中文摘要：

以辽棉19号和美棉33B为材料,研究了不同施氮量（0、240、480kg·hm-2）和不同种植密度（75000、97500、120000plants·hm-2）对东北特早熟棉区棉花棉铃生物量和氮素累积特征的影响.结果表明：棉花单铃、棉籽和纤维的生物量及其氮素累积随棉花生育进程的动态变化均符合＂S＂型曲线,种植密度和施氮量可以显著影响棉铃各部分生物量和氮素累积的动态特征,以及棉花产量与品质;在施氮量240kg·hm-2和种植密度97500plants·hm-2处理下,单铃、棉籽和纤维的生物量均达到最大,生物量和氮素累积的快速累积起始时间和终止时间较早但持续时间较短,生物量快速累积速率最大,生物量和氮素在铃壳中的分配系数最低,在棉籽和纤维中分配系数最高.

英文摘要：

Taking cotton cultivars Liaomian 19 and NuCoTN 33B as test materials,a field experiment was conducted to study the effects of nitrogen fertilization rate （0,240 and 480 kg·hm-2） and planting density （75000,97500 and 120000 plants·hm-2） on the boll biomass and nitrogen accumulation in the extremely early maturing cotton region of Northeast China.With the growth and development of cotton,the biomass and nitrogen accumulation of cotton boll,cotton seed,and cotton fiber varied in ＇S＇ shape.Both nitrogen fertilization rate and planting density had significant effects on the dynamic characteristics of boll biomass and nitrogen accumulation,and on the fiber yield and quality.In treatment 240 kg·hm-2 and 97500 plants·hm-2,the biomass of single boll,cotton seed and cotton fiber was the maximum,the starting time and ending time of the rapid accumulation period of the biomass and nitrogen were earlier but the duration of the accumulation was shorter,the rapid accumulation speed of the biomass was the maximum,and the distribution indices of the biomass and nitrogen were the lowest in boll shell but the highest in cotton seed and cotton fiber.