Selection in tetraploid rye. III. Frequency and performance of aneuploids

Abstract

Aneuploidy was studied in populations selected for high seed-set with regular meiosis and low -seedset with irregular meiosis and an unselected population of the same origin. The frequency of aneuplaids was significantly reduced in the high population that was characterised by increased bivalent frequency. In spite of a similar quadrivalent frequency in euploid plants of the low and the unselected population, the former population had a significantly higher frequency of aneuploids. However. there was no significant difference in the performance of aneuploid plants from the three populations. The results indicated that hyperaneuploid gametes were less functional than hypoaneuploid gametes but no significant difference was found in the performance of hypo-and hyperancuploids.

Test weight, kernel shrivelling, and aneuploidy frequency in triticale

“…Various researchers also have found similar supportive results (Guedes-Pinto et al 1984). This phenomenon can be explained either by meiotic irregularities resulting in chromosome loss or by hyperploid gametes being less functional than hypoploid gametes (Hossain 1979). Oudjehih & Boukaboub (2000) emphasised that the importance of aneuploidy depends on seed morphological characteristics: plants from unshrivelled small seeds were more affected (40%) than those from large normal seeds (5%) or large shrivelled seeds (15%).…”

Selection for meiotic regularity in tetraploid winter rye

“…Selection for increased seed-set has only been partly successful. This is due to the low heritability of this trait (h2 = 0.29) estimated by AASTVEIT (1968), and to the presence of aneuploids with a reduced seed set (HAGBERG and ELLERSTROM 1959;MOORE 1963;HOSSAIN 1978). AASTVEIT (1968) obtained an increased seed-set as a result of selection in three populations of tetraploid winter rye.…”