| Budget Amount *help |
¥54,860,000 (Direct Cost: ¥42,200,000、Indirect Cost: ¥12,660,000)
Fiscal Year 2005: ¥13,130,000 (Direct Cost: ¥10,100,000、Indirect Cost: ¥3,030,000)
Fiscal Year 2004: ¥13,520,000 (Direct Cost: ¥10,400,000、Indirect Cost: ¥3,120,000)
Fiscal Year 2003: ¥14,040,000 (Direct Cost: ¥10,800,000、Indirect Cost: ¥3,240,000)
Fiscal Year 2002: ¥14,170,000 (Direct Cost: ¥10,900,000、Indirect Cost: ¥3,270,000)
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| Research Abstract |
We carried out two projects on plant reproductive systems one on pollination systems of Hemerocalis and the other on sexual systems of Eupatorium.
While Hemerocalis fulva flowers at daytime and have reddish flowers without fragrance, a related species H.citrina flowers at night and have yellow flowers with fragrance. H.fulva is pollinated by butterflies and bees, and H.citrina is pollinated by nocturnal hawkmoths. Although the two species show conspicuous differentiation in floral traits, their hybrids are fertile, providing an extraordinary opportunity for studying genetic backgrounds of floral adaptation to different pollinators.
We crossed the two species and obtained F1 and F2 hybrids. In addition, we developed microsatellite markers and ESTs for QTL mapping.
Genetic analyses revealed that difference in flowering time is mostly controlled by single gene, the daytime flowering being dominant. Anthocyanin biosynthesis in petals of H.fulva is also determined mostly by single gene with a large phenotypic effect.
By searching candidate genes responsible for the contrasting floral traits among ESTs, we determined homologues of CHS (chalcon synthase gene) and MYB (transcription factor controlling anthocyanin biosynthesis) in Hemerocalis.
In a hybridizing population of H.fulva and H.citrina in the field, we observed natural selection on floral traits by various pollinators during four years. Reflecting yearly fluctuation of availability of diurnal and nocturnal pollinators, direction of natural selection on various floral traits fluctuated between years.
In the Eupatorium project, coevolution between geminiviruses and sexual and asexual plants of Eupatorium was studied. We discovered satellite DNA from leaves of asexual plants of Eupatorium and confirmed that geminivirus with satellite DNA can cause yellow vein disease in Eupatorium. The result is published on Nature.
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