The Barley Bydv Resistance And With Yd <sub> 2 </ Sub> Gene Molecular Detection Technology

Studies on the Molecular Assay Techniques of Resistance to BYDV and Yd2 Gene in Barley Abstract Barley yellow dwarf virus(BYDV) is the most economically devastating virus of cereals and cereal grasses such as barley, wheat, oat, rice, maize and rye, etc. The most efficient way of the control of such virus disease is to breed and plant good cultivars with high resistant to BYDV. One of the major difficulties in BYDV-resistant breeding is that resistant assays and resistant genotypes screening can not be accurately performed by routine technology of biologically resistant assay. By applying to the principles and technologies of Genomics and Molecular Biology and selecting barley and BYDV-PAV strain as an experimental system, the purpose of this research is to set up a simple, fast and efficient technological system of resistant assay to BYDV and resistant genotypes screening in barley and other cereals. The results are following: (1) A set of efficient viruliferous apid rearing and management strategies, which are applicable to resistant assay to barley BYDV, have been set up, and these strategies reared a quantitative of viruliferous aphids with high infectivity, but without cross contamination; (2) Quantitative dot-blot anylasis of resistant assay using BYDV genornic as probes was also established, and the level of resistance to BYDV in barley can be determined quantitatively. The roots, shoots and leaves of barley seedlings can all be used as tested samples for this method, and the roots were the best. (3) 2 PCR markers closely linked to barley Yd2 gene have been successfully used to screen I2 gene and its genotype. This work improved our existed marker- assisted selection strategy. The research demonstrated that above all these three strategies were reliable and efficient by using 12 known resistant and genotypic barley cultivars (lines) and related cross population as experimental niaterials for validity test. The results of this research can fuither be used to assay BYDV resistant levels in cereals, including barley and wheat, and to discover new resistant sources as well as to screen resistant genes and genotypes in breeding programes.