Micropropagation of Plectranthus edulis (Vatke) Agnew from meristem cultur

Abstract

Plectranthus edulis (Vatke) Agnew is a tuber-bearing food crop in Ethiopia. However, its productivity is hampered by shortage of pathogen-free planting materials. Therefore, the objective of this study was to develop micropropagation protocol for this plant using meristem to produce clean planting materials. Mersitems were collected from apical and axillary shoots from Holeta and Welayta areas and cultured on MS medium containing gibberellic acid (GA 3 ) (1.0 mg l -1 ), α-naphthalene acetic acid (NAA) (0.1 mg l -1 ) in combination with 6-benzylaminopurine (BAP) (0.1, 0.5, 1.0, 2.0 and 5.0 mg l -1 ). Shoots were multiplied on MS medium containing 0.1, 0.5, or 1.0 mg l -1 of BAP or 0.5, 1.0, 2.0 or 3.0 mg l -1 of Kinetin alone or their combination with 0.05 or 0.1 mg l -1 NAA. In vitro and ex vitro rooting was performed using different types of auxins followed by acclimatization. The highest percentage of shoots initiated from collected mersitem at Holeta (73%) was obtained on MS medium containing 1.0 mg l -1 BAP, 1.0 mg l -1 GA 3 and 0.1 mg l -1 NAA. The highest shoot number explants -1 (7.2) was obtained on MS medium containing 1.0 mg l -1 Kinetin and 0.1 mg l -1 NAA, whereas the highest root number shoot -1 (6.2) was obtained from ex vitro. All plants derived from Holeta and 96.7% of those from the Welayta survived after acclimatization. These results provided rapid and reproducible conditions for propagation of relatively pathogen-free planting material of this plant.

Critical Review on Plant Micropropagation of Ethiopian Plants Reported So Far: Existing Gaps, Required Standardization, and Future Research Direction

“…e stated objectives and results of the various micropropagation studies have wide coverage and include virus cleaning and disease-free plantlet production, screening for salt-tolerant plants, in vitro micropropagation of medicinal and high-value crops, identification of better microtuber induction under various levels of sucrose, optimization of various concentrations of sterilants and plant growth regulators, and in vitro conservations [10][11][12][13][14][15][16][17][18][19][20], [21][22][23][24][25][26][27][28][29][30][31], [32][33][34][35][36][37][38][39][40][41][42], [43][44][45][46][47][48][49][50][51][52][53][54][55]. Other objectives include hormonal and media treatments to overcome hyperhydricity (vitrification) of micropropagated shoots…”

“…Plant micropropagation reports in Ethiopia should thus pay attention to these presumed controversies and contribute their share to address some of the existing controversies in order to expand the application of micropropagation with the desired repeatability and standards. Diverse plant species including cereals, oil crops, spices, medicinal plants, high-value crops, fruit plants, root crops, and endangered multipurpose shrubs were utilized in various forms of plant micropropagation in Ethiopia [10][11][12][13][14][15][16][17][18][19][20], [21][22][23][24][25][26][27][28][29][30][31], [32][33][34][35][36][37][38][39][40][41][42], [43][44][45][46][47][48][49][50][51][52][53][54][55]. Critical assessment of these studies would facilitate the development of repeata...…”