Somatic Hybridization In Crop Improvement I

Thirty-five chapters on various aspects of fusion of plant protoplasts and somatic hybridization deal with the regeneration of interspecific and intergeneric somatic hybrids and cybrids in various plants: cereals, grasses, legumes, potato, tomato, eggplant, lettuce, Brassica, Datura, Hyoscyamus, Nicotiana, Catharanthus, Rauwolfia, Citrus, Poncirus, Prunus, Pyrus, Populus, algae, bryophytes, and ferns. The implications of somatic hybridization in gene transfer in wide crosses and for the induction of genetic variability in various crops are discussed. The book is an invaluable source of information for advanced students, teachers, and research scientists in the field of plant breeding, genetic engineering, plant tissue culture, and general plant biotechnology.

This richly illustrated volume describes how somatic hybrids can contribute to the improvement of crops. It comprises 24 chapters dealing with interspecific and intergeneric somatic hybridization and cybridization, providing valuable tools for plant breeders.

Wild taxa are invaluable sources of resistance to diseases, insects/ pests, nematodes, temperature extremes, salinity and alkalinity stresses, and also of nutritional quality; adaptation; genetic diversity and new species. Utilization of wild relatives of a crop depends largely upon its crossability relations with cultivated varieties. Sev eral wild species are not crossable with the commercial cultivars due to various isolation barriers. Furthermore, in a few cases, hybridiza tion is possible only in one direction and reciprocal crosses are not successful, thus depriving the utilization of desired cytoplasm of many species. However, techniques have been developed to over come many barriers and hybrid plants are produced. New crop species have been developed by overcoming the F 1 sterility and producing amphidiploids and such crops are commercially being grown in the field. The segregation pattern ofF 1 hybrids produced by distant hybridization in segregating generations are different from the intervarietal hybrids. In former cases, generally, unidirectional segregation takes place in early generations and accordingly, selec tion procedures are adopted. In most of the cases, backcross or modified backcross methods have been followed to utilize wild species, and thus numerous types of resistance and other economical attributes have been transferred in the recurrent parents. Protoplast fusion has been amply demonstrated in a number of cases where sexual hybridization was not possible and, as a result, hybrids have been produced.

A number of interdisciplinary fields related to Plant Cell Biotechnology are discussed. The two main directions are: Plant cell culture in agricultural applications for the improvement of crops and industrial applications in the production of secondary metabolites. A number of areas such as physiological and biochemical aspects of autotrophic cells, gene characterization in higher plants, transformation of plant cells, genetic stability in plant cell cultures, somatic hybridization and somatic embryogenesis are treated. Recent knowledge on somaclonal and gametoclonal variation as well as on the obtainment of protoplasts and their use for the isolation and culture of heterocaryons as tools for plant breeding are considered. Furthermore, the knowledge on biomass production in fermentor conditions and the role of immobilization for increased production and scale-up of plant cells are discussed.

We have taught plant molecular biology and biotechnology at the undergraduate and graduate level for over 20 years. In the past few decades, the field of plant organelle molecular biology and biotechnology has made immense strides. From the green revolution to golden rice, plant organelles have revolutionized agriculture. Given the exponential growth in research, the problem of finding appropriate textbooks for courses in plant biotechnology and molecular biology has become a major challenge. After years of handing out photocopies of various journal articles and reviews scattered through out the print and electronic media, a serendipitous meeting occurred at the 2002 IATPC World Congress held in Orlando, Florida. After my talk and evaluating several posters presented by investigators from my laboratory, Dr. Jacco Flipsen, Publishing Manager of Kluwer Publishers asked me whether I would consider editing a book on Plant Organelles. I accepted this challenge, after months of deliberations, primarily because I was unsuccessful in finding a text book in this area for many years. I signed the contract with Kluwer in March 2003 with a promise to deliver a camera-ready textbook on July 1, 2004. Given the short deadline and the complexity of the task, I quickly realized this task would need a co-editor. Dr. Christine Chase was the first scientist who came to my mind because of her expertise in plant mitochondria, and she readily agreed to work with me on this book.