Abstract:

To further study Narcissus genome and screen functional genes, a BAC library was constructed for the first time in the world. The high molecular weight DNA (HMW-DNA) was isolated from Narcissus etiolation leaves used improved Zhang’s method. The HMW-DNA was cut by Hind III and ligated to BAC vectors; the ligations were transformed into Escherichia coli DH10B. The results showed that the DNA isolated by improved Zhang’s method was higher than 1 Mb, which was suitable for BAC library construction. The ligation and transform methods were improved; the optimum mole ratio between vectors and DNA fragments was 5:1. The library consists of 69120 clones with an average insert size of 87 kb, about 50% clones contain 80 to 90 kb insert DNA, and less than 1% of the clones do not contain inserts. Screening of BAC library with chloroplast DNA probes by Southern blot indicated that less than 1% of the clones contained organelle-derived DNA.