Mode of phytochrome B action in the photoregulation of seed germination in Arabidopsis thaliana

Arabidopsis thaliana seeds imbibed for a short duration show phytochrome B (PhyB)-specific photo-induction of germination. Using this system, the relationship was determined between the amount of PhyB in seeds and photon energy required for PhyB-specific germination in two transgenic Arabidopsis lines transformed with either the Arabidopsis PhyB cDNA (ABO) or the rice PhyB cDNA (RBO). Immunochemical detection of PhyB apoprotein (PHYB) showed that the expression level of PHYB in ABO seeds was at least two times higher than that in the wild-type seeds, but in RBO seeds the PHYB level was indistinguishable from that in wild-type seeds. The photon fluence required for induction and photoreversible inhibition of germination was examined using the Okazaki large spectrograph. At the wavelengths of 400–710 nm, the ABO seeds required significantly less photon fluence than wild-type seeds for induction of germination, whereas the RBO seeds required similar fluence to wild-type seeds. A critical threshold wavelength for either induction or inhibition of germination of ABO seeds shifted towards the longer wavelengths relative to wild-type seeds. By assuming that PhyA and PhyB are similar in their photochemical parameters, amounts of P_fr at each wavelength were calculated. The photon fluence required for 50% germination was equivalent to the fluence generating a P_fr/P_tot ratio of 0.21–0.43 in wild-type seeds, and of 0.035–0.056 in ABO seeds. These results indicate that PhyB-specific seed germination is not strictly a function of the P_fr/P_tot ratio, but is probably a function of the absolute P_fr concentration.     

Lipid peroxidation, carbohydrate hydrolysis, and Amadori-Maillard reaction at early stages of dry seed aging

Processes underlying aging of air-dry seeds were investigated. Naturally aged seeds of pea (Pisum sativum L.), cucumber (Cucumis sativus L.), and buckwheat (Fagopyrum esculentum Moench.) were separated into three fractions of different quality according to their room temperature phosphorescence (RTP): fraction I contained strong seeds; fraction II comprised weak seeds; and fraction III was composed of dead seeds. These seed fractions were used to identify the processes in air-dry seeds that account for the initial deterioration in seed quality at early stages of aging and for the possible transient improvement of seed quality at further aging. Experiments with seed powders showed that the increase in thermochemiluminescence (TCL) in the temperature range of 50?C110°C was determined by the presence of lipid peroxidation products. No difference was observed between TCL levels in fraction I and fraction II seeds; hence, lipid peroxidation is not responsible for the transition of strong seeds to the fraction of weak seeds. The TCL intensity monitored upon heating in the range of 50?C110°C increased only in the fraction of dead seeds. In fraction II seeds, a twofold increase in TCL upon heating at 150°C was observed in aged seeds; this indicates that the products of oligosaccharide hydrolysis (glucose) were more abundant in fraction II seeds than in fraction I seeds under similar conditions. This assumption was confirmed by direct determination of glucose content with a glucometer. Hence, the transition of air-dry seeds from fraction I (strong seeds) to fraction II (weak seeds) occurred due to the activation of carbohydrate hydrolysis in aging seeds. Since air-dry seeds contain no free water during aging, the seed moisture content decreases during hydrolysis, presumably, because the bound water participates in the hydrolysis reaction. The decrease in ??improved?? seeds of glucose content and the increase in moisture content suggest the activation of amino-carbonyl reaction. It is proposed that the amino-carbonyl (Amadori-Maillard) reaction is responsible for closing water channels in improved seeds, as well as for the decreased water permeability of cell membranes during seed imbibition.     

Seed dispersal of Korean pine Pinus koraiensis labeled by two different tags in a northern temperate forest, northeast China

Two types of tagging methods, i.e., a 1 × 3-cm tin tag attached to seed with a 10- to 12-cm metal wire (total weight 0.32 g) and a 2 × 4-cm white plastic tag fastened to seed with an identical metal wire (total weight 0.57 g) were used to study their effects on seed dispersal of Korean pine by small rodents. A total of 600 seeds were released to assess four main points: (1) difference in seed survival rates, (2) difference in caching behaviors of small rodents, (3) difference in dispersal distances, and (4) proportion of seed missing. The results demonstrated that seed removal for wire-plastic-tagged seeds was faster than that for wire-tin-tagged seeds. There was no apparent difference in the proportion of seeds eaten in situ (42% and 52% for wire-plastic-tagged seeds and wire-tin-tagged seeds, respectively). We found 41% and 1% of seeds were moved and hoarded for wire-plastic-tagged seeds and wire-tin-tagged seeds, respectively. However, 2.33% and 14% of seeds were missing, and their ultimate fates were not known for wire-plastic-tagged seeds and wire-tin-tagged seeds, respectively. We found the wire-plastic-tagged seeds easier to track than the wire-tin-tagged seeds due to the fact that the white plastic tags were more salient than the tin tags in field environments. The average dispersal distances were 4.11 ± 2.40 m and 3.01 ± 2.06 m for wire-plastic-tagged seeds and wire-tin-tagged seeds, respectively, and showed great difference. Despite most being eaten in situ or after removal, 41% of seeds were cached for wire-plastic-tagged seeds, much more than for wire-tin-tagged seeds. A total of 71 primary caches (123 seeds) were found for wire-plastic-tagged seeds, with the average and maximum cache sizes being 1.73 and 6, respectively. However, only three caches were found, and cache size was equal to one for wire-tin-tagged seeds. The above data suggests there is some uncertainty in different tagging methods to used track seed fates. Despite their effectiveness in helping to trace seed dispersal or movement by seed-dispersing rodents, different tagging methods—including size, color, and mass—need to be fully understand in enclosure experiments .     

不同处理对海甘蓝种子发芽和幼苗生长的影响

由于受种子生理休眠作用的影响和硬而厚的种皮所产生的抑制作用,使海甘蓝（ＣｒａｍｂｅｍａｒｉｔｉｍａＬ．）种子发芽慢,发芽率低。为探索加快海甘蓝种子发芽和提高种子发芽率的有效方法,我们先后进行了８种不同的种子预处理试验和６种不同次氯酸钠溶液浸种的发芽试验。结果发现：（１）种子剥皮处理可以很大程度地促进发芽和提高发芽率;（２）用浓度为０．０５％的赤霉酸溶液浸种１８ｈ对海甘蓝种子发芽也有很好的促进作用;（３）用０．２０％的代森锰锌４５Ｍ（Ｄｉｉｔｈａｎｅ４５Ｍ）溶液浸种２０ｍｉｎ的消毒处理对海甘蓝种子发芽产生一定程度的抑制作用,但可减少海甘蓝幼苗死亡率;（４）适宜浓度的次氯酸钠漂白水（法文名１＇ＥａｕｄｅＪａｖｅｌ）的溶液（１０％）浸种５ｍｉｎ对促进海甘蓝种子发芽和减少幼苗死亡均有良好效果;浓度低于１０％时．不足以腐蚀种子硬而厚的种皮而促进种子发芽,也不足以杀死种子携带的病菌而减少幼苗死亡率;浓度大于１０％时,对种子的胚和种子内的酶活性产生不良影响,从而抑制种子发芽和影响幼苗的正常生长。     

Seed size selection by olive baboons

Seed size is an important plant fitness trait that can influence several steps between fruiting and the establishment of a plant’s offspring. Seed size varies considerably within many plant species, yet the relevance of the trait for intra-specific fruit choice by primates has received little attention. Primates may select certain seed sizes within a species for a number of reasons, e.g. to decrease indigestible seed load or increase pulp intake per fruit. Olive baboons (Papio anubis, Cercopithecidae) are known to select seed size in unripe and mature pods of Parkia biglobosa (Mimosaceae) differentially, so that pods with small seeds, and an intermediate seed number, contribute most to dispersal by baboons. We tested whether olive baboons likewise select for smaller ripe seeds within each of nine additional fruit species whose fruit pulp baboons commonly consume, and for larger seeds in one species in which baboons feed on the seeds. Species differed in fruit type and seed number per fruit. For five of these species, baboons dispersed seeds that were significantly smaller than seeds extracted manually from randomly collected fresh fruits. In contrast, for three species, baboons swallowed seeds that were significantly longer and/or wider than seeds from fresh fruits. In two species, sizes of ingested seeds and seeds from fresh fruits did not differ significantly. Baboons frequently spat out seeds of Drypetes floribunda (Euphorbiaceae) but not those of other plant species having seeds of equal size. Oral processing of D. floribunda seeds depended on seed size: seeds that were spat out were significantly larger and swallowed seeds smaller, than seeds from randomly collected fresh fruits. We argue that seed size selection in baboons is influenced, among other traits, by the amount of pulp rewarded per fruit relative to seed load, which is likely to vary with fruit and seed shape.     

Seed size and shape and persistence in the soil in the New Zealand flora

Seed size and shape predict seed persistence in the soil for British and Argentinian herbaceous plant species. Those species with small, rounded seeds tend to have persistent seeds while those with larger, more elongate or flattened seeds usually lack persistence. It has been suggested that the mechanism underlying this pattern may be ease of burial, as small, rounded seeds are incorporated into the soil more easily than large, elongate or flattened seeds and are therefore less likely to be eaten by seed predators. We tested whether seed size and shape were related to persistence in the soil for 47 species native to New Zealand forests. There was a tendency for species with persistent seeds to have smaller seeds than species with transient seeds. However, species with large and/or elongate or flattened persistent seeds were relatively common. This indicates that seed size and shape are not related to persistence in New Zealand in the same way as in Britain and Argentina. A similar negative result has been found in Australia. The underlying cause of the patterns observed is unlikely to be ease of burial, since incorporation of seeds into the soil is likely to operate in all countries in a similar manner on seeds without specialised seed burial mechanisms. Data from all four floras studied to date also suggest that species with small, rounded seeds that do not germinate immediately must have the ability to survive periods of burial.     

水稻种子内生细菌研究进展

水稻的根、茎、叶、种子等器官存在大量对植株生长和产量、品质、抗性等有重要作用的共生和伴生微生物,其中内生菌是种子共生和伴生微生物中的一个代表类群.水稻种子中普遍存在种类丰富且结构复杂的内生菌群落,会直接或间接地影响种子的萌发、生长和群体的产量特性.从水稻种子内生细菌的多样性、水稻种子与其内生细菌分布的相关性、水稻种子内...     

Role of Endogenous Plant Growth Regulators in Seed Dormancy of Avena fatua: II. Gibberellins

Gibberellin A₁ (GA₁) was identified by combined gas chromatographymass spectrometry as the major biologically active gibberellin (GA) in seeds of wild oat (Avena fatua L.) regardless of the depth of dormany or stage of imbibition. Both unimbibed dormant and nondromant seeds contained similar amounts of GA₁ as estimated by the d5-maize bioassay. During imbibition, the level of GA₁ declined in both dormant and non-dormant seeds, although the decline was more rapid in dormant seeds. Only in imbibing nondormant seeds did the GA biosynthesis inhibitor, 2-chloroethyltrimethyl ammonium chloride (CCC), cause a reduction in the level of GA₁ from that observed in control seeds. These results are interpreted as an indication that while afterripening does not cause a direct change in the levels of GAs during dry storage, it does induce a greater capacity for GA biosynthesis during imbibition.

Nondormant seeds imbibed in the presence of 50 millimolar CCC germinated equally as well as untreated seeds. When wild oat plants were fed CCC throughout the entire life cycle, viable seeds were produced that lacked detectable GA-like substances. These seeds afterripened at a slightly slower rate than the controls. Moreover, completely afterripened (nondormant) seeds from plants fed CCC continuously contained no detectable GA-like substances, and when these seeds germinated, dwarf seedlings were produced, indicating GA biosynthesis was inhibited during and after germination. In total, these results suggest that the increased capacity for GA biosynthesis observed in imbibing nondormant seeds is not a necessary prerequisite for germination. It is therefore possible that GA biosynthesis in imbibing nondormant seeds is one of many coordinated biochemical events that occur during germination rather than an initiator of the processes leading to germination.

     

Systemic spread of downy mildew in basil plants and detection of the pathogen in seed and plant samples

Downy mildew on sweet basil (Ocimum basilicum L.) occurs worldwide. Contaminated seeds are considered as the primary inoculum source. So far no strategy to control the disease is available. Hence, the use of pathogen-free seeds is the only alternative to prevent disease outbreaks. Therefore, a rapid diagnostic method for seed testing is urgently needed. The sensitivity of a specific PCR method for direct detection of the downy mildew pathogen Peronospora belbahrii on basil samples, particularly on seeds, was evaluated. The applied PCR method proved to be very sensitive for direct detection of the pathogen on seeds and plant samples. The PCR detection limit of P. belbahrii in artificially infested seeds corresponded to the DNA amount of a single spore per seed. Additionally, the systemic spread of the pathogen from naturally infected seeds was investigated. The experiments showed that outgrowing basil plants were latently infected with the downy mildew pathogen, and the infection continued within the plant. Contaminated seeds were harvested from symptomless latently infected plants. These results support the implementation of PCR-based detection in a seed certification scheme and the necessity to control the pathogen on seeds. The PCR method can also be used for evaluation of pathogen control on seeds based on detection of the pathogen in outgrowing plants.     

Indel seeds for homology search

We are interested in detecting homologous genomic DNA sequences with the goal of locating approximate inverted, interspersed, and tandem repeats. Standard search techniques start by detecting small matching parts, called seeds, between a query sequence and database sequences. Contiguous seed models have existed for many years. Recently, spaced seeds were shown to be more sensitive than contiguous seeds without increasing the random hit rate. To determine the superiority of one seed model over another, a model of homologous sequence alignment must be chosen. Previous studies evaluating spaced and contiguous seeds have assumed that matches and mismatches occur within these alignments, but not insertions and deletions (indels). This is perhaps appropriate when searching for protein coding sequences (<5% of the human genome), but is inappropriate when looking for repeats in the majority of genomic sequence where indels are common. In this paper, we assume a model of homologous sequence alignment which includes indels and we describe a new seed model, called indel seeds, which explicitly allows indels. We present a waiting time formula for computing the sensitivity of an indel seed and show that indel seeds significantly outperform contiguous and spaced seeds when homologies include indels. We discuss the practical aspect of using indel seeds and finally we present results from a search for inverted repeats in the dog genome using both indel and spaced seeds.     

Population dynamics of the shrub Acacia suaveolens (Sm.) Willd.: Dispersal and the dynamics of the soil seed-bank

Genet survival in seeds of Acacia suaveolens was examined through both dispersal and dormancy in the soil in populations near Sydney. Following initial passive seed-fall, the majority of seeds lie within a 1 m radius of the stem of the parent. Further dispersal is predominately mediated by ants. A. suaveolens seeds possess an elaiosome which attracts ants. When elaiosomes are removed, the potential for further dispersal of seeds is greatly reduced. Three species of ant disperse seeds of A. suaveolens and the fate of seeds following ant dispersal was observed to depend on the particular species of ant involved. Ants of both Iridomyrmex sp. and Pheidole sp. B are too small to drag seeds and, instead, ants of these species usually remove the elaiosome in situ, with little dispersal of the-seed resulting. Ants of Pheidole sp. A are larger and disperse seeds further, frequently taking them into their nests where the elaisosome is removed. Seeds are retained inside the nests and incorporated into the floors and walls of passageways and chambers. Several supposed ‘advantages’ of myrmecochory were examined but none were verified. Instead, two distinct ‘disadvantages’ were identified. These were: burial of seeds by ants of Pheidole sp. A into ‘unsafe sites’; and too deep a burial of seeds in nests for seeds to receive a stimulus to germinate during fires, and for seedlings to emerge successfully. Outside nests of Pheidole sp. A. seeds are concentrated in the top 5 cm of the soil, whilst within nests of these ants, seeds are found up to 15 cm deep. The dynamics of various components of the soil seed-bank were examined using seeds buried in nylon mesh containers. The seed-bank is persistent without annual recruitment to seedlings, enabling a population to persist as seeds after all above-ground plants have perished.     

云南西双版纳桑寄生植物传播与鸟的关系研究

在西双版纳地区桑寄生植物的种子是鸟类传播。传播的鸟类主要是啄花鸟科的纯色啄花鸟,红胸啄花鸟,朱背啄花鸟和黄肛啄花鸟等。桑寄生植物种子的传播方式,一是鸟类蚕食除去外果皮的种子或外果皮果肉相互连着的种子,经消化道消化吸收大部分果肉或外果皮后,将种子排出体外,其次是鸟在觅食中遗漏种子进行传播。     

Changes in Baboon Feeding Behavior: Maturity-dependent Fruit and Seed Size Selection within a Food Plant Species

Despite considerable inter- and intraindividual variation in fruit and seed size in many plant species, researchers have given little attention to the relevance of the traits for primate fruit choice within a food plant species and its implications for tree regeneration. We studied feeding behavior and selectivity of olive baboons (Papio anubis) in the African locust bean (Parkia biglobosa, Mimosaceae), via direct observations of habituated groups and indirect evidence from leftovers of pods after feeding events. Olive baboons acted as both seed predators and dispersers for Parkia biglobosa. They fed on and destroyed unripe seeds, and swallowed intact ripe seeds when consuming mature fruit pulp. Predation rate was high, and only 10% of the seeds were dispersed. Predation and dispersal of seeds is linked to seed number and size. Digestible unripe seeds accounted for 10% of the unripe fruit mass, while indigestible ripe seeds made up 28% of the mature fruit mass. With these constraints, olive baboons increased food gain per fruit by selecting unripe pods containing a high number of large and heavy seeds. Consequently, only pods with fewer and smaller seeds remained for maturation. Thereafter, baboons fed on mature pods containing the smallest seeds, and exploited pods with more seeds to a greater extent than those with fewer seeds. Thus, fruits with small seeds and an intermediate seed number contributed the most to dispersal by baboons.     

Allozyme evidence for polyzygotic polyembryony in Siberian stone pine (Pinus sibirica Du Tour)

Approximately 4000 mature seeds from 350 trees in nine populations (12–75 trees per population) of Siberian stone pine were investigated for multiple embryos (polyembryony). Haploid megagametophytes and embryos were genotyped for eight allozyme loci. Eight-yone seeds (2.11%) had more than 1 embryo. Of these, 71 seeds had 2 embryos (1.85%), 6 seeds had 3 embryos (0.16%), 3 seeds had 4 embryos (0.08%) and 1 seed had 6 embryos (0.026%). Allozyme comparison of megagametophytes and embryos could distinquish two types of polyembryony in 56 of the 81 seeds. In 28 seeds (50%) the polyembryony was polyzygotic (independent fertilizations of more than one egg cell in the ovule); 25 seeds (45%) had most likely monozygotic polyembryony (genetically identical embryos resulting from the cleavage of a single proembryo) and 3 seeds had both genetically different and genetically identical embryos. To the best of our knowledge, this is the first genetic evidence for the form of polyembryony in conifer seeds.     

Phytochrome intermediates and action spectra for light perception by dry seeds

It has previously been demonstrated that far-red irradiation of dry Lactuca sativa L. seeds results in inhibition of subsequent germination. Although red has no effect on dry seeds, a red irradiation following a farred irradiation reverses the effect of far-red. This phenomenon is most noticeable in seeds with artificially raised levels of phytochrome in the far-red absorbing form. Qualitatively similar results have been found for the seeds of Plantago major L., Sinapis arvensis L., and Bromus sterilis L. Action spectra studies on Plantago seeds show that the action peaks for promotion and inhibition of germination of hydrated seeds are at 660 and 730 nanometers, respectively. The action spectrum for inhibition of subsequent germination following irradiation of dry seeds is qualitatively and quantitatively similar to that for hydrated seeds, with an action peak at 730 nanometers, indicating absorption by phytochrome in the far-red absorbing form. However, the action spectrum for the reversal of this far-red effect on dry seeds has a broad peak at 680 nanometers and subsidiary peaks at 650 and 600 nanometers. It is proposed that this effect is due to light absorption by the phytochrome intermediate complex meta-Fa, and that the action spectrum reflects the in vivo absorption properties of this intermediate.     

Designing sensitive and specific spaced seeds for cross-species mRNA-to-genome alignment.

As the demand for accurately aligning gene sequences to the genome of a related species grows with the sequencing of new genomes, spaced seeds emerge as a promising vehicle for increasing alignment sensitivity. We extend the existing {0, 1} match-mismatch models for sensitivity evaluation to take into account the compositional structure of coding sequences and ultimately produce seeds better suited to this particular application. Designing seeds for alignment programs, however, needs to balance sensitivity and specificity.We assess the effects of seed variations on both sensitivity and specificity in an extended model that incorporates transitions and differentiates among the three codon positions, and show that spaced seeds with transitions offer a better sensitivity-specificity tradeoff. Furthermore, we propose a theoretical formulation for rigorously assessing seed specificity, starting from Bernoulli and Markov models of the mRNA and genomic sequences. Within this framework, we perform the first comprehensive analysis of seeds to serve as a blueprint for selecting sensitive and specific seeds for practical applications. Our analyses show that specificity is relatively constant for seeds of a given weight, while sensitivity varies widely, with the highest values attained by seeds allowing a small (2-6) number of transitions.A strategy for designing seeds, therefore, is to first select the weight of the seed by identifying the desired sensitivity-specificity tradeoff, then choose the most sensitive seed(s) within that weight group. We illustrate our methods with the alignment of chicken coding sequences against the human genome assembly version HG17.     

Seedling tolerance to cotyledon removal varies with seed size: A case of five legume species

It is generally accepted that seedlings from large seeds are more tolerant to defoliation than those from small seeds due to the additional metabolic reserves present in the large seeds. However, information on the effects of amount of seed reserves (cotyledon removal) from seedlings resulting from large vs. small seeds on seedling growth and long‐term survival in the field is limited. Five legume species with different sizes of seeds were sown in the field and none, one, or both cotyledons removed 7 days after seedling emergence. Seedling biomass, relative growth rate (RGR) and survival were determined at different time. Cotyledon removal, species, and their interaction had significant effects on seedling growth and survival. During the period between 33 and 70 days, seedlings from large seeds had a significantly lower RGR than those from small seeds. Biomass, RGR, and survival of seedlings from large seeds were significantly reduced by removal one or both cotyledons, whereas those of seedlings from small seeds were not affected. Seed energy reserves are more important for the early growth of seedlings from large seeds than for those from small seeds. The overall effect of cotyledon removal on growth and survival varies with seed size (i.e., energy reserves) with seedlings from small seeds being less sensitive than those from large seeds under field conditions.     

无菌猕猴桃种子采集方法研究

无菌的猕猴桃种子是猕猴桃胚乳培养、实生苗微嫁接等技术的基础材料,利用消毒剂灭菌是常用的无菌种子采集手段,应用最广泛的消毒剂为升汞(mercuric chloride)和次氯酸钠(NaClO)。为了避免使用消毒剂,该研究提出了一种新的无菌猕猴桃种子采集方法——无菌搅拌法,同时为探索其准确性和应用性,比较了0.2%升汞灭菌20 min、10%次氯酸钠灭菌20 min、无菌搅拌法三种方式采集无菌猕猴桃种子的效果,并对种子萌发和幼苗形成的影响进行了研究。结果表明:无菌搅拌法、0.2%升汞灭菌20 min是稳定有效的无菌猕猴桃采集方式,10%次氯酸钠灭菌20 min的采集效果不稳定;在相同的时间内,无菌搅拌法的种子发芽率最高,为89.90%,但发芽势较低,均可正常成苗; 10%次氯酸钠灭菌20 min的发芽率次之,与无菌搅拌法的种子无显著差异,发芽势和成苗率最高,分别为47.47%和67.86%,且有打破猕猴桃种子休眠的作用,整体作用类似于赤霉素(GA_3)浸种的效果; 0.2%升汞灭菌20 min对猕猴桃种子的萌发有抑制作用,各项指标均显著低于无菌搅拌法种子,且生长缓慢。此外,无菌搅拌法是物理处理,对种子、操作人员、环境均无害。这证实了无菌搅拌法的实用性和优势,发现了次氯酸钠在打破猕猴桃种子休眠方面的作用,为其它同类型果实的无菌种子采集提供了参考。     

Energetics and foraging behaviour of the European seed harvesting ant Messor capitatus: II. Do ants optimize their harvesting?

Abstract The preference in seed selection by Messor capitatus (Latreille) was studied with artificial seeds (weighted styropore spheres) in the laboratory and with natural seeds in the field. The laboratory experiments showed no strong preference for size of the artificial seeds in the range 3–8 mm (diameter). A mass of about 400 mg was selected when artificial seeds of 5-5.5 mm were offered at different distances from the nest.
In the field experiments, crushed seeds were placed 2 m from the nest and ants showed a clear preference for the size class 2.0–3.0 mm in diameter, which is much smaller and lighter than the preference for the artificial seeds. The preference of seeds from different plants showed very big variability. There was no correlation between the preference and any of the following variables of the seeds: fresh mass, dry mass, water content, energy content, and nitrogen content. No evidence for energy optimizing in food selection in Messor capitatus was found.
The energetic reward of bringing any seed back to the nest will, under all normal conditions, be much higher than the energetic expenditure. For example, the energetic content in a wheat seed is about 650 Joule, which is sufficient energy for a worker ant of Messor capitatus to carry the seed for a distance of 6.5 km at a temperature of 30^oC.