Waterlogging tolerance at germination in pea Md Shahin Uz Zaman PhD Candidate School of Agriculture and Environment Professor William Erskine Dr Imran Malik Dr Parwinder Kaur
Acknowledgements ACIAR UWA Tissue culture group Plant growth facilities staff BARI My Supervisors
Overview Background of the project Proposed research plan Progress to date
Dominant Cropping pattern in Bangladesh Rice-legume-legume/other crops (medium low land) Vegetable-vegetable-legume/other crops (upland) Rice-fallow-rice (low land) New idea: Rice-pea-rice (low land)
Pea sowing 2-3 weeks prior to rice harvesting Fallow 70-80 days Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Monsoonal rice Harvest in November Relay cropping Relay pea Irrigated rice Planting about 15 th February
NL-2 110 115 days BM-3 75 80 days Genotypic variation in relay cropping
Waterlogging in dryland agriculture Sandy soil Clay layer Duplex soil type
Confirmation of waterlogging (WL) tolerance at germination Identify the mechanism of waterlogging tolerance by whole genome transcriptome profiling Assessing genotypic variability to waterlogging tolerance by screening a diversity panel of pea germplasm Genetic basis of WL tolerance by genome wide association mapping
Confirmation of waterlogging (WL) tolerance at germination Treatment: Genotypes: 3 (BM-3, NL-2 and Kaspa WL duration: 0, 4 and 8 days then draining NL-2 BM-3
100 80 Percent germination ns ns ns ns ns ns BM- 3 NL-2 Kaspa 60 40 b b 20 0 Drained control 4 days WL 8 days WL a
Previous findings Glasshouse observation Seed coat color Leakage of seed solutes Enzymatic activities Mechanism at molecular level? Leakage of seed solutes BM-3 NL Kaspa
Identify the mechanism of waterlogging tolerance by whole genome transcriptome profiling Treatments: 2 (waterlogged and drained control) Time point: 4 (12 h, 24 h, 48 h and 96 h) Genotypes: 3 (two WL tolerant and one sensitive) Seed collection: WL soil and drained soil at each time point
Common and specific genes differentially expressed with logfc 2 Highly significant numbers (logfc 4): Tolerant genotypes: 43 and Sensitive genotype: 134
Key gene expression under WL stress Tolerant Sensitive Protein Upregulated Downregulated Lipid Downregulated Upregulated Carbohydrate Lignin and Phenolic precursors Downregulated Upregulated Non Functional Downregulated Seed solutes
Assessing genotypic variability to waterlogging tolerance by screening diversity panel of pea germplasm Treatment: Genotypes: 110 (diversity panel of pea) WL duration: 8 days
Percent germination Variation of WL tolerance
Traits associated with WL tolerance WL germination Traits Flower color Leaf axil color WL germination Flower color 0.50*** Leaf axil pigment 0.52*** 0.86*** Seed coat color 0.56*** 0.91*** Tolerant Sensitive Tolerant Sensitive 0.91*** Tolerant Sensitive
Genetic basis of WL tolerance by genome wide association mapping Populations used: Diversity panel of 110 germplasm Bi-parental population
Bi-parental population development through rapid generation protocol Crossing Confirmation of F1 7 th generation Fourth to Sixth Generation Second generation Third generation
Conclusion WL major problem to intensify pea in rice fallows and duplex soil in dryland agriculture Genotypic variation to WL tolerance found at germination in peas New mechanism for tolerance identified by transcriptome analysis Tolerant source and associated morphological traits identified Molecular markers and genomic loci associated with tolerance being mapped through GWAS
Take-Home Message Contribute to develop WL tolerant pea varieties for rice fallows in South Asia and duplex soil in Australia and others Can be translated to related legume species and other crop Will increase yield by reducing crop damage by waterlogging
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