Subsidies for propagation of native species in Brazil with medicinal potential: Calophyllum brasiliense Cambess

Calophyllum brasiliense Cambess. (guanandi) is a native species with medicinal potential and also generates expectation for commercial use (wood) and for recovery of degraded areas. These seeds have physical and mechanical dormancy, requiring techniques for dormancy release; knowledge of seed and seedling morphology that assists laboratory analysis and propagation of the species is also necessary. The objective of this study was to describe the morphological structures of the seeds and normal and abnormal seedlings of guanandi, and also investigate if complete extraction of the endocarp and the seed coat to overcome dormancy will affect the morphology and initial plant development, and consequently production of transplants. Guanandi seeds are large (1000 seed weight of 1480.9 g) with a hard seed coat; cotyledons account for most of the embryo and serve as a reserve; the embryonic axis is small (1.0-2.0 mm) in relation to the seed, yet it is differentiated. The seedlings have hypogeal cryptocotylar germination, with cotyledonary petioles, taproot, and epicotyl developing into a long stem and a tip protected by cataphylls. The main abnormalities in seedlings are related to the root system. Extraction of the endocarp and seed coat does not alter the morphology of seedlings and promotes their greater development, which may be an advantageous strategy.

Are seedlings diagnostic in Neotropical Entada (Leguminosae)? Seedling morphology supports the reinstatement of Entada polyphylla

Entada (Leguminosae) is a pantropical genus encompassing four Neotropical species, E. gigas (E. sect. Entada), E. polyphylla, E. polystachya and E. simplicata (E. sect. Entadopsis). However, the taxonomic status of E. polyphylla is still disputed, being treated as a separate species or a variety of E. polystachya. This article aims to take a comprehensive view of seedlings of Neotropical Entada, addressing the question of whether seedling morphology provide diagnostic characters that support the recognition of E. polyphylla at the species level. Seedlings of E. polyphylla were described and illustrated, whilst seedling data for the remaining Neotropical species were based on the literature. Entada polyphylla has an exclusive set of seedling characters within E. sect. Entadopsis, including cryptocotylar, hypogeal, reserve seedlings, long cotyledonary petioles, short cotyledon lobes, cataphylls and alternate, bipinnate eophylls. Therefore, seedling morphology supports the recognition of E. polyphylla as a distinct species and its reinstatement is here proposed. In addition, each of the four New World species of Entada can be diagnosed by their seedlings, and an identification key is also provided.

Organogenesis during plant regeneration in cotyledon culture of Trifolium michelianum Savi

Shoots of <em>Trifolium michelianum</em> Savi. could be induced directly from the cotyledonary petiole or through petiole-derived callus on EC6 medium (Mahewswaran and Williams 1984) supplemented with BAP at 4.4, 8.8 and 22.2 µM. The mode of caulogenesis highly depended on cytokinin concentration in the medium. Most of the shoots regenerated into mature plants when transplanted to half-strong MS (Murashige and Skoog 1962). The time of caulogenic determination was set for the first day of culture. The induction of determination for caulogenesis was accompanied by the loss of competence toward root formation. SEM studies revealed that caulogenesis was restricted to the distal end of the cotyledonary petioles, very close to but not at the site of excision. The sites of shoot regeneration were limited to abaxial and lateral surfaces of the petioles.

REGENERATION OF PISTACIA

Cotyledons and embryonic axes of Pistacia vera L. `Kerman' were cultured on modified DKW or MS media. Cotyledonary petioles regenerated shoots when cultured on DKW medium supplemented with (in g/liter) 2.5 Zn(NO3)2, 0.48 H3BO3, 100 KNO3 and (in mg/liter) 1 BA, 0.01 IBA, 2 kinetin and 250 glutamine whether under light (80 μmol·m-2·s-1) or dark conditions. Cotyledons regenerated floral parts from their abaxial surfaces when cultured on (1) DKW or MS, both supplemented with (in mg/liter) 600 glutamine, 300 glycine, 200 asparagine, 50 arginine, 20 ascorbic acid and 0.05-0.1 2,4-D plus 0.1 BA or 0.1 zeatin under light or dark conditions or (2) DKW medium supplemented with (in g/liter) 2.5 Zn(NO3)2, 0.48 H3BO3, 100 KNO3 and (in mg/liter) 0.002 thidiazuron plus 0.2 2,4-D under light conditions.

Germination of Jedda multicaulis Clarkson,J.r. (Thymelaeaceae). An Example of Cryptogeal Germination in the Australian Flora

The germination of Jedda multicaulis is figured and described. It provides the first record of cryptogeal germination for a member of the family Thymelaeaceae and demonstrates the habit for the first time in a woody dicotyledonous member of the Australian flora. Anatomical studies show the burying of the plumule is the result of a modification of the cotyledonary petioles. The germination pattern is considered to be primarily an adaptation to fire. It also provides a mode of recovery following grazing or trampling.

GLANDULAR TRICHOMES ON COTYLEDONARY PETIOLES OF LEGUMINOSAE TRIBE TRIFOLIEAE

Gland-tipped trichomes were found to occur on the cotyledonary petioles of a number of species of Medicago, Trigonella and Melilotus. Their location, seemingly protecting the plumule, and the known insect resistance provided by glandular hairs on stems and fruits of Medicago suggest that they are defensive, and may be useful in plant breeding.Key words: Medicago, alfalfa, Trigonella, Melilotus, glandular trichomes, pest resistance (immunity)

Heat-induced callose and lateral movement of assimilates from phloem

Brief localized heating of cotton cotyledonary petioles increased phloem callose and decreased lateral movement of 14C-assimilates. There was little or no increase in phloem callose when plants were heated directly after a dark period of 16 or more hours. Such heated low-callose petioles had more lateral movement than heated high-callose petioles. Phloem callose and lateral movement returned to normal within 1 day after heating. These results suggest that phloem callose caused part of the decrease of lateral movement in heated high-callose petioles. Excessive phloem callose would be expected to restrict lateral movement, if movement from sieve tubes were via plasmodesmata.