全 文 ：Field Research and Cultivation of Truffles
in New Zealand : an Update
Guerin-Laguetie A? , Hesom-Williams N, Parmenter G, Strong G, Wang Y .
( The New Zealand Institute for Plant & Food Research, Lincoln, Canterbury Agriculture &
Science Centre, Gerald Street, Lincoln 7608 , New Zealand)
Abstract : Thefirst Périgord black truffle (PBT, Tuber melanosporum) recorded in the Southern Hemispherewas produced
in NewZealand in1993 at aplantation established in1988 . Today, there areover 100 PBT plantations in NewZealand . Of
these, ten arecurrently fruitingwithmany moreexpectedto start in the next fewyears . In2005 a research project co-fund-
ed by theNewZealandTruffleAssociationandtheNewZealandgovernmentwas launched with theaimof improvingour un-
derstandingof the effects of the soil moisture and aeration on fruiting of PBT .
In order to ensurethat trees selected for the trial had PBT mycorrhizae ontheir roots, we first sampled roots fromthe
northern side of randomly selected trees at three PBT plantations . The diagnosis of PBT mycorrhiza was performed using
morphological (microscopy) and molecular (specific PCR primers for the rDNA ITS) analyses . On one plantation, trees
showed a very high level of PBT mycorrhization and a low level of contamination, therefore identifying 16 trees with PBT
mycorrhizae fromthis sitewas an easy task . For the other 2 plantations, we randomly sampled up to 34 trees in order to
find 16 trial trees at each site unequivocally mycorrhized by PBT . Our strategy to sample roots on the northern side of the
treeswas supported by the analyses of several trees sampled around all four aspects (North, South, East, West) , which
confirmed that mycorrhizae were always present on the northern side of the tree root systems . Following tree selection, a
number of treatments have been applied to test the hypothesis that soil aeration and soil moisture are important soil factors
that affectmycorrhizationandfruiting . Preliminary resultsshowedthat the irrigation treatment slightly reduced soil tempera-
ture around the roots of mycorrhized trial trees . Since2006 the New Zealand Institute for Crop and Food Research ( C &
FR) 1 has also performed over 140 root analyses fromPBT plantationssituatedthroughout NewZealand . Fromthis extens-
ive root survey we have obtained valuable insights into: (1) the persistence of PBT mycorrhizae on planted trees; (2) the
presence of other competing ectomycorrhizal fungi ; and (3) the presence of an unexpected truffle, Tuber brumale, which
has been found in very few plantations but, to our knowledge, has not fruited yet in NewZealand .
Recently, fruiting of twoother valuabletruffle species has been reportedfor thefirst timein NewZealand plantations:
Tuber borchii in 2006 and Tuber uncinatum (syn . T. aestivum) in 2007 .
Key words: Truffle cultivationl ; Truffle plantation; NewZealand
CLC number : S 646 Document Code : A Article ID: 0253 - 2700 ( 2009) Suppl.ⅩⅥ- 090 - 04
Introduction
The first Périgord black truffle ( Tuber melanospo-
rum) ever grown in the Southern Hemisphere was culti-
vated in Gisborne, New Zealand ( North Island) , in
July 1993 ( Fig. 1 ) . This fruiting rewarded the efforts
of the visionary Ian Hall and his colleagues, who start-
ed investigating truffle production in New Zealand in
the late 1970s . The successful truffièrewas established
in 1988 on a volcanic ash soil , where the pH was
brought to values compatible with the development of
T. melanosporum using large applications of lime ( 10
to 20 tonnes per pH unit per hectare) . Four years lat-
er, the first commercial crop (9 kg) was harvested from
this truffière .
Currently, New Zealand has more than one hun-
dred T. melanosporum truffières ( Fig. 2 ) . To date,
and to thebest of our knowledge, ten of themare pro-
ducing, or have produced, T. melanosporum truffles
( Fig. 3 ) . Many more recently established truffières
could become productive during the next few years .
云 南 植 物 研 究 2009 , Suppl . ⅩⅥ : 90～93
Acta Botanica Yunnanica
? ?Author for correspondence; E-mail : alexis.guerin@ plantandfood. com; Tel : + 64 3 325 9395 , Fax: + 64 3 325 9372
Fig. 1 The first Périgord Black truffles ( Tuber melanosporum)
harvested in the Southern Hemisphere in July 1993 in a plantation
near Gisborne, North Island of New Zealand
Fig. 2 Overview and location of the New Zealand T. melanosporum
plantations as of August 2007; A , North Island; B , South Island .
Productive truffières are indicated by shaded circles
TheNew Zealand TruffleAssociation (NZTA) and
the New Zealand Institute for Crop and Food Research
( C & FR )① developed a field research project to better
understand thesoil environment and the climatic factors
that may control T. melanosporumfruiting . Four treat-
ments affecting the soil environment were obtained
through the combination of two factors ( irrigation and
soil aeration) . Climate stations were established in
each trial plantation in order to record both the general
weather data of each trial site and some localized soil
data (soil temperature and soil moisture using probes)
(Fig. 4) . The present paper describes the progress to
dateof that project focusingon its first step: the selec-
tion of trial trees on which the presence of T. mela-
nosporummycorrhizaehas been confirmed .
The present report provides themycorrhization re-
sults obtained while selecting the trees required to set-
up this research project . Specifically, we needed to
ensure that all the trial trees, e. g . the trees on which
the soil treatment will be applied subsequently, did
host T. melanosporummycorrhizae .
We conclude the present paper with an updateon
the recent cultivation of other truffle species in New
Zealand .
Materials and Methods
Three truffières (2 in theSouth Island, 1 inNorth
Island) established in 1997 with a mixture of hazel
( Corylus avellana) or English oak ( Quercus robur )
trees were selected for this research .
Root sampling was performed on randomly select-
ed trees until 16 trees ( hazel or oak) showing evidence
of T. melanosporum mycorrhiza presence could be
found per truffière . Root samples (woody root segments
approx . 10 - 15 cmlong, bearing fine roots) were col-
lected fromthe North side of the trees . In addition, a
few composite root samples ( collected from the North,
South, East, and West sides of trees) were examined
in order to better evaluate the risk of findingfalsenega-
tive trees, e.g . trees for which a single root checking
would conclude to theabsenceof T. melanosporummy-
corrhizae while these mycorrhizae could be found in a
root sample fromanother sideof the tree .
Microscope and DNA analyses ( PCR and nested
PCR ) using published primers (Paolocci et al. , 1999 ,
Amicucci et al. , 1998) were used to detect mycorrhi-
zaeof the genus Tuber and to identify themto the spe-
cies level .
Results
The incidence of T. melanosporum mycorrhizae
differed significantly between the three truffières stud-
ied . On truffière No . 1 , all root samples had T. mela-
nosporummycorrhizae (Fig. 5) . Furthermore, only 3 of
19增刊ⅩⅥ Guerin-Laguetie A et al . : Field Research and Cultivation of Truffles in NewZealand: an Update
① ?Pleasenote that in December 2008 The New Zealand Institute
for Crop & Food Research (C & FR) merged with HortResearch
Ltd to form The New Zealand Institute for Plant & Food Re-
search ( P & FR)
20 root samples had another mycorrhizal species present
(a T. maculatum-likemorphotype) .
On the other two truffières, to find 16 trees with
T. melanosporum mycorrhizae on their roots required
checkingup to 34 trees per site . Furthermore, 46 of 73
root samples had several other mycorrhizal species pr-
esent, mainly T. maculatum-like and Scleroderma
sp ., but also several other unknown morphotypes .
The results obtained for the six trees from which
composite root samples were collected are shown in
Fig. 6 . Although these results are very preliminary,
they have shown so far that when a treehosts T. mela-
nosporum mycorrhizae, these have always been found
on the North side of the tree ( i . e . the sunny side of
the tree in the Southern Hemisphere) . Similarly, the
one tree in this study that did not show any T. mela-
nosporummycorrhizae on its North side did not show
these mycorrhizae on any other sides either (Fig. 6) .
Discussion
Finding trees with T. melanosporum mycorrhizae
was straightforward on one truffière, while this task
proved to be difficult and time-consuming for most of
the trees sampled in the other two truffières . It is not
Fig. 3 A good size (over 200g) T. melanosporum
truffle harvested in 2006 from a truffière
in Ashburton, South Canterbury
Fig. 4 Outlineof the four treatments ( high or low water level combined with or
without soil aeration) and of the field equipment used to monitor and control the
soil moisture levels under the trial trees and to record the climatic data .
Soil was aerated manually using a fork
Fig. 5 Tuber melanosporum mycorrhiza on a hazel
tree at the Waikari plantation
Fig.6 Results, e.g . presence ( + ) or absence ( - ) of T . melanosporum
mycorrhizae at each of the four geographic directions ( N = North)
of the six composite root samples analysed in this study
29 云 南 植 物 研 究 增刊ⅩⅥ
well understood whether this discrepancy relates with
different levels of mycorrhization of seedlings at the
time of planting or with different environmental condi-
tions and?or management practices at each site .
Detecting the presenceof a single ectomycorrhizal
species ( in this case T. melanosporum) on the rootsof
an established tree in a truffière is not a simple task .
Established trees often host many mycorrhizal fungi and
themorphology of a given mycorrhizal species may vary
significantly with several parameters such as the host
tree species, the soil condition, and the ageof themy-
corrhizae . Furthermore, root samples only represent a
minute part of the tree root system . Furthermore, the
amount of mycorrhizal root tipsobservedon agiven root
sample varies substantially even though the same root
sampling protocol is used for all root samples .
Although morphotyping, e.g . the characterization
of mycorrhizae based on their overall morphology ( dis-
sectingmicroscope) and ultrastructure ( compound mi-
croscope) , is the most practical and quickest way to
identify mycorrhizal root tips, in many situationsonly a
DNA analysis can provide a definitive identification of
mycorrhizal roots at the species level .
Under these circumstances, and given the small
resources mobilized for this project, our primary objec-
tivewas to detect and identifywith certainty mycorrhizae
of T. melanosporum in the root samples . No thorough
assessment could be made on the relative abundance of
T. melanosporum mycorrhizae when these were detect-
ed . The presence of other mycorrhizal species was
recorded, and identified to the genus or species levels,
while searching for T. melanosporummycorrhizae .
This work enabled us to select enough trees that
were unequivocally positive for T. melanosporum to al-
low the set-up of the environmental trial in each
truffière . It also provided useful informationon themy-
corrhization of the sampled trees to the owners of each
truffière .
As far as the soil treatments are concerned, irri-
gation and aeration are now controlled on all sites and
we have observed how irrigation affects ( i . e . lowers)
the soil temperature at 10 cm depth ( data not shown) .
The production of truffleswill bemonitored in the three
trial sitesduring thenext two years inorder to establish
whether the distinct soil treatments can impact on truf-
fle productivity .
Other truffle species recently cultivated in New
Zealand
The first Southern Hemisphere-grown bianchetto
truffle ( Tuber borchii ) was harvested in July 2006 un-
der Pinus pinea mulchedwith straw . More recently, in
June 2007, the first Southern Hemisphere-grown Bur-
gundy truffle ( Tuber aestivum) was harvested in a
plantation of oaks and hazels established in 2001 in
North Otago . Both the bianchetto and the Burgundy
truffles appear to be well-adapted to the climate of the
South Island of New Zealand in which their commercial
cultivation should develop further with time .
Acknowledgements : We would like to thank the New Zealand
truffle growers participatingto this project and Carolyn Dixon for
her help with the root sampling . Wealso thank the NewZealand
Truffle Associationfor itssupport andTechNZ, aprogrammefrom
the NewZealand Foundation for Research, Scienceand Technol-
ogy (FRST) which funded this work .
References:
Amic ?ucci A , Zambonelli A , Giomaro G et al. , 1998 . Identification of
ectomycorrhizal fungi of the genus Tuber by species-specific ITS
primers [ J ] . Molecular Ecology, 7 : 273—277
Paol ?occi F , Rubini A, Granetti B et al. , 1999 . Rapid molecular ap-
proach for areliable identification of Tuber spp . ectomycorrhizae [ J ] .
FEMS Microbiology Ecology, 28 : 23—30
39增刊ⅩⅥ Guerin-Laguetie A et al . : Field Research and Cultivation of Truffles in NewZealand: an Update