PRESENTATION: Avocado research at the E.E. la Mayora, Malaga

Avocado research at
the E.E. la Mayora,
Malaga, Spain
AVOCADO IN SPAIN
•
Commercial avocado orchards started to be planted in the 1970s.
•
Original plantings: seeds imported from Mexico as rootstocks (Topa Topa) and grafted with commercial varieties such as Hass and Fuerte.
•
Spain produces about 1/3 of European consumption
•
Current situation: • Rootstocks obtained from seeds and Duke 7
• Main cultivar Hass (more than 70% of surface) followed by Fuerte and Bacon
• Main problems: – soil fungi: Phytophthora and Rosellinia
– Persea mite: Olygonichus perseae
LA MAYORA EXPERIMENTAL STATION
- Latitude: 36º 45’ N
- Temperatures (last 40 years)
- Average: 19.4ºC:
- 29.4ºC (average highs in August)
- 9.3 ºC (average lows in January)
- Lowest temp on record: 0.5ºC in
January 2005
- Rainfall: 435 mm year
La Mayora Experimental Station
Main avocado research lines at the E.E. la Mayora Spanish Council for Scientific Research
Optimization of avocado cultural techniques
Plant Material
SAN JAVIER 13
LA CONSULA 12
SAN JAVIER 8
SAN JAVIER 19
SAN JAVIER 12
SAN JAVIER
JAVIER 6
1
SAN
SAN JAVIER
JAVIER 4
11
SAN
SAN JAVIER
JAVIER 28
29
SAN
LA CONSULA 6
LA CONSULA 9
MEXICOLA
SCOTT
78
THOMAS
BUENO
94
LA PISCINA
ALHAURIN
BENTAVOL GAR
DUKE
PARENT
100
83
DUKE 6
DUKE 7
FITO CHINEA
BENTAVOL
INV
CUPANDA
G6
SCHIDMT
SCHMIDT
MARVEL
BACON (BL 516)
LULA
SAN JAVIER 14
96
CO
ÍNTOPA
94
TOPA
HARVEST
LONHEISSS
LOHNEI
SHIAPACASSE
JIMENEZ
2
HASS
MOTRIL
100EUGENIM
EUGENIUM
H670
HASS
57
TACAMBARO
JIMENEZ 1
SIR PRIZE
OA184
58
FUNDACI
ÓN 2
REGAL
ADI
NOBEL (BL667)
62
BL122 HASS (BL122)
LAMB
64 52
GEM
50
BL5556
BL5552
IRIET
MONSALVE
EL VISO
VILLENA
FUERTE
ACUEDUCTOS
RR86 V33
COLIN
100SHEPARD
97
RINCOATL
EDEN
79
PINKERTON
TORO
NEGRACANYON
DE LA CRUZ
LONJAS
SRA.
S.
CHINEA
CHINEA
CLAVERO
2
MAOZ
ANAHEIM
100
GVAR13
FUSCH 20
FUCHS
G755A
1.00
0.62
0.81
1.00
64
56
79
Organic production:
Study of the effects of low or no
mineral N supply on yield, tree
growth and fruit quality using
different mulching applications
Pruning:
Different pruning dates in summer
are being studied.
Postharvest management:
Study of the effects of some T-RH
combinations and different physical
and chemical treatments on fruit
rots
Microelements
Different
doses
and
soil
aplication methods for B, Zn and
Cu have been evaluated for the
last 12 years.
Molecular fingerprinting
Fingerprinting of the germplasm collection:
about 30 local and 60 foreign genotypes
Alternate irrigation:
Alternate irrigation is being
compared
with
conventional
irrigation on yield, tree growth and
root system development as a
promising tool to control soil-borne
diseases.
Reproductive biology and optimization of yield
A correct understanding of the floral biology of avocado under our environmental conditions is necessary to optimize yield
Pollination: Effects of different pollinizers on alogamy rate and yield
LACONSULA12MW
67
45
0.23
0.23
0.42
0.42
0.62
0.81
Similarity
Coefficient
Agronomic evaluation of different cultivars
A dynamic cultivar collection, including several Hass-like
selections from all over the world is being evaluated for
traits of agronomic interest
Incidence and development of strategies for the biological
control of Persea mite
• Important pest in avocado in Spain since 2004
• Current studies directed towards evaluating the incidence of the pest and to develop adequate strategies of
biological control.
Study of the progamic phase and the effects of environment (temperature and humidity) on the dichogamous cycle
• The presence of different types of pollen on avocado plants seems to increase phytoseiid populations in
spring: pollen applications could be a promising tool to control mite populations in the field.
Flower Quality: Study of the causes behind flower abscission: starch content of individual flowers at anthesis and its
relation with flower fate
Optimization of genetic transformation
Fernando Pliego, University of Malaga
Control of avocado white rot. Rosellinia necatrix
University of Malaga
IFAPA
REGULATION AND CULTURAL METHODS
Remove the infected plants, irrigation control,
use of organic amendements
PHYSICAL CONTROL
INTEGRATED
MANAGEMENT
SOLARIZATION
GENETIC CONTROL
Use of resistant / tolerant rootstocks
CHEMICAL CONTROL
BIOLOGICAL CONTROL
Use of antagonistic microorganisms which
reduce the disease (Sordaria, Thichoderma,
bacterial strains)
Selection of avocado rootstocks tolerant to Rosellinia necatrix
Seedlings after inoculation
Seedlings from different origins
(Mexico, Australia, Spain)
Avocado trees surviving in
orchards infected with R. necatrix
Multiplication in vitro of escape trees or seedlings
Araceli Barcelo
IFAPA
Phase 0: pruning of escape
trees int he field
Phase I: establishment
in vitro
Phase II:
proliferation
Phase III: rooting
Artificially infested plot
Phase IV:
acclimatation
RESEARCH ON AVOCADO REPRODUCTIVE BIOLOGY AT
THE E.E. LA MAYORA, MÁLAGA SPAIN
♀
♂
Overlap
Protogynous
dichogamy
AVOCADO CHARACTERIZED BY LOW FRUIT SET
Massive drop of flowers and developing fruitlets
2 TYPES OF CULTIVARS
A and B
Some unpollinated flowers
Other factors must be involved
Inadequate pollination
OBJECTIVES
OBJECTIVES
1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSSCROSS-POLLINATION ON YIELD AND OUTCROSSING
3. EFFECT OF CROSSCROSS-POLLINATION ON YIELD AND OUTCROSSING
4. OPTIMIZING THE CHOICE OF POLLINIZERS
4. OPTIMIZING THE CHOICE OF POLLINIZERS
No adhered pollen grains
No adhered pollen grains
Pollen adhesion and germination observed both in female and male stages
Field
EFFECT OF TEMPERATURE
ON POLLEN ADHESION AND
GERMINATION
Relative humidity
Temperature
Female
Female
Male
Male
% Pollen germination
% Pollen germination
EFFECT OF RELATIVE
HUMIDITY ON POLLEN
ADHESION AND GERMINATION
Field
Temperature
Female
Male
Relative humidity
Female
Male
2
4
6
8
24
30
% flowers/fruits set
EFFECT OF TEMPERATURE ON POLLEN TUBE GROWTH
hours
48
10oC
20oC
Weeks after end of flowering
% fruit set similar
between on and off
years
30oC
Style 1/4
% flowers/fruits set
No temp
effect on
ovule
viability
Stigma
Style 1/2
Style 3/4
Ovary
Ovule
Weeks after end of flowering
Time after pollination (hours)
OBJECTIVES
1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
I2KI
- NO EXTERNAL DIFFERENCES AMONG FLOWERS
- GREAT DIFFERENCES IN STARCH CONTENT
No. of flowers
3. EFFECT OF CROSSCROSS-POLLINATION ON YIELD AND OUTCROSSING
. OPTIMIZING THE CHOICE OF POLLINIZERS
Optical density x104
1st Row
3rd Row
4th Row
Optical density x104
2nd Row
1st row 2nd row 3rd row
4th row
Place in the inflorescence
Differences in starch content between two populations of
flowers with different capacity to set fruits
Optical density x104
STARCH CONTENT IN INDIVIDUAL FLOWERS AND FRUIT SET
Early flowers
Late flowers
OBJECTIVES
1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSSCROSS-POLLINATION ON YIELD AND OUTCROSSING
Optical density x104
4. OPTIMIZING THE CHOICE OF POLLINIZERS
Dropped
Retained
Background
Increase distance to the pollen donor source
Outcrossing rate
(Vrecenas-Gadus and Ellstrans, 1985
Goldring et al., 1987)
Yield
(Bergh and Gustafson, 1958
Bergh and Garber, 1964
Bergh et al., 1966
Bergh, 1968)
Contradictory results
Goldring et al., 1987
Johannsmeier et al., 1989
Garner et al., 2008
Selective fruit drop
Most fruits in the tree result of crosspollination
OUTCROSSING RATE IN AN SOLID HASS BLOCK OPPOSITE TO A SOLID
FUERTE BLOCK
Fuerte
1038
1036
1034
999
997
995
960
958
956
879
877
875
Hass
Fuerte
20-30 fruits per tree: DNA extraction from the embryos
Hass
SSR analysis
AVAG21
Hass
186/201
Fuerte 183/203
Pearson correlation coefficient
Cross‐fertilization
Outcrossing rate
Distance to the pollen source
Outcrossing rate
‐0.7 (p= 0,014)
Row 1
Row 2
Row 3
p= 0,01
Row 1
Row 2
Row 3
FRUIT DROP
No significant effect of the distance to the pollen source was found during 13 years
% of crossfertilization
Mid fertil.
% of dropped
flowers related
to date of
fertilization
Early fertil.
85%
July
Hass Fuerte Hass Fuerte
48%
August
OBJECTIVES
1. ENVIRONMENTAL FACTORS AFFECTING THE PROGAMIC PHASE
Outcrossing rate
2. NUTRITIVE STATUS OF THE FLOWERS AT ANTHESIS
3. EFFECT OF CROSSCROSS-POLLINATION ON YIELD AND OUTCROSSING
4. OPTIMIZING THE CHOICE OF POLLINIZERS
Months after anthesis
SEARCHING FOR A POLLINIZER FOR HASS
Study of the flowering season of 27 cultivars
Requeriments
VARIEDADES
Type B
Overlap in flowering time with Hass
Currently in Spain Fuerte is used
Not enough overlap
ADI
HASS MOTRIL
BL 5552
BL122
IRIET
JIMENEZ I
BL516
BL667
JIMENEZ II
LONHEISS
COLIN V-33
EDEN
LONJAS
NEGRA DE LA CRUZ
FUERTE
FUNDACIÓN II
OA 184
PINKERTON
H670
GEM (3-29-5)
REGAL
RINCOATL
HARVEST
HASS
RT 5176
SHEPARD
CUPANDA
If possible: Hass-like fruits
OVERLAP BETWEEN SEXUAL STAGES
FLOWERING TIME
APRIL
ABRIL
MARZO
MARCH
13
16
19
22
25
28
31
3
6
9
12
15
MAYO
MAY
18
21
24
27
30
3
6
9
12
15
18
11 cultivars selected
21
FUERTE
CULTIVARES
HASS
FUERTE
BL 667 (NOBEL)
BL 516 (MARVEL)
BL 122
3-29-5 (GEM)
JIMÉNEZ 2
JIMÉNEZ 1
HASS T. MOTRIL
TACAMBARO
H 670
CUPANDA
SHEPARD
BL 122
BL 5552
BL 516
NEGRA DE LA CRUZ
RT 5176
JIMÉNEZ 1
REGAL
H 670
HASS MOTRIL
LONHEIS
EDEN
JIMÉNEZ 2
BL 667
LONJAS
3-29-5
Two trees per cultivar studied
IRIET
HASS
RINCOATL
PINKERTON
HARVEST
Flower stage followed every 2 hours: 8:00‐ 20:00
COLIN V-33
FUNDACIÓN II
OA 184
ADI
% Male flowers
Overlap
Sexual stage
OVERLAP IN SEXUAL STAGES BETWEEN FLOWERS OF 11 CULTIVARS
8:00
10:00
12:00
14:00
16:00
18:00
% Female flowers
OVERLAP AT THE BEGGINING OF FLOWERING SEASON
20:00
8:00
10:00
12:00
14:00
16:00
HASS
HASS
FUERTE
*
FUERTE
NOBEL
*
NOBEL
MARVEL
MARVEL
LAMB HASS
LAMB HASS
*
GEM
GEM
JIMENEZ 2
JIMENEZ 2
*
*
JIMENEZ 1
LOHNEISS
LOHNEISS
HASS MOTRIL
TACAMBARO
*
*
H670
Estado
femenino
Female
stage
Estado
masculino
Male stage
20:00
*
*
*
*
*
*
JIMENEZ 1
HASS MOTRIL
18:00
*
*
TACAMBARO
*
*
H670
Estado
femenino
Female
stage
Estado
Male masculino
stage
OVERLAP AT THE END OF THE FLOWERING SEASON
8:00
10:00
12:00
14:00
16:00
18:00
HASS
20:00
*
*
FUERTE
NOBEL
*
*
MARVEL
LAMB HASS
*
GEM
JIMENEZ 2
% Fruit set after handpollinations
JIMENEZ 1
LOHNEISS
BL 667 (NOBEL)
8,4%
BL 516 (MARVEL)
7,4%
FUERTE
2,8%
HASS MOTRIL
TACAMBARO
*
H670
*
Estado
femenino
Female
stage
Estado
masculino
Male stage
Avocado shows a fast progamic phase. This phase is clearly affect by
environmental conditions: high temperatures increase pollen tube
growth and low temperatures increase the time required for fertilization
CONCLUSIONS
Under conditions of 20-25ºC and high relative humidity, the estigma
conserves the capacity to allow germination and pollen tube growth in
the male stage, favoring self-pollination
Differences in yield between on and off years are due to the intensity of
flowering since fruit set % is not significantly different
The nutritive status of the pistil is related to the reproductive success of
the flower, since differences are observed in starch content among
flowers at anthesis. Starch content is higher in flowers that will set fruit.
Thus, the nutritive status of the flower seems to be a necessary condition,
but not the only one, for fruit set
The genotype of the embryo does not seem to be determinant in selective
fruit drop during the months following anthesis; the fruits that drop are
preferently those fertilized at the end of the ‘Hass’ flowering season.
Those fruits are mainly the result of self-fertilization since no flowers of
‘Fuerte’ are present at the end of the ‘Hass’ flowering season
The distance between two complementary cultivars (‘Hass’ and
‘Fuerte’) has an effect on cross fertilization; however, there are no
differences in yield with increasing distance
Taking into account the length of the flowering season, the overlap
between sexual stages and yield, ‘Marvel’ (BL516) and ‘Nobel’ (BL667)
could be interesting pollinizers for ‘Hass’ under our growing conditions