biology, the present work aims to describe the morphology and anatomy of bisexual and functionally male flower types in pomegranate. Morphological and histological evaluations of hermaphroditic and male flowers were conducted using light microscopy (LM
Hazel Y. Wetzstein, Nadav Ravid, Erik Wilkins and Adriana Pinheiro Martinelli
Ying Gao, Hao Liu and Dong Pei
comparisons of different studies. Morphological features that can be used as indicators of developmental stage have been identified in various plants. For example, flower bud development in Cyclocarya paliurus can be defined based on floret size, anther
Rogério Ritzinger and Paul M. Lyrene
Several morphological features of Vaccinium ashei Reade, V. constablaei A. Gray, their F1 hybrids, V. simulatum Small, and southern highbush blueberry (V. corymbosum L. hybrids) flowers were compared in Gainesville, Fla. Desirable characteristics that could increase the extent of honeybee pollination, such as a large corolla aperture and a short anther-to-stigma distance, were common in V. constablaei but not in V. ashei. F1 (V. ashei × V. constablaei) hybrids were generally intermediate between the two parents. Thus, it appears that V. constablaei could be used to breed V. ashei cultivars with improved flower morphology. Vaccinium simulatum and V. constablaei flowers were similar in all features. The corollas of southern highbush blueberry flowers were wide and had wide apertures, but the distance between stigma and anther pore was also large.
Deborah Buszard and W.W. Schwabe
`Cox's Orange Pippin' apple (Pyrus domestics Berth.) trees, which were previously heavily cropped compared to previously defruited trees, had smaller flowers, lower initial fruit set, and a shorter effective pollination period (EPP) than defruited trees. The morphology of apple flower styles and stigmas was studied using scanning and transmission electron microscopy. Virgin stigmas from previously unstressed trees had fully expanded papillae, but 7 days after pollination the papillae were collapsed and distinct pollen tubes penetrated the stigmatic surface. Virgin stigmas from flowers of previously heavily cropped trees were smaller than those from previously defruited trees. The virgin stigmas of the flowers of heavily cropped trees showed collapsed papillae, and differences were observed in the intercellular material in the subtending transmitting tissue. These differences may explain the poor fruit setting characteristics of apple flowers on trees that have borne a heavy crop in the previous year.
Susan H. Gordon and Richard J. Hull
Frequent winter injury to flower buds is a major deterrent to the widespread landscape use of evergreen azaleas in the northern United States and southern Canada. Field observations indicate that azalea cultivars differ greatly in their capacity for cold acclimation during the fall. Azaleas also express wide variation in morphological features, such as Ieaf number, density, percent abscission, twig Iength, flower bud development rate, number or bud scales, and petal color. We attempted to correlate these characteristics with the establishment of flower bud cold tolerance during the fall season. Young (3-year-old) plants of more than 60 azalea cultivars were investigated under nursery conditions. Twigs were subjected to controlled freezing to quantify frost tolerance of flower buds. Percent live florets per bud and number of dead florets per bud were correlated with morphological characters. Floret development (floret Iength and style Iength) correlated positively with cold acclimation. Stem and Ieaf characters showed no consistent correlation with bud cold tolerance. Petal coloration, although not expressed at time of study, also correlated with cold acclimation. The extent of flower bud development proved to be the best indicator of fall and early winter frost tolerance.
Renate Karle and Thomas H. Boyle
The effects of floral morphology and breeding behavior on flower longevity were investigated in Easter cactus [Hatiora ×graeseri (Werderm.) Barthlott)]. Four clones were studied: two diploid (n = 11) clones (`Evita' and `Purple Pride') that were highly self-incompatible (SI), and two cytochimeras (diploid epidermis and tetraploid subepidermis) that were recovered from the diploid cultivars, both of which were self-compatible (SC). The clones exhibited differences in the stage of floral development in which autogamy commenced. Autogamy commenced on the day of anthesis in the two `Evita' clones and occurred ≈5 days after anthesis in the `Purple Pride' cytochimera. In the `Purple Pride' diploid clone, anthers and stigmatic lobes remained spatially separated during the period from anthesis to senescence. Examination of styles collected from senesced, undisturbed flowers showed that few pollen tubes traversed to the base of the styles for the two SI diploid clones, whereas large numbers of pollen tubes were present at the base of the styles for the two SC cytochimeras. Flower longevity for the `Evita' cytochimera was significantly less than for `Evita' diploid, but the diploid and cytochimeral clones of `Purple Pride' exhibited similar flower longevities. Application of 2 mm silver thiosulfate, an inhibitor of ethylene (C2H4) action, did not affect flower longevity of `Evita' cytochimera. Our results show that flower longevity in Easter cactus is influenced by breeding behavior and the stage of floral development at which autogamy commences.
Blair J. Sampson, Stephen J. Stringer and Donna A. Marshall
’s’ floral morphology affected various components of O. ribifloris ’ pollination efficiency. Percent fruit set, fruit weight, and seed number per berry were compared for 25 racemes with normal flowers and 25 racemes with deformed flowers (see Fig. 1
Wen-Shaw Chen, Hsueh-Wen Chang, Wen-Huei Chen and Yih-Shyan Lin
Gibberellin A3 (GA3: 1, 3, or 5 (μg/shoot), 6N-benzyladenine (BA: 1, 3, or 5 μg/shoot), or both were applied to the flowering shoots of a white hybrid Phalaenopsis orchid (Leda) when they were 2 to 3 cm (stage 1, no flower primordial long at high temperature (30 °C day/25 °C night). When flowering shoots were treated with GA3, alone, deformed flowers were more frequent with increasing GA3 concentrations. The occurrence of GA3-induced deformed flowers was prevented by BA at the same dose as GA3 when applied 4 days after GA3 treatment. BA (1, 3, or 5 μg/shoot) was also applied 4 days before (time 1) or 4 days after (time 2) GA3 (1 (μg/shoot) treatment for regulating plant characteristics. The application of BA at 1 or 5 μg/shoot to stage 1 flowering shoots at time 2 resulted in short internodes between florets, whereas BA application at time 1 had no effect. Simultaneously, BA at 1 or 5 μg/shoot applied at time 1 or time 2 to stage 2 (5 to 6 cm long, two- to three-flower primordia) flowering shoots also shortened internode length between florets as compared to GA3 alone. When a stage 1 flowering shoot was given BA (3 or 5, but not 1 μg/shoot) and then treated with GA3 4 days later, flower count was slightly reduced as compared to treating with (GA3 alone. However, a high dose of BA applied at time 1 or time 2 on stage 2 flowering shoots had no effect on flower count. Chemical names used: N-(phenylmethyl)-lH-purine-6-amine [benzyladenine (BA)], gibberellic acid (GA3).
Group-author : R. Socias i Company
Bloom evolution and flower quality were studied in 10 almond [Prunus amygdalus Batsch syn. P. dulcis (Mill.) D.A. Webb] selections of the Zaragoza breeding program. The opening of individual flowers followed a normal distribution, with deviations reflecting temperature differences during the bloom period. The first open flowers are of better quality than later ones and may contribute more to fruit set. The relative stigma–anther position reflected the possibility of natural autogamy in three of the 10 selections. Natural autogamy might allow single-cultivar orchards without the need for pollinating insects.
Zhiyi Bao, Bo Chen and Hua Zhang
dead) obtained by analysis of nine morphological characterization variables. Results from this analysis showed that the cluster grouped first as a result of the similarity in leaf color. The accessions with similar flower color grouped into