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Cytology and Fertility of Advanced Populations of Elymus lanceolatus (Scribn. & Smith) Gould × Elymus caninus (L.) L. Hybrids
Author(s) -
Jensen Kevin B.
Publication year - 2005
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2004.0235
Subject(s) - biology , hybrid , elymus , pollen , bivalent (engine) , meiosis , ploidy , botany , polyploid , chromosome , genetics , fertility , poaceae , gene , population , chemistry , demography , organic chemistry , sociology , metal
Within the wheatgrasses and wildryes, amphiploids are frequently made as a means for introgressing desirable traits and restoring fertility in hybrids between diverse species. This study reports the cytology, fertility, and morphological characteristics of Elymus lanceolatus (Scribn. & Smith) Gould, E. caninus (L.) L., their F 1 hybrids, advanced generations (F 7 and F 8 ), and three generations of advanced amphiploid progenies (C 1 , C 2 , and C 3 ). Meiotic chromosome associations of E. lanceolatus and E. caninus are typical of allotetraploids. Chromosome pairing in the F 1 hybrids suggests a close relationship between the two parents. Bivalent associations most frequently observed in the F 7 and F 8 were 14 bivalents. After multiple generations of harvesting available seed each generation from 10 plants, an increase in meiotic regularity was observed in the advanced F generations. Aneuploidy in the amphiploids (C generation) was observed in the C 2 and C 3 generations with chromosome numbers ranging from 47 to 56. The C 1 generation had significantly fewer univalents per cell than the C 2 and C 3 generations. Combined across chromosome numbers, there was a significant decrease in the number of bivalents from 22.48 to 21.36 to 20.27 in each succeeding C generation, respectively. After seven generations of seed increase, pollen stainability increased from less than 1% in the F 1 hybrid to 87 and 85% in the F 7 and F 8 generations, respectively. Chromosome doubling significantly reduced pollen stainability in the C 1 , C 2 , and C 3 generations as compared to the parents and advanced F generations. Cluster analysis was able to separate the parents and the different hybrid populations.