摘要
水分胁迫时 ,小麦条锈病病叶的叶片扩散阻力(LDR)明显增大 ,蒸腾速率 (Tp)、相对含水量 (RWC)、水势 (Ψw)、渗透势 (Ψπ)和压力势 (Ψp)明显降低。亲和与不亲和性反应寄主病叶对水分胁迫的反应明显不同。亲和性反应寄主叶片在水分胁迫时表现出较低的反应型 ,产孢期推迟 ;Tp、LDR、RWC、Ψw、Ψp 和Ψπ 在产孢前轻微下降或升高 ;在开始产孢后病叶Tp 急剧升高 ,LDR、Tp、RWC、Ψw、Ψπ 和Ψp 大幅降低 ,在健叶尚可有效控制水分蒸腾散失时病叶已丧失了这种能力。不亲和性反应寄主病叶的蒸腾作用在显症期亦有轻微变化 ,但之后病叶Tp、LDR、RWC和Ψw 渐趋健叶水平 ,并保持了较健叶更低的Ψπ 和更高的Ψw,具备了更强的水分调控能力。
After 1 st leaves of wheat, under different levels of water stress, were inoculated with virulent race(CY 29) and its avirulent mutant (CY29 mut 3) ofPuccinia striformis West at various stages, water relations were compared in same time. The diseased leaves of wheat under water stress showed great increases in LDR (leaf diffusive resistance) (Fig.2) and apparent decreases in T p (transpiration rate) (Fig.1), RWC (relative water content) (Fig.4),Ψ w (water potential), Ψ π (osmatic potential) and Ψ p (turgor potential) (Fig.5), compared with diseased leaves of wheat with normal level of water contents. However, responses of diseased leaves of compatible and incompatible combination to water stress were significantly different. In the leaves of compatible combination,lower degree of reaction and later sporulation were observed. Slight variations in T p, LDR, RWC, Ψ w , Ψ π, and Ψ p occurred [HJ6”:2]before sporulation. Great increases in T p (Fig.1) and significant decreases in LDR (Fig.2) were observed during sporulation of the fungus, accompanied by obvious decreases of RWC (Fig.4), Ψ w, Ψ p and Ψ π (Fig.5). The leaves of wheat in compatible combination had lost the ability to control water loss and maintain normal water balance. For diseased leaves of incompatible combination, transpiration varied slightly in symptom appearing period and then recovered (Fig.1), with lower Ψ π and higher Ψ p (Fig.5) than the healthy leaves. The leaves of wheat in incompatible combination had maintained an effective mechanism to regulate their water balance. The healthy leaves of diseased wheat had similar stomatal behavior with diseased leaves of the same plant (Fig.3).
基金
高等学校博士学科点专项基金!(970 702)
国家"九.五"科技攻关项目!(960050102)
中国科学院土壤侵蚀与旱地农业国家重点开放实验室
关键词
小麦条锈病
水分胁迫
亲和性反应
不亲和性反应
wheat stripe rust, water stress, compatible combination, incompatible combination, water relations