(go to KOMUGI Home) (go to WIS List) (go to NO.79 Contents)

---

Wheat Information Service
December 79: 28 - 32 (1994)


The ineffectiveness of the ph1b gene on chromosome association in the F₁ hybrid, Triticum aestivum x Psathyrostachys huashanica

Genlou Sun and Chi Yen

Triticeae Research Institute, Sichuan Agricultural University, Dujiangyan City, 611830, China


Summary

An intergeneric cross was made between Chinese Spring ph1b mutant and perennial Psathyrostachys huashanica Keng. The meiotic chromosome pairing in the hybrid was 27.14 univalents and 0.43 bivalents. The result indicated that the ph1b gene did not induce homoeologous chromosome pairing between common wheat and P. huashanica, as well as among the common wheat chromosomes. Therefore, the presence of a Ph1 or Ph1-like gene in P. huashanica was suggested.


Introduction

The evolutionary success of many polyploid species is largely due to their diploid-like cytological behavior, which is expressed by the virtually exclusive formation of bivalents, rather than multivalents, at the first metaphase of meiosis. Common wheat, Triticum aestivum L., contains several unlinked diploidizing gene systems (Sears 1976). The ph1b gene mutant was obtained by Sears (1977). This mutant allows homoeologous pairing in common wheat and in its hybrids.

The transfer of alien genetic material to common wheat through homoeologous recombination is an importment step in the efforts to increase the genetic variation. The previous studies indicated that the ph1b gene has strong effect on inducing homoeologous pairing in the hybrids between bread wheat and Aegilops variabilis, Ae. triuncialis, Ae. turcomenica, Ae. triaristata, Ae. cylindrica, Ae. colmnaris, and Ae. ovata (Kushnir et al. 1982; Sharma et al. 1986; Fan et al. 1992, 1993). However, the effectiveness of the ph1b gene inducing chromosome pairing in the hybrid between common wheat and Psathyrostachys huashanica has not been demonstrated yet.

This paper reports the first production of an intergeneric hybrid between Chinese Spring ph1b mutant and P. huashanica, and the meiotic analysis of the hybrid. The possible presence of a Ph1-like gene in P. huashanica is discussed in connection with the result of the meiotic analysis.

-->Next

(go to KOMUGI Home) (go to WIS List) (go to NO.79 Contents)