No abstract

Poor germination of peach seeds is the major limiting factor for rootstock production under the Holetta condition because of the seed dormancy problem. Stratification plays an important role in shortening the dormancy and increasing the germination of peach seeds. The study aimed to find easy stratification techniques for the germination of peach seeds using shade and different bed types. The experiment was carried out at the Holetta Agricultural Research Center in two successive years of 2017 and 2018. We got seeds used for this study from peach trees, which were well adapted for the Holetta area. It was arranged in a completely randomized design with five treatments of under tree shade on a flatbed, under tree shade in sunken bed, out of tree shade on a flatbed, out of tree shade in sunken bed and refrigerator as a standard check. They put all treatments except the refrigerator under the grass shade constructed 1 m3 wide. The treatments replicated four times, and each replication contained 200 seeds. The results showed that temperature is the most important factor affecting the germination percentage of the peach seeds. Seeds sown under the temperature close to 8 0C which is in the refrigerator found to have better germination percentage (47.1%) followed by the seeds sown in the grass shade under the tree shade both on sunken (35.8%) and flatbeds (34.9%). Peach seeds stratified in the refrigerator had good germination percentage whereas survival of the seedling was better at out of tree shade in sunken bed and out of tree shade on the flatbed. Even though the germination percentage was lower and the germination speed index was higher than the refrigerator. Seeds stratified at a temperature of above 17 OC experienced a poor germination percentage.

Ginger is used in different medicinal systems of the world for a wide range of disorders. Commercially it is available in various forms, such as green ginger (fresh ginger), dry ginger, ginger powder, ginger oil, ginger oleoresin and preserved ginger. Now a day there is an outbreak of ginger wilt disease throughout the world which pushes researchers and experts to work on specifically;the application of plant tissue culture technique to produce disease free plant has been practiced. Thus the objective of the study is to review the influence of growth regulator and culture condition on micro propagation of ginger.Culture medium without growth regulator fails to stimulate the shoot bud initiation in the explants after four weeks of culture. Depending up on the type and concentration of growth regulators; number of days required for bud break varies from 6-10. Among the growth regulators, the medium containing BA (2.0-4.0 mgl) induced bud sprout in about 6-7 days. Auxin promotes the growth of intact roots and excised root sections but only at a relatively lower concentration range. If its concentration is high, it will suppress morphogenesis in cultured plants. The interaction of cytokinins and explant type had also significant differences for both leaf number and shoot length. The interaction of BAP and NAA produced high number of shoots (in the range of 14-19 shoots per explants) although BAP alone produced 12-13 shoots and 9 roots per explants.The influences of different growth regulators at different concentrations have important roles in promoting well developed roots. The pH condition of the medium should be adjusted to 5.8 before autoclaving at 1.04 kg/cm 2 pressure and 121°C temperature for 15-20 minute. All cultures should be incubated in 16 h light/8 h dark photoperiod (cool, white fluorescent light-30μ mol m-2 S-1) for successful production of plants.