Division of Crop Improvement, Central Rice Research Institute, Cuttack, 753006, Orissa, India.
Biotechnol Lett. 2013 Aug;35(8):1339-48. doi: 10.1007/s10529-013-1212-8. Epub 2013 May 21.
To incorporate durable resistance against bacterial blight, a major disease rice, three resistance genes, xa 5, xa13 and Xa21, from IRBB 60 were transferred through marker-assisted backcrossing using RG 556, RG 136 and pTA248 markers linked to the three genes to supplement the Xa4 gene present in Lalat, a popular rice cultivar. Effective selection enabled the transfer in three back-crosses and a generation of selfing and background selection employing morphological and grain quality traits and molecular markers, led to >90 % recovery of the recurrent parental genome. The gene pyramids exhibited high levels of resistance against the pathogen in multi-location evaluation trials conducted over several locations of bacterial blight in India. IL-2 (CRMAS2621-7-1), a gene pyramid, was identified as being promising for several endemic regions of bacterial blight and was released as Improved Lalat in one of the identified regions. The success of the study demonstrates the vast potential of marker-assisted selection for gene stacking and recovery of the parental genome with high precision.
为了使水稻具有持久的抗细菌性条斑病能力，一种主要的水稻病害，将三个抗性基因，xa5、xa13 和 Xa21，从 IRBB60 中通过标记辅助回交，利用与三个基因相连的 RG556、RG136 和 pTA248 标记，补充了在拉拉特（一种受欢迎的水稻品种）中存在的 Xa4 基因。有效的选择使得在三个回交和一代自交和背景选择中，利用形态和籽粒品质性状和分子标记，实现了>90%的轮回亲本基因组的恢复。在印度多个细菌性条斑病发生地点进行的多次多点评价试验中，基因塔表现出对病原菌的高水平抗性。IL-2（CRMAS2621-7-1），一个基因塔，被鉴定为在细菌性条斑病的几个流行地区具有潜力，并在其中一个确定的地区作为改良拉拉特发布。这项研究的成功证明了标记辅助选择在基因叠加和高精度恢复亲本基因组方面具有巨大的潜力。
