AFLP genetic variation, inbreds development, and QTL localization for plant height in lowland switchgrass
Abstract
Switchgrass (Panicum virgatum L.) has gained wider attention due to its recognition as a model herbaceous crop species for bioenergy production. The objectives of this research were to analyze genetic variation among and within five lowland switchgrass cultivars using amplified fragment length polymorphism (AFLP) markers; to develop (i) S3 inbreds from S2 populations and (ii) S4 inbreds from S3 populations using a bagging method; and to analyze phenotypic variation for biomass and plant height and to localize QTLs associated with the plant height. AFLP polymorphisms indicated the presence of high genetic variation within lowland switchgrass cultivars. 'Alamo' exhibited the highest genetic variation and 'Performer' had the lowest. The Nei's genetic diversity parameters revealed the lowest genetic distance between cultivars 'Alamo' and 'Cimarron' and highest value between cultivars 'Alamo' and 'Kanlow'. Using 195 S2 inbreds, 279 S3 inbreds and 224 S4 inbreds were produced by bagging and confirmed with simple sequence repeat (SSR) markers. Two lowland switchgrass mapping populations field established at Perkins and Stillwater, OK were deployed in the plant height associated QTL experiment. Large genetic variation existed for plant biomass and height within the two populations. Plant height was positively correlated with biomass yield. Twenty-one QTLs were identified on 11 linkage groups, including nine of the QTL markers were detected in the selfed population and remaining 12 QTL markers were identified in the hybrid population. The findings of this research and the advanced inbreds developed in these experiments would be useful for future plant breeding and genetic improvement programs in lowland switchgrass.
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- OSU Dissertations [11222]