both traditional and genetic engineering (GE), or “transgenic,” approaches to breeding for reduced fertility. Conventional forms include interspecific hybridization, polyploidization, and non-specific mutagenesis, all of which have led to commercialized
Kelly J. Vining, Ryan N. Contreras, Martin Ranik, and Steven H. Strauss
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
Chao Gao, Deyi Yuan, Ya Yang, Bifang Wang, Dongming Liu, and Feng Zou
Reproductive barriers in the intergeneric hybridization between Chrysanthemum grandiflorum (Ramat.) Kitam. and Ajania przewalskii Poljak. (Asteraceae) Euphytica 174 41 50 Ding, J.T. Shen, J.H. Li, W. Yang, H. 2009 Cytological observation of double
Rosanna Freyre and Erin Tripp
( Long, 1971 ), and variation in natural populations ( Long, 1974 ) of R. caroliniensis as well as artificial hybridization between this taxon and R. geminiflora ( Long, 1976 ). There has been no shortage of names that have been used to refer to a
Complete (100%) hybridization in lettuce (Lactuca sativa L.) was accomplished consistently using the clip-and-wash method of emasculation. The clip-and-wash method is a combination of washing and clipping, two previously described procedures for pollen removal. The wash and the clip methods produced 98% and 95% hybridization, respectively. The method is quick and easy and eliminates inadvertent self pollination; with it one can produce the many hybrid seeds necessary for backcross and F1 genetic analysis in lettuce.
Rosanna Freyre, Adam Moseley, Sandra B. Wilson, and Gary W. Knox
displacing native species, changing community structures or ecological functions, or hybridizing with natives” ( FLEPPC, 2011 ). The Institute for Food and Agricultural Science (IFAS) Assessment of the Status of Non-Native Plants in Florida's Natural Areas
P. Salas and L. Mansur
Gene flow between species of different ploidy levels is important in plant evolution and breeding. A cytological study was conducted on a natural population with individuals belonging to the diploid L. purpurea Gay (2n = 10) and to the tetraploid L. coquimbensis F. Phil (2n = 18) species, as well as intermediate phenotypes of apparent hybrid origin. The genus Leucocoryne is endemic to Chile and it exhibits heterogeneity, presumably genetic, for shape, size, and color of its flowers. The objective of the study was to determine if there is gene flow between species having different ploidy levels. From the karyotypic analyses of the seeds, only parental types having 2n = 10 and 2n = 18 individuals were observed. However, from the bulb analyses, 2n = 10, 2n = 18, 2n = 14, and 2n = 22 individuals were encountered. The karyotypes of the 2n = 14 and 2n = 22 individuals suggest the occurrence of natural interespecific hybridization between species with different ploidy levels in nature. Models which may account for the origin of these genotypes are proposed.
Cheryl R. Hampson and Anita N. Azarenko
Self-incompatibility, a genetic mechanism enforcing out crossing, is most commonly controlled by a single, multi-allelic gene, designated the S-gene. Sporophytic self-incompatibility (SSI), a form of incompatibility determined by the parent plant rather than the gametes, is present in the Brassicaceae, Compositae and other families, and also in hazelnut (Corylus avellana L.). Little is known about the molecular basis of SSI in plants other than crucifers. An S-gene cloned from Brassica oleracea (donated by Dr. June Nasrallah, Cornell University) was used to probe genomic DNA obtained from seven hazelnut genotypes. DNA hybridization was observed in cultivars `Hall's Giant' and `Willamette'. Gene similarity was estimated to be 70-80%.
Caihong Zhong, Shengmei Wang, Zhengwang Jiang, and Hongwen Huang
. Hybridization, especially interspecific hybridization, is a very important method to develop new kiwifruit cultivars, which can combine the good traits from different species in the genus Actinidia . The hybrid can be intermediate types or types with
Rosanna Freyre, Amy C. Douglas, and Michael O. Dillon
Reciprocal crosses, both intraspecific and interspecific, were made among five Chilean species of Nolana (Solanaceae), a genus native to western South America. With the exception of N. paradoxa, plants of all species used were grown from mericarps collected from wild populations. Self-pollinations were generally not successful, suggesting obligate allogamy. A total of 333 hybridizations were performed, of which 109 were intraspecific and 224 interspecific. Successful intraspecific hybridizations, as measured by formation of fruits, were produced for N. acuminata (83%), N. elegans (94%), N. paradoxa (82%), and N. rupicola (100%), however viable hybrids were only obtained for N. paradoxa. Interspecific combinations resulted in over 80% fruit set, however, viable hybrid success ranged from only 1% to 5%. Crosses included N. elegans × N. paradoxa with 20 viable hybrids, N. paradoxa × N. elegans with two hybrids, N. paradoxa × N. rupicola with seven hybrids, and N. rupicola × N. paradoxa with five hybrids. Exceptions included crosses involving N. aplocaryoides, with up to 20% fruit set. Also, the combination N. paradoxa × N. aplocaryoides with five hybrids, had a 26% success. All interspecific hybrids obtained had N. paradoxa as one of the parents, which could be related to artificial selection for high germination frequency.