The significance of meiotic chromosome behavior in breeding smooth bromegrass, Bromus inermis Leyss
1948
Elliott, F.C. | Love, R.M.
1. The clones of B. inermis examined had 2n=56. 2. Meiosis in the clones analyzed was quite irregular. The number of bivalents varied from 2 to 28 in different pollen mother cells. The average number of chromosomes involved in associations of five to eight ranged from 1.0 to 10.4 in the six clones. 3. No clear-cut correlations of univalents, bivalents, or other chromosome associations with normal pollen quartets and pollen stainability could be pointed out in the limited amount of material examined. 4. Natural selection in a cross-pollinated, long-lived perennial species capable of asexual increase, such as B. inermis, may favor the individual that is vegetatively aggressive. In fact, the more aggressive individuals could survive in spite of irregular bivalent formation and low fertility. Certain meiotic irregularities, e.g., inversion heterozygotes, may actually possess selective advantage. 5. Random sampling of a potential gamete population in B. inermis may not be possible because of selective elimination of gametes resulting from irregular meiotic chromosome behavior.
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