温度对棉纤维糖代谢相关酶活性的影响

Effects of air temperature on enzyme activities of cotton plants related to saccharide metabolism of cotton fiber

以棉纤维比强度高的科棉1号和中等强度的美棉33B2个基因型棉花品种为材料,于2005年在江苏南京(长江流域下游棉区)和徐州(黄河流域黄淮棉区)设置不同播期(4月25日和5月25日)试验,研究了不同温度下棉纤维发育过程中蔗糖酶、蔗糖合成酶、磷酸蔗糖合成酶和β-1,3-葡聚糖酶等糖代谢相关酶活性的动态变化特征及其与纤维长度和比强度形成的关系.结果表明:棉纤维伸长发育期,蔗糖酶、β-1,3-葡聚糖酶活性较高;纤维加厚发育期,蔗糖合成酶和磷酸蔗糖合成酶活性上升速度快、活性高,蔗糖酶和β-1,3-葡聚糖酶活性下降速度快.纤维伸长期,蔗糖酶活性升高对纤维的伸长具有明显促进作用;纤维加厚发育期,提高蔗糖合成酶、磷酸蔗糖合成酶活性及加快蔗糖酶和β-1,3-葡聚糖酶活性下降速度有利于提高纤维比强度.科棉1号前期蔗糖酶、β-1,3-葡聚糖酶活性及中后期蔗糖合成酶、磷酸蔗糖合成酶活性均较美棉33B高.在本试验条件下,23.3℃是高强纤维形成的适宜温度,23.3℃～25.5℃是纤维长度形成的适宜温度.

Taking two cotton euhivars with different fiber strength （ KC-1, average fiber strength 35 cN · tex^-1; and AC-33B, average fiber strength 32 cN · tex-1） as test materials, a field experiment with two planting dates （25 April and 25 May） was conducted in Nanjing of Jiangsu （lower reaches of Yangtze River Valley） and Xuzhou of Jiangsu （Yellow River Valley） to study the dynamic changes of plant suerase, sucrose synthase, sucrose phosphate synthase, and β-1,3-glueanase activities during the development of cotton fiber at different air temperatures and their relationships with fiber length and strength. In the development period of fiber elongation, sucrase and β-1,3- glueanase activities were higher; while during the period of fiber thickening, sucrose synthase and sucrose phosphate synthase activities increased rapidly and were high, but suerase and β-1,3-glucanase activities had a rapid decrease. The higher suerase activity in fiber elongation development period favored the fiber length development, while the rapid increase of sucrose synthase and sucrose phosphate synthase and the rapid decrease of sucrase and β-1,3-glueanase activity favored the development of fiber strength. For cotton variety KC-1, the sucrase and β-1,3-glueanase activities in its early development period and the sucrose synthase and sucrose phosphate synthase activities in its middle and later development periods were all higher than those of AC-33B. In this study, 23.3 ℃ was the optimal temperature for high strength fiber formation, and 23.3 ℃-25.5℃ was the optimal temperature for long length fiber formation.