The morphogenetic potential of parval or pointed gourd (Trichosanthes dioica Roxb.) shoot-tip explants was investigated to establish this species as a model tissue culture system. An effective multiple-shoot propagation method is described. Ten-millimeter shoot tips from young branches of greehouse-grown plants served as explants. They were initiated on a MS basal medium. Multiple shoots were encouraged by transferring established explants to a proliferation medium consisting of MSB + 1 mg BAP/liter, because lower concentrations of BAP (0.1 to 0.5 mg–liter–1) inhibited multiple shoot formation; however, the same concentrations promoted rooting in explants. Medium supplemented with 1 mg BAP/liter and 100 mg PVP/liter caused the best proliferation of shoot tips. Upon transferring to fresh medium of the same composition, these shoot tips elongated 24 cm with three to five nodes in 4 weeks of culturing. Shoot multiplication cultures were maintained by transferring segments of multiple-shoot clusters to medium containing 1 mg BAP/liter and 0.5 mg GA3/liter. Medium supplemented with TDZ inhibited the number of regenerating explants but enhanced the number of shoot buds. Eighty percent of these plantlets were successfully rooted on MS medium supplemented with 1 mg NAA/liter. Plantlets survived in potting soil and exhibited normal growth under mist in the greenhouse.
U.L. Yadava and S.K. Dhir
Methyl l-(butylcarbamoyl)-2-benzimidazolcarbamate (benomyl), a systemic fungicide, added to modified Murashige and Skoog's medium regulated asparagus shoot and root development. Low levels of benomyl (10 to 50 ppm) promoted multiple vigorous shoot development. Higher levels of benomyl (100 to 250 ppm) caused the development of abnormally short, thick shoots and inhibited root formation. The enlargement of the shoots is due to proliferation of cortex, phloem, and xylem cells.
L. Agus Sukamto
Shoot tip culture of Ficus benjamina L. `Variegata' produced multiple shoots on Murashige and Skoog (MS) medium with 1 μm 2,4-dichlorophenoxy acetic acid (2,4-D), 1 μm napthalene acetic acid (NAA), 1 μm benzylaminopurine (BAP), l-proline at 2 mg·liter–1, and l-glutamine at 1 mg·liter–1 without previously producing callus. Multiple shoots were more profuse on one-half MS medium with 4.44 μm BAP. Single shoot of multiple shoots produced roots on one-half MS medium with NAA at 2.69 μm. Leaf culture of the plant produced profuse calli on same media without plant regeneration. Calli subcultured on one-half MS or MS media with 1.7 μm indole-3-acetic acid (IAA) and 150 μm 6-(y,y-dimethylallylamino)-purine (2iP) did not induce plant regeneration.
Howard L. Malstrom and Darrell Sparks
All yield components individually correlated with yield. However, percentage of shoots fruiting, shoot fruiting intensity, and tree fruiting intensity were not independent variables; and, in multiple regression analysis, yield correlated only with percentage of shoots fruiting and tree size. The multiple relationship gave a poor estimate of yield since, 1) percentage of shoots fruiting and their relationship to yield varied with the portion of the tree canopy sampled and 2) the relation of yield to tree size was apparently obscured by irregular bearing among individual trees. As indicators of fruitfulness, tree fruiting intensity and percentage of shoots fruiting were essentially equal. Yield variation was governed more by percentage of shoots fruiting than by shoot fruiting intensity. Nut weight varied curvilinearly with yield and nuts per tree.
Abigail R. Debner, Harlene Hatterman-Valenti, and Fumiomi Takeda
) blackberry plants that develop a flower shoot and fruit within several months. Cuttings would be taken during the dormant season to root, flower, and fruit for an annual high-density (≈75,000 potted plants/acre) production system that should produce ≈5000 lb
Chad E. Finn, Andrew L. Thomas, Patrick L. Byers, and Sedat Serçe
, 2007 ). If a grower can successfully manage S. canadensis with its multiple shoots, it would probably be a better commercial choice. Although several of these S. canadensis genotypes are likely to do well in Oregon, ‘Johns’ and ‘York’ offer the most
Jocelyne Kervella, Loïc Pagès, and Michel Génard
Leaf emergence was studied on main and first-order shoots of peach and nectarine [Prunus persica (L.) Batsch.] trees belonging to nine standard cultivars, during their first growing season. The number of emerged leaves was recorded on main shoots (originating from the grafted buds) and on first-order shoots (inserted directly on main shoots). Similarly shaped leaf emergence curves were observed on main and first-order shoots for all the cultivars. Leaf emergence rate decreased gradually as the number of leaves increased. The number of emerged leaves could be modeled as a monomolecular function of accumulated thermal units. Significant differences were found between cultivars in a multiple analysis of variance of the model parameters, for main and first-order shoots. The ranking of the cultivars was similar for both types of shoots. Leaf emergence rate was lower on first-order shoots than on main shoots. Differentiating between shoot types is necessary for a reliable comparison of genotypes.
Joao L.C. Faria and Juan Segura
A protocol for in vitro propagation in yellow passionfruit (Passiflora edulis F. flavicarpa Deg) has been developed. Shoot apices from aseptically grown seedlings were used as initial explants. Multiple shoot formation was obtained by placing the explants on solidified Murashige and Skoog medium containing BA. Regenerated shoots were rooted on media without growth regulators. Following conventional procedures, plantlets were transferred to soil with more than 90% success. Chemical name used: N-(phenylmethyl)-lH-purin-6-amine (BA).
Meristem tips of Castanea sativa Mill. from in vitro cultures derived from seedling explants initiated multiple shoot-buds and developed shoot-bud in the presence of 1 mg/liter 6-benzyIamino purine (BA) + 0.01 mg/liter indolebutyric acid (IBA). Root formation was readily achieved within 20 to 25 days when excised single shoots were transferred onto a fresh medium supplemented with IBA (1 mg/liter).
S. V. Kossuth
Multiple treatments with benzylaminopurine, kinetin, isopentenyladenine and cyclo-heximide, each at 3 concentrations were applied to Pinus sylvestris L. All chemicals reduced shoot extension and needle length. Benzylaminopurine (BA) 225 ppm induced 100% fascicular bud development. Removing new growth of multiple shoots from pruned stems of the previous year’s growth induced fascicular buds on the last growth flush. Continued treatment resulted in fascicular bud-break and shoot growth in August.