摘要： 为了探讨不同熟性棉花品种之间是否存在钾效率和根系生长对钾缺乏响应差异,在室内水培条件下,以中熟/长季棉(百棉1号、鲁棉研28)和早熟/短季棉(中棉所50、百棉2号)为材料,将刚出苗的幼苗转移至含不同K浓度[钾缺乏(0.05 mmol/L)和钾充分(2.5 mmol/L)]的培养液中生长,于幼苗期开展研究。结果表明,幼苗在营养液中分别生长至7 d和13 d时,4个棉花品种的钾效率(钾缺乏条件下的幼苗干质量)和根系干质量及根系总长度、总表面积和总体积对钾缺乏响应方面均存在显著差异,但均没表现为长季棉类品种和短季棉类品种两大类别之间的一致性差异;4个品种的钾效率和根系生物参数(根干质量、根系总长度和总面积)呈正相关。13 d时,低钾对长季型棉花品种细根长度和面积的抑制率(61.8%~75.5%)明显高于短季型棉花品种百棉2号(47.7%~51.4%),并且明显提高了中棉所50的细根长度和面积;低钾对长季型棉花品种中根长度和面积的抑制率(40.7%~53.9%)也明显高于短季型棉花品种(18.0%~36.2%)。幼苗培养从7 d延长至13 d时,不论是高钾水平还是低钾水平下,细根长度和面积所占比例增加,中根长度和面积所占比例下降;低浓度钾条件下,2个短季型棉花品种的细根长度和面积所占比例上升幅度显著大于2个长季型棉花品种。因此,不同熟性棉花品种的细根生长对钾缺乏的响应存在差异性。

关键词: 棉花, 熟性, 钾效率, 根系

Abstract: To verify the differences between short- and long-season cotton genotypes in K efficiency and root responses to K deficiency,two early-maturity/short-season cotton genotypes(CCRI50,BAIMIAN2)and two mid-maturity/long-season cotton ones(BAIMIAN1,CCRC28)were used to carry out the seedling hydroponic experiment,in which the seedlings of cotton were transferred to the solutions containing two different K concentrations,i.e.2.5 mmol/L K as K-sufficiency and 0.05 mmol/L K as K-deficiency.The results showed that,after 7 d or 13 d hydroponics,the seedlings of four genotypes were significantly different in K efficiency(defined as dry shoot weight under K deficiency)and responses of dry root weight,total root length,total surface area and total volume to K deficiency,but no consistent difference was found between short- and long-season cotton categories.And all the four genotypes exhibited a positive correlation between K efficiency and root biomass parameters(dry weight,total length and total surface area).At 13 DAT,K deficiency inhibited the fine root length and surface area more severely for two long-season genotypes(by 61.8%-75.5%)than for the short-season genotype BAIMIAN2(by only 47.7%-51.4%)compared to K sufficiency,but increased significantly the fine root length and surface area of short-season genotype CCRI50.Simultaneously,K deficiency also inhibited the medium root length and surface area more severely for two long-season genotypes(by 40.7%-53.9%)than for two short-season ones(by 18.0%-36.2%).With the prolongation of solution cultivation from 7 d to 13 d,the ratios of fine root length and surface area to total root length and surface area increased,and the ratios of medium root length and surface area to total root length and surface area decreased for both K sufficiency and K deficiency treatments.For K deficiency,the increasing rates of fine root length and surface area were significantly higher in short-season genotypes than in long-season ones.This suggested that the growth of fine root had different responses to K deficiency between short- and long-season genotypes.

Key words: Cotton, Maturity, K efficiency, Root

中图分类号: 

• S143.3

• S562.01