The crossing of common wheat (Triticum aestivum L.) with cultivated rye (Secale cereale L.). I. crossability, pollen grain germination and pollen tube growth

The location of a gene for incompatibility between Hordeum vulgare L. and H. bulbosum L.

“…For example, some homoeology exists between barley chromosome 7 and wheat chromosome 5 (Islam and Shepherd, 1981), on both of which are located dominant incompatibility genes. Furthermore, pollen tube inflation and bursting which is found in the present material (Pickering, 1981), has also been shown to occur in incompatible hybridisations between wheat x rye (Jalani and Moss, 1980;Lange and Wojciechowska, 1976;Tozu, 1966;Zeven and van Heemert, 1970) and barley x wheat (Fedak and Jui, 1982). Similarly pollen tubes are inhibited before entry into embryo sacs of non-crossable wheats pollinated with H. bulbosum (Snape et a!., 1980).…”

Fine Mapping and Marker Development for the Crossability Gene SKr on Chromosome 5BS of Hexaploid Wheat (Triticum aestivum L.)

“…This confirms the first results of Riley and Chapman (1967) on the Kr1 mode of action wherein it was concluded that crossability is not promoted by recessive alleles but inhibited by dominant alleles. Later studies performed to determine the site of action of the Kr1 and Kr2 genes (Lange and Wojciechowska 1976;Jalani and Moss 1980;Jalani and Moss 1981) also demonstrated that dominant alleles from Hope, CS/Hope 5B, and CS/Hope 5A result in inhibition of the pollen tube growth between the style base and the embryo sac. Finally, Cameron and Reger (1991) showed that a soluble, dialyzed lysate extracted from the ovaries of Hope and CS/Hope 5B inhibits rye pollen tube elongation significantly more than a similar lysate from Chinese Spring ovaries.…”

“…At the moment, we can only speculate about the possible candidates found in the SKr orthologous rice region on chromosome 12L. Genetic and biochemical analyses both suggest that inhibition of crossability is an active mechanism and that the crossability genes may encode a product that stops the penetration of the rye pollen tube between the style base and the embryo sac, i.e., just before fertilization (Lange and Wojciechowska 1976;Jalani and Moss 1980;Jalani and Moss 1981). In dicots, molecular analyses of self-incompatibility and interspecies pollen tube rejection have identified key roles for S-RNAse genes (Franklin-Tong and Franklin 2003) as well as receptor kinases (Escobar-Restrepo et al 2007).…”

“…Kr1 and Kr2 genes were localized roughly on chromosome 5B and 5A, respectively (Riley and Chapman 1967) and subsequently located more precisely on the long arms of these two chromosomes (Lange and Riley 1973;Sitch et al 1985). Further studies indicated that the dominant alleles driving incompatibility of crossing wheat with rye act by actively inhibiting the production of intergeneric hybrids (Riley and Chapman 1967;Lange and Wojciechowska 1976;Moss 1980, 1981;Cameron and Reger 1991 ). Other crossability genes, such as Kr3 on chromosome 5D (Krolow 1970) and Kr4 on chromosome 1A (Zheng et al 1992), were identified later.…”

Effect of gamma radiations on the crossability of wheat, triticale and rye and on meiosis, pollen grain germination and pollen tube growth.

“…The dominant alleles of the crossability genes manifested themselves through retardation and eventually inhibition of pollen tube growth at the style base and in the ovary wall. However, the crossing barrier is not complete, because seed set can occur (Lange and Wojciechowska 1976).…”