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