Abstract:

The regeneration rate of wheat mature embryos is relatively low. Especially, the regeneration ability and transformation potential of the mature embryos of newly developed wheat varieties remains unknown. Twelve wheat cultivars developed in recent years in the main wheat regions of China were used in this study to investigate their regeneration characteristics and infectious sensitivity to Agrobacterium using the mature embryos as explants, including Yangmai18, Yangmai15, Yangmai16, Xindong18, Xiaoyan166, Zhoumai22 etc. The results indicated that the regeneration frequency from the mature embryos of these 12 wheat lines varied from 0 to 35.3%, in which Zhoumai27 was the highest followed by Yangmai19(27.9%), Xindong18 (21.1%) and Shimai B07-4056 (200%), but for the rest varieties the rate was less than 20.0%. When the mature embryos of the tested wheat cultivars were pre-cultured for 7 days and infected by Agrobacterium harboring GUS-Int gene, histochemical staining assay showed that the transient expression rate of GUS was between 0 and 33.3%, among which Zhoumai18 was the highest, followed by Yangmai15 (23.8%), while Yangmai18, Zhoumai22, Zhoumai27 and Shimai B07-4056 just gave blue spots with very low percentage (6.7%~9.1%), and no GUS expression was found in other wheat varieties. It is concluded that Zhoumai27 and Yangmai19 are appropriate varieties for mature embryo culture; Zhoumai18 and Yangmai15 are sensitive varieties to Agrobacterium infection, when their mature embryos are used as explants. The evaluation of new wheat varieties on regeneration ability and transformability based on mature embryo culture could prove basis for the improvement of wheat by cell engineering and genetic engineering approaches.

Key words: wheat, mature embryo, callus, plant regeneration, Agrobacterium-mediated transformation

摘要：

小麦成熟胚培养再生率比较低,尤其对优良小麦品种成熟胚再生性和农杆菌侵染敏感性还缺乏研究,一定程度阻碍了转基因小麦有效开展和产业化进程。以扬麦18、扬麦15、扬麦16、新冬18、小偃166和周麦22等12个优良小麦新品种为材料,研究了其成熟胚再生率及其对农杆菌侵染的敏感性。结果表明,12个小麦新品种成熟胚再生率0~35.3%,周麦27最高,扬麦19次之（27.9%）,新冬18、石麦B07-4056分别为211%和20.0%,其余品种再生率均低于20.0%；12个小麦品种成熟胚愈伤组织农杆菌侵染后GUS基因瞬间表达率0~33.3%,周麦18最高,扬麦15次之（23.8%）,扬麦18、周麦22、周麦27和石麦B07-4056虽有表达但频率较低（6.7%~9.1%）,其余品种没有观察到GUS基因瞬间表达。认为周麦27、扬麦19等品种适合进行成熟胚培养,周麦18、扬麦15等品种成熟胚适合进行农杆菌转化。优良小麦品种成熟胚再生性能和农杆菌敏感性评价为进一步利用细胞工程和基因工程途径改良小麦奠定了基础。

关键词: 小麦;成熟胚;愈伤组织;植株再生;农杆菌转化