid, i.e. ergosterol. The significance of fire‐derived cues on behaviour of oilseed rape seeds in the soil seed bank is discussed.

     

Spicing up restoration: can chili peppers improve restoration seeding by reducing seed predation?

Seed predation by rodents presents a significant barrier to native plant recruitment and can impede restoration seeding efforts. In nature, some plants contain secondary defense compounds that deter seed predators. If these natural defense compounds can be applied to unprotected seeds to inhibit rodent granivores, this approach could improve restoration seeding. Capsaicin is the active ingredient in chili pepper (Capsicum spp.) seeds that creates the burning sensation associated with human consumption of hot peppers. This compound has a similar effect on other mammals and is believed to have evolved as a deterrent to rodent seed predators. We used seed‐coating techniques to attach powder ground from Bhut Jolokia (Capsicum chinense) peppers to native plant seeds and evaluated the efficacy of these seed coatings for deterring rodent seed predation and enhancing native plant recruitment using laboratory and field experiments. Laboratory feeding trials demonstrated that native deer mice (Peromyscus maniculatus) consumed far fewer pepper‐coated seeds compared to untreated control seeds. Field seed‐addition experiments consistently demonstrated that rodent seed predation reduced native plant recruitment over the 4‐year study. Coating techniques used in the first 3 years were not persistent enough to reduce rodent seed predation effects on plant recruitment. However, a more persistent coating applied in conjunction with late‐winter sowing negated rodent seed predation effects on recruitment in year 4. Our results demonstrate that coating seeds with natural plant defense compounds may provide an effective, economical way to improve the efficacy of plant restoration by deterring seed predation by ubiquitous rodent granivores.     

Taxonomic importance of seed macro‐ and micro‐morphology in Abelmoschus (Malvaceae)

Seed morphology of Abelmoschus is known to be variable, but patterns of variation have never been critically studied. We studied seed macro‐ and micro‐morphological characters, including seed shape/size, seed coat pattern and trichome density/structure in multiple samples to evaluate the taxonomic significance of seed characters. Among the studied characters, seed shape and trichome structure were found to have major taxonomic importance and proved to be valuable characters for separating taxa. Two main seed types were present: seeds with deciduous trichomes and seeds with persistent trichomes. These characters offer significant evidence to the distinctness of certain species (A. esculentus, A. moschatus subsp. moschatus, A. moschatus subsp. tuberosus, A. crinitus and A. angulosus). Further, our results indicate that A. moschatus subsp. tuberosus should be maintained as a separate subspecies while A. manihot subsp. tetraphyllus var. pungens may be merged in A. angulosus. No significant intraspecific variation was observed, except in A. esculentus. We conclude that seed coat sculpturing and seed trichomes do indeed provide stable and diagnostic characters for many morphologically closely related taxa of Abelmoschus and that LM/SEM techniques can be useful in solving systematic problems and management of Abelmoschus genetic resources.     

Seed dynamics of resprouting shrubs in grassy woodlands: Seed rain,predators and seed loss constrain recruitment potential

Abstract Measuring the fate of seeds between seed production and seedling establishment is critical in understanding mechanisms of recruitment limitation of plants. We examined seed fates to better understand the recruitment dynamics of four resprouting shrubs from two families (Fabaceae and Epacridaceae) in temperate grassy woodlands. We tested whether: (i) pre‐dispersal seed predation affected seed rain; (ii) post‐dispersal seed predation limited seed bank accumulation; (iii) the size of the seed bank was related to seed size; and (iv) viable seeds accumulated in the soil after seed rain. There was a distinct difference in seed production per plant between plant families with the legumes producing significantly more seeds per individual than the epacrids. Seed viability ranged from 43% to 81% and all viable had seed or fruit coat dormancy broken by heat or scarification. Pre‐dispersal predation by Lepidopteran larvae removed a large proportion of seed from the legume seed rain but not the epacrids. Four species of ants (Notoncus ectatomoides, Pheidole sp., Rhytidoponera tasmaniensis and Iridomyrmex purpureus) were major post‐dispersal seed removers. Overall, a greater percentage of Hardenbergia (38%) and Pultenaea (59%) seeds were removed than the fleshy fruits of Lissanthe (14%) or Melichrus (0%). Seed bank sizes were small (<15 seeds m^?2) relative to the seed rain and no significant accumulation of seed in the soil was detected. Lack of accumulation was attributed to seed predation as seed decay was considered unlikely and no seed germination was observed in our study sites. Our study suggests that seed predation is a key factor contributing to seed‐limited recruitment in grassy woodland shrubs by reducing the number of seeds stored in the soil.     

Cultivated plant remains of the late Neolithic Michelsberg Culture at Heilbronn-Klingenberg (southwest Germany) - a comparison of different features, find assemblages and preservation conditions relating to the representation of archaeobotanical remains

A large area investigation was undertaken of the plant remains from a Michelsberg Culture (late Neolithic) settlement. The charred macroscopic remains and imprints in pieces of daub were expected to show both the spectrum of the cultivated plants there, and also the degree of their cultivation and use. The loess covered hill-top lies in a landscape with favourable climatic and soil conditions and is blocked off by two parallel ditches running in an arc. Ditches and pits filled with different sediments were investigated. The daub, unearthed in several pits, had been deliberately mixed with chaff of the glume wheats einkorn and emmer to temper it when it was originally made. The investigated imprints and charred plant remains give hints of spatial distribution of crop processing activities. To determine the amounts of the crops that were cultivated and used, it is necessary to study the charred remains. The degree of ubiquity (frequency of occurrence) of grains in the pit sediments seems to be the best indicator of the representation of cereals. Four main cereals were found: Triticum monococcum, T. dicoccum, T. aestivum/T. durum and Hordeum vulgare var. nudum. Pisum sativum also was an important cultivated plant, much more than Lens culinaris. The role of Linum usitatissimum and Papaver somniferum is less clear.     

A methodological approach to the study of archaeological cereal meals: a case study at Çatalhöyük East (Turkey)

This paper presents an integrated methodology for the analysis of archaeological remains of cereal meals, based on scanning electronic microscopic analyses of microstructures of charred food fragments from Neolithic Çatalhöyük (Turkey). The remains of cereal foods as ‘bread-like’ or ‘porridge-like’ small charred lumps of various amalgamated plant materials are frequently recovered from Neolithic and later archaeological sites in southwest Asia and Europe. Cereal food remains have recently attracted interest because the identification of their plant contents, the forms of food that they represent and the methods used in their creation can provide unique information about ancient culinary traditions and routine food processing, preparation and cooking techniques. Here, we focus on three methodological aspects: (1) the analysis of their composition; (2) the analysis of their microstructure to determine preparation and cooking processes; (3) the comparison with experimental reference materials. Preliminary results are presented on the botanical composition and cooking processes represented by the charred cereal preparations found at Neolithic Çatalhöyük (Turkey), for example cereals processed into bread, dough and/or porridge.