CHROMOSOME-NUMBER AND DNA CONTENT IN CELLS OF A BIOTECHNOLOGICALLY SELECTED SOMACLONE OF GARLIC (ALLIUM-SATIVUM L)

A somaclonal variant of Allium sativum L., selected in vitro through biotechnological procedures, was characterized by increased vigour and high productivity, both unchanged after five cycles of field cultivation. The same chromosome number was found in somaclonal variant metaphase cells and those of a control (2n = 16). However, Feulgen-DNA values in metaphases and interphase nuclei of the somaclonal variant were shown to differ from those of the control, a 4.5% DNA increase being found in the somaclonal variant metaphases. The possibility of gene amplification in the somaclonal variant cells could explain their slight increase in DNA content.16234735

REGENERATION OF GARLIC PLANTS (ALLIUM-SATIVUM L, CV CHONAN) VIA CELL-CULTURE IN LIQUID-MEDIUM

Aiming at the genetic improvement of garlic cultivars, a cell suspension protocol was established which includes the induction of friable callus, establishment of cells in liquid medium, plating, regeneration, and bulb formation. Calluses of various textures from compact to friable and from green to yellowish were obtained by culturing explants excised from inner leaves of garlic bulbs on Marashig-Shoog (MS) medium with 2,4 dichlorophenoxy acetic acid (2,4-D), (1.1 mg/liter [5.0 mu M]), picloram (1.2 mg/liter [5.0 mu M]), and kinetin (2.1 mg/liter [10 mu M]). Friable callus occurred on MS-A contained 2,4-D alone (1.0 mg/liter [4.52 mu M]) and this callus was used to develop cell suspension cultures, which were maintained in liquid MS-B medium with a 2,4-D/benzyl adenine (BA) (0.5 mg/liter [2.25 mu M]: 0.5 mg/liter [2.22 mu M]) ratio. High plating efficiency was obtained on MS-C medium with different naphthalene acetic acid/BA combinations. Regeneration occurred after transfer of the caulogenic mass to MS-C medium containing 10 mg/liter (74.02 mu M) and 20 mg/liter (148.04 mu M) adenine for 60 days, followed by transfer to adenine-free medium. Plantlets transplanted to soil showed normal phenology. Shoots grown on modified MS medium supplemented with indolylbutryic acid (3.0 mg/liter [14.7 mu M]) stimulated bulb formation by 30 days in culture.30P315015

Introgression of in vitro regeneration capability of Lycopersicon pimpinellifolium Mill. into recalcitrant tomato cultivars

The goal of this research was to study the introgression of the high regeneration capacity of Lycopersicon pimpinellifolium Mill line WV-700, in recalcitrant tomato cultivars ( L. esculentum Mill cvs. Petomech, Santa Rita and VFN-8) using backcrossing. Hypocotyl explants of in vitro germinated seeds were cultivated in half strength MS medium supplemented with 5mg/l 6-BA to assess their shoot regeneration capacity. The apical shoot of the in vitro germinated seeds were cultured on a separate medium. Apical shoots from genotypes showing high regeneration rates were acclimated in a glasshouse and used as pollen donors for the next backcrossing. After four backcrossings, the material showed a similar mean fruit weight for the cultivated tomato and a high regeneration capacity similar to the wild species. It is shown that L. pimpinellifolium can be used with success as donor parent to introgress in vitro regeneration capacity to recalcitrant tomato cultivars.1241596