Preservation of cultivar purity is a particular challenge for plants that are self-incompatible, and have easily germinating seeds and vigorously spreading rhizomes. Kostamo et al. develop and test molecular and morphological identification methods for arctic bramble, Rubus arcticus. They find that the best morphological parameters are the length-to-width ratio of the middle leaflet and leaf margin serration. A particular characteristic, fingertip touch, is shown by electron microscopy to be related to the density and quality of the leaf hairs. Red raspberry (R. idaeus) SSR marker no. 126 is useful for differentiation of the eight arctic bramble cultivars tested. These identification methods are critical to secure the maintenance and management of R. arcticus, and the approaches adopted are equally applicable to other species with similar biology.

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Populations of dioecious flowering plants (which have male and female individuals) often depart from the expected male:female ratio of 1:1. The causes of skewed sex ratios are complex and still poorly understood. As with many species that have two sexes, females must invest more resources in reproduction. In the case of flowering plants, this is the extra cost associated with flowering and subsequent fruit production. Consequently, females often delay flowering and are more susceptible to environmental stresses, suffering higher mortality rates compared with males. These factors can lead to a greater than equal representation of males in the population.

A recent AOB study attempts to untangle these complex causes of biased gender ratios. This meta-analysis of existing studies of dioecious flowering plant species found a large amount of variation in sex ratios between populations within a species. There was also much variation between species, although several patterns have emerged.

Due to delayed and less frequent flowering by females, younger populations tend to have a greater bias towards males. This was demonstrated elegantly by looking at fire-adapted species, which recolonise an area following a fire, so that the age of the population can be exactly known. Males are also more frequent in populations at higher altitudes, reflecting greater mortality of females as the environment becomes more stressful. Chance historical effects can also play an important role in skewing the sex ratio. For example, in clonal species, where a few individuals colonise an area and largely reproduce vegetatively, chance biases in the representation of the sexes can be preserved over long periods.

You can read the study, free, at the Annals of Botany.

Ecological context and metapopulation dynamics affect sex-ratio variation among dioecious plant populations (2013) Ann Bot 111(5): 917-923. doi:10.1093/aob/mct040

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Parasitic plants – angiosperms that directly attach to another plant via a haustorium, a modified root that forms a morphological and physiological link between the parasite and host – tend to get a bad press. And it’s little surprise with the antics of such villains as Striga, the ‘violet vampire’, which greatly reduces the production of staple foods and commercial crops such as maize, sorghum, millet, rice, sugarcane and cowpea in many African countries, and can cause up to 100% crop loss. Slightly less devastating and livelihood-threatening is Rhinanthus minor – ‘yellow rattle’ – a hemiparasite on grasses, which is found in Europe, Russia, western Siberia, northern USA and Canada.

Whilst it is generally recognised that such plants have major negative impacts on plant community structure via influence on host productivity and competitive ability, James Fisher et al. show that nutrient-rich leaf litter from R. minor has a positive effect on plant community structure: ‘critically, in the case of grass and total community biomass, this partially negates biomass reductions caused directly by parasitism’. From sub-terranean to supra-terrestrial community impacts now, with another hemiparasite – mistletoes – and work by David Watson and Matthew Herring. Having already been established as ‘keystone resources’ – species providing important resources for a broad range of taxa and determining local diversities in these habitats – Watson and Herring experimentally investigated the role of Australian mistletoes such as Amyema miquelii (Loranthaceae, bog mistletoe) in eucalyptus woodland. After 3 years, sites from which mistletoe was removed lost, on average, a fifth of their total species’ richness, 26.5% of woodland-dependent bird species and more than one-third of their woodland-dependent residents.

The researchers, from The Institute for Land, Water and Society at Australia’s Charles Sturt University suggest that ‘nutrient enrichment via litter-fall is the main mechanism whereby the mistletoe promotes species’ richness, driving small-scale heterogeneity in productivity and food availability for woodland animals’. They further propose that this explanation applies to other parasitic plants with high turnover of enriched leaves, and that the community-scale influence of these plants is most apparent in low-productivity systems. I wonder if they had R. minor in mind? Prescience is, after all, a virtue…

[In the interests of fairness, it should be stated that Fisher et al. do cite Watson and Herring’s paper – Ed.]

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Today the State of Nature report is out, detailing the current challenges facing wildlife across the UK and its territories. You can download it for yourself from the RSPB’s site, and it’s an excellent read. It’s not just birds that are the focus of the report. A number of charities have got together to produce an expansive report including Plantlife.

The report tackles various habitats found around the UK, lowlands, forests, marine and so on. There are a few recurrent themes. One is that a report like this is needed badly. There are simply too many gaps in our knowledge to know exactly what is under threat in the countryside. Secondly where we do have comparison data, it looks like a lot of UK wildlife is in trouble. Sixty per cent of species have declined, thirty per cent strongly more than 10% are under threat of extinction. In some cases, like 97% of lowland meadow disappearing from the UK there’s an obvious cause. However, elsewhere in the report it is clear that there are many different factors impacting on nature.

The other common thread is that it doesn’t all have to be doom and gloom. There are species that are doing better. Otters have done well, and peregrine falcons are on the rise. I think the message that damage to wildlife is a choice, not an inevitability, is important. One of the surprises to me was how important Brownfield sites are for biodiversity. This is important news because it’s usually targeted for development over Greenfield sites. Protection for Brownfield sites might turn out to be necessary, but it’s going to be a hard sell.

The report also covers UK territories overseas, like Saint Helena photographed right. Again, the report highlights the poor state of knowledge of overseas territories, from the South Atlantic, to the Caribbean, to Pitcairn. The UKOTs Online Herbarium gets a shout-out for digitising research and making a base for a botanical assessment of the territories.

Individual warnings over species loss pose a double danger. To start there’s the problem of making it news, today it’s Scottish wildcats, which is a difficulty for the less fluffy species. The other is the constant low-level warnings mean that people see large numbers of species under threat of extinction as part of everyday life. The State of Nature report helps put this into perspective in a public-friendly format. If this becomes a regular publication then it could be a powerful voice for conservation.

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Brunonia australis and Calandrinia sp. are Australian native herbs with commercial potential as flowering potted or bedding plants. Both species are best grown as annuals and flower naturally during spring and early summer. However, many ornamental plants are grown outside their natural flowering period to align flowering with peak market demand, which requires the capacity to predict flowering date under changing or different environments. Scheduling crop production using quantitative flowering time models can have considerable advantages as they can be tailored for individual requirements, unlike traditional scheduling methods that are typically based on calendar date and have no particular reference to the environment.

Most development rate models for ornamental species predict flowering time in relation to temperature, photoperiod and/or daily light integral as observed for the above models. However, there are few flowering time models for ornamental plants that include a vernalization function. Vernalization is important for early and complete flowering of many traditional herbaceous crops. Plant responses to vernalization have been incorporated into some models for field crops and arabidopsis, which reportedly improved accuracy. A new paper in Annals of Botany quantifies temperature and photoperiod or vernalization responses of B. australis and Calandrinia sp. and model development for the purpose of scheduling year-round flowering. The effects of temperature and photoperiod or vernalization on plant quality characteristics, including flower and branch number, were defined.

Modelling temperature, photoperiod and vernalization responses of Brunonia australis (Goodeniaceae) and Calandrinia sp. (Portulacaceae) to predict flowering time. Ann Bot (2013) 111 (4): 629-639.
doi: 10.1093/aob/mct028
Crop models for herbaceous ornamental species typically include functions for temperature and photoperiod responses, but very few incorporate vernalization, which is a requirement of many traditional crops. This study investigated the development of floriculture crop models, which describe temperature responses, plus photoperiod or vernalization requirements, using Australian native ephemerals Brunonia australis and Calandrinia sp.
A novel approach involved the use of a field crop modelling tool, DEVEL2. This optimization program estimates the parameters of selected functions within the development rate models using an iterative process that minimizes sum of squares residual between estimated and observed days for the phenological event. Parameter profiling and jack-knifing are included in DEVEL2 to remove bias from parameter estimates and introduce rigour into the parameter selection process.
Development rate of B. australis from planting to first visible floral bud (VFB) was predicted using a multiplicative approach with a curvilinear function to describe temperature responses and a broken linear function to explain photoperiod responses. A similar model was used to describe the development rate of Calandrinia sp., except the photoperiod function was replaced with an exponential vernalization function, which explained a facultative cold requirement and included a coefficient for determining the vernalization ceiling temperature. Temperature was the main environmental factor influencing development rate for VFB to anthesis of both species and was predicted using a linear model.
The phenology models for B. australis and Calandrinia sp. described development rate from planting to VFB and from VFB to anthesis in response to temperature and photoperiod or vernalization and may assist modelling efforts of other herbaceous ornamental plants. In addition to crop management, the vernalization function could be used to identify plant communities most at risk from predicted increases in temperature due to global warming.

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“PLOS is delighted that AoB PLANTS is bringing together leaders in the field to articulate an open access vision that is aligned with the future of scholarly communication.”
Cameron Neylon, PLOS Advocacy Director

“At this time of uncertainty in the future of scientific publications, AoB PLANTS is showing the path forward by combining open access with the long-term experience and reputation of Oxford University Press.”
Osvaldo E. Sala, Wrigley Chair & Foundation Professor, Arizona State University

“With broad coverage of the plant sciences and an intensifying focus on environmental biology, AoB PLANTS publishes articles of great interest and employs an open-access policy that ensures they are widely read.”
Daniel Simberloff, Nancy Gore Hunger Professor of Environmental Science, University of Tennessee

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If you’re not sure who he is, Robin Ince is the sane voice on the Infinite Monkey Cage, the BBC’s science/comedy show. When Brian Cox goes off on one of his surreal rants about Physics being the best science* it’s Robin Ince who pulls him back to reality. A person looking at things sensibly doesn’t sound like the basis for good comedy but, a bit like Douglas Adams, Robin Ince is a normal person in a bizarre world.

The show is about how weird the world is. Despite the frequent description of Robin Ince as grumpy, at its heart the show is actually very positive. Ince argues that now is the greatest time to be alive. Partly this is because not only do we know more about the universe than ever, our we also have a better idea about our ignorance. There is so much we don’t know that we could now investigate. Another reason for wanting to be alive now is that if you were alive in the fifteenth century you’d probably be dead.

Actually reviewing all the jokes, and critiquing how accurate he is about orchids would be missing the point. It’s a comedy show. Is he funny? Yes. But even if you have no sense of humour and are an expert on evolution, he’s still worth watching. The show uses Powerpoint. That means he has to be able to perform with Powerpoint or everything falls flat. Much as I like sites like Presentation Zen you can learn a hell of a lot on how to capture the audience by watching someone like Robin Ince. Like Dave Gorman he works with, and not against, Powerpoint.

It’s not a simple thing to copy, the presentation works holistically. You can’t simply watch the show and then lift ideas wholesale. What you can see is the difference talking with excitement and enthusiasm about a subject can make. I’ll be keeping an eye on his website so I can catch him again next time he comes close to Radnorshire.

The video below Science versus wonder? is a very compressed exploration of similar themes to the show.

* I’ve used Science to confirm that Physics is not the best discipline. I took a survey of scientists in the Annals of Botany office, and no one put Physics top.

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Understanding the production of L-ascorbic acid (L-AsA), its cellular roles and its accumulation in fruit has advanced considerably over the last decade. The importance of irradiance on fruit relative to leaves, in tomato, suggests that there is little linkage between leaves and fruits in the supply of L-AsA. While manipulation of kiwi vine temperature supports fruit-based production, others have observed variability in long-distance phloem L-AsA transport from leaves to developing fruit. In apple, fruit L-AsA concentration is dependent on production which declines with maturation, despite L-AsA accumulating with increasing fruit weight. Tomatoes show pectin polymer degradation as a source of precursors for L-AsA synthesis and accumulation via L-galactonic acid. What is clear are species differences in the mechanism by which total fruit L-AsA production is modulated during development; in some fruits, e.g. strawberry, melon and tomato, it remains constant while in others, e.g. apple and orange, it declines). An explanation of how total fruit L-AsA is modulated during fruit development may differ with species. L-AsA is detected in leaf phloem, but what remains unclear is what contribution long-distance transport from potential sources, such as leaves, makes to the pattern and amount of AsA that accumulates in fruit tissues at maturity.

A new paper in Annals of Botany aims to determine the role of green leafy tissues in the development and growth of fruits and how these processes influence L-AsA production and accumulation in fruit. It uses black currants (Ribes nigrum) as a model plant because its fruit have high L-AsA concentrations and there is some knowledge of the pattern of biosynthesis and accumulation of L-AsA over time. What remains unclear is the location of fruit L-AsA synthesis and under what circumstances, if any, does fruit growth compete with L-AsA production.

Linking ascorbic acid production in Ribes nigrum with fruit development and changes in sources and sinks. (2013) Ann Bot 111 (4): 703-712. doi: 10.1093/aob/mct026
Understanding the synthesis of ascorbic acid (L-AsA) in green tissues in model species has advanced considerably; here we focus on its production and accumulation in fruit. In particular, our aim is to understand the links between organs which may be sources of L-AsA (leaves) and those which accumulate it (fruits). The work presented here tests the idea that changes in leaf and fruit number influence the accumulation of L-AsA. The aim was to understand the importance of leaf tissue in the production of L-AsA and to determine how this might provide routes for the manipulation of fruit tissue L-AsA.
The experiments used Ribes nigrum (blackcurrant), predominantly in field experiments, where the source–sink relationship was manipulated to alter potential leaf L-AsA production and fruit growth and accumulation of L-AsA. These manipulations included reductions in reproductive capacity, by raceme removal, and the availability of assimilates by leaf removal and branch phloem girdling. Natural variation in fruit growth and fruit abscission is also described as this influences subsequent experimental design and the interpretation of L-AsA data.
Results show that fruit L-AsA concentration is conserved but total yield of L-AsA per plant is dependent on a number of innate factors many of which relate to raceme attributes. Leaf removal and phloem girdling reduced fruit weight, and a combination of both reduced fruit yields further. It appears that around 50% of assimilates utilized for fruit growth came from apical leaves, while between 20 and 30% came from raceme leaves, with the remainder from ‘storage’.
Despite being able to manipulate leaf area and therefore assimilate availability and stored carbohydrates, along with fruit yields, rarely were effects on fruit L-AsA concentration seen, indicating fruit L-AsA production in Ribes was not directly coupled to assimilate supply. There was no supporting evidence that L-AsA production occurred predominantly in green leaf tissue followed by its transfer to developing fruits. It is concluded that L-AsA production occurs predominantly in the fruit of Ribes nigrum.

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Le programme LANDSAT a été créé par la NASA au milieu des années 60 à des fins civiles d’observation de notre planète. Sept satellites ont été lancés entre 1972 et 1999 et un huitième doit l’être en 2013. Des millions d’images ont pu être capturées par ses instruments, pour des visées scientifiques ou économiques d’observations de l’agriculture ou encore du changement climatique.^[1] Ces satellites photographient tous les 16 jours l’intégralité de la planète depuis 41 ans et ont été les témoins privilégiés de bien des changements à la surface de notre bonne vieille planète.

Le projet TIMELAPSE, créé par Google, a permis d’agréger les photos prises depuis 30 ans en différents points de la planète pour présenter des cartes interactives, saisissantes par les transformations qu’elles présentent. Celles-ci sont co-publiées sur le site du géant de l’internet et par le prestigieux magazine TIME.^[2]&[3]

En plus de leur beauté, ces cartes nous amènent à réfléchir sur l’impact de l’Homme sur sa planète et son milieu de vie, sans cesse en accélération. On peut par exemple y voir verdir le désert Saoudien devant nos yeux ébahis, ou constater notre impuissance face à la déforestation galopante en Amazonie.^[2]&[4]

Dans un contexte où le changement climatique est une notion qui a rencontré beaucoup de difficultés à s’insérer dans les programmes scolaires (il vient juste d’être introduit dans les programmes scolaires officiels américains alors qu’il est actuellement question de le retirer du programme national britannique, et si en France depuis 2004 l’éducation à l’environnement et au développement durable est enseignée, elle reste morcelée entre les filières et disciplines sans connaître une approche globale), ^[5]&[6] ces images ne peuvent que nous amener à la réflexion…

Bibliographie

[1] Wikipédia, Programme Landsat, http://fr.wikipedia.org/wiki/Programme_Landsat

[2] Garric A., Voir la Terre vieillir en 30 ans, Le Monde, 10 mai 2013, http://ecologie.blog.lemonde.fr/2013/05/10/explorez-comment-la-terre-a-evolue-ces-30-dernieres-annees/

[3] Kluger J., Time and Space, TIME, http://world.time.com/timelapse/

[4] GIF Google, https://plus.google.com/photos/+GoogleEarth/albums/5875822979804092129

[5] Garric A., Les salles de classe anglo-saxonnes, nouvelles cibles des climatosceptiques, Le Monde, 10 mai 2013, http://www.lemonde.fr/planete/article/2013/05/10/les-salles-de-classe-anglo-saxonnes-nouvelles-cibles-des-climatosceptiques_3174945_3244.html

[6] Mougey A., En France, L’enseignement sur le climat est morcelé, Le Monde, 10 mai 2013, http://www.lemonde.fr/planete/article/2013/05/10/en-france-l-enseignement-sur-le-climat-est-morcele_3175062_3244.html

The Earth is growing old too!

The LANDSAT programm was created by the NASA in the middle of the 60s in the main purpose of getting a dynamic view of Earth by satellite imagery (in the public domain). Seven satellites were launched between 1972 and 1999, and an eighth satellite should be launched in 2013. Millions of images have thus been captured by these instruments, for scientific as well economic aims in order to get up to date pictures of agriculture, forestry, cartography,… all over the world, representing a unique resource for global change research.^[1] These satellites have taken pictures for 41 years, with one picture every 16 days of the entire planet, and have been the privileged witnesses of a lot of changes on the surface of our good old planet.

The TIMELAPSE project, created by Google, aggregates photos taken for 30 years on various spots of the planet to present interactive and surprising maps of the transformations they show. These maps are co-published on the internet giant’s site in collaboration with the prestigious TIME magazine.^[2]&[3]

Besides their beauty, these maps make us think about the human impact on Earth and our living environment, constantly accelerating. For example, we can see the Saudi desert turning green in front of our stunned eyes, or we can evaluate our powerlessness in front of the galloping deforestation in Amazonia.^[2]&[4]

If we think about the fact that the climate change topic has met many difficulties to be taught at schools and universities (it has just been introduced into the American official courses of study while it is currently questioned to remove it from the British national school curriculum; in France, education to environment and sustainable development is taught since 2004, but it remains split between diploma and disciplines without taking into consideration any global approach),^[5]&[6] these images should drive us to think urgently of the future of our planet…

Bibliography

[1] Wikipédia, Programme Landsat, http://fr.wikipedia.org/wiki/Programme_Landsat

[2] Garric A., Voir la Terre vieillir en 30 ans, Le Monde, 10 mai 2013, http://ecologie.blog.lemonde.fr/2013/05/10/explorez-comment-la-terre-a-evolue-ces-30-dernieres-annees/

[3] Kluger J., Time and Space, TIME, http://world.time.com/timelapse/

[4] GIF Google, https://plus.google.com/photos/+GoogleEarth/albums/5875822979804092129

[5] Garric A., Les salles de classe anglo-saxonnes, nouvelles cibles des climatosceptiques, Le Monde, 10 mai 2013, http://www.lemonde.fr/planete/article/2013/05/10/les-salles-de-classe-anglo-saxonnes-nouvelles-cibles-des-climatosceptiques_3174945_3244.html

[6] Mougey A., En France, L’enseignement sur le climat est morcelé, Le Monde, 10 mai 2013, http://www.lemonde.fr/planete/article/2013/05/10/en-france-l-enseignement-sur-le-climat-est-morcele_3175062_3244.html

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Correct identification of Napier grass accessions is a prerequisite because the existing germplasm information is scanty and cannot be relied upon for crop improvement, since cultivar discrimination has predominantly relied on morphological and agronomic features and is the major cause of inconsistency in identification. Consequently, a number of Napier grass cultivars have been in circulation, often with more than one name. Molecular markers have proven useful in distinguishing among morphologically related individuals within cultivars of the same plant species. Thus the genetic assessment of various Napier grass accessions from the Eastern Africa region is important for correct cultivar identification in order to exploit them fully in crop improvement strategies.

A new study in AoB PLANTS assessed the genetic variation between and within Napier grass collections comprising 281 accessions from selected regions in Eastern Africa (Kenya, Uganda, Tanzania and Ethiopia). The methodology developed in this study was able to discriminate among different Napier grass accessions and could be useful in screening cultivars.

Genetic diversity in Napier grass (Pennisetum purpureum) cultivars: implications for breeding and conservation (2013) AoB PLANTS 5: plt022 doi: 10.1093/aobpla/plt022
Napier grass is an important forage crop for dairy production in the tropics; as such, its existing genetic diversity needs to be assessed for conservation. The current study assessed the genetic variation of Napier grass collections from selected regions in Eastern Africa and the International Livestock Research Institute Forage Germplasm-Ethiopia. The diversity of 281 cultivars was investigated using five selective amplified fragment length polymorphism (AFLP) markers and classical population genetic parameters analysed using various software. The number of bands generated was 216 with fragments per primer set ranging from 50 to 115. Mean percentage polymorphic loci was 63.40. Genetic diversity coefficients based on Nei’s genetic diversity ranged from 0.0783 to 0.2142 and Shannon’s information index ranged from 0.1293 to 0.3445. The Fst value obtained was moderately significant (Fst = 0.1688). Neighbour-joining analysis gave two distinct clusters which did not reflect geographical locations. Analysis of molecular variance showed all variance components to be highly significant (P < 0.001), indicating more variation within (91 %) than between populations (9 %). Results suggested moderate genetic differentiation among Napier grass populations sampled, which could imply a high germplasm exchange within the region. The AFLP markers used in this study efficiently discriminate among cultivars and could be useful in identification and germplasm conservation.

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