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SELFED POLLINATION IN SWITCHGRASS USING A POLYESTER BAGGING METHOD. Laxman Adhikari and Yanqi Wu Department of Plant and Soil Sciences. Outline. Introduction Objectives Materials and Methods Results Acknowledgements . Introduction .
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SELFED POLLINATION IN SWITCHGRASS USING A POLYESTER BAGGING METHOD LaxmanAdhikari and Yanqi Wu Department of Plant and Soil Sciences
Outline • Introduction • Objectives • Materials and Methods • Results • Acknowledgements
Introduction • Switchgrass (Panicumvirgatum L.), potential bioenergy crop for cellulosic biofuels in the US • Intensive breeding works, since early 1990s a b c Fig 1 Switchgrass flowering panicle (a), seedlings (b), and a lowland switchgrass plant (c)
Introduction Contd.. • Naturally cross pollinated species • Control pollination, selfed seed or selected hybrid production • Increased biomass yield, high yielding cultivar • Molecular breeding combined with conventional breeding works to develop new cultivars
Introduction Contd.. • Self incompatibility (Reyna and Vogel, 2002) • No selfed seed in field (Liu and Lu, 2013) • No reliable bagging method available for selfing switchgrass in field (Todd, 2011) • Bagging methods tested before: paper bag, muslin cloth, pillow case and microfibers resulted into significant outcrossing contamination
Objectives • To evaluate the efficacy of polyester bagging method • To develop advanced inbreds in lowland switchgrass genotypes • To develop F2 plants via selfing of upland and lowland F1 plants.
Materials and Methods a b Fig 2 Bagged switchgrass plant in field (a), bagged upland-lowland in greenhouse (b)
Materials and Methods contd… • Polyester bags, T- post and metal cord • Lowland plants in field: Northern lowland advanced inbreds (S2) • Upland and lowland hybrids in greenhouse • SSR markers, PCR techniques
Materialsand Methods Contd... • DNA isolation: CTAB method • DNA measurement: Nano- Drop 1000 spectrophotometer a b Fig 3 Genogrinder(a), 1000- Spectrophotometer (b)
Materials and Methods Contd… • Used Duplex-SSR technique developed in our lab Fig 4 Genotyping of 60 progeny of NL94/85/3 with a duplex set (PVCAG-2207/8 and PVCAG-2289/90) PCR. P stands for parent, M for standard DNA ladder in kilo base pair unit. Number from 1 to 77 indicate progeny numbers.
Materials and Methods Contd... • PCR products separation: Using polyacrylamide gels on a LI-COR 4300 DNA Analyzer • Gels scoring and analysis: SAGA generation 2 software, version 3.3
Results Table 1 Information about inbred seeds and their genetic origin
Results Contd… • Some F2 seedlings developed are currently being grown in greenhouse to test the efficacy of bagging in greenhouse condition. • Some F1 plants in greenhouse: C-7-5, C-7-6, C-8-2, C-8-11 and C-9-7 did not produce seed • Strong wind blew off 3 bags of each NL94/85/1 and NL94/85/5 in field at evening, possible cause of seed contamination
Conclusions • The polyester bags were more reliable and can be recommended for switchgrass selfed seed production in the field and greenhouse condition • The third generation advanced inbreds developed in this study would be used in development of heterotic hybrids and advanced inbreds in switchgrass
Acknowledgements Committee Post Doc/Research associate Dr. Tim Samuel Dr. Linglong Liu Dr. Tiling Fang Field Support Gary and Sharon William, PuFeng, Seth Davis and Ethane Purkins Funding NSF, EPSCoR • Dr. Yanqi Wu, Advisor. • Dr. Ulrich Melcher. • Dr. Arthur Klatt. • Dr. Michael P. Anderson Colleagues/ labmates • Shiva, Angela, Chengcheng, Yuanwen and Hongxu.