CONTROLLED RELEASE FERTILIZER IN THE ROOTING AND PERFORMANCE OF CLONES OF Paratecoma peroba

ABSTRACT Paratecoma peroba is a native forest species of great economic and ecological interest, currently at risk of extinction. In addition to the difficulty of finding adult individuals of this species, plant production is limited, so the use of mini-cuttings can facilitate the spread of P. peroba. Thus, the objective of this study was to analyse the effect of different doses of controlled release fertilizer (CRF) on rooting, growth, photosynthetic metabolism and nutritional balance of P. peroba clones propagated by mini-cuttings. Five doses of CRF (0, 2, 4, 6 and 8 kg.m-3) were tested, arranged in a completely randomized design with 12 repetitions and each repetition consisted of eight clones. Evaluations were carried out in the three stages of clones production: 1) Survival at 60 days in a greenhouse, 2) Rooting at 105 days in a shade house; and 3) Evaluation Productivity index, morphological variables, physiological metabolism, and nutritional through macronutrient contents, diagnosis and recommendation integrated system (DRIS) indices and the average nutritional balance index of clones at 120 days in the area of hardening. There was no influence of CRF on survival and rooting of mini-cuttings. The CRF favoured a higher productivity index, vegetative growth and physiological activity of the clones. The 6 kg.m-3 dose was sufficient to obtain nutritionally balanced clones.

摘要 帕拉泰科马木（Paratecoma peroba）是一种兼具重要经济与生态价值的本土森林树种，目前正濒临灭绝。该物种不仅成年个体难以寻觅，且苗木繁育产量受限，因此采用微型扦插（mini-cuttings）技术可助力该物种的推广繁育。为此，本研究旨在分析不同剂量控释肥料（controlled release fertilizer, CRF）对通过微型扦插繁育的帕拉泰科马木无性系的生根、生长、光合代谢及营养平衡的影响。
本实验设置5个控释肥料剂量梯度（0、2、4、6、8 kg·m⁻³），采用完全随机试验设计，共12次重复，每次重复包含8个无性系。测定工作在无性系繁育的三个阶段开展：1）温室培养60天时的存活率；2）遮阴棚内培养105天时的生根情况；3）炼苗阶段120天时，通过大量元素含量、诊断推荐综合系统（diagnosis and recommendation integrated system, DRIS）指数以及无性系平均营养平衡指数，对生产力指数、形态指标、生理代谢及营养状况进行评估。
研究结果表明，控释肥料对微型插穗的存活率与生根情况无显著影响；但可显著提升无性系的生产力指数、营养生长水平与生理活性。其中6 kg·m⁻³的剂量即可培育出营养平衡的无性系。