Realized genetic gain observed in second-generation seedling seed orchards of Acacia mangium in South Kalimantan, Indonesia

Abstract

Realized genetic gains brought by the firstgeneration tree improvement of Acacia mangium were evaluated by analyzing the 1-year growth performance of growth (height, dbh) and form (stem straightness, multi-stem) traits using data collected from three secondgeneration orchards: groups B, C, and D. Each orchard was composed of improved families derived from openpollinated seed of plus trees selected from the firstgeneration seed orchards and newly added unimproved families collected from the same geographic region. The number of improved families and that of the unimproved in each orchard were 31 and 23 for group B, 28 and 39 for group C, and 24 and 30 for group D. Gains were calculated as percentage increase of improved families over unimproved ones. Improved families performed better than unimproved ones in 11 out of 12 comparison cases: four traits each in the three orchards. Averages of the realized genetic gain across the three seedling seed orchards were 3.1%, 5.2%, 4.3%, and 0.5% for height, dbh, stem straightness, and multi-stem, respectively. Except for multi-stem, the performances of improved families were significantly better than those of unimproved families in all the three orchards for dbh and in two out of three orchards for height and stem straightness.

Realized genetic gains observed in second generation seedling seed orchards ofEucalyptus pellitain Indonesia

“…Since the realized gains can be regarded as consequences of the previous selection, the whole selection process in the orchard of E. pellita, including plus tree selection and within plot selection, appear to have favored improvements in growth rather than stem form. The gains were generally greater than those found in previous studies of most acacia and conifer species (Nirsatmanto et al 2004;Matziris 2000Matziris , 2005Carson et al 1999) except A. auriculiformis (Luangviriyasaeng and Punyapusaserk 2002). Although realized gains will depend on the intensity of selection as well as the magnitude of heritability, the realized gains obtained in this study would make significant contributions to increasing the productivity of operational E. pellita plantations in Indonesia.…”

“…If similar percentage gain could be continued, the volume productivity in the E. pellita plantations could be greatly improved at rotation age. However, the feasibility of prolonging such gains is currently difficult to assess since most relevant studies have assessed realized gains at only one time point (e.g., Matziris 2000Matziris , 2005Luangviriyasaeng and Pinyopusarerk 2002;Nirsatmanto et al 2004). Therefore, further measurements should be continued to examine changes over time in percentage gains during the full course of the rotation.…”

“…Therefore, there seems to be promising scope for increasing its volume productivity to match that of Acacia within a few generations of breeding. In tropical Acacia species, gains varied considerably, Nirsatmanto et al (2004) found gains of ca. 5% for growth and stem form in 1-year-old A. mangium, while Luangviriyasaeng and Punyapusaserk (2002) observed gains of 12.4 and 28.2% in height and diameter, respectively, in 3-yearold A. auriculiformis.…”

Ganancia genética esperada en Acacia mangium en San Carlos, Zona Norte de Costa Rica

“…La acacia (A. mangium) ha sido conocida por su capacidad de crecimiento y alta producción de biomasa, en suelos degradados, ácidos, de baja fertilidad y poco contenido de materia orgánica (Nirsatmanto et al 2004;Kim et al 2008).…”

“…Algunas especies del género Acacia, perteneciente a la familia de las Fabáceas, han tenido éxito en los programas de reforestación comercial en la zona oriental del trópico asiático: en Vietnam, van Bueren (2004) estima una superficie de 127000 ha plantadas con híbridos de acacia; en este mismo país, Kim et al (2008), estiman 500000 ha plantadas con A. mangium, A. auriculiformis y el hibrido de ambas; en Indonesia, Nirsatmanto et al (2004) estiman 800000 ha de A. mangium. Lo anterior refleja que en el trópico asiático esta especie se ha convertido en la opción de plantación que genera la mayor productividad en ciclos cortos de crecimiento.…”