1. 1. MORPHOLOGICAL PLASTICITY IN WHEAT (Triticum aestivum L.) ROOT DEVELOPMENT UNDER PEG- TREATED HYDROPONIC CULTURE Supervisor Dr. Arif Hasan Khan Robin Associate Professor Co-supervisor Dr. Md. Abdullah Al Bari Associate Professor Presented by ID: 14AgGPB JJ02 M Reg. No.: 36293 Department of Genetics and Plant Breeding Bangladesh Agricultural University
2. 2. Presentation Outline Introduction/background of the study Objectives of the study Materials and Methods Results Discussion Conclusions References Acknowledgements
3. 3. Background Wheat is a vital crop and among cereals it stands next to rice and maize. It grows in 0.43 million ha in rabi season and production is around 1.3 M ton in our country In Bangladesh, wheat yield ranges from 4.5 to 5.5 t ha-1 Potential yield is more than 9 t ha-1 Sources: FAOSTAT 2013; BBS, 2014; USDA, 2014; BARI, 2015
4. 4. Background (Contd) Sources: FAOSTAT, 2013; USDA, 2014
5. 5. Background (Contd) Wheat production is greatly affected by drought in the country Grain yield of wheat reduced upto 50-66% during reproductive stage, 18-53% at pre-anthesis and 13-38% at post-anthesis. Efficient root system can exploit residual soil moisture to avoid drought stress. Polyethylene glycol (PEG) can successfully create drought condition at hydroponic culture Sources: Michel and Kaufmann, 1973; Majid et al., 2007; Kili and Yabasanlar, 2010
6. 6. Background (Contd) So, three hydroponic lab experiments with PEG-8000 treatment was conducted in this research Fig. 1 Root architecture in wheat 1. Primary root; 2. First order lateral root; 3. Secondary order lateral root; 4. Branching interval; 5. Adventitious root; 1. Primary root branching angle; 2. First order lateral root branching angle; 3. Secondary order lateral root branching angle. 1 2 3 4 5 1 3 2
7. 7. Objectives To investigate the effect of 0.5% PEG-8000 mediated stress on seminal wheat root development To explore the outcome of prolonged stress by PEG-8000 on lateral roots and on root hairs of adventitious roots To perceive the responses of high resolute PEG-8000 on root growth during booting stage of wheat.
8. 8. Materials and Methods Experimental site and periods with spell Growth chamber, Dept. of GPB, BAU. Duration April to November A hydroponic experimentation Three subsequent experimentation was conducted. Experimental Design Completely randomized design(CRD). Plant materials and sources Ten (10) elite wheat varieties. Collected from Wheat Research Centre, Bangladesh Agricultural Research Institute (BARI)
9. 9. Materials and Methods (Contd) Variety Released year Yield (t ha1) Features BARI Gom 21 (Shatabdi) 2000 3.65.0 Good level of tolerance to terminal heat BARI Gom 24 (Prodip) 2005 4.35.1 High yielding, but heat sensitive BARI Gom 23 (Bijoy) 2005 4.35.0 Moderately heat tolerant BARI Gom 25 2010 3.65.0 Moderate level of tolerance to heat stress BARI Gom 26 2010 3.55.0 Tolerant to terminal heat stress in late seeding BARI Gom 28 2012 4.05.5 Tolerant to terminal heat stress in late seeding Kheri Indigenous cultivar Sonalika 1973 1.72.1 Kanchan 1983 3.5 4.6 Leaf rust susceptible Akbar 1983 3.5 4.5 Leaf rust tolerant Table 1. Characteristics of the selected wheat varieties
10. 10. Materials and Methods (Contd) Germination of seeds On polystyrene sheets inside the trays in the growth chamber, temp 2020 C and light 572 PPFD. After 2-3 days germination occurred. Fig. 2 Germination of seeds on polystyrene sheets.
11. 11. Materials and Methods (Contd) Seedling raising and transferring into hardwood sheet After one week seed were grown in seedling. Timely nutrient supply and thinning was done. Then transferred into hardwood sheet. A B Fig. 3 A) Seedling raising; B) Transferred seedlings into hardwood sheet
12. 12. Materials and Methods (Contd) Nutrient solution Modified Hoagland solution. Electrical Conductivity (EC) is maintained to 0.6-1.0 Table 2. Composition and concentration of the minerals used in the solution Components Concentration NH4NO3 62.46 mM NaH2PO4.H2O 43.48 mM MgSO4 39.46 mM KNO3 59.35 mM CaCl2.H2O 16.12 mM H3BO3 3.43 mM MnSO4.4H2O 0.76 mM ZnSO4.7H2O 0.059 mM or 59.12 M CuSO4.5H2O 0.039 mM or 39.47 M NaMoO4.2H2O 0.009 mM or 9.13 M FeSO4 16.46 mM EDTA 10.27 mM
13. 13. Materials and Methods (Contd) PEG treatment Fig. 4 Controlled condition (0.0% PEG) Fig. 5 Treated with 0.5% PEG Table 3. PEG application time and duration in the experimentations Experiment Concentration Treatment given DAT Duration of treatment Seminal 0.5% 20 10 Adventitious 54 20 Booting stage 75 20
14. 14. Materials and Methods (Contd) Data recording Harvest 1: At 30 DAT during seminal root formation Harvest 2: At the 67 DAT during adventitious root formation Harvest 3: At 97 DAT during reproductive stage or booting stage Preparation of Safranin Stain Solution Safranin solution of 0.5% was used for staining root hairs Measured variables Live leaves Number of primary axis root Main axis root hair number Secondary axis root hair number Growth status Primary root axis length Main axis root hair length Secondary axis root hair length Total root number Primary root axis diameter Main axis root hair diameter Secondary axis root hair diameter Number of phytomer Number of secondary root axis Primary axis root hair number Root dry weight Main root axis length Secondary root axis length Primary axis root hair length Shoot dry weight Main root axis diameter Secondary root axis diameter Primary axis root hair diameter Chlorophyll content
15. 15. Materials and Methods (Contd) Measurement of traits under microscope The measurements were done at 40x and 100x magnifications under microscope. Fig. 6 Measurements of root traits under microscope. a) diameter of main axis root under control condition; b) diameter of PEG-treated main axis root; c) number of lateral roots under controlled condition; d) lateral root numbers under PEG-treated condition; e) number of root hairs under controlled condition; f) number of root hairs under PEG treatment.
16. 16. Materials and Methods (Contd) Root dry weight and shoot dry weight Roots and shoots were put in the oven with envelop and kept at 600 C for 7 days Chlorophyll content measurement With Chlorophyll meter (SPAD502 Plus, 3V; 200mW), chlorophyll content of live leaves were measured. Statistical analysis Data were analyzed using MINITAB 17 statistical software packages. Fig. 7 Chlorophyll content measurement
17. 17. Results Length of root hair at seminal root formation Fig. 8 Length of root hairs originated at the main root axis of wheat varieties for two PEG treatments on 10 days after two (0.0% and 0.5%) PEG treatment (P