不同基因型抗虫棉氮磷钾养分吸收与分配特征

Characteristics on uptake and distribution of nitrogen, phosphorus and potassium in different genotypes of Bt cotton

【目的】探讨不同抗虫棉品种植株干物质与氮、磷、钾养分积累分配特点,为制定棉花高产栽培管理措施提供依据。【方法】在大田条件下,选用三个抗虫棉品种(冀棉169、鲁棉研21号和岱字棉99B)为研究对象,比较研究了三个品种的干物质积累与氮磷钾吸收特性。【结果】冀棉169产量最高,两年分别比鲁棉研21号提高了27.9%和25.5%,分别比岱字棉99B提高了65.9%和41.1%。三个品种单铃子棉重的变化趋势与产量一致,而单株结铃数和衣分则不同。冀棉169棉株各器官干物质和氮磷钾积累量均较高,尤其在生育中后期,营养器官保持最高的氮磷钾养分积累量,促使其干物质积累量显著高于其他两个品种,为棉铃发育提供了充足的物质基础,铃叶比较大,因此结铃最多,单铃子棉重最大,皮棉产量最高,使得养分利用效率也最高。鲁棉研21号棉株各器官干物质和氮磷钾积累量均最低,主要是由于营养器官氮磷钾养分快速积累期结束最早,加之向棉铃分配比例最高,从而限制了营养器官的生长发育,影响生育中后期棉铃的发育,使之不仅结铃数最少,单铃子棉重较小,产量也较低。岱字棉99B棉株各器官干物质和氮磷钾积累量虽最高,但其快速积累期出现在盛花期以后,棉株贪青,结铃数虽较多,但单铃子棉重最小,使之产量最低,养分利用效率也最低。【结论】不同年代抗虫棉品种产量提高的主要原因是单铃子棉重的增加,其次是单株结铃数的提高。单铃子棉重和单株结铃数的增加主要归因于棉株总生物量和向生殖器官转运量的协同提高,特别是生育中后期保持高的同化物和生殖器官运转比例;而生物量的增加依赖于养分积累量和利用效率的提高。

【Objectives】The uptake and distribution characteristics of NPK nutrient of different genotypes of Bt cotton were investigated to provide a theoretical foundation for high yield cotton cultivation.【Methods】A field experiment was conducted to study the accumulations characteristics of dry matter, N, P and K in different genotypes of Bt cottons and their relationship in 2015 and 2017.【Results】The yield of Jimian169 was the highest, which was 27.9% and 25.5% higher than Lumianyan21, 65.9% and 41.1% higher than Daizimian99 B in2015 and 2017, respectively. The differences of boll weight among the three genotypes were consistent with the lint yield, while the number of bolls and lint percentage were not. The accumulation of dry matter, N, P and K in various organs of Jimian169 was higher than that of Lumianyan21, especially in the medium-late stages. And the highest content of N, P and K in vegetative organs of Jimian169 promoted a higher amount of dry matter, which provided sufficient material basis for boll development. In addition, the boll/leaf ratio was higher, thereby the boll number and the boll weight were the highest, which resulted in the highest lint yield and the efficiency of nutrient utilization. The accumulation of dry matter, N, P and K in every organ of Lumianyan21 was the lowest, and the highest transfer proportion of biomass to bolls, which restricted the growth of vegetative organs and the development of bolls in middle-late growth-stages. As a result, the number of bolls was the lowest, the boll weight was lower, and the lint yield was lower in Lumianyan21. Although Daizimian99 B exhibited the highest accumulation of dry matter and N, P and K in various organs, its rapid accumulation period appeared after the fullflowering stage. The cotton plant was over-green, boll weight was the smallest, lint yields was the lowest, and the efficiency of nutrient utilization was also the lowest.【Conclusions】The increase in lint yield of Bt cotton in different eras is attributed to the enlargement of boll weight, followed by the increase in boll number, which are induced by the synergistic increase in total biomass of cotton plant and the transfer proportion to reproductive organs, particularly in the medium-late stages. And the greater biomass of cotton plant and reproductive organs depend on the rising nutrient accumulation and utilization efficiency.