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ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #125483
Title: VARIATION IN THE ALLELOPATHIC EFFECT OF RICE WITH WATER SOLUBLE EXTRACTS

Author
item EBANA, KAWORU - NIAR, TSUKUBA, JAPAN
item YAN, WENGUI
item DILDAY, ROBERT - USDA ARS RETIRED
item NAMAI, HYOJI - UNIV TSUKUBA, JAPAN
item OKUNO, KAZUTOSHI - NIAR, TSUKUBA, JAPAN

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Genetics is one factor which influences the quality of rice. Environmental and cultural practices are also factors that influence rice quality and may play an even greater role than genetics. Koshihikari is a premium rice used by the Japanese. It is imperative that any Koshihikari exported to Japan be of good quality and that we understand how growing conditions affect quality. The objective of this research was to examine the effect growing location would have on the chemical (i.e., amylose, protein) and physical properties of Koshihikari. Koshihikari from the same seed stock was grown in ten different locations in Arkansas. The samples were different for protein, viscosity and instrumental textural analysis. This study will benefit scientists and farmers in understanding the effect environmental and cultural practices on the quality of Koshihikari rice.

Technical Abstract: The allelopathic effect of rice (Oryza sativa L.) on lettuce (Lactuca sativa l.) and ducksalad [Heteranthera limosa (Sw.)Willd.] was investigated with water soluble extracts. Ducksalad is a major weed in southern USA rice fields. 'PI312777' and 'Rexmont', which are suppressive and nonsuppressive to ducksalad in the field, were used to establish the bioassay of allelopathic activity in rice. Water soluble compounds, which were extracted from rice seedlings and adult plants, were applied to lettuce seeds. Leaf extract of pi312777 inhibited the root growth of lettuce more strongly than those of Rexmont. Extracts from the leaves of rice seedlings at the six-leaf stage inhibited the growth of ducksalad and lettuce, and a close relationship existed between the inhibitory effect and the two test plants. A wide range of variation in allelopathic activity among rice cultivars was assessed using water soluble extracts from their leaves and lettuce as a test plant.