Journal of Weed Science and Technology
Online ISSN : 1882-4757
Print ISSN : 0372-798X
ISSN-L : 0372-798X
Search
Advanced search
OR
Browse
Search
Volume 53, Issue 3
Displaying 1-7 of 7 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Original Reports
  • Distribution of sulfonylurea-resistant biotypes of Monochoria vaginalis in Shizuoka Prefecture, Japan
    Hidehiro Inagaki, Toshiyuki Imaizumi, Guang-Xi Wang, Tohru Tominaga
    2007 Volume 53 Issue 3 Pages 123-127
    Published: 2007
    Released on J-STAGE: November 04, 2008
    DOIhttps://doi.org/10.3719/weed.53.123
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The distribution of Monochoria vaginalis biotypes that are resistant (R) to sulfonylurea (SU) herbicides in Shizuoka Prefecture, Japan, was investigated by studying their rooting responses in an SU solution and analyzing the point mutation sites in the acetolactate synthase (ALS) genes. The SU-R biotypes of M. vaginalis were found to be distributed over a wide area in Shizuoka Prefecture. In this study, we have for the first time, discovered the substitution of proline (Pro197) with threonine in 2 of these SU-R biotypes. The amino acid substitutions in the ALS genes of each SU-R biotype in the Izu area differed among the biotypes, although the SU-R biotypes were located merely within a distance of 1 km. The SU-R biotypes developed independently in each location. From these results, we conclude that the SU-R biotypes of M. vaginalis probably exist widely in rice paddy fields, where their dominance has not been previously reported.
    View full abstract
    Download PDF (861K)
  • Characterization of seed dormancy and germination patterns of weedy rice in Japan
    Jun Ushiki, Maiko Akasaka, Mitsuaki Tezuka, Toshio Ishii
    2007 Volume 53 Issue 3 Pages 128-133
    Published: 2007
    Released on J-STAGE: November 04, 2008
    DOIhttps://doi.org/10.3719/weed.53.128
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Characteristics of seed dormancy and germination patterns of weedy rice in Japan were studied by germination tests conducted at 100days after heading. Seventy-four and forty accessions of weedy rice collected from Nagano and Okayama Prefectures were studied, respectively. The results indicated that about 25% of the weedy rice accessions exhibited dormancy, and the most dormant seeds of the accessions germinated at about 200days after sowing. Although there were variations in germination patterns between the accessions, three distinct germination patterns predominated. The accessions were categorized into three germination patterns. About 75% of all weedy rice accessions germinated immediately similar to cultivated rice, and 95% of the seeds of these accessions germinated within 30days after sowing (germination pattern 1, GP1). On the other hand, about 18% of all weedy rice accessions germinated gradually, taking more than 30days to germinate 95% of the seeds (germination pattern 2, GP2). About 7% of all weedy rice accessions did not germinate for several weeks and then began germinating (germination pattern 3, GP3). The accessions with a high degree of dormancy such as GP2 and GP3 were collected from areas in Nagano or Okayama Prefectures where weedy rice occurred extensively. These results suggests that most weedy rice accessions currently found in Japan have little dormancy, similar to that found in cultivated rice, however, particular accessions occurring in limited areas have strong dormancy that might be related to the severity of occurrence in the field.
    View full abstract
    Download PDF (974K)
Short Report
The Society Award Lectures
Contribution
Note
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top