TDZ处理对棉花叶片脱落率及酶活性的影响

【目的】研究棉花在 TDZ (Thidiazuron, TDZ)处理后叶片脱落的机制。【方法】以中棉所35号、新陆早19号、农大5号、XND1378和新陆早50号5个棉花品种为材料,于2017和2018年在塔城沙湾新疆农业大学棉花基地和塔城奎屯农七师农科所实验地,吐絮期分别设置两个处理 T1(大田喷施 TDZ 时间前4 d)和 T2(与大田处理时间相同), TDZ 处理后,研究脱叶率,根据脱叶率给5个棉花品种排序,于0、6、18、42、66和96 h测定叶托、叶片、叶柄的多聚半乳糖醛酸酶(PG)和纤维素酶活性,统计叶片脱落率、吐絮率和棉花产量。【结果】喷施 TDZ 后,T1的棉花产量显著低于 CK 和 T2 (P＜0.05);两个处理下棉花各材料的脱落率和吐絮率均极显著高于 CK (P＜0.01);叶托的 PG 活性在6、18 、42、66和96 h五个时期显著高于 CK (P＜0.05);纤维素酶活性在6、66 和96 h三个时期显著高于 CK (P＜0.05),在18、42 h两个时期极显著高于 CK (P＜0.01)。【结论】中棉所35号和新陆早50号对TDZ最敏感,TDZ处理可调节脱落叶片的 PG 活性和纤维素酶活性,提高叶片脱落率,有利于棉花机械采收。

Effects of Spraying TDZ on Leaf Loss Rate and Leaf Enzyme Activity of Cotton

【Objective】 This project aims to study the mechanism of cotton leaf abscission after TDZ (Thidiazuron, TDZ) treatment.【Method】Five cotton varieties (Gossypium spp) were used as materials. In the cotton base of Shawan, Xinjiang Agricultural University in Tacheng and the experimental field of Kuitun Agricultural Institute of Agricultural Division 7 in Tacheng in 2017 and 2018, two treatments T1 (4 days before TDZ application in the field) and T2 (the same time as the treatment time in the field) were set during the boll opening period. After TDZ treatment, the defoliation rate was investigated and five materials were sorted according to it. The activities of polygalacturonase (PG) and cellulase were measured at 0 h, 6 h, 18 h, 42 h, 66 h and 96 h, and the rates of leaf abscission, bulling and cotton yield were also counted.【Result】The results showed that after spraying TDZ, the cotton yield of T1 was significantly lower than that of the CK and T2 (P < 0.05); the shedding rate and flocculation rate of cotton materials by the two treatments were significantly higher than that of the CK (P < 0.01); the PG activity of leaf receptacle was significantly higher than that of the CK (P < 0.05) at 6 h, 18 h, 42 h, 66 h and 96 h; and the cellulase activity was significantly higher than that of the CK (P < 0.05) at 6 h, 66 h and 96 h (P < 0.05), and at 18 h and 42 h, it was extremely higher that of the CK (P < 0.01). 【Conclusion】The results showed that CIRI 35 and Xinluzao 50 were most sensitive to TDZ. TDZ treatment could regulate the activity of PG and cellulase in the exfoliated leaves, improve the rate of leaf abscission, and facilitate the mechanical harvesting of cotton.