Open AccessExtraction of ancestral constituents of natural polyploids
Author(s) -
SIDDIQUI K. A.
Publication year - 1972
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1972.tb01007.x
Subject(s) - biology , backcrossing , loss of heterozygosity , botany , chromosome , chromosome number , genetics , gene , karyotype , allele
Varieties Chinese Spring, Peko, Koga and Svenno of Triticum aestivum (L.) T hell . (2n = 6x = 42), AABBDD, were used as recurrent parents in the third backcross of the pentaploids and 34‐chromosome plants obtained from the second backcross (S iddiqui 1972). The B 2 pentaploids involving Chinese Spring gave a seed set of 5%, whereas the F 1 and B 1 pentaploids involving the same hexaploid had given 15% and 10% seed set respectively. The B 2 pentaploids involving Peko and Koga both gave a higher seed set (18 and 10%, respectively) than the B 2 pentaploids of Chinese Spring. Although, with successive backcrossings, the genes of the original tetraploid parent become more and more diluted, morphological resemblance of pentaploids to hexaploids might be misleading. Persistence of aestivum X durum heterozygosity would defeat the very purpose of extraction. Use of primitive tetraploids such as Triticum dicoccoides Körn, Triticum persicum (B oiss ) A itch . and H emsl . and Triticum polonicum L., instead of Triticum durum D esf ., in the production of the original pentaploids (S iddiqui 1969 a), might be a means of circumventing persistent hexaploid X tetraploid heterozygosity.