organism: Acacia mangium
description: Plant materials were collected from one A. auriculiformis (AA6) and one A. mangium (AM20) individual growing in the Forest Research Institute Malaysia (FRIM), Kepong. AA6 and AM20 are parents of an Acacia hybrid mapping population. Both trees were about 5 years old at the time of sampling. The trees were propagated by marcotting the 4-year-old mother trees in FRIM’s field station at Bidor, Perak and planting took place at Bukit Hari field plot in FRIM Kepong in 2004. Three different tissues, namely young stem, intermediate inner bark and old inner bark tissues were sampled. Young stem tissues consisted of ~5cm of non-lignified stem, starting from the shoot tip. Inner bark tissues from intermediate and old developmental stages were sampled by cutting the largest branch on each tree into two halves. The upper half represented the intermediate stage while the lower half represented the old stage. The halves were further cut into disks about 3cm each. The outer bark tissues were peeled off and we collected the inner bark tissues by separating it from the sapwood. The inner bark tissues are cut into smaller pieces and immediately frozen in liquid nitrogen and stored at -80°C until further use. RNA extraction was carried out using QIAGEN RNeasy Mini Kit for each tissue. A single RNA sample for each individual was generated from 20 µg RNA samples pooled from each of the three tissues.