ISHS Acta Horticulturae 475: VII International Symposium on Pear Growing
THE VARIATION OF SEED CONTENT OF FRUITS IN PEAR VARIETIES, ALSO AS FUNCTION OF DIFFERENT CONDITIONS OF FERTILIZATION, AS OPEN POLLINATION, NATURAL AUTOGAMY AND ALLOGAMY |
| Authors: | J. Nyéki, M. Soltész |
| Keywords: | number of carpels, content of viable seeds per fruit, aborted seeds, variation of seed content, seed set in triploid pear varieties |
| Abstract:
Results are presented of an experiment aiming to explore functional relations between fertilization and fruit seed content in an extensive assortment and gene bank collection of pears from 4 growing sites during 2–4 years each, lasting 11 years altogether (loc.x year). The number of carpels of the pear fruit seems to be a varietal character, because there are deviations from number 5 resulting means of 3.5 – 5.5 in some items. No proofs of apomictic seeds exist. Natural autogamy occurred with low (0.4–1.9 %) fruit set and very few viable seeds (0.4–1.9 seed/fruit). The yearly variation of seed content was lower (5.4–6.9) than the variation of fruit set ratios (8.9–18.9 %). The mean rate of fruit set and the number of seed per fruit was higher as the result of purposeful allogamy, i.e. cross pollination than on open pollinated flowers at the same variety and growing site. Authors assigned each of the 107 pear varieties to 4 groups according to their viable seed content in the fruits resulting from open pollination: (1) very low (0.1 – 1), (2) low (1.1 – 3), (3) medium (3.1 – 5), (4) high (5.1 – 10). Seven varieties produced in addition to a low (less than 3) content of viable seeds aborted seeds with endosperm but no germ. The rate of fertilization and number of seeds has been assessed in 142 cross combinations. The seed content was higher (5.4 – 6.6) in varieties showing high rates of fruit set. Varieties known as good pollen producers caused higher seed content (6.6–6.7) in fruits pollinated by them. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
