(f) Study on agronomically useful characteristics
As stated previously in this paper, Japanese islands are seasonally under "Baiu" during a period of June-July, heavy raining season, which produces conditions with long lasting high humidity for days and weeks under relatively high temperature. Under the condition, fungus infection, especially of scab (Fusarium scab, Fusarium graminearum, or Fusarium sp.), became prolific on the spikes and grains to various degrees depending on lines . Also, powdery mildew (Erysiphe graminis) and leaf rust (Puccinia recondita) are found among susceptible cultivars.

In studying reactions of the hybrids to inoculation by powdery mildew spores, Muramatsu et al. (1983) considered the differentiation into forma specialis of powdery mildew fungus, t2 for wheat and a2 for the Japanese indigenous Agropyron. Every F₁ hybrid plants were tested with lines of forma specialis, kindly supplied from Dr. U. Hiura, Research Institute for Bioresources, Okayama University. Of two cross combinations, A. tsukushiense x hexaploid wheat, Chinese Spring and Inayamakomugi, the hybrid plants did not get infected by the a2 spores, although both parent species, Agropyron and hexaploid wheat cultivars are susceptible to each forma specialis fungus spores, respectively.

On the other hand, infections occurred with t2 spores that represent a forma specialis of wheat. However, in the backcrossed generation of the F₁, A. ciliare x hexaploid wheat cv. Inayamakomugi, pollinated by the wheat parent, the infection in slight degree was observed probably indicating chromosome instability, which eliminated chromosome(s) carrying gene (or genes).

With the cross using A. elongatum and hexaploid wheat non infection by t2 strain, with one exception, was observed (Muramatsu and Ikeda 1983).

Many of the Western cultivars of wheat and barley from dry summer areas are severely infected by scab. Since Japanese lines of Triticeae particularly A. tsukushiense, A. humidorum and A. ciliare show adaptation, tolerance to the Baiu, they will be suitable lines to study these attributes. I have even never seen any single infection of scab on these species for many decades of years.

For the reaction to scab fungus Fusarium scab field observations were made whenever the hybrids material was available in June to July, and tendencies were found for the relative tolerance of the hybrids as compared with wheat and barley cultivars in general. However, in addition to the highly variable field conditions, the sterility of the hybrid plants made results not certain for obtaining any conclusive result. Once in a while, weak infection of glumes thought to be caused by Fusarium scab were found but the degree of such spots showed fluctuations indicating that further detailed and quantitative studies are required.

Summer survival of the hybrid plants were interesting under conditions of high humidity and high air temperature that continued throughout day and night. The result of the observations summarized by the 1984 season (Muramatsu 1985) is not conclusive but tendencies are that hybrids with A. elongatum and A. intermedium (both are classified Tinopyrum in the different classification system) tolerated the summer season through at least 3 years, while wheat-rye F₁ hybrids, as expected, showed completely annual life form. The hybrids involving Japanese indigenous species A. tsukushiense,A. ciliare and A. yezoense said to display phenotypes ranging from intermediate of the parents to the annual; only a small number of tillers from the hybrid plants, A. tsukushiense x hexaploid wheat, showed summer survival at most 3 years.

In addition to the indigenous species, some of Western Triticeae lines, if tolerated will be useful. At least two Agropyron (Tinopyrum) clones, which had been introduced by Matsumura S in 1930's, have survived vegetatively, during a period of almost 70 years. These Tinopyrum lines were used as the parents for obser ved hybrid plants.

(g) Chromosome behavior at cell division not showing regular distribution or random assortment, rather anomalous divisions are prevalent.
In addition to the description made above, from cytological observations on hybrid plants, there are various kinds of irregularities and disturbances in cell division, depending on the cross combinations. The occurrence of anomalous phenomena that are in connection with the preceding descriptions is thought to be important to summarize here. When A. tsukushiense and A. ciliare were hybridized to A. intermedium, the spikes of the hybrids were perennial to tolerate summer conditions and showed vigorous growth. At meiotic cell divisions showed strong abnormalities, including abnormal spindle fiber formation, and lacking concomitant cell divisions. The abnormality may be due to disturbances of cytokinesis rather than caused by chromosome inhomology. The plants were sterile. Fertile sector was not obtained by colchicine treatment (Muramatsu 1992). Similar, but much more extensive anomalous phenomena were observed at MI of the hybrid, A. ciliare x Hystrix longearistata (Muramatsu 2001). Also, the author experienced that in another cross combination similar effects of the genotype has been cytogenetically segregating frequently in the progeny of the cross hexaploid wheat and A. elongatum. At least, some amphiploids or autoploids have been obtained in the lines where cell division and chromosome behavior were not disturbed by cytokinesis failure.