The International Network for Edible Aroids. Second Annual Meeting - Montpellier December th 2013

Transcription

1 The International Network for Edible Aroids Second Annual Meeting - Montpellier December th 2013

2 EuropeAid/ /C/ACT/TPS DCI-Food/2009/45 Adapting clonally propagated crops to climatic and commercial changes WP 5: Evaluation of drought resistance in taro elite cultivars. Miguel Ângelo A. Pinheiro de Carvalho ISOPlexis Genebank. University of Madeira. Portugal

3 Table 1. Taro germplasm classification by growing conditions and crom morpho-types Growing type Growing conditions Crom morpho-type Cultivars recognized by farmers Central corm without Branco sequeiro cormels Dasheen (C. esculenta var. esculenta) Dry cultivation Central corm with lateral cormels (small number) Roxo sequeiro Vermelho sequeiro Eddoe (C. esculenta var antiquorum) Others Flooded Central corm Branco Flooded, wetlands Corm and cormels Enxerto same development Wild escaped To be established To be established Rain fed cultivation S m a l l c o r m a n d Cormos cormels

4 Roxo cultivar Branco cultivar

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6 WP 5 Planning and Execution. Project start date: 2011 Project end: March 2016 Six phases approach is proposed to implement the work package Phase I: Reception of taro accessions. Phase II: Accessions multiplication, acclimatization and preassessment of stress tolerance. Phase III: Realization of screening drought tolerance in taro cultivars. Phase IV: Realization of cooperative trials for studying of drought tolerance. Phase V: Sampling for physic-chemical and molecular screening. Phase VI: Processing, data treatment and publication

7 State of art about drought tolerance in Taro Do not exist a model of the impact of drought on this crop. Crop have high water requirements, from 2 to 16 mm.day -1, which its tolerance to drought a major concern to maintain the crop productivity in conditions of climatic changes. Situation is aggravated by the crop vegetative propagation that reduces the plant genetic variability. Some authors studied the influence of drought in taro aiming to identify best traits, screening and select plant material, study drought tolerance mechanisms. Difficulties arise long crop vegetative cycle, and make reproducible the drought conditions.

8 State of art about drought tolerance in Taro Approaches based on the study of variation of specific characters of parameters under drought conditions Phenological stages (Leaves formation, corm formation, maturation). Agronomic and morphological characters (Plant height, leaves and corm sizes, root density, leaf area, coloration, plant productivity, yield indexes and quality. Physiological characters and processes (evapotranspiration, water use and efficiency, stomata conductance, photosynthesis rates, biomass production). Biochemical processes ( 13 C/ 12 C discrimination, dehydrins, aminoacids accumulation). Drought tolerance (DTI) and susceptibility (DSI) indexes

9 Phase I. Reception of taro accessions From SPC or Edible Aroids Network partners Duration: October 2011 / December 2013 Sampling: 49 accessions. Size of samples: Ranging from 5 to 20 individuals. Total number of plants: 282 plants Material received from Edible Aroid network. SPC 125 plants belonging to 25 accessions. India 12 plants. Papua New Guinea 65 plants belonging to 12 accessions (recently). European partners. Other material Cyprus 10 plants. Canary Islands 42 plants belonging to 4 accessions. Azores 28 plants belonging to 3 accessions.

10 Phase I. Reception of taro accessions Requirements to be aware UMa duties Registration as importer / exporter of vegetative propagating material. Obtain an import license. Partner duties Phytosanitary certificates (CF) on the part of shippers (SPC, Partner). Official letter declaring that material will be used for research purposes Both documents should follow the samples.

11 Phase II. Samples multiplication, acclimatization and pre-assessment to stress tolerance Tasks: 1. Multiplication (in vitro) of accessions to create a safe duplicate of plant material. Duration: 4 months, April to July Acclimation of taro accessions to local soil and climate conditions. Duration: 12 months, June 2012 to June Plant samples collected and send to other partners for genetic studies and virus screening.

12 Phase II. Samples multiplication, acclimatization and pre-assessment to stress tolerance Accessions samples sizes in acclimatization 34 accessions 10 plants per accession. Total number of plants: 400 plants Deliverables / outputs: Obtain of plant material for full assay test in similar vegetative conditions and development (beginning of 2013) Study of variation of characters and traits to be used in assays for drought tolerance (2012 to July 2013). Pre-assessment analysis of characters to be use in tolerance tests (January 2013).

13 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance In this phase the pre-assessment of drought stress was transform in pilot assays to modulate drought conditions in taro Pilot assays in a greenhouse at University of Madeira were performed (a total of 3 from, which 2 all ready realize) Rationality. Critical aspects of drought stress studies. Establishment of the real conditions of drought stress for taro. Difficult to make reproducible the stress conditions for long periods. High variability in crop answers to stress factor from susceptibility to resistance. Need to identify and have available crop standards of drought tolerance (genotypes, ecotypes or varieties acting as out groups).

14 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance First Pilot assays (November 2011 to June 2012) 4 local accessions (3 from Madeira, 1 from Canary Islands) 9 plants per accession in a total of 28 plants. Experimental design: Control and 2 watering regimes. Use of 7 control nonplanted pots Table 2. Table shows the taro accessions, their variety, origin and number of plant used in pilot assays. Accession Species Variety Origin Number of plants EXOP 2059 C. esculenta Blanco Canary Islands 6-7 ISOP 2207 C. esculenta Roxo Madeira 9-10 ISOP 2216 C. esculenta Branco Madeira 9-10 ISOP 2220 C. esculenta Vermelho Madeira 9-10

15 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance First Pilot assays (November 2011 to June 2012) Reasons to use local varieties According to our knowledge local varieties require less water. Madeiran dasheen cultivars are cultivated under rain-fed conditions, getting less 4,5 mm water per day (about 2.8. Need to identify drought tolerance standards. Deliverables / outputs Definition of water regimes, soil water capacity, measurement of taro evapotranspiration (done). Pre-assessment of the variation of characters/ traits to be use in tolerance tests (done).

16 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Drought pilot assays. Experimental design

17 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Drought pilot assays. Experimental design Table 3. Distribution of 40 pots among drought assay variants Variants (batches) Planted pots Non-planted pots Control (full water irrigation, batches 1) 11 2 Experimental variant 1 (55% irrigation, batches 2) 11 2 Experimental variant 2 (40% irrigation, batches 3) 11 2 Absolute control (not irrigated) 0 1

18 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance. Drought pilot assays. Experimental design

19 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Second pilot assays (length 222 days, October 2012 to July 2013) 4 local accessions (3 from Madeira, 1 from Canary Islands) 9 plants per accession in a total of 28 plants. Experimental design: Control and 2 watering regimes (55 and 40% watering regime). Parameters assessment: 23 parameters and characters. Data obtained: 140 key data point Environmental parameters: daily temperature; atmospheric and soil moisture; pot weight; volume of water; and PAR variation. Plant traits: number of emerged and died leaves; plant height; total plant weight; fresh and dried weight of plant aerial part; leaf width and length; leaf number; corm width and weight; petiole insertion; and chlorophyll content

20 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Drought pilot assays. Some results Control (non-planted) pots Experimental (planted) pots pot weight, kg pot weight, kg

21 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Drought pilot assays. Some results Table 4. Variation of water capacity and efficiency use by taro-soil system during the assay (values of evapotranspiration, evaporation and transpiration) Parameters Experimental variants Full assay Drought period Total, L Mean values, ml.day -1 Total, L Mean values, ml.day -1 Total irrigation Control % irrigation % irrigation Evapotranspiration Control % irrigation % irrigation Evaporation Control % irrigation % irrigation Transpiration Control % irrigation % irrigation

22 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Second pilot assays. Some results 120 Fresh Total Biomass 120 Fresh Corm Biomass %Fresh Total Biomass control 55% irriga8on 40% irriga8on % Fresh Corm Biomass control 55% irriga8on 40% irriga8on 0 ISOP2220 Varie1es ISOP ISOP2220 Varie1es ISOP2207 ISOP 2220 DTI 40% ISOP 2207 DTI 40% ISOP 2220 DTI 40% ISOP 2207 DTI 40%

23 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Drought pilot assays. Some results Table 5. Water Use efficiency (WUE) in each experimental variants per accession, calculations are based on fresh total biomass and total evapotranspiration, during assay Accessions Control (g/l) 55% irrigation (g/l) 40% irrigation (g/l) ,84±3,03 18,94±7,83 13,27±0, ,01±3,28 16,27±3,87 9,45±2, ,06±3,06 23,02±5,48 14,09±7, ,11±2,39 16,27±0,32 12,00±0,00

24 Phase II. Samples multiplication, acclimatization and pre-assessment of stress tolerance Second pilot assays (length 222 days, October 2012 to July 2013) Deliverables / outputs: Preliminary classification of local accessions according to their tolerance (done). Identification of key characters/traits to screen the taro accessions (under way). Definition of simplified protocol to be used in assays of drought tolerance (under way). Major gaps Assay length is not sufficient to assess the full corm formation.

25 Phase III. Realization of screening drought tolerance in taro cultivars. Full assay for screening of drought tolerance Accession samples size 34 accessions (SCP 25 accessions; 9 European accessions) 10 plants per accession in a total of 680 plants. Experimental design: Control and 1 experimental variant (40% watering). Start date: June 2013 Assay duration: 8 months To be clarified: Duration of assays/ tests. Full the vegetative cycle versus 2 to 3 months. Full vegetative cycle is required because need to assess the formation of corm

26 Full assay for screening of drought tolerance

27 Phase III. Realization of screening drought tolerance in taro cultivars. Experimental design: 2 variants (control and 40% watering). Two assay phases initial growth (full irrigation) and stress implementation phase. Three sampling/assessment points (minimum) Traits and parameters to be monitored. Preliminary 7 Environmental parameters: Soil water potential and capacity; photosynthetic active radiation (PAR); temperature; air moisture; edaphic conditions; soil water capacity. 12 Plant traits: Water use efficiency and potential; photosynthesis ratios; plant weight, area and sizes; yield and productivity; corm sizes and ratios; biomass production. Tolerance and susceptibility ratios

28 Full assay for screening of drought tolerance

29 Phase III. Screening of drought tolerance in taro cultivars. Initial planning and timeline Experimental design testing for drought tolerance. Timeline: November 2013 / April 2014 (Done). Confirmation and revision of the protocols developed for testing taro drought tolerance (Phase III and IV). Timeline: April 2014 (To be conclude) Implementation and conclusion of full assays for screening to drought tolerance in taro cultivars. Timeline: April 2013 / May Creation a model of drought tolerance and cooperation with other partners in the implementation of G E experiments, aiming to validate the model. Timeline: April 2014 / May 2015 (revision).

30 Phase III. Screening of drought tolerance in taro cultivars. Deliverables / outputs Model of drought tolerance in taro. Identification of traits and markers that can be use in selection of material. Classification of accessions based on its tolerance or sensitivity to drought. Selection of tolerant and sensitive accessions/ genotypes to be used in open field trials (G E trials). To be discussed: Establish the partners who want to be involved in the open field trials (G E). Distribute responsibilities in such studies. Create a task group for results review and publication.

31 Phase IV. Realization of cooperative trials for studying of drought tolerance Two growing seasons or vegetative cycles is required. Duration: 24 months (April 2014, March 2016, new planning). Trials length/ duration Probably we could only implement one growth season, because the delay in the full assay implementation, resulting from the need to acclimatize received samples. Tasks 1. Delineation of cooperative trials and selection of eligible accessions. 2. Release of common protocol, and selected accessions and standards for testing (still to be define local partners). 3. Monitoring of soil and climatic conditions (still to be define local partners). 4. Trial implementation and evaluation of key traits variation aiming to validate drought tolerance model in open field conditions (still to be define local partners). 5. Data documentation, analysis and results treatment (methodology to be define).

32 Phase IV. Realization of cooperative trials for studying drought tolerance Open trial Experimental design: Similar to the full assay, but performed at open field under variable environmental conditions, during dry season, with goal to validate drought model. Sampling sizes: 20 accessions (initial planning, will be less). Expected a decrease of 50% in the number of accessions initially screened. Total number of plants: 220 plants (initial planning will be less. 120 plants or less)

33 Phase IV. Realization of cooperative assays for studying drought tolerance Experimental design A minimal number of traits and parameters will to be monitored Defining the parameters and traits (Preliminary) Environmental parameters Soil water potential and capacity Photosynthetic active radiation (PAR) Temperature Air moisture Soil moisture and edaphic conditions Plant traits Biomass production. Yield and productivity ratios. Pairs of traits with stable as with stable association, under drought conditions. Traits with the DTI higher 1.0.

34 Phase IV. Realization of cooperative trials for studying drought tolerance Open field trials Deliverables / outputs Variation of crop key tolerance traits will be evaluate in relation to trial conditions. Genotypes holding drought tolerance and better performing in different environments will be selected. Timeline: March of 2016.

35 Phase V. Sampling for physic-chemical and molecular screening. Duration: 2-3 months (expected in March or June 2014 and 2015). Depends on the length of the vegetative cycle and the experiments duration (8 months or 12 months). Tasks 1. Sampling of material, preparation and expenditure of samples for physic-chemical and molecular screening. Deliverables / outputs Study the linkage of the drought tolerance with traits of physic-chemical quality. Timeline: Beginning of To be discussed/ problems Conditions and requirements of samples to be send for the partner 1 and 3. Sizes of material samples and if need number of duplicates.

36 Phase VI. Processing, data treatment and publication Duration: 10 months (June 2015 to March 2016) Deliverables / outputs: 1. Model of taro drought tolerance (under construction) 2. Association of key morpho-agronomic traits with drought (identification underway). 3. Linkage of key morpho-agronomic traits (associated with drought tolerance) with physic-chemical and molecular markers will be attempted. 4. One MSc thesis on drought tolerance (finished until June 2014). 5. Two papers published in international journals (to be done).

37 International Network for Edible Aroids ISOPlexis Genebank local team Miguel Pinheiro de Carvalho Filipe Ganança, PhD student Humberto Nobrega Gregório Freitas Vanessa Rodrigues, Master student Thank you