Resistance to Striga hermonthica in a maize inbred line derived from Zea diploperennis
Resistance to Striga hermonthica in a maize inbred line derived from Zea diploperennis
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DOI：
10.1111/j.1469-8137.2007.02355.x
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发表时间：
2008-01-01
期刊：
影响因子：
9.4
通讯作者：
Ejeta, Gebisa
中科院分区：
文献类型：
--
作者：
Amusan, Idris O.;Rich, Patrick J.;Ejeta, Gebisa
由于供体来源和已知抗性机制的缺乏，玉米抗独脚金的育种一直具有挑战性。在国际热带农业研究所（International Institute of Tropical Agriculture）对两个玉米自交系进行了监测，这两个玉米自交系被选择用于对独脚金的田间抗性和敏感性反应。组织学检查了寄生虫侵入这些自交系根部的吸器，观察了感病自交系和抗病自交系根部的形态差异。与感病自交系相比，抗病自交系的寄生虫附着量少，寄生发育延迟，寄生虫死亡率高。感病自交系上的独脚金通常穿透木质部，并表现出大量的内部吸器发育。抗性自交系上的吸器侵入常止于内皮层。相对于入侵易感根的寄生虫，能够到达抗性宿主木质部导管的寄生虫表现出吸器发育减弱。这些结果表明，抗性近交系对独脚金寄生表现出发育障碍和不相容反应。
Breeding for resistance to Striga in maize (Zea mays), with paucity of donor source and known mechanisms of resistance, has been challenging.Here, post-attachment development of S. hermonthica was monitored on two maize inbreds selected for field resistance and susceptibility reactions to Striga at the International Institute of Tropical Agriculture. Haustorial invasion of the parasite into roots of these inbreds was examined histologically.Morphological differences were observed between roots of the susceptible and the resistant inbreds. The resistant maize had fewer Striga attachments, delayed parasitic development and higher mortality of attached parasites compared with the susceptible inbred. Striga on the susceptible inbred usually penetrated the xylem and showed substantial internal haustorial development. Haustorial ingress on the resistant inbred was often stopped at the endodermis. Parasites able to reach resistant host xylem vessels showed diminished haustorial development relative to those invading susceptible roots.These results suggest that the resistant inbred expresses a developmental barrier and incompatible response against Striga parasitism.