关键词: 小麦;成熟胚;愈伤组织;植株再生;农杆菌转化

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