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Title: Studies of genetic transformation of higher plants using irradiated pollen

Thesis/Dissertation ·
OSTI ID:6110323

Pandey has reported extensively on an unusual genetic phenomenon he called egg transformation. When compatible pollen was treated wth genetically lethal dosage of ..gamma..-radiation (100,000 rad), and used as mentor pollen to overcome selfincompatibility of several Nicotiana species, some genetic characters were found to be transferred from the radiation killed pollen to nonhybrid progeny. Observed transformants were fertile, cytogenetically normal, and had maternal phenotypes except for those specific traits transferred from the donors. Heavily irradiated pollen was believed to discharge its radiation-fragmented DNA (chromatin) into the embryo sac and bring about the transformation of the egg. The frequency of gene transfer was reported to be over 50%, and happened for all three characters Pandey studied - self incompatible specificities, flower color, and pollen color. Plant species studied were tomato, pea, apple, rapeseed, and Nicotiana species, including various stocks from Dr. Pandey. Treatments included pollinations with soley irradiated donor pollen, with a mixture of irradiated donor and normal self pollen, with a mixture of normal donor and self pollen, and double pollinations with irradiated donor pollen and normal self pollen, using different time intervals to separate the two pollinations. A total of 6210 pollinations were made, and 17,522 seedlings representing 87,750 potential transformational events were screened. In no case was an unambiguous transformant recovered. This research was unable to confirm or expand upon the findings of Dr. Pandey, or elucidate the mechanisms underlying such phenomena. Alternative explanations for Pandey's data were postulated. This approach to gene transfer by using irradiated pollen appears to be of little practical use to plant breeders.

OSTI ID:
6110323
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English