Mini grafts: alternative to obtain complete plants of Pinus patula propagated in vitro

Resumen

Micro-grafting and mini-grafting trials were carried out in order to obtain complete Pinus patula plants generated in vitro, derived from the fact that the formation of roots in micro-propagated shoots is very low or null. On the other hand, there is the possibility of generating clones with outstanding genetic characteristics. P. patula seeds were established in aseptic conditions and geminated in vitro in DCR medium; the aerial part was dissected from the base and roots were kept in DCR medium added with 0.5 mg l-¹ of NAA to maintain them and served as mini rootstock, the shoots were transferred to DCR medium added with 2.0 mg l-¹ of BA to form seedlings with an average of 3.9 shoots per explant at 30 days. On the other hand, 2-month-old nursery seedlings were used as rootstock for the mini-grafts. For the micro-graft tests, the shoots obtained were taken and the apical meristems with approximately 5 mm were isolated to conduct micro-grafting at the base with roots, and in the case of mini-grafts the shoots generated were allowed to grow to a length of 3 cm on average and grafted onto nursery seedlings. In both cases, the achievement of the grafted materials and the length were evaluated to measure the growth of the materials that had positive success. The response of micro-grafts was very low, 10% success, in addition to the manipulation of the meristems being very complex, which generated oxidation in the tissues. On the contrary, the mini-grafts showed 93.3 of grafting success and average growth of 26.05 cm, two months after the grafting process