Morphological Relationships between Weedy Rice Morphotypes and Commercial Rice Varieties in Perak, Malaysia

Weedy rice has become a major problem in Malaysia for the last few decades. A comparative morphological study was conducted to characterize weedy rice population by collecting weedy rice morphotypes from six sites among the Perak rice granaries in Malaysia. 420 plant accessions were collected and scored based on the plant height, panicle type, lemma and palea color, and presence of awn and apiculus color. Total 14 weedy rice morphotypes were identified from these six sites based on 27 morphological characteristics. Four commercial rice varieties MR84, MR185, MR211 and MR219 were also planted for comparison.APrinciple ComponentAnalysis explained 52.46% of the total variation observed among the studied population. Three principal components factorial values clearly separated commercial varieties from weedy rice morphotypes. Most of weedy rice population matured early with less percentages of filled grain and had greater percentage of shattering. Besides, most of weedy rice plants had longer ligule length, panicle exertion, culm length, flag leaf and leaf 1 length. Some weedy rice plants were characterized by having different lemma and palea color, smaller grain size, lower thousand grain weight and presence of awn. All of these morphological characteristics of weedy rice might help us to identify and control them effectively in the farmers’ field.