| Mahaleb CDR-1 is a variety of Mahaleb cherry(Prunus mahaleb L.),it is selected from the seedlings of natural hybrids,because it produces few root suckers,it is generally suitable for seedling propagation,however,the reproductive cycle of seedling propagation is long and the uniformity of seedlings is not well,which affects the efficiency of seedling propagation.Cutting propagation has the advantages of short reproductive cycle,low cost,simple operation,and the cuttings can retain the excellent characteristics of the plant,which is suitable for mass production of seedlings.Sweet cherry grafted on Gisela 6 rootstock can show significant dwarfing effect,it is widely popularized in north area of China,it belongs to clonal rootstock,and it generally propagated by cutting and tissue culture,the breeding coefficient of tissue culture is high and the seedlings grow well.Melatonin is a research hotspot in the field of life sciences.Natural melatonin exists in plants.It has been proved that melatonin can regulate the growth and development of plants and induce adventitious roots.In this study,Mahaleb CDR-1 was used as cutting material,indolebutyric acid(IBA)and naphthalene acetic acid(NAA)of different concentration gradients were used for studying the rooting effects and rooting mechanism of Mahaleb CDR-1 cuttings;The tissue culture test using Gisela 6 as material,the treatment of exogenous melatonin on the adventitious root induction was investigated by single hormone and compound hormone.The specific results are as follows:1、IBA and NAA can improve the callus and rooting rate of Mahaleb cuttings,the effect of two hormones on rooting can be expressed as IBA > NAA > CK.The callus rate,rooting rate and rooting number of cuttings treated with 1000mg/L hormone were the highest,among which the callus rate of softwood cuttings treated with 1000mg/L NAA was 68%,and the rooting rate treated with 1000mg/L IBA was 61%,and rooting number was 9.33(p<0.05);The callus rate and rooting rate of hardwood cuttings treated with 1000mg/L IBA were 31% and 24%,respectively.The rooting number was 4.3(p<0.05).On the whole,1000mg/L IBA was the best treatment;The rooting type of Mahaleb cuttings is mixed rooting type.2、During the rooting process of softwood cuttings of Mahaleb,the POD and PPO activities increased first and then decreased,IAAO activity and soluble sugar content decreased first,then increased,soluble protein content increased gradually,and tissue water content decreased first and then stabilized;During the rooting process of hardwood cuttings,POD,PPO activity and tissue water content showed a trend of ’up-down-up’,and IAAO activity showed a trend of ’down-up-lower’.The soluble protein content first stabilized and then increased.The soluble sugar content first decreased and then increased.3、Melatonin can induce adventitious root formation of Gisela 6.In the single hormone test,the rooting rate treated with 1.0μM MLT was the highest,reaching 50%,and the length of adventitious roots was the longest,reaching 11.83cm(p<0.05),the diameter of adventitious root was the thickest,reaching 1.75mm(p<0.05),the rooting number was about 2.67 treated with 0.05 and 0.5μM MLT.In the compound hormone test,the rooting rate treated with 0.6mg/L IBA+1.0μM MLT combined reached 100%,the root length was the longest,reaching 8.00cm(p<0.05),the thickest diameter of adventitious root reached 1.93 mm,and the rooting number was about 6(p<0.05);the rooting rate treated with 0.6mg/L NAA+5.0μM MLT combined reached 100%,the rooting number treated with 0.6mg/L NAA+1.0μM MLT combined was about 10.67(p<0.05),the length of roots was 5.33 cm,and the diameter of roots was about 1.85 mm.On the whole,the rooting effect of single hormone treated with 1.0μM MLT was the best,and the combination of 0.6mg/L NAA+5.0μM MLT and 0.6mg/L IBA+1.0μM MLT achieved the best rooting effect. |
