铁春1号"小麦耐白粉病机制研究

 铁春1号小麦耐小麦白粉病的机制是:①光合补偿作用:"铁春1号"小麦旗叶的表现光合速率下降较小,而真正光合速率比健康植株高,表明侵染点间的绿色组织具有光合补偿作用,一定程度上弥补病原菌的破坏与消耗。②超氧化物歧化酶活性增强,能及时清除因病害胁迫产生的超氧自由基(O₂·),避免了O₂对细胞膜的伤害。"铁春1号"膜磷脂种类在染病后没有变化,而感病品种膜磷脂在染病后增加了2个组份。③贮存物质运转的补偿作用:"铁春1号"在病害胁迫下,叶、茎、叶鞘中的干物质,以及氮、磷等养分的运出率增大,通过充分利用贮存物质部分的补偿光合产物低之不足。最终使籽粒中氮、磷及碳水化合物不减少。

ON MECHANISMS OF TOLERANCE TO POWDERY MILDEW IN SPRING WHEAT CULTIVAR “TIECHUN 1”

Mechanisms of powdery mildew tolerance possessed by spring wheat cultivar "Tiechun 1" are as follows:① Compensation in photosythesis:True photosythetic rates in the flag leaves of the cultiv enhanced after infection by the mildew despite a slight reduction of the apparent photosynthetic rates, means that the green tissue around infected sites had photosynthetic compensation ability compensatin the damage and depletion by the pathogen. ② The increase of superoxide dismutase (SOD) activity; S could clear O₂·:which was formed during the stress of the disease, preventing cell membrane from damage caused by O₂· Two new components of membrane phosphorus lipid were detected in susceptible cultivar in ‘Tiechun 1’ but they were not found to have any change. ③ The compensation in product transportation:When ‘Tiechun 1’ was under the stress of the mildew, the dry matter, nitrogen and phosphorus in the leaves, stems and sheaths were transfered much faster to the sink than those in susceptible cultivars. Thus, the deficiency of photosynthetic product was offsetted by making the best use of stored products.