Increasing the efficiency of disease resistant breeding by utilizing genomic in situ hybridization method

大穗燕麦（Avena macrostachya）是原产于阿尔及利亚的野生四倍体燕麦，对大麦黄矮病毒（BYDV）表现高抗。通过种间杂交，将抗黄矮病基因转入糙伏毛蒿×大穗蒿.目前，在杂种BC2代，通过连续回交和染色体选择，获得了异源染色体附加系。平卧燕麦（Avena prostrata）是原产于西班牙南部的野生二倍体燕麦，对白粉病表现高抗.利用特有的基因型促进同源染色体间的染色体配对和体细胞无性系变异，已建立了从平卧燕麦到栽培燕麦的基因转移系。利用原位杂交技术研究了野生种染色体片段大小与抗病性的关系。但遗憾的是，它们之间没有检测到正相关。GISH法可以在不使用寄生虫的情况下检测抗性品系，节省了大量的人力和时间。当需要在下一代中进一步改良抗性品系时，利用GISH方法检测外源染色体片段是燕麦基因转移最实用的方法之一。

Avena macrostachya showing high resistance to barley yellow dwarf virus (BYDV) is wild tetraplod oats originated in Algeria. Interspecific cross, A.strigosa x A.macrostachya has been made to transfer the BYDV resistant genes. Right now, in BC2 generation of the hybrids, alien chromosome addition lines were obtained by successive backcrosses and chromosome selection. Avena prostrata showing high resistance to powdery mildew is wild diploid oats originated in southern Spain. Gene transferred line from the A.prostrata into cultivated oat has already established by utilizing special genotype promoting chromosome pairing between homeologous chromosomes and somaclonal variations. Stable chromosome lines are still selected to establish a disease resistance cultivar.Relationships between size of the chromosome segments from wild species which incorporated into the cultivar and degree of resistance were estimated by in situ hybridization methods. But unfortunately positive correlation was not detected between them. It is possible to detect resistant line without using parasite, and GISH method saved a lot of labor and time. When a further refinement of the resistant lines are requested in the next generation, the use of the GISH method to detect alien chromosome segment is one of the most practical method for gene transfer in Avena.