tailieunhanh - Báo cáo khoa học: "Increase of flowering in Pinus nigra Arn subsp salzmannii (Dunal) Franco by means of heteroplastic grafts"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Increase of flowering in Pinus nigra Arn subsp salzmannii (Dunal) Franco by means of heteroplastic grafts. | Ann Sci For 1997 54. 145-153 Elsevier INRA 145 Original article Increase of flowering in Pinus nigra Arn subsp salzmannii Dunal Franco by means of heteroplastic grafts JM Climent MA Prada LA Gil JA Pardos Unidad de Anatonúa Fisiologia y Genética Forested ETSI de Montes Ciudad Universitaria 28040 Madrid Spain Received 9 August 1995 accepted 22 February 1996 Summary - Behaviour of black pine Finns nigra suhsp salzmannii ramets grafted in 1987 on p nigra and p hrutia rootstocks was compared in a clonal seed orchard located in Guadalajara Spain . Graft take percentage was lower on average and more variable between clones for interspecific unions than for intraspecific ones however later field survival was rather similar. Between 1990 and 1994. heteroplastic grafts displayed a female flowering ranging from four to 13 times higher than homoplastic ones depending on the year and with 5 years of age. interspecific grafts produced male strobili nearly absent in the second group. Although seed production is still scarce due to lack of pollination heteroplastic ramets seem to yield bigger cones with more sound seeds per cone. Significant differences between both types of grafts were observed regarding stem diameter branching pattern apical dominance and crown width. Differentiation of lateral shoots both floral and vegetative was higher in heteroplastic grafts resulting not only in more branches but also in more strobili of both sexes per branch. Heteroplastic ramets displayed a marked tendency to lose apical dominance thus supporting their higher number of shoots since the number of branches per whorl is equal in both groups. These results suggest that utilization of p nigra grafts on p bnitia rootstocks in similar site conditions may be a helpful tool to obtain more precocious and abundant fruit yields than those derived from the more common use of homoplastic grafts. seed orchard flowering heteroplastic graft Pintis nigra Pinus brutia Resume - Accroissement de la floraison