A wild rice (BKK) strain showing sterile spikelet and big leaves inhabited at the basin of the Chao Phraya river of Bangkok city, Thailand. The BKK strain was found as a natural triploid and thus its origin has been i...A wild rice (BKK) strain showing sterile spikelet and big leaves inhabited at the basin of the Chao Phraya river of Bangkok city, Thailand. The BKK strain was found as a natural triploid and thus its origin has been interested long time. Three different-sized fragments were amplified in RNA polymerase I largest subunit (<i>PolA1</i>) gene, which is a single-copy nuclear gene per haploid genome. Short type (0.14 kb) intron 20 sequence of BKK strain was identical to that of <i>O. rufipogon</i> and <i>O. sativa</i>. Phylogenetic analysis showed that long type (1.5 kb and 1.8 kb) intron 20 sequences of BKK strain were closely related to that of <i>O. longistaminata</i> and <i>O. officinalis</i>, respectively. We analyzed protein tag (Ptag) sequence encoded by exons 19 to 21 of <i>PolA1</i> gene. Determined three Ptag sequences of BKK strain were identical to that of <i>O. rufipogon</i>, <i>O. longistaminata</i>, and <i>O. officinalis</i>, respectively. Relative DNA content of nuclei in <i>O. officinalis</i> and BKK strain was 1.5 and 1.75 times than that in <i>O. sativa</i>, respectively. And BKK strain contained CentO-C1 repeats, which were unique to <i>O. officinalis</i>. These results indicated that BKK strain comprised three genomes of <i>O. rufipogon</i>, <i>O. longistaminata</i>, and <i>O. officinalis</i>.展开更多
文摘A wild rice (BKK) strain showing sterile spikelet and big leaves inhabited at the basin of the Chao Phraya river of Bangkok city, Thailand. The BKK strain was found as a natural triploid and thus its origin has been interested long time. Three different-sized fragments were amplified in RNA polymerase I largest subunit (<i>PolA1</i>) gene, which is a single-copy nuclear gene per haploid genome. Short type (0.14 kb) intron 20 sequence of BKK strain was identical to that of <i>O. rufipogon</i> and <i>O. sativa</i>. Phylogenetic analysis showed that long type (1.5 kb and 1.8 kb) intron 20 sequences of BKK strain were closely related to that of <i>O. longistaminata</i> and <i>O. officinalis</i>, respectively. We analyzed protein tag (Ptag) sequence encoded by exons 19 to 21 of <i>PolA1</i> gene. Determined three Ptag sequences of BKK strain were identical to that of <i>O. rufipogon</i>, <i>O. longistaminata</i>, and <i>O. officinalis</i>, respectively. Relative DNA content of nuclei in <i>O. officinalis</i> and BKK strain was 1.5 and 1.75 times than that in <i>O. sativa</i>, respectively. And BKK strain contained CentO-C1 repeats, which were unique to <i>O. officinalis</i>. These results indicated that BKK strain comprised three genomes of <i>O. rufipogon</i>, <i>O. longistaminata</i>, and <i>O. officinalis</i>.
