Mass propagation of pitaya (dragon fruit)

Introduction. To facilitate establishment of pitaya (Hylocereus undatus) cultivations in new areas, factors affecting its propagation by cuttings and seeds were studied. Materials and methods. Firstly, cuttings of (5, 15 and 25) cm length were tested in three substrates: peat moss (pm), peat moss and sand mix (1:1) (pm/sa) and sand (sa). Indole-3-butyric acid (IBA) solutions were prepared at [0, 5, 10 or 15] mM dissolved in 70% ethanol. After the basal cuttings were dipped for 10 s in these IBA solutions, cuttings were planted in (pm/sa). After (1, 2 or 3) weeks, the cutting rooting, number and length of the developed roots were measured. Moreover, germination was tested at four temperatures [(16, 20, 24 and 28) °C] by placing seeds on wetted filter papers in Petri dishes. Light effect was tested at four white light intensities of (0, 500, 1000 or 2000) lx. Seed viability was tested at 24 °C in darkness with 1000 seeds. The effect of (pm), (pm/sa) and (sa) was tested on germination and seedling growth. The percentage of germination, days to emergence and growth rate of seedlings were measured. Results and discussion. After two weeks, 25-cm pitaya cuttings rooted successfully in the three substrates, but the number and length of the developed roots were affected by the type of substrate. A significant effect of cutting size on root initiation, and number and length of the developed roots was found. IBA consistently improved rooting percentage and root number and length. Overall, 5-cm-long cuttings treated with IBA (10 mM) could be efficient at propagating pitaya. The seed viability was 83%. Germination, which varied between (71 and 83)% depending on the temperature, began after 6 days at (24 and 28) °C. Light intensity at (1000 or 2000) lx reduced seed germination. Potted seedlings grew successfully in the greenhouse

A microculture approach towards enhanced productivity and genetic improvement of pecan (Carya illinoensis)

Mature pecan nuts provide a more convenient, practical, and readily available explant source, and extend the sampling period for in vitro research on this species to a year-round basis. Axenic cultures from mature pecan embryos were established in vitro by reducing the water availability in the initial explanting media. This enabled study of the regenerative capacity of the mature pecan embryo explants, and the factors affecting shoot multiplication and rooting. A simple procedure was adapted for the measurement and comparison of water availability in the explanting media. Disinfestation of up to 65% of the cultures was accomplished, depending on the medium formulation, compared to 100% loss to contamination on control medium. Prolific production of axillary and adventitious shoots from the embryonic axis was induced by adding 5 $\mu$M IBA and 20 $\mu$M BAP to the culture media. The retention of cotyledons was essential for shoot initiation and long-term shoot development. TDZ at 25 $\mu$M produced somatic embryos and adventitious buds. Sixty-one percent of the excised cultured cotyledon segments formed adventitious roots at 50 $\mu$M NAA. Axillary buds on microcuttings were induced to grow only when media were supplemented with gibberellic acid. Microcuttings cultured on auxin-free media after preculture on media with 20 $\mu$M IBA in the dark for one week gave the best rooting results (30%). A new micrografting technique was developed as an alternative clonal propagation method. A unique apparatus was designed to splice the in vitro-derived scion and rootstock together during the micrografting process.U of I OnlyETDs are only available to UIUC Users without author permissio