Classification of population structure for allelopathic properties in itchgrass (Rottboellia cochinchinensis)

Abstract

Biodiversity of itchgrass from different areas were studied by morphological traits and AFLP analysis for classify of an allelopathic ability. The correlation of the similarity/distance between AFLP markers (Jaccard coefficient) and morpho-logical traits (Euclidean distance) was significant with r = − 0.84**. Itchgrass were divided into two groups from both UPGMA and STRUCTURE analyses: the group A consisted of itchgrass from Chaehom-Lampang, Si Thep-Phetchabun, Phrom Phiram-Phitsanulok, Amphur Muang-Nakhon Sawan, Kamalasai-Kalasin, Amphur Muang-Chachoengsao and Bang Yai-Nonthaburi, whereas itchgrass from Amphur Muang-Chiang Mai, Pak Chong-Nakhon Ratchasima and Kamphaeng Saen-Nakhon Pathom constituted the group B. Allelopathic properties of itchgrass as representative from different group were determined in bioassay test, the aqueous extract of itchgrass from Chaehom-Lampang area has a strong allelopathic ability on growth of Echino-chloa crus-galli, Bidens pilosa and Lactuca sativa than the other group. Molecular analysis was strongly supported in morphological clustering with bioassay test, specific morphological traits were soft trichomes, dark purple stems and roots which can be used for the preliminary classification of allelopathic ability. This suggests that itchgrass classification by morphological traits is related to the analysis of the genetic relationship of itchgrass with AFLP analysis, that allowing the assessment of bio-diversity of itchgrass and their allelopathic potentials.