花铃期干旱对棉纤维素累积及纤维比强度的影响

Cellulose accumulation and fiber strength affected by drought during flowering and bolling stage in cotton

为揭示干旱影响棉纤维素累积和纤维比强度的生理代谢基础,以美棉33 B为材料,于棉花中部果枝开花时进行干旱处理,正常灌水为对照,研究花铃期干旱对棉纤维发育关键物质的累积和酶活性的影响。结果显示:花铃期干旱处理花后17~38 d蔗糖和β-1,3-葡聚糖含量均降低,花后0 d干旱处理的蔗糖转化率增加,而β-1,3-葡聚糖转化率降低,纤维素累积速率快但持续期短;花后10 d干旱处理对蔗糖和β-1,3-葡聚糖转化率影响较小,纤维素累积速率慢但持续期长。干旱处理使棉纤维比强度降低,且以花后0 d干旱处理影响较大。干旱处理棉纤维蔗糖合酶活性增加,蔗糖磷酸合酶和β-1,3-葡聚糖酶活性降低。

To evaluate the effects of drought on cellulose accumulation and fiber strength during flowering and bolling stage in cotton, 2?year experiments were conducted on NuCOTN 33B subjected to drought stress at anthesis of middle fruiting branches. Conventional watering was set as control. The results showed that the contents of sucrose andβ?1,3?glucan both decreased at 17 to 38 days post anthesis under drought stress. As compared with control, the conver?sion rate increased for sucrose but decreased for β?1,3?glucan when drought treatment initiated at the right day of anthe?sis, which as a result, increased cellulose accumulation speed but shortened the duration of cellulose accumulation. The conversion rates of sucrose and β?1,3?glucan were less affected when drought treatment initiated at 10 d after anthesis, which decreased the cellulose accumulation speed but prolonged the duration of cellulose accumulation. The cotton fiber strength decreased at the end of drought stress, and the drop was more at the right day of after anthesis. As drought las?ted, the sucrose synthase activity increased, and the activities of sucrose phosphate synthase and β?1, 3?glucanase decreased.