Histological analysis and transcription profiles on somatic embryogenesis in interspecific hybrids of &amp;lt;i&amp;gt;Elaeis guineensis &amp;#215; E. oleifera&amp;lt;/i&amp;gt;

Paula Cristina Da Silva Angelo,Ricardo Lopes,Raimundo Nonato Vieira Da Cunha,Miguel Pedro Guerra,Douglas André Steinmacher

doi:10.4236/as.2013.411a001

Abstract

Elaeis guineensis (African oil palm) and E. oleifera (American oil palm) are bred to attain high oil yields, disease resistances, and decelerated shoot elongation. We cultivated immature zygotic embryos from backcrossed and F1 interspecific progenies on media containing 110, 150, or 200 mg·l-1 2,4-diclorophenoxyacetic acid (2,4-D) to obtain embryogenic cultures. These were set to multiply on medium containing 8 mg·l-1 2,4-D or lower concentrations of auxins and finally we induced plantlets regeneration, from each zygotic embryo, independently, in order to have the clones organized according to their respective origins. Reductions in auxins induced cultures to revert from highly embryogenic into competent for embryogenesis and finally to organogenic degenerated callus lines. Histology and the expression of SOMATIC EMBRYOGENESIS RECEPTOR KINASE, DEHYDRIN, DEFENSIN, TRANSPOSASE, and LIPID TRANSFER PROTEIN were analyzed on four callus lines representative of morphological aspects consistently observed. The highest number of embryogenic cultures was obtained on 150 mg·l-1 2,4-D. Maturation and multiplication of somatic embryos through secondary embryogenesis occurred simultaneously on 8 mg·l-1 2,4-D. LIPID TRANSFER PROTEIN expression was detected in one of the embryogenic cultures and correlated with protoderm onset. Three six-week cycles on induction medium yielded 1.5 shoots above 6 cm per poly-embryogenic complex, which performed better than embryoids individualized mechanically. Rooting was observed for 77% and 82% of shoots from these two types of explants, respectively. Rooted plantlets ready for acclimatization were obtained nine months after shoot induc

Highlights

Elaeis guineensis (Jacq.) tp. tenera cultivars are considered the best producers of oil, which is used in food, biofuels and cosmetics [1,2,3]
E. guineensis × E. oleifera immature zygotic embryos were maintained for more than 12 months on induction medium, because embryogenesis in palms often depends on long-term cultivation [27,28]
The explants were primary compact calli or calli that had given raise to embryogenic cultures, which were first observed in the second month (Table 1)

Summary

Introduction

Elaeis guineensis (Jacq.) tp. tenera cultivars are considered the best producers of oil, which is used in food, biofuels and cosmetics [1,2,3]. Tenera cultivars are considered the best producers of oil, which is used in food, biofuels and cosmetics [1,2,3]. In Latin America, tenera plantations are harmed by the lethal yellowing anomaly. It does not eliminate F1 hybrids between E. guineensis and the Amazon native species, E. oleifera (Kunth) Cortés, growing in the same impacted areas. E. oleifera has a lower rate of annual shoot growth and a higher content of unsaturated fatty-acids [4]. Guineensis × oleifera hybrids are backcrossed with E. guineensis [4], and the progenies resulting from this complex breeding strategy present variability.

Methods

Results

Conclusion