Temperature and leaf wetness duration affect phenotypic expression of Rlm6-mediated resistance to Leptosphaeria maculans in Brassica napus
Temperature and leaf wetness duration affect phenotypic expression of Rlm6-mediated resistance to Leptosphaeria maculans in Brassica napus
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DOI：
10.1111/j.1469-8137.2006.01651.x
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发表时间：
2006-01-01
期刊：
影响因子：
9.4
通讯作者：
Fitt, BDL
中科院分区：
文献类型：
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作者：
Huang, YJ;Evans, N;Fitt, BDL
利用携带或缺乏Rlm6抗性基因的近等基因甘蓝型油菜株系，研究了温度和叶片湿润时间对Rlm6介导的抗性表型表达的影响。用携带效应基因AvrLm6的斑点细粒绦虫子囊孢子或分生孢子接种叶片。评估了从潜伏期到病变开始发展，病变数量和病变直径。利用携带avrl6 . l的绿色荧光蛋白（GFP）表达分离物，研究了黄斑乳酸菌从叶片病变到茎部的无症状生长。黄斑病在5-25℃时在Darmor（缺乏Rlm6）和25℃时在DarmorMX（携带Rlm6）上产生大的灰色病变，在5-20℃时在DarmorMX上产生小的黑斑和“绿岛”。随着温度/湿度持续时间的增加，病变/斑点的数量普遍增加。在25℃而不是15℃的条件下，表达gfp的黄斑乳杆菌在DarmorMX上从叶片损伤沿叶柄向下生长到茎部。我们得出结论，温度和叶片湿润时间影响rlm6介导的抗性在叶片中的表型表达，随后黄斑乳杆菌沿叶柄向下扩散产生茎溃疡病。
Near-isogenic Brassica napus lines carrying/lacking resistance gene Rlm6 were used to investigate the effects of temperature and leaf wetness duration on phenotypic expression of Rlm6-mediated resistance.Leaves were inoculated with ascospores or conidia of Leptosphaeria maculans carrying the effector gene AvrLm6. Incubation period to the onset of lesion development, number of lesions and lesion diameter were assessed. Symptomless growth of L. maculans from leaf lesions to stems was investigated using a green fluorescent protein (GFP) expressing isolate carrying AvrLm6.L. maculans produced large grey lesions on Darmor (lacking Rlm6) at 5-25 degrees C and DarmorMX (carrying Rlm6) at 25 degrees C, but small dark spots and 'green islands' on DarmorMX at 5-20 degrees C. With increasing temperature/wetness duration, numbers of lesions/spots generally increased. GFP-expressing L. maculans grew from leaf lesions down leaf petioles to stems on DarmorMX at 25 degrees C but not at 15 degrees C.We conclude that temperature and leaf wetness duration affect the phenotypic expression of Rlm6-mediated resistance in leaves and subsequent L. maculans spread down petioles to produce stem cankers.