Intergeneric hybrids F₁ were obtained in 1982 (Xue et al 1982) using H. vulgare (2n=14) cv. "Azosan" as female in cross with the intervarietal hybrid F₁ of two wheat varieties, TJB 368/251 and Ning 7840 with the help of the embryo rescue method (Kruse 1973). The ears of the hybrids were morphologically similar to those of wheat parent. No pistilliod phenomena were detected, which was different from the previous report by Islam (1975). However, the plants appeared to have abnormal pollen and to be self sterile. The young spikes of the plants were used as explants in tissue culture in vitro to induce calli which gave rise to a great number of regenerated plants (Xu et al 1985). Some of regenerated plants were used to backcross successively three times to the wheat parent Ning 7840 used as male, which produced many seeds in each generation.

The BC3 seeds were sown in November 6th, 1986. 'Twenty five plants developed normally from the seeds appeared to have interesting agronomic characters such as sturdy plants with prolific tillers, larger and wider flag leaves, earlier heading and vigorous in growth etc., comparing with those of wheat parent Ning 7840. Main stems of all the plants showed self fertile in bagging but some of spikes of the later tillers appeared to be partial sterile.

Cytological observation on BC3 plants showed seven plants examined out of twenty-five had somatic constitution of 2n=43. Examination of PMC's at MI showed that the average frequency of bivalents was 20.6 with a range of 18-21 and univalents varied from 0-3 with a mean of 0.66 per cell. The cell at anaphase I with 1-2 and 3-4 lagging chromosomes were observed at frequencies of 27% and 0.47% respectively 67% of pollen grains examined were stainable.

The data above suggest that the fertile alloplasmic wheat- barley addition lines have been developed.

Progenies of the alloplasmic addition showed unstable in somatic number, ranging from 2n=41 to 44, among the plants (Table 1). Only 4.30% progenies have the somatic constitution of 2n=43. In the plants with 2n=43, the total of bivalents was found to be twenty or twenty-one (Table 2). The most frequent MI configuration observed was 21. Chromosome separations noted at anaphase I were 20-21, 21-21 and 21-22. The 20-21 AI separation of chromosomes was the most frequent class.

It is most likely that potential valuable materials could be derived from the fertile alloplasmic addition which could be expected useful in the study of breeding and genetics.

References:

Islam, A. K. M. R. et al. 1975. Addition of individual barley chromosomes to wheat. Barley Genetics 3, Garching 260-270.

Kruse, A. 1973. Hordeum X Triticum hybrids. Hereditas 73: 157-161.

Jie et al. 1985. Production and characterization of regenerated plants from young spike calli in barley- wheat hybrids. Journal of Agricultural Sci. Vol. 1, No. 2.21-26.

Xue, Shu-lun et al. 1982. A basic study on transferring barley chromosomes to wheat. 1. Production and characterization of barley-wheat hybrids. Jiangsu Agricultural Sci. 10:10-15.