Round-up of Fascination of Plants Day 2016

On May 18th, botany geeks around the world shared their love of plants in this year’s Fascination of Plants Day! Here’s our round-up of some of the best #fopd tweets!

First things first, test your skills with this challenging plant science quiz:

Check out some of the amazing work done by Botanic Gardens Conservation International (BGCI):

Have you read this thought-provoking post from The Guardian?

Check out these amazing ears of maize! 

Read on to learn how signals are converted to epigenetic memory:

More from BGCI:

Includes the amazing subheading “Ovules before brovules”!:

Great to hear from some of our younger plant scientists:

Some fun facts to share with your friends:

A fantastic image featuring the adaptations of marram grass to its sand-dune home:

This fascinating mutation results from an elongated apical meristem:

How long does this starch need to last? Plants use their internal circadian clock to ration their energy stores:

The loblolly pine’s genome is over seven times larger than yours!

Need more Fascinating Plants? There are lots of great ‘Roots and Shoots’ articles on eLife‘s Medium page

How did you celebrate Fascination of Plants Day this year? Let us know in the comments below!

Underutilized crops and insects replace fishmeal in aquaculture feed

Farmed fish are often fed with fishmeal, produced from the dried tissues of caught marine fish. In 2012, a total of 16.3 million metric tons of fish were caught to produce fishmeal and fish oil, 73% of which was used in aquaculture. This practice is unsustainable, and as the global human population is expected to rise to 9 over billion by 2050, capture fisheries will not be able to satisfy the demand for fish protein.

Barramundi

Barramundi fish

In recent decades there has been extensive research into ingredients to replace fishmeal, but this has focused mainly on sources of plant carbohydrate and protein such as maize and soy, which also serve as human foods. While these crops are now used in some commercial aquaculture feeds, they are not suitable for many species and have had less than optimal results. In addition, many countries do not grow these mainstream crops and are left in the undesirable position of having to import fishmeal alternatives, which can be cost prohibitive, and increase carbon emissions.

An alternative to fishmeal

Insect based feed

Insect based fish feed

The Crops for the Future (CFF) team in Malaysia is working with the University of Nottingham, UK, to investigate insect-based aquaculture feed as a replacement to fishmeal use in fisheries. Both organizations recognize that current rates of wild fish depletion are unsustainable and will not meet future demand for fishmeal under a ‘business as usual’ scenario. With support from the Newton-Ungku Omar Fund Institutional Linkages Programme, they have shown that the quality of insect larvae as an aquafeed ingredient is affected by the substrate on which the insects feed.

The CFF ‘FishPLUS’ program has revealed that black soldier fly (BSF; Hermetia illucens) larvae fed with underutilized crops can be used to produce insectmeal and replace up to 50% of fishmeal in formulated aquaculture. These crops are not used for human food and can be grown on marginal land close to areas of aquaculture production in tropical climates, increasing the sustainability of the process.

Producing insectmeal with underutilized crops

Ground Sesbiana

Ground Sesbania is used to feed the black soldier fly larvae

Over a year, the researchers worked with a private sector supplier to develop laboratory-scale BSF breeding pods in which different substrate combinations of underutilized crops could be trialed. BSF feeding trials were conducted using five separate or combined underutilized crops as substrate, i.e. Sesbania (Sesbania sp.); 90% Sesbania with 10% Moringa (Moringa oleifera); Bambara groundnut (Vigna subterranea) leaf; Bambara groundnut flour; and Moringa leaf.

The best results were obtained by feeding the larvae on Sesbiana, a nitrogen-fixing legume that grows well in marginal tropical landscapes and is not a human food crop. Overall, nutrient analyses indicated that the amino acid profile for insectmeal is encouraging and closely resembles fishmeal.

Successful feeding trials

Black soldier fly larvae

Black soldier fly larvae

Fish feeding trials using the BSF insectmeal were undertaken in Malaysia at the CFF Field Research Centre. The trial fish, barramundi, accepted a formulated feed with up to 50% replacement of fishmeal with Sesbania-fed BSF insectmeal. The feed conversion ratio, mortality rate and biomass growth rate were all comparable to control trials with commercial fishmeal aquaculture feed. Back in the UK, complementary antinutritional studies at the University of Nottingham contributed essential information to guide the development of an optimal aquaculture feed formulation in the future.

Waste not, want not

Amaranth alternative fertilizer

Amaranth growing with either commercial fertilizer (right) or FishPLUS substrate compost (left)

This project also embraces the use of undigested material from the insect feeding as compost for crops like okra and amaranth. For example, 10kg of Sesbania leaves produces 1kg of BSF pre-pupae and 9kg of undigested waste material. When used as a soil conditioner in our agronomy trial, this waste material improve the crop growth at a comparable level to commercial fertilizer. This could be used by terrestrial crop farmers to reduce their fertilizer bill.

The findings of this project are of importance to world food security. As leaders in this field of research, the UK and Malaysian partners are well placed to leverage these preliminary results and explore scalability and options for commercialization of benefit to both economies.


CFF is the world’s first and only organization dedicated to research on underutilized crops. Professor M.S. Swaminathan, World Food Prize Laureate and Father of the Asian Green Revolution, described CFF as `the need of the hour.’

You can see more about the FishPLUS project from Crops for the Future in the video below:



This article was written by FishPLUS Team, for Crops for the Future.

Newton-IUCAP workshop

Newton-IUCAP workshop

University_of_Nottingham CFFlogo

This work is supported by:

Funders links

Choosing your growth media for plant science

Considering its weedy nature, Arabidopsis thaliana is a fussy little plant. This can be a pain – even tiny environmental fluctuations can have significant impacts on the physiology and development that many of us are investigating.

As silly as it sounds, my labmates and I have spent many months debating the best compost media to use when growing Arabidopsis for research. It began when our trusted compost supplier changed the formula of its peat-based compost, which stressed our plants and turned them a lovely shade of purple! The conversation has continued to develop as we learn about the different media used in other laboratories.

A new paper from Drake et al. at my university (University of Bristol, UK) has added a new depth to the debate, so I thought I’d bring it all to your attention and perhaps receive some other suggestions to consider!

 

Peat-based vs non-peat compost

Arabidopsis growth media

Arabidopsis growth on peat-based and peat-free growth media. Drake et al., 2016.

The experiment, led by Dr Antony Dodd, was designed to test whether peat-based composts could be replaced by alternatives in Arabidopsis research, in an attempt to reduce plant science’s use of unsustainable peat extraction. The researchers grew two ecotypes of Arabidopsis (Col-0 and Ler) on both autoclaved and non-autoclaved composts, including peat-based compost and some formed of coir, composted bark, wood-fiber, and a domestic compost.

In terms of reducing peat use, Arabidopsis unfortunately grew best on the peat-based growing media, although some vegetative traits were comparable in some peat-free composts.

 

Autoclaving compost

This study caught my eye for another reason, however. We always sterilize our compost before growing Arabidopsis to reduce its contamination by fungi and insect pests; however, after learning that manganese toxicity can become a problem, we no longer autoclave it. As you can see in Boyd’s 1971 paper, manganese is converted to a more bioavailable form during the autoclave process, which can be toxic to plants.

Interestingly, Drake et al.’s research revealed no differences in Arabidopsis growth on autoclaved vs. non-autoclaved media, but I expect that in other environmental conditions the elevated manganese availability could become a problem. They did find that the autoclaved soil actually had more issues with mildew and algae, possibly because the natural microbiota had been killed and the compost was therefore easier to colonize.

 

Insecticide treatment

One of the biggest issues our lab has with non-autoclaved soil is the presence of small insects, which can predate our precious plants. A potential alternative to autoclaving is to treat the media with insecticide, such as imidacloprid, a neonicotinoid. However, many labs have stopped using these pesticides; in 2010, Ford et al. showed that several neonicotinoids, including imidacloprid, induce salicylate-associated plant defense responses associated with enhanced stress tolerance, while in 2012, Cheng et al. found 225 genes were differentially expressed in rice plants treated with imidacloprid. In experiments designed to measure precise physiological responses, I’m not convinced that it’s a good idea to use these pesticides!

 

Potential alternatives

To avoid using autoclaves and insecticides, you could consider baking compost overnight at 60°C (140°F) to try and kill fungal spores and insects, freezing the media, and/or using biocontrols to tackle insect pests, such as nematodes or mites.

In the peat vs. non-peat debate, it looks as though peat-based media are still the frontrunners in terms of compost, but hydroponic systems are becoming more popular as a way of tightly controlling nutrient regimes and manipulating whole plants more easily. Check out this video from Associate Professor Matthew Gilliham (University of Adelaide, Australia) to learn more about the technique:

If you have any other suggestions, please leave a comment and share your methods and ideas!