Ballardini Marco, Mercuri Antonio, Littardi Claudio, Abbas Summar, Couderc Marie, Ludeña Bertha, Pintaud Jean-Christophe
Centro Studi e Ricerche per le Palme - Sanremo (CSRP), Corso F. Cavallotti 113, I-18038 Sanremo (IM), Italy.
Consiglio per la Ricerca e la sperimentazione in Agricoltura - Unità di Ricerca per la Floricoltura e le Specie Ornamentali (CRA-FSO), Corso degli Inglesi 508, I-18038 Sanremo (IM), Italy.
Zookeys. 2013 Dec 30(365):71-82. doi: 10.3897/zookeys.365.5725.
The genus Phoenix (Arecaceae) comprises 14 species distributed from Cape Verde Islands to SE Asia. It includes the economically important species Phoenix dactylifera. The paucity of differential morphological and anatomical useful characters, and interspecific hybridization, make identification of Phoenix species difficult. In this context, the development of reliable DNA markers for species and hybrid identification would be of great utility. Previous studies identified a 12 bp polymorphic chloroplast minisatellite in the trnG (GCC)-trnfM (CAU) spacer, and showed its potential for species identification in Phoenix. In this work, in order to develop an efficient DNA barcode marker for Phoenix, a longer cpDNA region (700 bp) comprising the mentioned minisatellite, and located between the psbZ and trnfM (CAU) genes, was sequenced. One hundred and thirty-six individuals, representing all Phoenix species except P. andamanensis,were analysed. The minisatellite showed 2-7 repetitions of the 12 bp motif, with 1-3 out of seven haplotypes per species. Phoenix reclinata and P. canariensis had species-specific haplotypes. Additional polymorphisms were found in the flanking regions of the minisatellite, including substitutions, indels and homopolymers. All this information allowed us to identify unambiguously eight out of the 13 species, and overall 80% of the individuals sampled. Phoenix rupicola and P. theophrasti had the same haplotype, and so had P. atlantica, P. dactylifera, and P. sylvestris (the "date palm complex" sensu Pintaud et al. 2013). For these species, additional molecular markers will be required for their unambiguous identification. The psbZ-trnfM (CAU) region therefore could be considered as a good basis for the establishment of a DNA barcoding system in Phoenix, and is potentially useful for the identification of the female parent in Phoenix hybrids.
海枣属（棕榈科）包含14个物种，分布于佛得角群岛至东南亚地区。其中包括具有重要经济价值的海枣。该属物种在形态和解剖学上缺乏可用于区分的有用特征，且存在种间杂交现象，这使得海枣属物种的鉴定变得困难。在此背景下，开发可靠的DNA标记用于物种和杂交种鉴定将具有重要实用价值。先前的研究在trnG（GCC）-trnfM（CAU）间隔区鉴定出一个12 bp的多态性叶绿体微卫星，并显示了其在海枣属物种鉴定中的潜力。在本研究中，为了开发一种高效的海枣属DNA条形码标记，对一个包含上述微卫星且位于psbZ和trnfM（CAU）基因之间的更长的叶绿体DNA区域（700 bp）进行了测序。分析了代表除安达曼海枣之外所有海枣属物种的136个个体。该微卫星显示12 bp基序有2至7次重复，每个物种的7个单倍型中有1至3个。匍匐海枣和加那利海枣具有物种特异性单倍型。在微卫星的侧翼区域还发现了其他多态性，包括替换、插入缺失和同聚物。所有这些信息使我们能够明确鉴定出13个物种中的8个，以及所采样个体的80%。岩海枣和叙利亚海枣具有相同的单倍型，大西洋海枣、海枣和野生海枣（按照潘托德等人2013年的定义为“枣椰复合体”）也具有相同的单倍型。对于这些物种，需要额外的分子标记来进行明确鉴定。因此，psbZ-trnfM（CAU）区域可被视为建立海枣属DNA条形码系统的良好基础，并且可能有助于鉴定海枣杂交种中的母本。
