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大田栽培条件下,于2005~2006年在江苏南京(118o50′E,32o02′N,长江流域下游棉区)以美棉33B(平均比强度32cN/tex)和科棉1号(平均比强度35cN/tex)2个品种为材料,进行氮素水平(0(零氮),240(适氮)和480kgN/hm2(高氮))实验,研究棉花纤维发育关键酶(蔗糖合成酶和β-1,3-葡聚糖酶)活性变化特征对氮素的响应及其与纤维比强度形成的关系.结果表明,棉纤维发育关键酶活性及其基因表达强度均受氮素影响,并影响棉纤维素的累积特征及纤维比强度的形成.蔗糖合成酶活性随铃龄增加呈单峰曲线,峰值出现在铃龄31天,其基因表达强度在7~21天维持较高水平;氮素水平间比较,以240kgN/hm2处理的蔗糖合成酶活性及其基因表达强度最高,酶活性高表达持续时间长.β-1,3-葡聚糖酶活性随铃龄增加呈下降趋势,其基因表达在铃龄7~24天间呈单峰曲线,铃龄18天时达到峰值;氮素水平间比较,以240kgN/hm2处理的β-1,3-葡聚糖酶活性最高,其基因表达量在纤维发育前期(铃龄9~12天)较低,之后大幅增加且稳定表达.240kgN/hm2下棉纤维发育关键酶的上述变化促进纤维素累积持续期长且整个纤维发育过程中纤维素累积速率平缓,最终形成纤维比强度较高.
Field cultivation conditions, in 2005-2006 in Nanjing, Jiangsu (118o50’E, 32o02’N, the lower reaches of the Yangtze River valley) with the United States cotton 33B (average specific strength of 32cN / tex) and Kemian 1 (average specific strength of 35cN / tex) were used as materials to study the effects of nitrogen (0 (zero nitrogen), 240 (suitable nitrogen) and 480 kg N / hm2 (high nitrogen) , 3-glucanase) on nitrogen and its relationship with the specific strength of the fiber.The results showed that the activity of the key enzyme in cotton fiber development and its gene expression intensity were affected by nitrogen and affected the cotton fiber The accumulation of sucrose synthase activity showed a single-peak curve with the increase of boll age, the peak appeared at 31 days of age, and its gene expression intensity maintained a high level from 7 to 21 days. The nitrogen level Compared with 240kgN / hm2 sucrose synthase activity and the highest gene expression intensity, high expression of enzyme activity lasting a long time.β-1, 3-glucanase activity decreased with the increasing age, the gene expression in the The chongling age was single peak curve from 7 days to 24 days and peaked at 18 days of boll age. Compared with the nitrogen level, 1, 3-glucanase activity was the highest, and its gene expression was lower in early stage of fiber development (9 to 12 days of age), then increased and stably expressed.The above changes of key enzymes in cotton fiber development at 240 kgN / hm2 promoted Long accumulation of cellulose and cellulose throughout the fiber accumulation rate of the slow, the final formation of fiber strength is higher.