Fruit - small green fruit!

The first poroporo bears fruit! Small fruit mind, nothing yet over 2cm. I have my vernier calipers at the ready (think Clint Eastwood, with scientific instruments), and once the fruit starts to enlarge and ripen I will be searching for that elusive, freakishly large specimen from which to start next year's generation.

I was informed recently that the newly incurred disease of potatoes and tomatoes in New Zealand -  Liberibacter - happily takes residence on poroporo as a wild host. Consternations! The bacterium can be spread from crop to crop via a weeny insect called a psyllid. Creature plus gut contents, which happened to include the bacterium, apparently crossed the biosecurity border at the same time, raising their ugly spectre in the tomato and potato community  http://www.rhizobia.co.nz/downloads/Weir_CS23.pdf   This adds a certain unpredictability to the success of the poroporo breeding enterprise.

Still, no looking back now. I have a fence-line of the plants growing, growing, growing like the weeds they are. The flowers are quite pretty actually, though the shrub's architecture is a little open and lanky. Not ideal for the back border of the vegetable garden - but this is science!

Speaking of plant diseases, I've just ripped up a rather large tomato plant which was showing odd symptoms of brown streaking on the stems. It has bucketed down with rain the past two days (yes, it must be nearly Christmas in Wellington) and the symptoms have spread to leaves and flowering stems. It had lots of unripe fruit, but it had to go, lest it bring into disrepair the good health and integrity of the other tomatoes in the garden. Being a recent convert to the alluring world of plant phytopathology, I can't quite pick whether it's Early blight, a nasty bacterial canker or viral. Maybe someone else can diagnose from the picture below?  I will be sterilising my secateurs with meths at the next available opportunity.

Fiddling with science

"Although man does not cause variability and cannot even prevent it, he can select, preserve, and accumulate the variations given to him by the hand of nature almost in any way which he chooses; and thus he can certainly produce a great result" - Charles Darwin.

Charles Darwin is a hero of mine, not for his most obvious work on natural selection and survival of the fittest, but for his smaller experiments, his potting-shed projects and back-lawn experiments. He is famously known as the naturalist on-board the Beagle, charting various stretches of the coast of South America. But some of his most interesting work was done when he was back on dryland, experimenting, dissecting, and making observations in the meadows and woodlands surrounding his home at Down House.

Darwin tinkered with his science. He played music to earthworms to understand whether they could ''hear'' and played with his venus fly-traps in the conservatory to understand what triggered the traps to snap shut. He soaked different seeds in sea-water to see which could be dispersed on oceanic currents from mainland to islands. He floated a dead-pigeon in salt water for thirty days to see whether seeds from the pigeon's crop would germinate [they did]. He spent eight years fiddling about with barnacles, and wrote a book on barnacle taxonomy. He got into pigeon breeding and had sixteen different breeds at the height of his hobby. He was genuinely curious about the natural world.

Knowledge about Darwin's little experiments has prompted me to try something at home in my back-garden - How quickly can selective breeding bring about change in fruit size in poroporo?

Some thoughts I have had in the past week:
1. The birds are eating all my strawberries at the moment, before they are fully ripe and the boys get to them.   Will the birds leave my fruiting poroporo alone, or do I need bird-netting to keep them off?
2. If I don't use bird-netting, will the entire shire of Karori be covered in poroporo seedlings in the next few years, dispersed by birds from my back garden?!
3. Will the natural pollinators cross-pollinate my experimental plants with those in the wild, and mute any breeding effort to increase fruit size?
4. Will the fruit end up so large that birds can no longer disperse them?
5. And perhaps most importantly, will poroporo jam taste any good?

Poroporo dreaming

I am congratulating myself on the good fortune of selecting such a quick-growing [some would say weedy] plant to work with. The first five poroporo were kindly donated by a local bird, and I have carefully transplanted them from underneath the trampoline to a narrow garden bed running the entire length of the back fence. The first poroporo is in bud already, only five months after being transplanted, and I am patiently awaiting the purple blooms. At this rate, thirty generations of selective breeding in poroporo is going to take thirty years.

Happily the tray of poroporo seeds have germinated too, and so far there looks to be more than forty wee plants. They look almost identical to tomato seedlings, of course, being in the same family - Solanaceae.

Imagine that until just a few hundred years ago, tomatoes were not part of the cultural cuisine of Italy! They originated in the New World and were not immediately accepted in Europe when they were first introduced. Probably because they looked similar to local poisonous members of the same family, the deadly nightshades*. Another Solanum, potatoes, were similarly regarded with fear and superstition in Europe. Under the 'Doctrine of Signatures', the swollen potato tubers were thought to cause leprosy!  These superstitions and prejudices against the Solanaceae family have been generally abandoned, but where does poroporo fit into this picture - seeing as it actually is a poisonous plant, and all parts are poisonous except the very ripe fruits?

I had a dream about poroporo this morning! In my dream the poroporo berries were ripened to the point of being over-ripe, yet I hesitated to eat one ... I couldn't really fancy it. The fruit had turned slightly brown, not as firm as it had been the week before, the skin was slightly wrinkled, the smell was floral. I wasn't afraid of being poisoned, but I was afraid I wouldn't enjoy the taste sensation. Back in the light of day I find it remarkable my experiment has reached through to my subconcious mind! And what is all the fuss about? Tomatoes don't taste better now than they did two hundred years ago in Italy - the difference is perception.


* My father, in his best sense of humour, used to refer to deadly nightshade as "deadly lampshade". Bon mot!

Wellington in 1873

I walked to the city this morning through the Bolton Street memorial cemetary. One of the larger burial sites caught my attention and I stopped to read the headstone. It was the last resting place of an entire family of early settlers - children first, five children, lost within two weeks in the summer of 1867/1868.  A baby, an 8 year old a day later, then the 10 year old, 3 year old, and finally the 5 year old child. Devastating. I can't imagine what the parents must have felt, surviving their children two full decades.

What could it have been. An epidemic, influenza perhaps?  I wasn't able to pin-point a major Wellington pandemic which coincided with those dates. There was an influenza outbreak in 1918 - the spanish flu - but no mention of anything earlier in the national library. I did however come across a letter to the editor of the Wellington Independent in 1873 which described conditions in Wellington at the time, and typhoid fever was rife.  I have included some of the letter below - the sanitary conditions as described paint a vivid picture of the conditions which could easily have brought about the children's deaths (and with no penicillin or antibiotics to fall back on).

http://paperspast.natlib.govt.nz/cgi-bin/paperspast?a=d&d=WI18730410.2.6

Wellington Independent, Volume XXVIII, Issue 3776, THURSDAY, 10th APRIL 1873, Page 2

It is almost twelve months since that the City Council went so far as to recognise that drainage was a necessary thing, yet the city remains at the present moment as undrained as ever. There has never been exemplified any realization of the necessity for establishing a thorough sanitary system in Wellington. There has been much talk about it, but nothing has been done, although every week deaths occur which are beyond doubt traceable to the absence of those precautions which science has proved to be effectual as against many of the fatal epidemics which periodically attack centres of population. 

The City Council may urge in extenuation that they could not provide a thorough system of drainage until the waterworks are completed, and this may be true. But there are many directions in which sanitary action could be taken, but which have been criminally neglected. It is sufficient for anyone to walk along any of the principal thoroughfares of the city to be able to understand the origin of the sickness which is now so prevalent. Every drain grating is simply a channel of miasma. After sundown, when evaporation is greatest, the foul and fetid fumes which are discharged from every opening to the drains is simply overpowering. Surely the least that the City Council could do is to provide traps so as to prevent the noxious effluvium from contaminating the outer air. 

It is well known that at this moment the worst form of typhoid fever is prevalent in the city. Several lives have been lost from this cause already, and there is a strong probability that many others will follow. Now, if there is one thing above another which modern science has been able to establish it is that zymotic diseases, such as typhus fever and typhoid disorders generally, are entirely traceable to the neglect of sanitary precautions. If the City Council cannot yet undertake a thorough system of drainage, they can, at least, mitigate the evils consequent upon the absence of such a system. They can and ought to take measures for ensuring the regular and constant clearance of the closets within the city. This, of itself, would be a very considerable step, for anyone who knows anything about the average state of the back premises of the city knows that it is simply disgraceful. In various parts of the town are to be seen filthy streams of pollution reeking in the sun and breeding disease around them. 

What is required and and what should be done is that a regular house-to-house inspection should be made ; the City Council should establish means for the 1 regular clearance of outhouses, and we are sure that the ratepayers would gladly pay the cost. If something of the kind, is not done speedily the metropolis of the colony will become a place to be avoided.

The tomato analyzer

I came across this useful piece of software for tomatoes, which could be very usefully employed in the poroporo experiment. All I need is a flatbed scanner and a license to kill (fruit that is), and probably also a license to use the analyzer. Looks wonderful for documenting fruit size and dimensions, and any changes in morphology as the years go by.
http://oardc.osu.edu/vanderknaap/tomato_analyzer.htm

So far they have not replied to my emails...

History

History... celebrates the battlefields whereon we meet our death, but scorns to speak of the ploughed fields whereby we thrive; it knows the names of the king's bastards, but cannot tell us of the origin of wheat. That is the way of human folly - J. Henri Fabre.

 Jack and the Wheat Stooks - a bedtime story 

I love this quote, though it is probably a little unfair. After all, the history of modern hexaploid bread wheat is extraordinarily complicated. But it does speak to the fact that agriculture and horticulture are not especially well regarded professions, these days as in old, possibly because of the dirty knees and gumboots. Also most definitely the story of wheat would take some explaining in an oral account or bedtime story. Two separate hybridization events, leading to polyploid evolution and trigenomic accumulation (= 6n). {Einkorn wheat (Triticum monococcum) x goat grass (T. longissima) = 4n (Durum and Emmer wheat, T. turgidum) x another goat grass (T. taucschii) = 6n (Bread wheat, Triticum aestivum)}. No wonder the wheat genome is five times bigger than ours!!

Feeding the world is all very important, but the story of plant breeding is about ornamental plants too, even  stripey petunias! I have been reading the book "Hybrid" by Noel Kingsbury, and he talks about a "domestication syndrome" - with traits favourable to domestication being genetically linked, so that an increased dependence on humans for reproduction is linked to compact size and a tendency towards self-pollination. The examples he gives are two from the Solanaceae plant family - tomatoes and capsicum pepper. Can I invoke this syndrome through selecting poroporo fruit?

I don't know much about the Solanum aviculare plant yet - save the Maori did eat the berries (calling them kai tamariki, meaning childrens food) and they are also found in Australia (where they are called kangaroo apple). So imagine my surprise this week to find the seedling I transplanted four months ago has flower buds on it already, being only itself about 20cm high. This is good, this is very good. If the plants would flower only in their second year, my experiment would take 60 years to complete, and I would have to come up with a fascinating bedtime story to pass to the younger generation in order to complete it ;)

Just do it

I found three poroporo growing underneath the trampoline today! Seeded there by a bird no doubt. The light is good under there actually, and the cool conditions make an excellent plant nursery. Perhaps I should move the seed tray with 40 poroporo seeds underneath there with full expectation of good things (except the birds might dig it over).

I received my Wellington Botanical Society newsletter by email yesterday. This quarters' bulletin remembers Tony Druce and Eric Godley, each very well known botanists, who both passed away in the last few months. I feel connected to Eric's work through my study on kowhai in the 1990s. My thesis looked at the rbcL-atpB sequence from all New Zealand populations and offshore populations of Sophora microphylla, S. prostrata, S. tetraptera, and S. howinsula - collections that Eric put together at DSIR in Lincoln, now Landcare Manaaki Whenua.

I must write an article for the next newsletter, emploring local botanists to help me locate large poroporo fruit (or good specimens to collect from). I am not sure whether this will be of interest to a group who are largely concerned with the serious business of ensuring lesser-known plants don''t disappear into extinction. My experiment seems a little trivial in comparison, maybe even reckless. Who knows, maybe the birds won't be able to get their beaks around my poroporo of the future! (Yeah right!).

Forty seeds

So I'm starting my selective breeding experiment with forty seeds which I purchased off Trade-Me a week ago. Hopefully they were selected from nice big fruit. I own to experiencing a few doubts that forty plants will give sufficient variation to select from in the first generation. Quite probably they will all produce fruit of such similar size that it will be difficult to know whether individual fruits are larger due to environmental effects rather than genetic differences. And also I am preparing myself for the reality that a single bush may exhibit as much variation in fruit size as I might find between different bushes. But I have to start somewhere. Potentially I need to scout around the province a little, looking for likely candidates in the wild populations as well. Maybe I'm thinking about this all wrong, and I should select for something else and cross my fingers that pleitropy will take care of the fruit size?

 

From this....                                 to this!

There are some clever things happening with New Zealand plants these days being used in the food and beverages markets. ETA started marketing a balsamic vinaigrette last year enhanced with the wonderful native horopito, or peppertree (Pseudowintera colorata). It has a subtle peppery flavour - quite delightful.
Waituna ale uses kawakawa leaves in it's brewing process http://www.waitunabrewing.com/Gallery/gallery.html and I recently became aware of a new startup company called Wai kawa, who make mixers like tonic water with kawakawa (Macropiper excelsum), and a cola with horopito http://www.wai-kawa.co.nz/

Bitters are supposed to be jolly good for us - and we don't get enough of them in our diet. I have yet to determine whether poroporo jam is a good substitute for marmalade on toast in the morning.

Horopito leaves - gorgeous colours

Kawakawa leaves


 

Poroporo to pepino in thirty generations?

Darwin’s great idea was that plants and animals evolve through time, accumulating changes which gradually morph them from the ancestral to modern form. Left to natural selection, these changes would happen imperceptibly slowly, but given human selection it could happen quite quickly. Darwin used many examples of domesticated animals to labour this point.

A fascinating experiment of the rapidity of human selection was proposed by the Russian geneticist Dimitri Belyaev, who was interested in domesticating the silver fox. After six generations of selecting cubs for breeding based on tameness, the foxes had started to act more like dogs, and after thirty generations, not only did they behave like dogs but they looked like them too. Gone was their foxy pelage which was replaced with a soft, piebald black and white coat, floppy ears and an upright waggy tail!

Thirty generations is not very long is it? How long did it take to select for the food plants we use today? Could one domesticate a plant in thirty generations, or substantially change some of its characteristics?
To tackle the first and last question, I am going to undertake an experiment. With any luck I will have at least thirty five years of mental and physical faculties left. How splendid to sit on my rocker-chair on the porch when I am seventy-five and reflect back on an experiment which took half a lifetime to conceive, and the other half to achieve.

The subject of this endeavour is to be the New Zealand shrub – poroporo – or Solanum aviculare. The outcome I am aiming for - improved fruit size, let's say pepino, or tamarillo. The plan: starting with wild plants, selectively breed for larger fruit each generation.

Year 1:  take 40 poroporo seeds and germinate them. Plant along the entire length of the fence in my back garden. Wait for fruit to ripen completely and utterly*. Select the largest fruit, remove seeds and repeat.

I may need to cut out existing plants to make space for new cohort.

Use remaining fruit in jam.

Hopefully by selecting for larger fruit, edibility will not be compromised. Never having actually eaten a poroporo fruit, however, I cannot tell you whether they taste good, bad or indifferent. Ripe fruit are eaten by Aborigines in Tasmania and were eaten by Maori here in New Zealand - only the very ripe fruit mind you, as *unripe fruit (and all other green parts of the plant are poisonous).

One of the earliest accounts of poroporo in Wellington was by Colenso with the early pioneers using the ripe berries for jam. Were the early pioneers so desperate for something to make jam out of, or are poroporo actually very edible? I will have to come back to you on this one,  posting both the jam recipe and progress.

The following blog is not too hopeful...

David McCutcheon blogged in 2006 that he "Tasted a very ripe fruit from this plant, once is enough. I can't adequately describe how grossly bitter, sour and HOT the sensation of that taste was. It lingered for ages, I mean to say it persisted, really persisted, in my mouth and on through the digestive tract - expelling other digested nutrients afterward it totally burnt the local orifice chairing that motion. Hey, if I had passed wind just then, a glowing cloud of superhot gas would surely have devastated any fauna and flora in my vicinity. Assuredly I have done planet Earth great service with this incredibly important finding: DO NOT TASTE THIS FRUIT!"