水分胁迫对棉花不同部位主茎叶14C同化、分配的影响

以新棉33B为试验材料,在防雨棚中设置严重干旱、中度干旱和正常供水3个处理(土壤水分分别为田间持水量的35%～45%、45%～65%、65%～85%),利用14CO2同位素示踪技术研究了水分胁迫对棉花不同层次主茎叶光合同化物运转分配的影响.结果表明:干旱胁迫使叶片光合产物合成受阻,降低了叶片14C的同化量.并且随着干旱...

Effects of Water Stress on Assimilation and Partitioning of ~(14)C of Different Leaves on the Main Stem of Cotton

An experiment was conducted under the shelter at Teaching Experiment Station of Hebei Agricultural University in 2007, with the help of ¹⁴C tracer technique, and used Bt-transgenic cultivar(cv. NuCOTN 33B) as the experimental material, during which three field moisture capacity degrees were set up: Severe drought (SD, 35%～45% of field moisture capacity); Middle drought (MD, 45%～65% of field moisture capacity); and normal water supply (CK, 65%～85% of field moisture capacity). The results showed that the characteristics of ¹⁴C photosynthetic assimilation and partitioning varied with different water conditions and different parts and growth stages of cotton stem leaves. The synthesis of photosynthetic products of cotton leaves was inhibited under drought stress and ¹⁴C assimilation decreased. With the worsening of drought stress, the photosynthetic output of source leaves increased. The partitioning of source leaves photosynthate varied between different growth stages under different levels of water stress. Severe drought promoted the distribution of photosynthate to root and main stalk growing points at budding stage, but to neighboring bolls at flowering and bolling stage as well as boll-opening stage. Middle drought stress promoted the partitioning of photosynthate to root and main stalk growing points at budding and early flowering stages, to the lower organs at full flowering stage and mainly to the neighboring bolls at boll-opening stage. In a word, absorption and assimilation of ¹⁴C in leaves were inhibited and leaves photosynthesis were affected under water stress, accordingly the partitioning pattern in every organ of leaf photosynthetic products changed.