Relationship of Seed Quality to Genetic Variation in Pollen
{'Code': '08010207', 'Directorate': {'Abbreviation': 'BIO', 'LongName': 'Direct For Biological Sciences'}, 'Division': {'Abbreviation': 'DEB', 'LongName': 'Division Of Environmental Biology'}}
{'SignBlockName': 'Tarri Joyner', 'PO_EMAI': 'tjoyner@nsf.gov', 'PO_PHON': '7032927742'}
Many plant species, including numerous economically                        important ones, regularly shed (abort) a large portion of their                 fruit crop.  Recent study of fruit abortion on the common and                   important forage crop, birdsfoot trefoil, shows that this plant                 not only selectively aborts those fruits with the fewest seeds                  but, by doing so, it improves the average quality of its seed                   (progeny).  In another study of common zucchini squash, the                     number of pollen grains placed onto the stigmas of the flowers                  were varied.  Again those fruits with the fewest seeds were the                 most likely to abort.  Moreover, the fruits with the most seeds                 produced progeny that germinated more rapidly, were more vigorous               as seedlings, and had greater flower and fruit production as                    adults than did the fruits with fewer seeds.  Dr. Stephenson                    proposes to examine the hypothesis that these observed                          differences in seed quality are due to genetic differences in the               pollen grains that fathered the seed.  That is, when there are                  more pollen tubes than eggs, only the best pollen fathers mature                seed.  In contrast, when there are fewer pollen tubes than eggs,                both the good and the mediocre pollen fathers mature seed.                      Therefore, by aborting those fruits with the few seeds (produced                when there were fewer pollen tubes than eggs) the plants                        eliminate those progeny fathered by the mediocre pollen while                   retaining the fruits fathered only by the best pollen.                               These findings should not only far reaching implications for               basic evolutionary biology and ecology but will also have                       significance for applied areas of plant science.  For example,                  the ability to rapidly screen large numbers of pollen grains for                agriculturally desirable traits, using only limited space,                      represents enormous potential gains for plant breeders.  Such                   screening could prove to be less expensive, more rapid, and                     easier to implement than many of the other state-of-the-art                     techniques, such as recombinant DNA and tissue culture.
[{'FirstName': 'James', 'LastName': 'Winsor', 'PI_MID_INIT': 'A', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'James A Winsor', 'EmailAddress': 'WMI@PSU.EDU', 'NSF_ID': '000278304', 'StartDate': '05/01/1989', 'EndDate': None, 'RoleCode': 'Co-Principal Investigator'}, {'FirstName': 'Andrew', 'LastName': 'Stephenson', 'PI_MID_INIT': 'G', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Andrew G Stephenson', 'EmailAddress': 'as4@psu.edu', 'NSF_ID': '000269364', 'StartDate': '05/01/1989', 'EndDate': None, 'RoleCode': 'Principal Investigator'}]
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{'Code': '1127', 'Text': 'Evolutionary Processes'}
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