Direct somatic embryogenesis and synthetic seed production from Paulownia elongata

Abstract

We have developed a reproducible system for efficient direct somatic embryogenesis from leaf and internodal explants of Paulownia elongata. The somatic embryos obtained were subsequently encapsulated as single embryos to produce synthetic seeds. Several plant growth regulators [6-benzylaminopurine, indole-3-acetic acid, alpha-naphthaleneacetic acid, kinetin and thidiazuron (TDZ)] alone or in combination were tested for their capacity to induce somatic embryogenesis. The highest induction frequencies of somatic embryos were obtained on Murashige and Skoog (MS) medium supplemented with 3% sucrose, 0.6% Phytagel, 500 mg l(-1) casein hydrolysate and 10 mg l(-1) TDZ (medium MS10). Somatic embryos were induced from leaf (69.8%) and internode (58.5%) explants on MS10 medium after 7 days. Subsequent withdrawal of TDZ from the induction medium resulted in the maturation and growth of the embryos into plantlets on MS basal media. The maturation frequency of somatic embryos from leaf and internodal explants was 50.8% and 45.8%, respectively. Subculturing of mature embryos led to their germination on the same medium with a germination frequency of 50.1% and 29.8% from leaf and internode explants, respectively. Somatic embryos obtained directly on leaf explants were used for encapsulation in liquid MS medium containing different concentrations of sodium alginate with a 30-min exposure to 50 m M CaCl(2). A 3% sodium alginate concentration provided a uniform encapsulation of the embryos with survival and germination frequencies of 73.7% and 53.3%, respectively. Storage at 4 degrees C for 30 days or 60 days significantly reduced the survival and complete germination frequencies of both encapsulated and non-encapsulated embryos relative to those of non-stored somatic embryos. However, the survival and germination rates of encapsulated embryos increased following storage at 4 degrees C. After 30 days or 60 days of storage, the survival rates of encapsulated embryos were 67.8% and 53.5% and the germination frequencies were 43.2% and 32.4%, respectively. These systems could be useful for the rapid clonal propagation and dissemination of synthetic seed material of Paulownia elongata.

Induction Somatic Embryogenesis Used 2,4-Dichlorophenoxyacetic Acid (2,4-D) and Kinetin in Spindle Leaf Explant Sugarcane

“…Proses perendaman Na-alginat di dalam larutan CaCl 2 dilakukan selama 40 menit. Hal tersebut berfungsi untuk menyempurnakan pembentukan kapsul (Ipekci & Gozukirmizi, 2003). Kapsul yang telah terbentuk kemudian diinkubasi didalam media semi solid pada intensitas cahaya ±88 lux dengan suhu 4 o C.…”

Artificial Seeds (Principle, Aspects and Applications)

“…Artificial seeds of Paulownia elongata were produced by the encapsulation of somatic embryos with a conversion rate that was assessed to be 50.3% [51]. A 26% conversion rate was obtained by culture-encapsulated somatic embryos of Quercus robur in P 24 medium supplemented with 0.1 µM IBA, 0.9 µM BA, and 3% sucrose [51]. Kumar et al [53] reported a 47% conversion rate of Oryza sativa cultured in Whatman filter paper.…”

“…artificial seeds produced by the encapsulation of their somatic embryos. Artificial seeds of Paulownia elongata were produced by the encapsulation of somatic embryos with a conversion rate that was assessed to be 50.3% [51]. A 26% conversion rate was obtained by culture-encapsulated somatic embryos of Quercus robur in P 24 medium supplemented with 0.1 µM IBA, 0.9 µM BA, and 3% sucrose [51].…”

“…The production of artificial seeds via somatic embryos have been investigated in several plant species including carrot (Daucus carota) [44], alfalfa (Medicago sativa), Norway spruce (Picea abies) [45], sandalwood [45], pistachio (Pistacia vera) [46], sandalwood (Solanium album) [47], grape (Vitis vinifers) and mango (Mangifera indica L.) [48], citrus reticulata [49], Hopea parvitflora [50], Paulownia elongata [51], sugarcane [52], Oryza sativa (hybrid rice) [53], Rotula aquatic (takad) [54], Daucus carota (Latif et al, 2007), Pinus radiata [55], Nothofagus alpina [35], Catharanthus roseus (L.) G. Don [56], and many others (Table 1).…”

RNA-seq analysis of the salt stress-induced transcripts in fast-growing bioenergy tree, Paulownia elongata

“…Studies conducted at Fort Valley State University, Fort Valley, GA, U.S.A. indicate that three-year-old trees can reach a diameter of 14.8 cm and achieve a height of 8.31 m (Basu et al 2015). The tree benefits from not requiring replanting and can be used for fodder and medicinal purposes (Ipekci & Gozukirmizi 2003). New shoots sprout from a stump after harvesting and grow as much as 20 feet in the first growing season (Basu et al 2015).…”