siu1.jpg (4081 bytes) dna1.jpg (3330 bytes)Plant Biotechnology and Genome Centerdna1.jpg (3330 bytes)

 

 

Inheritance of field resistance in soybean [Glycine max (L.) Merr. In "Forrest" cultivar (Peking source) to soybean cyst nematode (SCN) race 3(Heterodera glycines i.) is conditioned by two loci: Rhg1 on linkage group G and Rhg4 on linkage group A2.

We have constructed a physical genetic map for the 5 cM interval carrying Rhg1 and rfs1 as well as the 3 cM interval carrying Rhg4.

Two AFLP markers that place Rhg1 within a 1cM interval (134 Kb BAC) were cloned sequenced and converted to SCAR markers. Along with two microsatellite markers: rhg1 and rfs1 could be separated. SCARs were also developed from the three AFLP markers that place Rhg4 within 0.5 cM. The new SCAR markers have been used successfully in our Marker assisted selection (MAS) program. They are more effective than the existing microsatellite markers across a range of breeder’s material because the resistance allele is constant. They have been adapted for use with TaqMan technology.

Matrix mill DNA preparation from the leaves was used in our lab. To overcome the problem: time, money and the greenhouse space needed to get leaves for DNA preparations in MAS. We developed new method for DNA isolation directly from the seed, called: Radicles Extraction.

A single person can process 1,000 DNA extraction per day. The same single seed used for DNA extraction can be germinated and grown normally for seed production.