Dusabenyagasani M, Fernando W G D
Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
Plant Dis. 2008 Jun;92(6):903-908. doi: 10.1094/PDIS-92-6-0903.
Blackleg of rapeseed and canola (Brassica napus) is caused by various pathogenicity groups (PG) of Leptosphaeria maculans. The disease occurring in the Canadian prairies for the last two decades was caused by PG2 and was controlled by host resistance. PG3 and PG4 isolates have been found recently in Canada, but there is no resistance available against these pathogenicity groups in commercial Canadian varieties. This study sought to identify canola cultivars that could be used as sources of resistance to PG3 and to develop molecular markers for marker-assisted selection. Resistance to PG3 specifically was found in B. napus 'Dunkeld' and 'Quinta', while B. juncea 'Cutlass' and 'Domo' proved to be resistant to PG2, PG3, and PG4. A set of F progeny of 'Westar' (susceptible) × 'Dunkeld' was used to identify genetic markers linked to PG3 resistance. These markers were physically located on a BAC clone from B. rapa subsp. pekinensis containing a homolog to a serine threonine 20 (ste20)-like kinase in Arabidopsis thaliana. Thus, we have developed a sequence characterized amplified region (SCAR) marker available for marker-assisted selection in breeding canola for resistance against blackleg caused by L. maculans PG3. This work has received a provisional patent (serial # 60/977,933 - Oct. 5, 2007).
油菜（甘蓝型油菜）黑胫病由大茎点菌的不同致病型（PG）引起。过去二十年在加拿大大草原发生的该病是由PG2引起的，通过寄主抗性进行控制。最近在加拿大发现了PG3和PG4分离株，但加拿大商业化品种中没有对这些致病型的抗性。本研究旨在鉴定可作为对PG3抗性来源的油菜品种，并开发用于标记辅助选择的分子标记。在甘蓝型油菜‘邓卡德’和‘昆塔’中发现了对PG3的特异性抗性，而芥菜型油菜‘弯刀’和‘多莫’对PG2、PG3和PG4具有抗性。利用‘韦斯塔’（感病）ב邓卡德’的一组F子代来鉴定与PG3抗性相关的遗传标记。这些标记在物理上位于来自白菜亚种北京油菜的一个BAC克隆上，该克隆含有与拟南芥中丝氨酸苏氨酸20（ste20）样激酶同源的基因。因此，我们开发了一个序列特征性扩增区域（SCAR）标记，可用于在油菜育种中进行标记辅助选择，以培育对大茎点菌PG3引起的黑胫病具有抗性的品种。这项工作已获得临时专利（序列号60/977,933 - 2007年10月5日）。
