Evaluating multiple resistance to major diseases in a core set of inbred
lines of Brassica rapa at seedling stage
Società Italiana di Patologia Vegetale (S.I.Pa.V.) 2018
Years of continuous cropping of Brassica rapa crops in main producing areas in China lead to the outbreak of some diseases,
such as downy mildew (DM), turnip mosaic virus (TuMV), black rot (BR), verticillium wilt (VW), and club root (CR), causing
severe loss in yield and quality. Resistance to the aforementioned diseases of 302 inbred lines of Brassica rapa to DM, TuMV,
BR, VW, and CR were evaluated under controlled conditions at seedling stage. Forty lines were identified to be highly resistant to
DM, 13 to TuMV, 0 to BR, 30 to VW, and 24 to CR. Among the 302 lines, 121 exhibited high resistance to two diseases, 70 to
three diseases, and eight to four diseases, but none of these lines showed comprehensive resistance to all the five diseases.
Chinese cabbage lines XDYFX, 536S, 536Q, DY×T, and CR-C, and Pak choi lines DFAK×SH, NB, and SYHTC showed high
resistance to four diseases and therefore represent elite materials in multiple-disease resistance breeding. In addition, different
disease resistance tendencies were discovered in diverse Chinese cabbage groups which were classified in different ways, such as
the ecotype, heading-type, and geographical origin.
Keywords Brassica rapa
Brassica crops are an important source of human nutrition and
provide opportunities for investigating genome evolution.
Brassica crops include vegetables such as B. rapa (Chinese
cabbage, Pak choi, and turnip) and B. oleracea,aswellas
oilseed crops which provide 12% of the world’s edible vege-
table oil crop (Nagaharu 1935). The three subspecies (Chinese
cabbage, Pak choi and turnip) of B. rapa play critical roles in
vegetable production and supply in China and other Asian
countries (Labana and Gupta 1993). The planting area of these
crops in China is approximately 2, 667 km
17.4% of the total vegetable planting area (Ministry of
Agriculture PRC 2012).
B. rapa vegetable crops often suffer infections from vari-
ous pathogens. Disease-resistant germplasm resources are the
basis for breeding, however, due to the limited germplasms
used in breeding and the changes in resistance characteristics
caused by plant–pathogens interactions and climate
change, traits such as disease-resistance can change.
Meanwhile, pathogen races constantly undergo mutation
to adapt to new antigens and environmental conditions
(Grenfell et al. 2004). Therefore, it is important to pay
close attention to discovery, identification and preservation
of disease-resistant germplasm.
Here, we focused our study on downy mildew (DM),
turnip mosaic virus (TuMV), black rot (BR), verticillium
wilt (VW), and club root (CR). DM is a fungal disease
specific to horticultural Brassica species, which is caused by
Hyaloperonospora parasitica (H. parasitica)(Niuetal.
1983). In China, H. parasitica causes one of the most severe
foliar diseases of Chinese cabbage. However, study of the
Tongbing Su, Shuancang Yu and Zhenping Gong contributed equally to
Electronic supplementary material The online version of this article
(https://doi.org/10.1007/s42161-018-0095-x) contains supplementary
material, which is available to authorized users.
* Fenglan Zhang
Beijing Vegetable Research Center, Beijing Academy of Agriculture
and Forestry Science, Beijing 100097, China
Graduate School of Chinese Academy of Agricultural Sciences,
Beijing 100081, China
Journal of Plant Pathology