4种植物生长调节剂对棉花生长发育、光合特性及产量的影响

【目的】研究萘乙酸钠(NAA-Na)、6-苄氨基嘌呤(6-BA)、24-表油菜素内酯(EBR)和脱落酸(ABA)对棉花幼苗生长、叶片光合特性及籽棉产量的影响,评价其促生增产效果。【方法】在棉花幼苗2叶期和4叶期喷施10.0 mg/L NAA-Na、2.0 mg/L 6-BA、0.2 mg/L EBR和0.5 mg/L ABA,测定不同处理下棉花苗期株高、茎粗、叶片数、蕾数、叶片叶绿素相对含量(SPAD值)和光合参数,收获期测定产量及其构成因素。【结果】各处理棉花株高、茎粗、叶片数和蕾数日增长量分别为(0.96~2.78) cm/d、(0.06~0.44) mm/d、(0.15~0.58)片/d和(0.14~0.86)个/d,喷施4种植物生长调节剂后棉花株高、茎粗、叶片数和蕾数日增长量均高于CK,喷施5 d时棉花叶片SPAD值、净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)较CK分别增加8.02%~10.99%、8.95%~16.13%、93.14%~110.17%和6.58%~19.44%,喷施10~20 d时各处理指标间无差异。喷施植物生长调节剂对棉花收获株数和单铃重无差异,单株成铃数和籽棉产量较CK分别增加0.53%~7.54%和0.73%~9.39%。EBR处理对棉花促生增产效果优于NAA-Na、6-BA和ABA。【结论】供试4种植物生长调节剂能不同程度促进棉花由营养生长向生殖生长转化,增加棉花叶片SPAD值和光合特性,通过增加单株成铃数来提高籽棉产量。EBR处理优于其他植物生长调节剂。

Effects of Four Plant Growth Regulators on Growth and Development,Photosynthetic Characteristics and Yield of Cotton

【Objective】 This experiment was conducted to study and evaluate the effects of NAA-Na, 6-BA, EBR and ABA on cotton growth, leaf photosynthetic characteristics and yield. 【Methods】 NAA-Na (10.0 mg/L), 6-BA (2.0 mg/L), EBR (0.2 mg/L) and ABA (0.5 mg/L) were sprayed when cotton seedlings grew to two-leaf and four-leaf stage, plant height, stem diameter, leaf number, bud number, SPAD value, photosynthetic parameters, were detemined during the seedling period,yield and its components were determined during the harvest period. 【Results】 After spraying the four plant growth regulators, the daily average growth of plant height, stem diameter, leaf number and bud number in each treatment were 0.96-2.78 cm/d, 0.06-0.44 mm/d, 0.15-0.58 slices/d and 0.14-0.86 pieces/d, respectively, which were higher than that in the control treatment; SPAD value, net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of leaves were respectively increased by 8.02%-10.99%, 8.95%-16.13%, 93.14%-110.17% and 6.58%-19.44% compared with CK at 5 d. Spraying plant growth regulators had no significant differences on the number of harvested cotton plants and boll weight, while compared with CK, the boll number and seed cotton yield per plant were increased by 0.53%-7.54% and 0.73%-9.39%, respectively. EBR treatment was superior to NAA-NA, 6-BA and ABA treatment in promoting growth and yield of cotton. 【Conclusion】 The tested four plant growth regulators could promote the transformation of vegetative growth to reproductive growth, increase the SPAD value and photosynthetic characteristics of cotton leaves, and increase the seed cotton yield by increasing the boll number per plant. EBR treatment was superior to other plant growth regulators.