@article{oai:ir.kagoshima-u.ac.jp:00000995, author = {Yamamoto, Masashi and 山本, 雅史 and Tominaga, Shigeto and 冨永, 茂人}, issue = {2}, journal = {園芸学会雑誌}, month = {}, note = {We characterized the mechanism of seedlessness of Keraji (Citrus keraji hort. ex Tanaka), cultivar grown in Kikaijima island, Kagoshima. This cultivar is a diploid (2n=18) that produces a medium amount of fertile pollen which readily fertilizes other citrus cultivars. It is highly parthenocarpic, setting 30-50% of unpollinated flowers. When Keraji flowers are hand-pollinated with 'Hassaku' pollen, these fruits produce only 2 to 3 seeds. However, 19-20% of these hand-pollinated flowers set seedless fruits, whereas 30-38% of open-pollinated flowers set parthenocarpically. Self-pollinated flowers resulted in 91-93% parthenocarpic fruits ; the remaining 7-9% of the fruits had only one seed. Six days after pollination, the self-pollinated flowers had 1.4 pollen tubes at the base of the style, a figure that is much lower than that in cross-pollinated flowers with 'Hassaku' pollen (61±7.4). These observation demonstrated that seedlessness of Keraji results from strong female sterility, self-incompatibility and parthenocarpy., ケラジ(Citrus keraji hort. ex Tanaka)は, 無核性で果実に特有の芳香を備えた鹿児島県喜界島の特産カンキツである.本研究ではその果実の無核性機構の解明を行なった.1999年には, 自然受粉果の含核数は1.9個で, 無核果率は30.0%であった.他家受粉区でも含核数は2.6個と少なく, 自家受粉区では含核数は0.1個で無核果率は93.1%にもなった.花粉遮断区の果実は小さかったが, 30%が結実した.本種は二倍体(2n=18)であり, 花粉稔性は73.8%で, その量も多かった.2000年も1999年とほぼ同様の結果が得られた.また, 受粉6日後において他家受粉では61.0本の花粉管が花柱の基部まで達していたのに対して, 自家受粉ではわずかに1.4本の花粉管が花柱基部に達していたにすぎなかった.以上から, ケラジの示す無核・少核性は, 本種が雌性不稔性, 自家不和合性および単為結果性を備えていることに起因することが明らかになった.}, pages = {183--186}, title = {Relationship between Seedlessness of Keraji (Citrus keraji hort. ex Tanaka) and Female Sterility and Self-incompatibility}, volume = {71}, year = {2002}, yomi = {ヤマモト, マサシ} }