棉花早、中熟品系营养器官碳氮含量变化的差异及与干物质积累的相关性

为探究不同生育期棉花品种的干物质积累及产量与其碳氮代谢相关性，采用生育期不同的2个陆地棉近等基因系早熟系4003-10和中熟系4003-6，测定生殖生长阶段蕾期至吐絮期根、茎、叶的全氮、氨基酸、非结构性碳水化合物（己糖、蔗糖和淀粉）含量及棉株各部位生物量，比较2个品系的差异，并分析营养器官含氮量与生物量的相关性。结果表明，4003-6比4003-10具有更大的铃重、衣分及皮棉产量。生殖生长阶段4003-6叶片比4003-10具有较高的全氮、氨基酸、非结构性总碳、淀粉含量及碳氮比，表明前者叶片具有较强的碳氮代谢活性和碳水化合物生产能力；4003-6的根系氨基酸水平高于4003-10，且具有更高的氮素吸收效率。在营养器官中，根系含氮量对棉花植株地上部、根系、营养器官和生殖器官的生物量积累影响最大。早熟系4003-10单株根、茎、叶的含氮量与生殖器官生物量的相关系数均高于中熟系4003-6，表明早熟品系的吸氮能力对产量影响更大。

Comparison of Carbohydrate and Nitrogen Contents in Vegetative Organs between Early- and Middle-Maturing Cotton Lines and the Relationships to Dry Matter Accumulation

In order to explore the correlation in dry matter accumulation and yield between cotton cultivars differing in growth period and its carbon and nitrogen metabolism, two near-isogenic cotton lines with different growth period were employed to examine the single plant total nitrogen, amino acid, and nonstructural carbohydrates (hexose, sucrose, and starch) contents in the roots, stems and leaves and the biomass of various plant organs during squaring to boll opening stages. The differences between two lines were compared. The correlation between the nitrogen content and biomass was analyzed. The results showed that 4003-6 exhibited greater boll weight, lint per centage and lint cotton yield than 4003-10. The leaves per plant recorded higher total nitrogen, amino acid, total nonstructural carbohydrate, starch contents and carbon to nitrogen ratio in 4003-6 than in 4003-10 at reproductive growth stage, which means the former expressed greater activities of carbon and nitrogen metabolism and produced more carbohydrates. Greater amino acid content with roots and higher nitrogen uptake efficiency were found in 4003-6 than in 4003-10. Among vegetative organs, root nitrogen contents brought the greatest effects to each of the biomass of shoots, roots, vegetative and reproductive organs. The correlation coefficients between nitrogen content per plant in roots, stems and leaves and reproductive biomass per plant were greater in 4003-10 than in 4003-6, indicating the nitrogen absorbing ability of early maturing line affected yield more than that of middle maturing line.