Produção sexuada e biometria de progênies inermes de jurema branca (Piptadenia stipulacea (Benth.) Ducke).

Abstract

Brazil has many natural resources that can result in socio-economic benefits to its population, specially its highly diverse flora that constitutes an important source of genetic resources. In the Caatinga biome this diversity is also present and contributes to the survival of the population. Many Caatinga trees have their management hindered by the presence of spines or thorns, but spineless mutants have been identified for some species [e.g.: jurema preta (Mimosa tenuiflora), favela (Cnidoscolus quercifolius) and sabiá (Mimosa caesalpiniifolia)]. The identification of trees capable to produce thornless progenies allows to sexually propagate seedlings with this phenotype to establish plantations with a wide gene pool. This study had the objective to identify jurema preta trees capable to produce thornnless progenies, estimate the percentage of seed germination, viable seedlings and thornless progenies of each tree, and compare the growth of thorny and thornless 125-day-old progenies. The statistical design was a completely randomized design with 15 treatments (thony and thornless progenies and 15 trees). Seed germination averaged approximately 50%, however less than 25% of the seeds resulted in viable (≥ 10 cm high) 125-day-old thornless seedlings. Mean seedling height and diameter of thorny progenies tendend to be higher than those of their thornless counterparts. However, the thornless progenies of two trees showed mean height and diameter of 31 cm and 2,5 mm, respectively, and these values are similar to the reported in the literature for this species and were surpassed by the thorny progeny of only one of the 14 other tress. Thus, there are trees capable to produce a significant amount of good quality thornless seedlings.