species, as well as genetic deficiencies in good or specific traits for some fruit trees ( Yang et al., 2004 ). A large number of studies have shown that distant hybridization is a more effective method of enriching species and genetic diversity compared
L.X. Zhang, W.C. Chang, Y.J. Wei, L. Liu, and Y.P. Wang
Cryopreservation of pollen from two ginseng species —Panax ginseng L. and P. quinquefolium L.—was studied. Freezing anthers that served as pollen carriers to –40C before liquid N storage affected pollen viability little after liquid N storage. Anther moisture content affected pollen viability significantly when stored in liquid N. The ideal anther moisture content to carry pollen for liquid N storage was 32% to 26% for P. ginseng and 27% to 17% for P. quinquefolium. Viability of pollen from P. quinquefolium anthers with 25.3% moisture content changed little after 11 months of liquid N storage.
Thomas G. Ranney and Paul R. Fantz
Franklinia alatamaha Bartr. ex Marshall represents a monotypic genus that was originally discovered in Georgia, USA, but is now considered extinct in the wild and is maintained only in cultivation. Although Franklinia is very ornamental, with showy flowers and crimson/maroon fall foliage, it tends to be short lived when grown as a landscape tree and is known to be susceptible to a variety of root pathogens. Gordonia lasianthus (L.) Ellis is an evergreen tree native to the southeastern United States, typically growing in riparian habitats. Gordonia lasianthus has attractive foliage and large, white, showy flowers, but limited cold hardiness. Hybridization between F. alatamaha and G. lasianthus could potentially combine the cold hardiness of F. alatamaha with the evergreen foliage of G. lasianthus and broaden the genetic base for further breeding and improvement among these genera. Controlled crosses between F. alatamaha and G. lasianthus resulted in intergeneric hybrid progeny. A morphological comparison of parents and the progeny is presented. ×Gordlinia grandiflora Ranney and Fantz (mountain gordlinia) is proposed as the name for these hybrids and is validated with a Latin diagnosis.
Thomas G. Ranney, Thomas A. Eaker, Paul R. Fantz, and Clifford R. Parks
Franklinia alatamaha Bartr. ex Marshall represents a monotypic genus that was originally discovered in Georgia, but is now considered extinct in the wild and is maintained only in cultivation. Although Franklinia is very ornamental, with showy flowers and crimson/maroon fall foliage color, it tends to be short lived when grown as a landscape tree and is known to be susceptible to a variety of root pathogens. Schima argentea Pritz is an evergreen tree that is native to Asia and is valued for its glossy foliage, late-summer flowers, and broad adaptability in mild climates. Hybridization between these genera could potentially combine the cold hardiness and desirable ornamental characteristics of F. alatamaha with the greater adaptability, utility, and genetic diversity of S. argentea. Controlled crosses between F. alatamaha and S. argentea resulted in new intergeneric hybrid progeny. A morphological comparison of parents and the progeny is presented. ×Schimlinia floribunda Ranney and Fantz (mountain schimlinia) is proposed as the name for these hybrids and is validated with a Latin diagnosis.
Malcolm W. Smith, Debra L. Gultzow, and Toni K. Newman
phenomenon in distant hybridization, known as late-acting lethality. For example, the first intergeneric hybrids in coffee breeding between Psilanthus Hook.f. and Coffea L. resulted in 41 plants, but 78% of these wilted and died during the first five
Liuhui Yang, Jianjun Zhang, Jaime A. Teixeira da Silva, and Xiaonan Yu
hybrid group (HG) uses P. lactiflora , P. officinalis , P. macrophylla , and other species as the parents, whereas members of the Itoh group (IG) are the product of distant hybridization in which peony (section Paeonia ) served as the female parent
Qijing Zhang and Dajun Gu
characterized by their cold resistance, dwarfing, and early fruiting. Further, distant hybridization within Prunus species has been widely applied as the preferred strategy for fruit production and has yielded a number of cultivars. For example, ‘Colt’ ( P
Chao Yu, Le Luo, Hui-tang Pan, Yun-ji Sui, Run-hua Guo, Jin-yao Wang, and Qi-xiang Zhang
possible. Although not discussed in this article, attention must be given to the relationship between the ploidy difference and the success of distant hybridization. Detailed analysis of the Solanum polyploid series, where the endosperm behavior has been
Xuejuan Chen, Ming Sun, Jianguo Liang, Hui Xue, and Qixiang Zhang
background. Furthermore, more distant hybridization with wild species can broaden the genetic base of chrysanthemum cultivars. Consequently, AFLP markers can provide valuable molecular data for investigating genetic relationships among closely related groups
Ryan N. Contreras and John M. Ruter
Bot. Mag. Tokyo 103 57 66 Kush, G.S. Brar, D.S. 1992 Overcoming the barriers in hybridization 47 61 Kalloo G. Chowdhury J.B. Distant hybridization of crop plants. (Monographs on theoretical and applied genetics; vol. 16) Springer-Verlag New York, NY