CYTOGENETIC STUDIES ON THE VARIATION AMON G STRAINS OF ASATSUKI, ALLIUM-SCHOENOPRASUM L COLLECTED IN JAPAN

A cytogenetic investigation was carried out for elucidating the variat ion among 38 cultivated or native strains of asatsuki (including Alliu m schoenoprasum L. var. foliosum Regel) grown in various places in Jap an. 1. The somatic chromosome numbers of 29 strains were 16, 16+1 B (d iploid), and those of 9 strains were 24 (triploid). 2. C-banded karyot ypes of 17 diploid strains were divided broadly into two types, ''A'' and ''B'', based on the overall banding pattern of 8 V-shaped chromoso mes which were distinguishable from each other. Some chromosomes of th e ''A''-type strains exhibited a variation of banded figures. Five of 6 triploid strains had almost similar C-banded karyotypes in which 12 V-shaped chromosomes were distinguishable from each other. 3. Meioses in pollen mother cells were normal in 7 diploid strains, whereas abnor mal meioses occurred after the tetrad stage in 2 strains which conside rably reduced pollen fertility. The mean frequency of chromosome pairi ng of one triploid strain was 6.68(III)+ 1.32(II)+1.32(I) at meiotic m etaphase-I; subsequent chromosome behavior was irregular. 4. Pollen fe rtilities varied among diploid strains;normal (90.1 similar to 98.2%, 18 strains), reduced (69.8 similar to 85.2%, 4 strains), and considera bly reduced (7.9 similar to 28.0%, 5 strains). Those of 5 triploid str ains ranged from 63.2 to 86.9%. 5. Seed setting capacity (number of ge rminable seeds per flower) ranged from 0 to 0.54 among 19 diploid stra ins, whereas it was 0 to 0.05 among 6 triploid strains. 6. Based on th e C-banded karyotypes, meiotic behaviors and pollen fertilities, 9 of 12 ''A''-type strains had 8 pairs of homologous chromosomes; 5 ''B''-t ype strains had heterozygous C-banded karyotypes. The pollen fertility and seed setting capacity of the latter were considerably lower than those of the former. Our research discloses that strains of asatsuki a re cytogenetically diverse and that they can be effectively classified accordingly.