Cytotype Variation and Cytogeography of Scilla Sinensis (LOURIRO) Merrill (Hyacinthaceae) in China

Abstract

One thousand eight hundred and eighty six individuals in the Scillu sinensis complex were sampled from 45 populations at 41 localities in 16 provinces of China and investigated cytologically. Six cytotypes, AA, AB, BB, AAA, BBB, AABB were found. AAA was recorded for the first time in this complex and BBB was found for the first time on the continent. Most of the populations were composed of only one cytotype (AA, BB or AABB), while one mixed population of AA and AAA, one of AA and BB, one of BB, BBB and AABB, two of AA and AABB, and one of AA, AB and BB were recorded. AA occupies almost the entire range of this complex in China except the eastern part of Central China; BB occurs only in eastern Central China, while AABB spreads over the north of eastern Central China, the southeast in the Northeastern district and Taiwan. The distribution of cytotypes is mapped in this paper. In addition, the mean numbers of B-chromosomes per individual and percentages of individuals with B-chromosomes in each population were calculated. These measures are distinctly higher in BB cytotype than in AABB cytotypes, while it is the lowest in AA. The B-chromosome content of AA cytotype may be positively related to the latitude. Kuiyu Ding, Luhorutory of

Karyotypes of Amphidiploid of <i>Scilla scilloides</i> Complex in Taiwan with Special Reference to Secondary Constriction of the A Genome

“…In Taiwan, karyotypes of S. scilloides were reported previously by Chang and Hsu (1974), Uchino et al (1992), and Ding et al (1998). The karyotype of the AA diploid was reported in the population of Taouyen and possessed secondary constriction on a 2 chromosomes (Uchino et al 1992) similar to that of AA diploids of other localities in China and Korea (Araki 1985, Yu and Araki 1991, Hizume et al 1993, Ding et al 1998. Ding et al (1998) reported on plants of AABB karyotype in a population of Suao without mentioning secondary constriction, suggesting that they would regard AABB karyotype of Taiwan as common-type AABB.…”

“…Therefore, the a 2 chromosomes without secondary constriction seemed to function as NORs and to organize small nucleoli. In Taiwan, karyotypes of S. scilloides were reported previously by Chang and Hsu (1974), Uchino et al (1992), and Ding et al (1998). The karyotype of the AA diploid was reported in the population of Taouyen and possessed secondary constriction on a 2 chromosomes (Uchino et al 1992) similar to that of AA diploids of other localities in China and Korea (Araki 1985, Yu and Araki 1991, Hizume et al 1993, Ding et al 1998.…”

“…All 26 plants of S. scilloides collected in two localities of Northern Taiwan had 2n=34 chromosomes and no small supernumerary chromosome observed frequently in this species (Araki 1985, Choi and Bang 1990, Yu and Araki 1991, Bang and Choi 1993, Ding et al 1998. The characteristic chromosomes for each genome, such as the longest metacentric a 1 chromosome of the A genome and b 1 chromosomes with secondary constriction and four short metacentric chromosomes of the B genome, were easily identified in each chromosome complement of all plants examined (Fig.…”

“…Diploids and/or polyploids with various combinations of two genomes were recognized in populations over different habitats (Sato 1935, Okabe 1938, Haga and Noda 1956a, b, 1976, Araki 1971, 1972, 1975, Araki et al 1976. To reveal the geographic distribution of plants with various genome constitutions and an origin for amphidiploids having AABB genomes, many populations were analyzed for karyotype in Japan Noda 1976, Ihara 1977), then investigated in other parts of East Asia including Korea (Araki et al 1979, Araki 1985, Choi and Bang 1990, Bang and Choi 1991, Choi et al 2004, China (Fu and Hong 1989, Yu and Araki 1991, Yu et al 1992, Hizume et al 1993, Ding et al 1998, 2005a and Taiwan (Chang and Hsu 1974, Uchino et al 1992, Ding et al 1998. From the deposits of cytological analyses, we were able to draw geographic distributions of diploids of A and B genomes, and we found that amphidiploid and polyploids with various genome constitutions were as follows.…”

“…The karyotype of Okinawa AABB (Okinawa-type) was different from that of AABB (common-type) of most localities having secondary constriction only on the a 2 chromosome. In three localities of Northern Taiwan, S. scilloides plants were studied cytologically and karyotypes of AA and AABB genome constitutions were recorded (Chang and Hsu 1974, Uchino et al 1992, Ding et al 1998. Only the genome constitutions of AABB plants were reported without mention of secondary constriction.…”