|Mattice, J - UNIV ARKANSAS|
|Moldenhauer, K - UA RREC|
Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 27, 2000
Publication Date: N/A
Technical Abstract: A total of 412 rice accessions were identified in field tests in 1988, 1989 and 1990 that had an area of activity >10 cm to ducksalad and in 1994 a total of 94 accessions demonstrated apparent allelopathic activity to barnyardgrass in field tests. The rice accessions that showed activity in the field had 2-3 time more root biomass than cultivars that did not show the activity. In barnyardgrass infested plots the grain yield reduction o rice accessions that demonstrated apparent allelopathic activity was about 37% as compared to a 68% reduction in grain yield of non-allelopathic accessions. Chromatograms of allelopathic and non-allelopathic accessions fall into two types, one which is represented by the allelopathic accession PI 312777 and the other by the non-allelopathic cultivar "Rexmont". Individual F2 populations from hybrids involving PI 338046 with "Adair", "Katy", "Lemont"/RA 73, "M-201"/Katy and ?Newbonnet" were evaluated in the field at Stuttgart in 1992. Eight F6 lines from the crosses PI 338046/Lemont/RA73, PI 338046/Alan, PI 338046//M201/Katy and PI 338046/Katy were field evaluated in replicated tests in 1996. One line from the cross PI 338046/Katy was high yielding (9882 kg/ha) and had significantly fewer ducksalad plants. In an F2 population involving PI 312777/Lemont there was a normal distribution for allelopathic activity which indicates that allelopathic activity is quantitatively inheritated.