So crop breeders must race to develop varieties with the right Rgenes before new disease strains render existing varieties useless.
因而农作物培育者需要赶在新型疾病使现有品种失去价值之前，开发具有正确的R基因的品种。
2
Most of plant disease resistance (r) genes cloned so far belong to NBS LRR group which contains nucleotide binding sites (NBS) and a leucine rich repeat (LRR).
大部分已克隆的植物抗病基因都包含有核苷酸结合位点区(NBS)和富含亮氨酸的重复序列区(LRR)。
3
However, major challenge to rice breeders is to make the appropriate selection of resistance (r) genes.