Matsui K, Nishio T, Tetsuka T
National Agricultural Research Center for Kyushu Okinawa region, Nishigoshi 861-1192, Japan.
Ann Bot. 2004 Dec;94(6):805-9. doi: 10.1093/aob/mch206. Epub 2004 Oct 1.
Common buckwheat (Fagopyrum esculentum) is a dimorphic self-incompatible plant with either pin or thrum flowers. The S supergene is thought to govern self-incompatibility, flower morphology and pollen size in buckwheat. Two major types of self-fertile lines have been reported. One is a type with long-homostyle flowers, Kyukei SC2 (KSC2), and the other is a type with short-homostyle flowers, Pennline 10. To clarify whether the locus controlling flower morphology and self-fertility of Pennline 10 is the same as that of KSC2, pollen tube tests and genetic analysis have been performed.
Pollen tube growth was assessed in the styles and flower morphology of KSC2, Pennline 10, F1 and F2 plants that were produced by the crosses between plants with pin or thrum and Pennline 10.
Pollen tubes of Pennline 10 reached ovules of all flower types. The flower morphology of F1 plants produced by the cross between thrum and Pennline 10 were thrum or pin, and when pin plants were used as maternal plants, all the F1 plants were pin. Both plants with pin or short-pin flowers, whose ratio of style length to anther height was smaller than that of pin, appeared in F2 populations of thrum x Pennline 10 as well as in those of pin x Pennline 10.
The results suggest that Pennline 10 possesses the s allele as pin does, not an allele produced by the recombination in the S supergene, and that the short style length of Pennline 10 is controlled by multiple genes outside the S supergene.
普通荞麦（苦荞麦）是一种具有针状花或柱状花的二型自交不亲和植物。S 超基因被认为控制着荞麦的自交不亲和性、花形态和花粉大小。已报道了两种主要类型的自交可育系。一种是具有长同型花柱花的类型，即 Kyukei SC2（KSC2），另一种是具有短同型花柱花的类型，即 Pennline 10。为了阐明控制 Pennline 10 花形态和自交可育性的基因座是否与 KSC2 的相同，已进行了花粉管试验和遗传分析。
在由针状花或柱状花植株与 Pennline 10 杂交产生的 KSC2、Pennline 10、F1 和 F2 植株的花柱和花形态中评估花粉管生长情况。
Pennline 10 的花粉管能到达所有花型的胚珠。柱状花与 Pennline 10 杂交产生的 F1 植株的花形态为柱状或针状，当以针状花植株作为母本时，所有 F1 植株均为针状花。在柱状花×Pennline 10 以及针状花×Pennline 10 的 F2 群体中均出现了花柱长度与花药高度之比小于针状花的针状花或短针状花植株。
结果表明，Pennline 10 与针状花一样具有 s 等位基因，而非 S 超基因重组产生的等位基因，并且 Pennline 10 的短花柱长度受 S 超基因之外的多个基因控制。
