FRST couriermail.com.au January 5-6, 2013 The Courier-Mail 49

49SCIENCE INSIGHT

On the trailof an iconictree’s rootsDr Craig Hardner is on a quest to show themultimillion-dollar global macadamia industryoriginated from a single tree on the Gold Coast

ROB KIDDHigher education reporter

PIMPAMA PASSION: University of Queensland researcher Craig Hardner (above) and (left) with the Jordan Tree, which

he believes may be the source of the first commercialised macadamias. Main picture: Glenn Barnes

❝We’re quitecertain weknow a tree onthe Gold Coast(known as theJordan Tree atPimpama)where theseeds werecollected from

AN INVESTIGATION into thefamily tree of an Aussie icon will leada researcher to Hawaii, to track downa piece of Queensland’s horticulturalheritage.

Dr Craig Hardner, from theUniversity of Queensland, has beenawarded a Churchill Fellowship totrace the domestication of themacadamia nut and hopes to provethe origins of the multimillion-dollarglobal macadamia industry can betraced back to a single tree atPimpama on the Gold Coast.

This year, Hardner will travel tothe islands of Hawaii and Oahu forfive weeks to search for the originalplantings of the first macadamiascultivated commercially.

The seeds were taken to the USstate in 1892 by US Navy CaptainRobert Jordan.

Hardner says though the group ofPacific islands will be a pleasant placeto conduct the research, it will taketime to find what he’s looking for.

‘‘We’re quite certain we know atree on the Gold Coast (known as theJordan Tree at Pimpama) where theseeds were collected from and takento Hawaii,’’ he says.

‘‘They were planted on what wasthen the outskirts of Honolulu andwhat is now downtown Honolulu. Sothere have been freeways put in, butreports are there is one tree stillalive.’’

Macadamias, which are found inlowland tropical rainforest fromBallina, in NSW, through to justsouth of Maryborough, were eaten byindigenous Australians before beingdiscovered by Europeans in 1828.

A significant amount of seed wasput into commercial orchards inHawaii and the industry took off inthe 1930s.

‘‘Essentially from the 1970s, themacadamia industry started todevelop worldwide, includingAustralia,’’ Hardner says.

‘‘Initially Australia hadn’t reallyhad an industry – a little bit ofbackyard and small plantings, but notthe scale of Hawaii.

‘‘But in the ’70s there started tobecome an interest in the industry.’’

In 1997, Australia surpassed the USas the major producer of macadamias.

As well as the Jordan Tree,Hardner believes some of the firstplantings in Hawaii developed fromseeds from trees around the MtBauple area, between Gympie andMaryborough.

After the plantings are located,their leaves will be sent back toAustralia for DNA paternity analysis.

Hardner was drawn to macadamiaresearch through a desire to work inthe native Australian bush and sayshis main motivation is the heritagevalue of the plant.

‘‘I think this is one of the uniqueopportunities we’ve got in Australia –that although the forests have beendisturbed, they haven’t beendisturbed anywhere near as much as

in Europe or North America,’’ he says.‘‘To me, there’s a special value in ourheritage. For example, there’s theTree of Knowledge in Barcaldine(central west Queensland) that’s got aspecial meaning for the heritage ofAustralia with the Labor Partyformed underneath it.

‘‘Macadamia nut was No.9 in thelist of ‘Typically Queensland’ iconsfor the (state’s) 150th anniversarycelebrations. I think it came behindXXXX (beer) but XXXX alongside amacadamia isn’t too bad.’’

If he is successful in establishing alineage between the plantings inHawaii and the Jordan Tree, Hardnersays the tree would, like the Tree ofKnowledge, have heritage value.

‘‘There’s been good support fromGold Coast City Council for this . . .they want to put a reserve around it toprotect the tree.

‘‘I think there’s no doubt seed wastaken from this tree to Hawaii so it’sjust finding out how important thattree is in the commercialdevelopment of macadamias.’’

The macadamia is mainlyconsumed as a delicacy or is turnedinto cosmetic or cooking oil.

Australia produces about 35 percent of the world’s production, ofwhich about 70 per cent is exported.The industry is worth more than$120 million annually.

rob.kidd@news.com.au

PLAIN SCIENCE A ROUND-UP OF THE EXTRAORDINARY

BLOOD-PRESSURE TRIUMPH

A NEW study of a procedure calledrenal denervation, which involvesadministering radio waves to thearteries around the kidneys, hasfound it to be a safe and effectivemeans of treating drug-resistant highblood pressure.The results of the one-year study ofpatients who received the treatmenthave been published in Circulationand are drawn from an international

study to evaluate the treatment,according to the Baker IDI Heart &Diabetes Institute.Lead author of the study and seniordirector at Baker IDI, ProfessorMurray Esler, says the findings couldhave significant public healthimplications in the treatment ofresistant hypertension – a major riskfactor for stroke and heart attack.The study found 83 per cent of thetreatment group experienced a dropin systolic blood pressure of at least

10mm Hg at six months, with 79 percent maintaining it after a year.Esler says further studies will soondetermine whether the procedure –which so far has not produced any illeffects in patients – can cure mildhypertension ‘‘producing drug-freenormalisation of blood pressure’’.

MUSTERING GOES HI-TECH

A ‘‘SOPHISTICATED combination’’ ofhard and software developed to

identify and sort cattle may soonrevolutionise mustering and cattlemanagement. So says a release from

the Co-operative Research Centre forRemote Economic Participation aboutthe Remote Livestock ManagementSystem technology, developed byPrecision Pastoral in Alice Springs.‘‘The RLMS uses telemetry toidentify, weigh and draft individualanimals when they come in for a drinkof water,’’ Precision chief executiveTim Driver says, explaining solar-

powered radio-frequency ID readersrecognise electronic tags in eachanimal’s ear as it passes a gate.