## 3 Results
### DNA Fingerprinting of 10 broccoli Accessions  
Using 21 pairs of SSR markers to amplify 10 broccoli germplasm materials to construct DNA fingerprints, a total of 90 polymorphic bands were obtained, and the SSR amplification results were encoded as a string of zeroes and ones. These strings were arranged in a digital fingerprint of the 10 tested broccoli resources. Table 4 shows the digital DNA fingerprint was constructed by five core SSR markers (LTSSR94, LTSSR688, LTSSR13, BoSF2587, BoSF2860) and that all 10 broccoli resources could be uniquely identified. The SSR marker LTSSR13 appeared as heterozygous bands in only one material (B1024), LTSSR94 appeared as heterozygous bands in seven materials (B606, B611, B831, B910, B936, B1019, and B1027), LTSSR688 appeared as heterozygous bands in seven materials (B606, B831, B910, B936, B1019, B1024, B1027), no bands were amplified in two materials (B368 and B611), BoSF2587 appeared as heterozygous bands in eight materials (B606, B611, B831, B910, B936, B1019, B1024 and B1027), and BoSF2860 appeared as hybrid bands in all materials. The QR codes for the 10 accessions are shown in Figure 2 with corresponding genetic information: species carrying five to seven CR genes and DNA fingerprinting based on five core SSR markers. For example, by scanning the QR code of B368, you could obtain the following information: the variety was B368, whichever was broccoli (_Brassica oleracea_ L. var. _italica_) hybrid with wild cabbage (_Brassica macocarpa_ [PERSON]) and then with Rape (_Brassica napus_ L.), and it contained clubroot resistance genes _CRa_, _CRb_, _CRc_, _Crr_2 and _Crr3_. The binary molecular identity card was 11000100000000000000100000100000100, and DNA fingerprinting was based on 5 core SSR markers: LTSSR94, LTSSR688, LTSSR13, BoSF2587 and BoSF2860.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Rank** & **Name** & **Binary Molecular Identity Card** \\ \hline
1 & B368 & 110001000000000000010000001000000100 \\
2 & B578 & 1100010000100000101001010100100010 \\
3 & B606 & 00100000011100001101010001101001 \\
4 & B611 & 001000001000000101010101001001 \\
5 & B831 & 001000000001100110010000001000101 \\
6 & B910 & 00100000001101100100100010000100001000 \\
7 & B936 & 100101010000000100000100000100000100 \\
8 & B1019 & 100110001111000011100001000010000010000 \\
9 & B1024 & 01100010101000000110100000100001000 \\
10 & B1027 & 0010000000010000000110101010000 \\ \hline \hline \end{tabular}
\end{table}
Table 4: DNA fingerprinting of 10 broccoli resources by SSR markers.  
Figure 2: QR codes of the tested materials.  
Accessions of B611 and B606 were identified uniquely by as many as 4 pairs of SSR markers, followed by accessions of B831 and B910 by 2 SSR markers, whereas each of the other 6 accessions was identified by one specific pair of SSR markers. The amplified fragments of marker LTSSR94 are shown in Figure 1. Among these 21 pairs of SSR markers, 5 identified either one or two accessions, and LTSSR94 identified 7 resources, followed by BoSF2860, BoSF2587 and LTSSR688, with 6 resources each. LTSSR13 and LTSSR349 identified 5 resources, 7 SSRs identified 4 accessions, and 3 SSRs identified 3 accessions.