Capsule Growth Research Articles

Phenolamides during the ripening of dormant and non‐dormant seeds in different Petunia lines

Phenolamides were extracted from reproductive organs and different capsule parts (fruit wall, placenta and seeds) of dormant and non‐dormant lines derived from the species Petunia hybrida hort,. Petunia axillaries Lam. B.S.P. and Petunia parodii Steere. The different compounds were separated by high‐pressure liquid chromatography and analyzed before pollination, during ripening, at ripeness and after 2 weeks of after‐ripening of the seeds. The extracts were examined particularly for the presence of an alkaline compound (X), which is a phenolic derivative of tryptophanamide and appears to be a biochemical marker for the dormancy of ripe dry seeds of Petunia. During capsule growth and seed ripening, compound X was not a marker for dormancy, although it occurred in the reproductive organs of seed‐parent plants. After pollination and fertilization, accumulation of compound X started mainly in the fruit wall, but in ripe dry capsules it was present entirely in the seeds. In contrast to compound X, neutral phenolamides were not detected in extracts from the fruit wall: and from the early stages of the capsule growth substantial accumulation took place only in the seeds.Absence of compound X from ripe dry seeds appears as a necessary but not a sufficient condition for non‐dormancy.

Growth, synthesis and regional specialization of the embryonic chicken lens capsule

The growth, synthesis and regional specialization of the lens capsule has been studied in chicken embryos and compared to adult chickens and mammals. During the final 15 days of embryonic development the surface area of the capsule increased 11-fold. This represents the minimum estimate of capsule growth, since it also increased in thickness during this period. Autoradiographic examination of [ 3H]proline- or 35SO 4-labeled, detergent-cleaned, flat-mounted capsules suggested that all lens cells participated in capsule synthesis. This was supported by the observation that both lens epithelial and fiber cells incorporated [ 35S]-methionine into collagenase-sensitive proteins with molecular weights similar to type IV collagen. Histochemical staining of detergent-cleaned capsule explants (DCCEs) revealed regional differences in the carbohydrate composition of the capsule. Differences in collagenous proteins were also seen between the anterior and posterior regions of the capsule of the embryonic lenses. Following SDS-PAGE and silver staining a total of six collagenase-sensitive proteins were seen with molecular weights between 150 and 180 K. Three of these polypeptides were common to both anterior and posterior capsules, one was found only in the anterior capsule and the other two were found predominantly in the posterior capsule. No regional differences were seen in the collagenous proteins of capsules from adult chickens, rats or hamsters. The possibility is discussed that the unique pattern of collagenous polypeptides seen in embryonic capsules is related to the rapid growth of the embryonic lens.

The morphogenesis of nematocytes in Hydra and Forsklia: An ultrastructural study

The morphogenesis of nematocytes in Hydra attenuata and Forsklia sp. involves the complex processes of capsule formation, growth, and differentiation; establishment of nematocyst thread regions within the external tube and invagination; development of pericentriolar processes and the cnidocil-associated apparatus; and the differentiation of the armament and operculum. Several important morphological questions are clarified in the present ultrastructural study. Throughout all stages of capsule development, including the earliest one observed, the two main structural layers, sklera and propria, are present in addition to the unit membrane. The external tube structure is directly proportional to the mature nematocyst thread and is encircled by a basket of microtubules the number of which is also dependent on size. The microtubules seem to be nucleated by the pair of centrioles or its pericentriolar processes. The wall of the external tube consists of three layers and the controversial invagination process is shown to be actually a modified invagination since only the middle layer invaginates. Nematocyte development overall is characterized by a close correlation between the formation of the nematocyst and the formation of the sensory apparatus.

Changes in Amount of Polyphenols and Activity of Related Enzymes during Growth of Tobacco Flower and Capsule

Developmental stages of tobacco (Nicotiana tabacum L. cv. Burley 21) flower and capsule were correlated with tissue contents of polyphenols and activities of phenylalanine ammonialyase, polyphenoloxidase, and peroxidase. Chlorogenic acid, scopolin, and scopoletin were present in most tissues, whereas rutin and two dihydroxyphenolic glycosides concentrated primarily in the corolla and placenta, respectively. Ovules contained only chlorogenic acid. As development progressed, polyphenols accounted for nearly 15% of the dry weight in the green capsule of field-grown plants. Fertilization triggered a rapid increase of chlorogenic acid in the ovary. When l-phenylalanine-U-(14)C was fed to the detached green capsules and capsule parts, an incorporation of radioactivity into chlorogenic acid and dihydroxyphenolic glycosides occurred which suggested in situ synthesis of these compounds. This was subtantiated by a positive correlation between phenylalanine ammonia-lyase activity and polyphenol accumulation. High polyphenoloxidase activity was associated mainly with the ovary, whereas peroxidase activity was maximal during senescence of all tissues. Polyacrylamide gel slab electrophoresis revealed five cathodic bands and one diffuse zone with poly-phenoloxidase activity in flower extracts. Two anodic poly-phenoloxidase isozymes appeared only in the fertilized ovary. Among 17 peroxidase isozymes, six cathodic forms were present throughout floral development, and the anodic ones increased in number and activity at the later stages of capsule growth.

STUDIES ON THE BREEDING OF PELARGONIUM SPECIES USED FOR THE ESSENTIAL OIL PRODUCTION. : V. Variation of Some Characters among Interspecific Hybrid Plants between P. roseum and P. denticulatum.

Reciprocal crosses were made between Pelarganium denliculatum, 4x and P.roseum 4x, and 51 hybrids were obtained. The variation of different plant characters among the F1 hybrids, such as capsule length, seed size, growth habit, leaf shape, flower shape and flower colour, was examined. The hybrids ranged between both parental species in each of the above-mentioned morphological characters. Signiflcant differences were found in both the number of essential oil glands and the yield of oil among the hybrid plants as well as among sampling dates. The components of essential oil in the hybrids were approximately intermediate between both parents.

BREEDING EUCALYPTUS REGNANS—FIVE YEAR PROGRESS REPORT

SUMMARY The breeding programme at Traralgon aims to improve Eucalyptus regnans F. v. M. as a forest tree by increasing the rate of growth, improving wood quality, and increasing resistance to damage by fire. Improvement may be accomplished in three ways:—(1) provenance trials (to determine the best place to collect seed for afforestation in a given location), (2) selection of individual trees within the chosen provenance, and (3) hybrids with species with greater resistance to fire and the ability to grow on poor sites. The major part of the work has been the provenance trials which show continuous genetic variation with altitude on the south eastern side of Mount Erica, Victoria. Seed for the trials was collected in October 1959 from 68 trees on Mount Erica. with an average of 10 trees at each of seven altitudes from 1200 feet to 3250 feet. Studies were made of capsule size, germination, cotyledon area, and growth of seedlings in the nursery. Sixty-four open pollinated progenies were planted in a cubic l...