In order to determine the feasibility of using SRAPs for
cDNA fingerprinting, we have amplified cDNA isolated
from different tissues of B. rapa generated in another
study aimed to clone genes expressed specifically in pol-
len mother cells (Li and Quiros, unpublished). We found
tissue-specific bands, which most likely correspond to
genes expressed specifically in those tissues (Fig. 4c).
Therefore, SRAP can be also used to fingerprint cDNAs.
In conclusion, the SRAP marker system is a simple and
efficient marker system that can be adapted for a variety of
purposes in different crops, including map construction,
gene tagging, genomic and cDNA fingerprinting, and map-
based cloning. It has several advantages over other systems:
simplicity, reasonable throughput rate, discloses numerous
co-dominant markers, allows easy isolation of bands for se-
quencing and, most importantly, it targets ORFs.
Acknowledgements We are indebted to Vince D’Antonio for
technical assistance, to Darush Struss and Riaz Ahmed for testing
the technique on their materials, and to Douglas Brouwer and
Blake Meyers for critical reading of the manuscript. The experi-
ments carried out in this study comply with the current laws for
biological research in the USA.