摘要:
水稻的花发育是稻米形成的基础,研究水稻花发育的机制具有十分重要的意义。在水稻组培后代中发现一个生殖发育突变体,暂命名为function of reproductive organ(fro1(t)),主要性状为内、外稃片扭曲变形抱合,小穗外形酷似辣椒,但小穗始终闭合不开花;副颖多数退化;浆片转变成薄叶状;雄蕊花丝膨大扭曲,花药表面扭曲变形,无花粉,雄蕊个数2～6枚,部分雄蕊转化为底部为叶状,顶部有类似柱头的雌蕊状器官;子房发育正常,但是多数花柱融合,柱头簇生,3～4个。扫描电镜结果显示,决定fro1(t)性状的基因调控着水稻花分生组织的分化及花器官决定的特化。利用图位克隆等技术对基因进行定位,最终将该突变位点定位在水稻8号染色体长臂上InDel0802和RM23432标记之间,目的基因与两个标记的遗传距离分别为0.58cM和1.3cM。据以上结果推测,该基因可能是一个调控水稻各轮花器官发育的新基因。
Abstract:
It's important to study the mechanisms of the rice floral development,because the rice floral organs provides the basis of the rice grain formation.We found a rice floral organ mutant from tissue culture mutation generations,called function of reproductive organ(fro1(t)).The floret shape of fro1(t) mutant is similar to that of tiny green capsicum with a couple of distorted lemma and palea,but the spekelets cannot bloom even though after heading;the glumes almost degenerated and lodicules are homeotically transformed into leaf-like organ;stamen had a distorted and enlarged filament,and the anter also showed a distorted surface yet without any pollen;the number of stamen is 2-6,and noticely some of that are homeotically transformed into pistil-like organ with stigmas-like structure on the top;the ovary showed a nomal development,but most of styles cause a fusion with 3-4 stigmas.By SEM we found that the gene regulates the determination of the floral meristem and specification of floral organ identity.We carried out fine mapping of the gene responsible for the mutated trait.The result showed that the mutated trait was located on the long arm of rice chromosome 8 between the marker InDel0802 and RM23432,with genetic distance of 0.58 cM and 1.3 cM respectively.All the above suggests that the FRO1(t) gene may be a novel gene which regulates all whorls of floral organs in rice.Study of FRO1(t) will support a key evidence to uncover the molecular mechanisms of the rice floral development.
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