@article{oai:repository.naro.go.jp:00002052,
 author = {松井, 勝弘 and MATSUI, Katsuhiro},
 journal = {九州沖縄農業研究センター報告, Bulletin of the NARO Kyushu Okinawa Agricultural Research Center},
 month = {Jun},
 note = {Common buckwheat (F. esculentum) is an annual crop and is widely cultivated in the northern hemisphere. The cultivated areas of buckwheat have been increasing because it can be grown in relatively less fertile fields and buckwheat provides high nutrition. Common buckwheat exhibits heteromorphic sporophytic self-incompatibility and needs insects or wind to mediate crosspollination between pin and thrum plants. The yield of buckwheat is influenced by insects because the movement of insects is restricted by the weather. The breeding of buckwheat is also difficult because of self-incompatibility. In this study, I have combined the basic science of genetics and breeding in order to produce a highly constant yield of cultivar in buckwheat. 1. Production of self-compatible buckwheat lines and a genetic analysis of a self-compatible gene Self-incompatibility, flower morphology, and pollen size are governed by the S supergene. We have produced self-compatible buckwheat lines by an interspecific cross between F. esculentum and F. homotropicum by embryo rescue. The flower morphology of these lines is a long homostyle, and the pollen size is similar to that of thrum. The pollen size of F_1 plants produced by a cross between a pin plant and the self-compatible plant was similar to that of the self-compatible line and segregated together with flower morphology without exception. The pollen tubes of the selfcompatible plants were compatible with styles of the pin plants but incompatible with the styles of thrum plants. On the other hand, the pollen tubes of pin flowers were incompatible with the styles of self-compatible plants, but the pollen tubes of thrum flowers were compatible with the styles of self-compatible plants. These results indicated that the self-compatibility allele, S^h, retains heteromorphic incompatibility and suggests that the S^h allele was derived from a recombination in the S supergene. 2. A genetic analysis of the self-compatible gene in Pennline 10 The S supergene is thought to govern self-incompatibility, flower morphology, and pollen size in buckwheat. Using two self-fertile lines, one with long homostyle flowers (KSC2) and the other with short homostyle flowers (Pennline 10), I investigated whether the locus controlling flower morphology and self-compatibility of Pennline 10 is the same as that of KSC2. I assessed the pollentube growth in styles and flower morphology of F_1 and F_2 plants produced by crosses between plants with pin, thrum, or long-homostyle flower types and Pennline 10. The pollen grains of Pennline 10 were compatible with the style of all flower types. Both plants with short-pin flowers, whose ratio of style length to anther height was lower than that of the pin, and pin plants appeared in F_2 populations of thrum x Pennline 10 as well as in those of pin x Pennline 10. These results suggested that Pennline 10 possesses the s allele as does the pin and that the short style length of Pennline 10 is controlled by multiple genes outside the S locus. 3. Genetic analysis of brittle pedicels in buckwheat Shattering in buckwheat occurs because of brittle or weak pedicels. Brittle pedicels have been observed in wild buckwheat but not in cultivated buckwheat. Using two self-compatible lines, 01AMU2 with brittle pedicels and Kyukei SC2 (KSC2) with non-brittle pedicels, produced by an interspecific cross between Fagopyrum esculentum cv Botansoba (non-brittle) and F. homotropicum (brittle), we investigated the inheritance of brittle pedicels. F_1 plants derived from crosses between Botansoba x 01AMU2 and Botansoba x KSC2 had brittle pedicels. The F_2 population derived from the cross between Botansoba x 01AMU2 exhibited a segregation of brittle and non-brittle pedicels that fit the expected 3 : 1 ratio, suggesting that non-brittle pedicels in Botansoba are controlled by a single recessive gene (sht1). Another F_2 population, derived from the cross between Botansoba and KSC2, exhibited a segregation of brittles and non-brittle pedicels that fit an expected ratio of 9 : 7, suggesting that non-brittle pedicels in KSC2 are controlled by a different single recessive gene (sht2). Thus, brittle pedicels are achieved by two complementary genes Sht1 and Sht2. The sht1 locus is linked to the S locus with a recombination frequency of 5.46 ± 1.18 (%). We investigated whether common buckwheat has the allele sht2 by crossing six common buckwheat lines with KSC2. An analysis of the preliminary data demonstrated that some of the F_1 had brittle pedicels and others had non-brittle pedicels, suggesting that some common buckwheat lines possess both the Sht2 and sht2 alleles. 4. Identification of DNA markers for rapid selection of non-brittle pedicel plants Brittle pedicels in buckwheat are produced by two complementary, dominant genes, Sht1 and Sht2. The sht1 locus is linked to the S locus ; almost all common buckwheat cultivars possess the allele sht1. To detect molecular makers linked to the sht1 locus, we used an amplified fragmentlength polymorphism (AFLP) analysis in combination with a bulked-segregant analysis of segregating progeny of a cross between a non-brittle common buckwheat line and a brittle selfcompatible buckwheat line. We screened 312 primer combinations and constructed a linkage map around the sht1 locus by using 102 F_2 plants. Five AFLP markers were linked to the sht1 locus. Two of these, e54m58/610 and e55m46/320, co-segregated with the sht1 locus without recombination. The two AFLP markers were converted STS markers according to the sequence of the AFLPs. The STS markers are useful for marker-assisted selection of non-brittle pedicel plants and provide a stepping-stone for map-based cloning and the characterization of the gene encoding non-brittle pedicels., 普通ソバ (Fagopyrum esculentum) は1個体では種子を生産することができない自家不和合性作物であり, 結実には蜜蜂などの昆虫を媒介した交配が必要である。本研究では効率的に安定多収良質品種を開発するため, 自家和合性ソバ品種の開発に向けての基礎的研究を行った。普通ソバと近縁野生種 F. homotropicum を交配して自家和合性系統を作出した。この系統の普通ソバとの交雑和合・不和合性を調査した結果, 自家和合性対立遺伝子 S^h は S supergene 内の組換えにより生じたと推定できた。また, 普通ソバから選抜された Pennline 10 は高自殖稔性を示すが, 長花柱花と同じ s 対立遺伝子を持っており, Pennline 10 の短等花柱花は S supergene 以外の量的遺伝子により支配されていると推定された。一方, 作出した自家和合性系統に多く見られたソバの子実脱落性は2つの独立に遺伝する優性の補足遺伝子 (sht1 および sht2) により支配されていることが分かった。sht1 遺伝子座はほとんどの栽培種に劣性のホモ型で保持され, S 遺伝子座と連鎖していることが分かった。sht2 遺伝子座に関しては, Sht2 および sht2 の両方の対立遺伝子が普通ソバ集団中には存在していることが分かった。効率的に子実非脱落性の系統を選抜するため sht1遺伝子座に連鎖する DNA マーカーを開発した。},
 pages = {1--42},
 title = {自殖性普通ソバ品種育成のための異形花型自家不和合性および子実脱落性の遺伝育種学的研究},
 volume = {47},
 year = {2006},
 yomi = {マツイ, カツヒロ}
}