Low temperature,IBA concentrations and optimal time for adventitious rooting of Eucalyptus benthamii mini-cuttings

Eucalyptus benthamii is a forest species of economic interest that has difficulty with seed production and also is considered to have difficulty with adventitious rooting using propagation techniques, such as cutting or mini-cutting. We aimed to assess the adventitious rooting percentage under different storage times in low temperatures and at various IBA （indole-3-butyric acid） concentrations to determine the optimal time of permanence for rooting Eucalyptus benthamii minicuttings in a greenhouse. Shoots collected from mini-stumps cultivated in a semi-hydroponic system were used to obtain the mini-cuttings. For the first experiment, the mini-cuttings were stored at 4℃ for 0 （immediate planting）, 24, 48, 72, 96 and 120 h. The second experiment evaluated the rooting dynamic to determine the optimal time of permanence for minicuttings in a greenhouse. The basal region of the mini-cutting was treated with various IBA solutions： 0 （free of IBA）, 1,000, 2,000, 3,000 and 4,000 mg.L^-1. Every seven days （0 （immediate planting）, 7, 14, 21 and 28 days）, destructive sampling of the mini-cuttings was performed to evaluate the histology of the adventitious rooting. Eucalyptus benthamii minicuttings should be rooted immediately after the collection of the shoots. The 2,000 mg.L^-1 IBA concentration induced a greater speed and percentage of adventitious rooting, and an interval of 35 to 42 days was indicated for permanence of the mini-cuttings in the greenhouse. Expo- sure to low temperature induced adventitious root formation with diffuse vascular connections.

Effect of mini-cutting size on adventitious rooting and morphophysiological quality of Ilex paraguariensis plantlets

As the energizing and therapeutic effects of infusions of mate(Ilex paraguariensis A.St.-Hil)leaves are increasingly recognized,rising global consumption is also increasing the demand for plantlets with high genetic and morphological qualities.Mini-cuttings are an alternative for clonal plantlets;however,more details are needed on factors that affect the success of this technique.Here,toward maximizing production,we evaluated adventitious rooting competence of mini-cuttings of different sizes and the morphophysiological quality of the resultant plantlets.Small(one bud;length up to 2.5 cm),medium(multiple buds;length 2.6–5.0 cm),and large(multiple buds;length 5.1–10.0 cm)mini-cuttings were planted in a mixture of commercial substrate,vermiculite,and coarse sand(1:1:1 v:v:v),grown in a humidity chamber,then evaluated after 45,60,75,and 90 days for survival,percentage of callus and shoot formation,number and length of shoots,percentage of rooted cuttings,and number and length of roots.Any rooted mini-cuttings were then cultivated in commercial substrate and subsurface soil(2:1 v:v)and evaluated after 30,60,90 and 120 days of cultivation for morphophysiology of the plantlets,percentage of survival,number of leaves,shoot height,stem diameter,and ratio of shoot height to stem diameter.After 120 days,the plantlets were evaluated for the ratio of shoot and root dry mass,total length,surface area,total volume,and mean diameter of roots and Dickson quality index.Adventitious rooting of the mini-cuttings and the morphophysiological quality of the plantlets were not influenced by the size of the vegetative propagule.Therefore,single-bud mini-cuttings have similar adventitious rooting competence,and result in plantlets with adequate morphophysiological quality,based upon leaf development,shoot height,stem diameter and length,and surface area,volume and diameter of roots.Single-bud mini-cuttings up to 2.5 cm long can thus be used to maximize production of mate plantlets by mini-cuttings.

Large Scale Multiplication of Casuarina junghuhniana Miq. Clonal Plants through Mini-cutting Technique

The modern concept of meeting the customer’s requirements in better products at low costs in a sustainable manner is possible only through innovative methods.The nodal cutting technique is the most widely used method for large scale propagation of Casuarina,Eucalyptus and other pulpwood species in India.Tamil Nadu Newsprint and Papers Limited(TNPL)has started large scale multiplication of Casuarina junghuhniana Miq.using mini-cutting technique from indoor clonal mini hedges raised in sand beds.When compared to stem/nodal cuttings,indoor clonal mini hedges raised in sand beds improve the rooting potential,quality of root systems and are time-and cost-saving.The productivity of cuttings is increased five times in indoor clonal hedge orchard than conventional stem/nodal cutting.The rooting percentage also improved to 90%without rooting hormone whereas the same is only 50%in stem cutting.The plant developed through mini-cutting technique has more lateral root system which helps the plants/trees to withstand during heavy winds.Replacing such stump derived stock plants by intensively managing indoor sand bed clonal mini hedges resulted in a noticeable enhancement of cutting capacity for adventitious rooting as well as the overall quality of the plants produced in much shorter period with easier and cheaper maintenance.The study reveals that mini-cutting method is ideal propagation technique for large scale propagation of C.junghuhniana clones in India.

Vegetative propagation of Apuleia leiocarpa(Vogel)J.F.Macbr

Apuleia leiocarpa is an environmentally and economically significant Atlantic Forest species threat-ened by ongoing exploitation.The vegetative propagation of the species could be a step forward to enable implanta-tion of clonal seed orchards and multiplication of selected trees but remains unknown to date.This study assessed the mini-cutting technique for propagation of A.leiocarpa and determined the time required for rooting and viable mini-cutting type and sizes.The results show that it is possible to propagate A.leiocarpa with mini-cuttings derived from mini-stumps produced with seeds;the mini-stumps pre-sented regrowth capacity and remained constantly produc-tive for 1 year;10-cm A.leiocarpa mini-cuttings should remain under misting conditions for at least 40 days,and the vegetative propagation of A.leiocarpa with intermediate 7-to 10-cm mini-cuttings resulted in more vigorous clonal seedlings than smaller mini-cuttings.