The transmission of rye B chromosomes in natural pollination

✍ Scribed by M. J. Puertas; J. R. Lacadena

• Publisher: Springer
• Year: 1974
• Tongue: English
• Weight: 615 KB
• Volume: 45
• Category: Article
• ISSN: 0040-5752
• DOI: 10.1007/bf00264999

✦ Synopsis

This paper examines the transmission of B chromosomes in natural (but controlled) pollination, in order to obtain results which can be applied to natural populations of rye. The frequencies of the female gametes in both 2n= 14+1 and 2n=14+2 rye plants have been estimated with reference to their chromatid constitution. From the results obtained on the offspring, it seems that preferential distribution takes place during female meiosis of 2n= 14+2 plants. It has been demonstrated that pollen carrying B chromosomes formed in plants of 2n=14+2 was more competitive than normal pollen. On the contrary, when it was formed from plants 2n=14+1, B chromosome elimination by pollen was total. This process may be considered as sporophytic determination. The genetic significance of the presence of B chromosomes in natural populations is discussed. It is proposed that B chromosomes may be the cytological expression of a complex evolutionary system which results in conservation of population genetic variability.