A complete cdna of 1047 bp was obtained by means of 5 ' - race ( 5 ' - rapid amplification of cdna end ) techniques using gene specific primer p1a5 - 1 Rtpcr结果证明它在苞片中强烈表达而在处于同时期的叶片中几乎检测不到其表达。
In the early december , the first bract primordium was formed in the axil scale at the cone base , then bract initiation had occurred in acropetal direction 12月初，最初的苞片原基在雌球果原基的鳞片的叶腋处产生，之后其由基部向顶部连续发生。
Each individual floret of the spikelet is also subtended by two bracts , the lower being called the lemma and the upper the palea 每一朵能发育的花的外面又有两片鳞片状的薄片包住，称为稃片，外面的一片称外稃，是花基部的苞片，里面的一片称内稃。
At the end of february , the bract attained approximately their full size , and a pair of anatropous ovules were initiated on the adaxial surface at the base of the fertile ovuliferous scale 2月底，苞片体积不再发生变化，珠鳞膨大端的基部的近轴面分化出2个倒生胚珠。
A unique developmental aspect involved in the life cycle of davidia involucrata baill . is the formation of two or three large - sized attractive white bracts surrounding a relatively small - sized capitulum 珙桐生活史中较独特的发育事件是其较小的头状花序下形成的2 3个大型苞片。
Sequence analyses for those limited amount of inserts indicated that , ( 1 ) a few particular gene populations are expressed in d . involucrata sprouting bract , e . g . , 分析本试验获得的烘桐苞片差异表达的有限几个部分或全长序列的cdna发现： ）处于生长发育初期的苞片中有一些较为独特的基因表达。
In virtue of the technique of suppression subtractive hybridization , we had successfully constructed a subtractive library of d . involucrata sprouting bract by taking homochronous leaf as driver in this study 本研究利用新近发展的抑制性差减杂交技术( ssh )成功构建了珙桐幼嫩苞片和叶片差减文库。
On the other hand , some characters used by the previous authors for distinguishing the varieties are extremely variable both within and among populations , but they are important in studying the evolution of the complex 同时认识到一些性状(如总苞片宽度等)作为检索表特征是不可靠的。结合细胞学、细胞地理学研究成果，探讨了形态学性状演化趋势。
Nonetheless nothing has been done on its role and function in the evolutionary and reproductive biology and in the life cycle of this species , saying nothing of its developmental mechanism , since the species was found from west china in 1869 然而自1869年珙桐被发现以来，未见关于珙桐苞片在该物种进化生物学、生殖生态学及其生活史中的作用和地位的报道。
Reverse northern hybridization indicated that p1a5 gene was over - expressed in bract compared with that in leaf . this expression pattern was further conformed by rt - pcr . sequence analyses revealed that it is a partial sequence of a lipid transfer protein gene 通过抑制性差减杂交的到克隆pias ，反向northern杂交表明它在玖桐苞片中优势表达，即在苞片中的表达水平远远超过在处于同时期的叶片中的表达水平。
