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Article|24 Feb 2016|OPEN
Isolation of prostrate turfgrass mutants via screening of dwarf phenotype and characterization of a perennial ryegrass prostrate mutant
Junmei Chen1,2 , Chandra Thammina2 , Wei Li2 , Hao Yu2 , Huseyin Yer2 , Rania El-Tanbouly2 , Manon Marron2 , Lorenzo Katin-Grazzini2 , Yongqin Chen2,3 , John Inguagiato2 , Richard J. McAvoy2 and Karl Guillard2 , Xian Zhang4 , Yi Li,2 ,
1College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
2Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT 06269, USA
3College of Life Sciences, Hubei University, Wuhan 430062, China
4College of Horticulture, Northwest A&F university, Yangling 712100, China
*Corresponding author. E-mail: yi.li@uconn.edu

Horticulture Research 3,
Article number: 3 (2016)
doi: https://doi.org/10.1038/hortres.2016.3
Views: 993

Received: 10 Jan 2016
Revised: 18 Jan 2016
Accepted: 18 Jan 2016
Published online: 24 Feb 2016

Abstract

Prostrate turf varieties are desirable because of their increased low mowing tolerance, heat resistance, traffic resistance and ground coverage compared with upright varieties. Mutation breeding may provide a powerful tool to create prostrate varieties, but there are no simple, straightforward methods to screen for such mutants. Elucidation of the molecular basis of the major ‘green revolution’ traits, dwarfism and semi-dwarfism, guided us to design a simple strategy for isolating dwarf mutants of perennial ryegrass (Lolium perenne L.). We have shown that gamma-ray-mediated dominant dwarf mutants can be easily screened for at the three-leaf stage. About 10% of dwarf mutant lines also displayed a prostrate phenotype at mature stages (>10 tillers). One prostrate line, Lowboy I, has been characterized in detail. Lowboy I had significantly shorter canopy, leaf blade and internode lengths compared with wild type. Lowboy I also exhibited greater tolerance to low mowing stress than wild type. Exogenous gibberellic acid (GA) restored Lowboy I to a wild-type phenotype, indicating that the dwarf and prostrate phenotypes were both due to GA deficiency. We further showed that phenotypes of Lowboy I were dominant and stably inherited through sexual reproduction. Prostrate turfgrass mutants are difficult to screen for because the phenotype is not observed at young seedling stages, therefore our method represents a simple strategy for easily isolating prostrate mutants. Furthermore, Lowboy I may provide an outstanding germplasm for breeding novel prostrate perennial ryegrass cultivars.