Climatic change: callenge for
training of applied scientists
Symposium and Training course V.
Breeding new varieties of oil seedpumpkins in Austria
Peter Ruckenbauer
Institute of Agronomy and Plant
Breeding,Vienna /Austria
Ölkürbis
Evolution
Cultural history
Botany
Developmental procedure
Genetic background
Breeding systems
Resistance breeding
ZYMV-resistance
Varieties
Harvesting procedure
Summary
Oil-seed pumpkin areas in
Austria
1997 -2002 : 10 - 15 000
hectares
2003 : 15 500
2004 : 12 500
2005 : 16 000
2006 : 16 400
2007 : 17 800
2008 : 16 300
2009 : 19 000
2010 : 26 500
Oil-seed pumpkins
Cucurbita pepo
(2n = 40 Chromosomes, diploid)
Evolution and cultural history
Derived from the New World (Central-america), some
species (C. maxima, C. moschata) are present, intercrosses are feaseable
Multiple utilization: oil, fruit as vegetable (Zucchini etc.),
dried fruits for decoration and drinking or storing purposes
Styrian Oil Pumpkin: Hull-less (delete mutation), therefor
specific high oil content.Utilization as an oil crop known
sinced the 19th century.
hulled
(Quelle:
Vollmann & Rajcan, 2009)
-
“dehulled”
hulled (a), partly lignified (b, c), hull-less (d)
Histology of the seed coat: Caused by delete mutation
(therefore is the thin seed coat is not lignified and the outer
layers are collapsed)
(Quelle:
Lelley et al., 2009)
C. pepo - types
(Paris et al., 2009)
Genetic diversity between 103 Cucurbita pepo - Genotypes
Evaluated by SSR-markers
Genetic Diversity
Name
pep5
pep6
pep2
pep3
pep4
pep1
max4
max5
max2
max3
max1
max6
mos5
mos6
mos4
mos3
mos2
mos1
s
s
v
v
s
v
hun
fr
chi
jap
usa
mon
pr
pr
pr
por
usa
nig
Num
5
6
2
3
4
1
10
11
8
9
7
12
17
18
16
15
14
13
Rescaled Distance Cluster Combine
0
5
10
15
20
25
+---------+---------+---------+---------+---------+
Genetic diversity between 18 Cucurbita-Genotypes based
upon RAPD-markers
Genetic diversity
In Austria, all cultivated varieties of oil see pumpkins are
characterized by their hull-less seed coat and the green seed
colour (founder effect).Therefore the genetic base of all our
derived varieties is rather very narrow….
Practical consequences: high genetic vulnerability….
All varieties in the past have been susceptible for ZYMV
( Zuccini yellow mosaic virus )
Breeding goals and activities:
Intercrosses with different pumpkin species to increase the
genetic diversity ,followed by reselection for hull-less seed
characters and adapted fruit types !
Oil seed pumpkin
Botany
Fam. Cucurbitaceae,
frost intolerance,
Fruit type :berry
male and female flowers
monoecious
Sexual reproduction
Self- and open pollination (by insects),
inbreeding depression and heterosis visible
Female and male pumpkin flowers (Monoecious)
Male and female flower types of pumpkins
Genetic characters desireable
Hull-less types are monogenic inherited: but
different modification were observed,Xenia are
possible.
Resistence:
Monogenic resistance against the Zuccini yellow
mosaic virus is transferable from Zuccini-types
Molecular markers :
Utilized to improve the genetic variability and
resistance characters mainly for virus diseases.
Hull-less pumpkin seeds
Hulled pumpkin seeds
Passport of the ZYMV:
Family : POTIVIRIDAE
Tribe
: POTIVIRUS
Shape : flexible bar – form
Size
:750 nm,12 nm diameter
Genom: one +RNA strand,10.ooo nucleotids
Transcription product: on big polyprotein (346 kD)
Transfer : aphids, seeds, mechanically
Aphid transfer: non persistant
Oil seed pumpkins
Breeding and breeding goals
Population breeding up to 2002,now only
Hybrid breeding performed
Breeding for quality : High oil content >50 %,
hull-less seed, green seed colour,seed type and
High content of tocopherol
Breeding for resistance: Zuccini yellow mosaic
virus, Erysiphe ssp., Fruit rottening
Breeding for agronomic characters: Yield, dwarf
types with short wines,early ripening performance
Pumpkin fruit diseased with ZYMV
Prevention procedures against ZYMV
-virus free seeds
-removal of diseased plants
-aphid protection
-spraying non toxic oils
-reflectory plastic ( mulch ) cover
-cultivation under UV absorbing covers
-cross protection
-resistance breeding
Breeding goals for ZYMV-resistance

Search for new sources of resistance

Crosses between Austrian hull-less varieties
and tolerant or resistant genotypes

Backcross procedures to maintain oil seed
productivity and quality + resistance character

Development of molecular markers for MAS
Sources of resistance against ZYMV
Cucurbita pepo L.
- no resistance detected
Cucurbita moschata L. - described resistance genes
Cucurbita maxima L.
- resistance presumed
Resistance donors:
Solar
Medina
Nigerian Local
What are molecular markers?
X
AA
Cross
AA
Backcross
X
aa
F1 (Aa)
BC1 F1 Population
Second backcross
AA
X
Selbstung
AA Aa Aa aa
AA
AA
AA
AA
AA
AA
AA Aa Aa aa
Ein Virusinfektionstest von je 10 BC2F3 Pflanzen der BC2F2 Pflanzen identifiziert
die heterozygoten BC2F2 Pflanzen, diese werden erneut geselbstet
AA Aa Aa aa
AA Aa Aa aa
Selbstung
AA
Aa
AA
Aa
Aa
aa
Aa
aa
oil-pumpkin
zucchini
BC1F1
BC1F2
Locus for resistance and for marker
First disease symptoms with ZYMV
Breeding strategies
for resistance
against ZYMV in
oil seed pumpkins:
RAPD markers for
tolerant and
susceptible plants
(LELLEY, 2002)
Marker aided
selection
procedures
Bacterial rottening of pumpkin fruit
solved by intercrossing (C.maxima)
Pumpkin oil quality characters
• Typical green oil colour caused by Chlorophyll
and Phaeophytin (Chl.degradation product)
• Linolic acid (C 18:2) as main fatty acid
• Big differences in vitamin E –content
• (Tocopherol ) within various oil-seed
pumpkin breeding material and hybrids
Oil-seed pumpkins
Old variety types
Gleisdorfer Ölkürbis, Sepp, Markant (v.l.)
Present oil seed pumpkin varieties in Austria
(Quelle: Österr. Sortenliste, AGES 2010)
Testing results: fruit weight and seed %
(Quelle:
Neubauer et al., 2010)
Thank you for your attention !