interspecific hybridization is the direction of the cross, as this may affect its rate of success, the number of seeds produced, as well as the dormancy of the seeds due to maternal effects ( Morgan et al., 2010 ). In this respect, using S. melongena as the
Mariola Plazas, Santiago Vilanova, Pietro Gramazio, Adrián Rodríguez-Burruezo, Ana Fita, Francisco J. Herraiz, Rajakapasha Ranil, Ramya Fonseka, Lahiru Niran, Hemal Fonseka, Brice Kouassi, Abou Kouassi, Auguste Kouassi, and Jaime Prohens
Mary Lewis, Matthew Chappell, Paul A. Thomas, Rebekah C. Maynard, and Ockert Greyvenstein
successful, naturally occurring interspecific hybridization via pollinator activity ( Wyatt and Broyles, 1994 ). Asclepias is also unusual in that they have two independent ovaries and, if pollinia are inserted perfectly, all subsequent seed will share a
Li Jiang, Yun-wen Wang, and Bruce L. Dunn
produced relatively few seed setting flowers, seeds per capsule, and number of germinated seeds. The results indicated that some interspecific cross-compatibility barriers prevented hybridization and obtaining normal seeds from crossing combinations
Chunqing Sun, Zhihu Ma, Zhenchao Zhang, Guosheng Sun, and Zhongliang Dai
lilies. To obtain desired traits of interest in cultivars, breeders have tried to make interspecific hybridizations. In the past, interspecific hybridizations in water lily have been performed for the hope of creating a blue hardy water lily hybrid, but
Randall J. Marek and Ronald D. Parker
An interspecific hybridization program involving ancestral species of the Begonia Semperflorens Cultorum Group was initiated to expand the genetic base of this group. Viable seeds were recovered from four reciprocal crosses. F, progenies were sterile and phenotypically intermediate between parental types. Fluorescence microscopy revealed evidence of both sporophytic and gametophytic incompatibility. Post-pollnation responses of flower petals were positively correlated with pollen tube growth in stigmatic, stylar, and ovarian tissue. A digital image analyzer was used to facilitate seed counts and to determine the percentage of ovules that developed into seeds. Seed germination percentages ranged from 0-91 for crosses to 80-99 for selfs.
Maryke A. Cleland, Cynthia Jones, and Mark H. Brand
An interspecific hybridization program involving five species of Impatiens was initiated to delineate incompatibility barriers. With the exception of one cross, no viable hybrid seed was recovered. Fluorescence microscopy revealed foreign pollen tubes to reach ovules in all crosses, although not all ovules were approached. A histological study involving I. auricoma Baill. and I. walleriana Hook f. ensued to confirm the presence of hybrid embryos. Developing I. walleriana × I. auricoma and reciprocal hybrid embryos were compared to self embryos. Development of hybrid embryos was delayed as early as five days post-pollination. I. walleriana × I. auricoma embryos continued to develop for 8 days post-pollination, but did not reach a size greater than a 5-day self embryo. Excessive endosperm was observed in the hybrid. I. auricoma × I. walleriana embryos continued to enlarge up to ovary abortion but did not reach a size greater than a 7-day self embryo and little to no endosperm developed. Disintegration of ovules included disorganization and collapse of the endosperm, and vacuolization and loss of turgidity of the embryo.
Margaret R. Pooler and Ruth L. Dix
Interspecific hybridizations among members of the genus Hamamelis (the witchhazels) and Corylopsis were carried out in 1993, 1994, 1995, and 1996 at the U.S. National Arboretum. Specifically, crosses involving the native witchhazel (H. vernalis and H. virginiana) and the Asian taxa (H. mollis, H. japonica, and H. × intermedia) were attempted in order to combine the ornamental qualities of the Asian species with the adaptability and fall blooming characteristics of the native species. Additionally, C. platypetala, a hardy species with small inflorescences, was crossed with C. himalaica, which has large showy inflorescences but is less hardy. Approximately 50 seedlings resulting from these crosses have been analyzed using randomly amplified polymorphic DNA (RAPD) markers to verify interspecific hybridization. Based on these assays, we report the first incidence of controlled interspecific hybridization between the Asian and native witchhazel taxa.
Sarah M. Smith and Zhanao Deng
plant species are brought into close proximity for seed production or planting, interspecific hybridization can occur ( Ellstrand, 1992 ). Interspecific hybridization could lead to genetic contamination of native wildflower seed being produced. If
Nicholi Vorsa and James J. Polashock
The flavonoids of american cranberry (Vaccinium macrocarpon Ait.) are documented to be beneficial for human health. Among their benefits is a high antioxidant potential, with anthocyanin glycosides being the main contributors. Flavonoid glucose conjugates are reported to be more bioavailable than those with other sugar conjugates. The anthocyanin glycosides of V. macrocarpon fruit are mainly galactosides and arabinosides of the aglycones, cyanidin and peonidin, with less than 8% glucosides. In contrast, the fruit anthocyanins of another cranberry species, V. oxycoccus L. were found to be largely glucosides of cyanidin and peonidin. Interspecific hybrids between these two species were intermediate to the parental species in the proportion of fruit anthocyanin glucosides. About half the progeny (1:1 segregation) in a backcross population (to V. macrocarpon) maintained the relatively high anthocyanin glucoside ratio. In this study, we demonstrate the genetic manipulation of anthocyanin glycosylation in cranberry using interspecific hybridization, resulting in dramatically increased glucose-conjugated anthocyanins.
Jiang Lu and Bernard Prins
The grape belongs to the genus Vitis L., which are divided into two subgenera, Euvitis Planch. and Muscadinia Planch. The Euvitis has 50 to 70 species, in which V. vinifera L. is a predominant species with hundreds of known commercial cultivars grown world wide. The Muscadinia (muscadine grapes) consists of only two to three species predominated by V. rotundifolia and only commercially cultivated in the southeastern United States. V. rotundifolia is known by its multiple resistance to almost all grape diseases and insects found on the Euvitis species, while the latter possesses good fruit characteristics that do not exist in muscadines. Attempts to produce rotundifolia-vinifera hybrids to combine good fruit quality and disease resistance of both into F1 hybrids have been made by grape breeders for many years. Limited success was reported when the V. vinifera was used as seed parents. This research extended the interspecific crosses beyond V. vinifera into other Euvitis species. Among the Euvitis species, A. aestivalis, V. cinerea, V. champinii, V. labrusca, V. monticola, V. nesbittiana, V. riparia, V. rupestris, V. thunbergii, V. quinguangularis, all with pistillate flowers, were used as female parents pollinated with V. rotundifolia pollen. Eight out of the 10 cross combinations except V. cinerea and V. thunbergii set fruits. However, most of the Euvitis-rotundifolia crosses had extremely low fruits set (<1% of pollinated flowers). The only exception was V. labrusca cv. Woodruff, which had very high percentage of fruit set (70%). Interestingly, the fruits of V. labrusca cv. Woodruff × rotundifolia were pathonocarpic that had only half size of regular fruits set from open pollination with pollen sources from other Euvitis species. In the reciprocal crosses, three pistillate V. rotundifolia cultivars, `Fry', `Higgins', `Jumbo', were used as female pollinated by pollen from Euvitis species. Limited fruit sets were found from the crosses of V. rotundifolia × V. shuttleworthii, V. cordifolia, V. rupestris, V. Piasezkii, V. quinquagularis. Results from this study indicated that hybridization between Euvitis and muscadinia species is indeed very difficult but it is possible, and some Euvitis species are cross more compatible with V. rotundifolia than the others.