Abstract: To study the effect of reduced irrigation on the growth and development of transgenic cotton with drought resistance in different periods,  the stable genetically transgenic ScALDH21 cotton line T14-96 was used as the  material, and receptor Xinnongmian 1  as negative control. The differences  of agronomic traits, yield traits and fiber quality between transgenic material and recipient cotton were studied under normal watering during the whole growth period (CK), 30% reduced irrigation at the seedling bud stage (M3), 30% reduced irrigation at the blooming stage (H3), and 30% continuously reduced irrigation at the seedling bud stage and blooming stage (W3). The results showed, compared with CK, the plant height, the height of first fruit branch, the number of fruit branches and the number of bolls per plant of the transgenic ScALDH21 cotton and its receptor were all decreased  under reduced irrigation. Under the M3 and H3 treatments, the seed cotton yields of Xinnongmian 1 and T14-96 were respectively increased by 1.6%, 1.4% and 5.1%, 4.1%, respectively, while under the W3 treatment, all yield traits were almost  decreased except the lint percentage and lint cotton yield. Principal component analysis showed that plant height, the height of first fruit branch, fruit branch number, single boll weight, seed index, seed cotton yield and lint yield were significantly affected by transgene. Therefore, these indexes could be regarded as the main indexes to distinguish transgenic plant from receptor. The transgenic ScALDH21 cotton line T14-96 was more drought-resistant, growth advantages and higher yield than wild-type in treatments of reduced irrigation.  ScALDH21  had a positive effect on increasing cotton yield, but no significant effect on fiber quality. In the seedling bud stage, appropriately reduced irrigation could achieve the effects of water-saving and yield increasing. These results would provide theoretical basis for breeding of new varieties resistanting to drought and optimizing irrigation methods.

Key words: transgenic cotton, Xinnongmian 1, water stress, agronomic trait, yield

摘要： 为研究不同时期减量灌溉对转抗旱基因棉花生长发育的影响，以稳定遗传的转ScALDH21棉花株系T14-96为材料，受体新农棉1号为阴性对照，探究转基因材料与受体棉花在全生育期正常灌溉（CK）、苗蕾期减量灌溉30%（M3）、花铃期减量灌溉30%（H3）以及苗蕾期和花铃期连续减量灌溉30%（W3）下农艺、产量和纤维品质性状的差异。结果表明，与对照正常灌溉相比，转ScALDH21棉花和受体在减量灌溉后株高、第一果枝高度、果枝数和单株结铃数均下降；M3和H3处理下，新农棉1号和T14-96的子棉产量分别提高了1.6%、1.4%和5.1%、4.1%；而W3处理下，除衣分和皮棉产量外，其余指标均下降。株高、第一果枝高度、果枝数、单铃重、子指、子棉产量和皮棉产量是区分转基因与受体植株农艺和产量性状差异的主要指标。转ScALDH21基因棉花在不同生育期灌溉量减少30%，其耐旱能力、生长优势及产量的显著高于受体，但对纤维品质无显著影响，且苗蕾期适当水分胁迫，可达到较好的节水增产效果，为选育棉花抗旱新品种和优化灌溉方式提供了理论参考。

关键词: 转基因棉花, 新农棉1号, 水分胁迫, 农艺性状, 产量