(d) Chromosome pairing configurations of high autopolyploids
A. elongatum (2n=10x=70), despite its high polyploidy had been producing seed set in a peculiar manner. Matsumura S (1941, 1948) had concluded that the species is amphiploid. However, the higher chromosome association had not been completely analyzed. Then with suggestion of Matsumura S, the present author with a given clone studied the chromosome mechanics in detail.

A. elongatum showed a regular process of meiotic division, on the other hand showed highly complicated chromosome associations difficult to analysis and also high associations might have been caused by chromosome rearrangement. Nevertheless, the result showed that the species (then the clone) is autodecaploid forming chromosome association up to decavalents (Muramatsu 1990. The important point is that there must be certain proper chromosome arrangement before starting homologous pairing and then chiasmata formation. Choosing partner chromosome ends may not be random. With regard to this non-randomness, the RabI orientation (see Fussell 1987, i e. the configuration and position of the chromosomes within the nucleus during the cell cycle) would be one of the important factors.

Further test and evidence for the decaploid nature were made and confirmed by observing chromosome associations at MI of a F₁ hybrid of the cross combination, an autotetraploid line of Ae. squarrosa (2n=4x=28, DDDD) as female to the decaploid A. elongatum. The result completely supported autodecaploidy, because up to quinquevalent formation was observed (Muramatsu 1984, unpub).

In observation of the chromosome associations in the hybrid materials involving Japanese indigenous species, evidently a genetic system controlling chromosome pairing is not receiving from or not producing adequate effects on each other.ei Presumably, the systems controlling pairing may not be very similar in the component genomes. Chromosome association at MI of polyhaploid plant of the A. tsukoshiense is very similar to the amount of bivalents shown in hexaploid wheat. Slightly higher association was observed in the F₁, which seen under favorable growth condition (Takahashi and Muramatsu 1981), is surely by higher number of homoeologous chromosomes involved in the hybrid; six genomes are involved instead of three in each single, polyhaploid of the parent species. In knowing chromosome pairing since prophase association should be important, a microscopic observation was made in the F₁ A. tsukushiense x 6x wheat, The result was a general tight association at a stage apparently, pachytene, although unpaired single chromosome regions were also observed. This indicated that the high number of univalents of the F₁ is due to desynapsis or to lack of chiasma formation (Muramatsu 1982).

(e) Production of alien addition lines
Since the same system of the pairing control is involved, alien addition lines will be expected accordingly. Utilizing the amphiploid and backcrossed generations originated from the cross, A. ciliare x hexaploid wheat backcrossed to the wheat parent as female, the chromosome assortment was quite normal and showed random distribution to progeny. Ciliare chromosome addition lines were expected to be successful in the later generations. Production projects were carried out by early 1990's (Muramatsu and Ohasa 1992; Takata and Muramatsu 1992; Muramatsu and Takata 1993).

B₂F₁ (the generation back crossed twice) plants of crosses of an amphiploid (2n=10x 70) derived by colchicine treatment of plants, A. ciliare "Hyakkengawa" strain x T. aestivum cv. Inayamakomugi, were backcrossed to the wheat parent twice. A higher rate for disomic addition plants was obtained in progeny of parent plants with several ciliare chromosomes than plants with single chromosome addition. So far, 22 disomic lines were selected and examined for morphological differences and for the flowering date and seed fertility.