Morpho-physiological Characters and Geographical Distribution of japonica and indica Weedy Rice (Oryza sativa) in Okayama Prefecture, Japan

• Ushiki Jun

  National Agricultural Research Center

• Ishii Toshio

  Okayama Prefectural General Agriculture Center

• Ishikawa Ryuji

  Hirosaki University

Bibliographic Information

Other Title

• 岡山県に発生した日本型およびインド型雑草イネの生理・形態的形質と分布の特徴
• オカヤマケン ニ ハッセイ シタ ニホンガタ オヨビ インドガタ ザッソウ イネ ノ セイリ ケイタイテキ ケイシツ ト ブンプ ノ トクチョウ

Abstract

In Okayama Prefecture, which is located in the midwestern part of Japan, weedy rice whose grain is characterized by a white pericarp and a very easy shattering habit has become a serious problem in direct-seeding rice production since the 1990s. We examined 23 weedy rice accessions collected from 11 districts in Okayama. First, we classified each accession into japonica or indica ecotype using three diagnostic characters: phenol reaction, KClO₃ resistance, and apiculus hair length. The results indicated that in eight districts, only japonica weedy rice (14 accessions) occurred, in one district only indica weedy rice (two accessions) occurred, and in two districts both types of weedy rice (four japonica and three indica accessions) were observed. Second, we classified the accessions into nine clusters (types) with distinct characteristics by cluster analysis using four morpho-physiological characters: culm length, heading date, position of panicle neck node, and ratio of grain length to grain width. Eleven japonica accessions (about half of the total number examined) were classified into Type 1, and they closely resembled the cultivars ‘Akebono’ and ‘Asahi’. Another japonica accession of Type 3 resembled another cultivar ‘Omachi’. Each type of accession was collected from a rice field where morphologically similar cultivars were grown. Other groups of japonica weedy accessions also resembled certain rice cultivars, although the culm length was 15 cm shorter in Type 2 than in Type 1, and Types 5 and 6 headed 2 and 3 weeks earlier, respectively, than Type 1. The indica weedy accessions were markedly different from the rice cultivars grown in the fields where they were collected and also from the abovementioned japonica weedy rice accessions. For example, in the indica accessions of Type 7, the culms were 30 cm longer than that of ‘Akebono’, and in the indica accessions of Type 9, the culms were 50 cm shorter than those of Type 1 accessions. Although the japonica accessions were widely distributed in many districts that were geographically separated by a distance of up to about 20 km, the indica accessions were distributed over a limited area within a radius of 3-km. The differences in the morpho-physiological characters and geographical distribution between the japonica and indica weedy rice accessions suggested that they developed different strategies for survival and that they differed in reproductive fitness in the rice fields of Okayama Prefecture.<br>

Journal

• Breeding Research

  Breeding Research 7 (4), 179-187, 2005

  Japanese Society of Breeding

Keywords

• <i>Oryza sativa</i>
• weedy rice
• <i>japonica</i>
• <i>indica</i>
• survival strategy
• habitat distribution

Details

• CRID: 1390282679445644544
• NII Article ID: 110004049593
• NII Book ID: AA11317194
• DOI: 10.1270/jsbbr.07.179
• ISSN: 13481290
• ISSN: 13447629
• NDL BIB ID: 7753774
• Web Site: https://agriknowledge.affrc.go.jp/RN/2010721624
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7753774
• Web Site: http://www.jstage.jst.go.jp/article/jsbbr/7/4/7_4_179/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • IRDB
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed