| Peppers are rich in vitamins and active ingredients,which provide nutritional components and promote metabolism for human health.In our country,peppers have a great proportion in the vegetable production.During the research of pepper breeding,the breeding and utilization of male sterile lines play an important roles in the production of hybrid seeds,which can enhance the seed purity and seed production efficiency,but reduce the production costs.The male sterile line of pepper mainly comes from natural mutations and natural hybridization in the field.Therefore,it is particularly important to conserve the precious male sterile germplasm before finding its maintenance line.Cutting with water culture is a method to promote the rooting of pepper’s young organs by treated with plant growth regulators.The plant growth regulators can increase the rooting rate of pepper cut seedlings,and promote the cutting to produce a strong root system,which makes them survive,grow and produce after being transplanted to the field.Using the germplasm resources of pepper from our research group,this experiment studied the effects of the types and concentrations of growth regulators on the rooting of pepper cuttings,and the pre-treatments and the managements of cutting materials,aiming to establish the technical system of cutting propagation of pepper by water culture.This system will provide technical supports for the preservation and reproduction of pepper male sterile plants and other precious breeding materials.The main results are as follows:(1)In order to determine the appropriate types and concentrations of plant growth regulators of auxin for capsicum cutting propagation by water culture,alpha-naphthalene acetic acid(NAA)and indole-3-acetic acid(IAA)were selected.The pepper variety Qinjiao 3 was used as material,and the seedlings with 4-6 leaves were used to perform this experiment.The NAA concentrations gradient were designed as 25 mg/L,50 mg/L,75 mg/L,and 100 mg/L,and the IAA concentrations gradient were 50 mg/L,100 mg/L,150 mg/L,and 200 mg/L.The water with equal volume was taken as the control.At the 15 th day after cutting,the root numbers,root length,rooting rate,and root activity were measured.The results showed that low concentrations of NAA and IAA had better effects on the rooting of Qinjiao 3,and the optimal concentration of NAA was 50 mg/L,and that of IAA was 100 mg/L.Compared with the control with water,NAA can promote the initiation of rooting,but inhibit the elongation of roots,while IAA displayed obvious effects on both the increase of root number and the root elongation.(2)In order to better understand the influencing factors of pepper cutting propagation by water culture,based on the above experimental results,further experiments were carried out on 18 pepper varieties/lines,in which NAA concentration was 50 mg/L and IAA concentration was 100 mg/L.Eighteen pepper varieties/lines were treated by NAA and IAA respectively with the concentrations mentioned above,and the Root number,root length,rooting rate,and root activity were measured after 20 days of cutting.The results showed the root number and root length displayed significant differences among the cuttings of different pepper varieties/lines cuttings,even with the same type of plant growth regulator.However,there were no significant differences in other indexes.Generally,the rooting of pepper varieties of Qinjiao were better than those of other lines. |
