In vitro Propagation to Conserve the Local Endemic and Endangered Medicinal Plant Helianthemum germanicopolitanum Bornm

Abstract In this study, in vitro propagation and acclimatization of Helianthemum germanicopolitanum Bornm. plant, a local endemic in Çankırı Province (Turkey) with arid and semi-arid lands, and an endangered species taking part among medicinal and aromatic plants were accomplished, which is under-researched. In this study, three basal media [a) Murashige and Skoog b) Gamborg's B5, and c) Nitsch & Nitsch], two gelling agents (agar 7 g/L, and gelrite 2.1 g/L), eight cytokinins and eight auxin doses of plant growth regulators [a) 6-benzyladenin, b) Kinetin-(0, 0.5, 1, and 2 mg/L), c) Indole-3-butyric acid, d) α-napthaleneacetic acid-(0, 0.25, 0.5, and 1 mg/L)] prepared in 64 different combinations with 30 g/L sucrose was added to the basal media and adjusted to pH 5.7 for in vitro propagation of H. germanicopolitanum. During in vitro propagation of the plant, external and internal infections were frequently encountered and this was solved by the developed protocol. The best shoot growth (1.141 cm) and shoot length (0.572 cm) were obtained in the Gamborg's B5 medium in combination with Kinetin (0.5 mg/L)+Indole-3-butyric acid (0.5 mg/L)+gelrite. The maximum number of shoots (19.50) and the best multiplication rate (94%) were obtained in the media containing benzyladenin (1 mg/L)+Indole-3-butyric acid (0.5 mg/L) plant growth regulator in Murashige and Skoog medium solidified with agar. At the rooting stage, the maximum number of roots (30) was reached in the Murashige and Skoog medium containing gelrite and the best rooting rate (92%) with agar. A hundred plants representing the best shoot and root growth were taken to acclimatization stage, and 32 of these plants adapted to external conditions.

Abilities of Trichoderma Species to Persist within Maize (Zea mays) Stem Long after Inoculation.

Different Trichoderma species were examined for their abilities to persist within the maize (Zea mays) stem at different points above and below inoculation points. Different Trichoderma species were isolated from different parts of the maize (Z. mays) plant and its rhizosphere. They were later sent to International Mycological Institute, England for identification. Maize seeds (DMR-LSRW) were planted in pots in the screenhouse. Four weeks after planting, each of the Trichoderma species was inoculated into the stems of the potted plants at the 2nd internodes using the toothpick method. Toothpicks dressed with sterile distilled water served as control. Cut sections of the inoculated stems were examined for presence or absence of the inoculated Trichoderma species at different points far from the inoculated point in the upper and lower internodes after 2, 3, 4, 5 and 6 weeks of inoculation. Ten Trichoderma species were identified; these include five strains of T. pseudokoningii, three strains of T. harzianum, T. hamatum and T. longibrachiatum. All the Trichoderma species were able to move within the stem tissues into the upper and lower internodes. All of them were re-isolated at distant points from inoculation point in the upper and lower internodes even after 6 weeks of inoculation. T. pseudokoningii strain 2 and T. harzianum strains 1 to 3 had the best endophytic movement into the upper and lower internodes. T. hamatum and T. longibrachiatum had the weakest movement into the upper and lower internodes. All the Trichoderma species could thus be said to possess the abilities to persist (endophytic capability) within the maize (Z. mays) stem. T. pseudokoningii and T. harzianum could also be said to be among the best species in the genus Trichoderma with good prospect of biocontrol potential.