PJB-2018-99
MORPHOLOGICAL AND MOLECULAR VARIATION IN WILD OAT (Avena fatua) FROM PAKISTAN
Madiha Islam
Abstract
Wild oat (Avena fatua) is a weed in cereal crops worldwide. Characterization of its germplasm is important to design effective weed management strategies. Using 11 morphological traits and 10 microsatellite markers, we characterized 209 samples of two wild oat morphotypes, black-seeded or black morphotype (74 samples) and white-seeded or white morphotype (135 samples). These samples were collected from 16 districts in Pakistan, including six districts where both morphotypes were collected. Principal component analysis and clustering of the samples based on the Euclidean distance matrix of the morphological traits highlighted differences between the two morphotypes. Total gene diversity (HT) was found to be 0.69. When accessions were partitioned into 22 groups (district-morphotype grouping), within-group diversity (HS) was 0.49, while among-group diversity (GST) was 0.29. The analysis of molecular variance (AMOVA) showed among-groups diversity (PhiPT) of 0.026 between the black and white morphotypes, and 0.286 for the 22 groups defined above. Reduced gene flow (NM = 0.62) among these 22 groups might be indicative of substantial differentiation in this germplasm due to genetic drift and local adaptation. A Mantel test showed a weak correlation (r = 0.16) between the Euclidean distance matrices of seed storage protein polymorphism data we reported previously, and microsatellite data for the same set of samples. Weak correlation (r = 0.47) was observed between the Euclidean distance matrices of microsatellite data of the black and white morphotypes collected from same six districts. These observations indicate that the two morphotypes might have experienced differential rate of evolution.
To Cite this article:
Download
