Analyses of karyotype and quantitative growth were carried out in Allium nutans L. introduced from USSR to obtain the data for breeding and improvement on culturing environment.
1) Chromosome number of A. nutans was 2n=32. It was autotetraploid consist of 28 metacentric or submetacentric chromosomes and 4 subterminal chromosomes with satellites. The karyotype was K(2n)=32=28V+4J^t, The length of chromosomes were 11.15. 9 pm and the ratios of short arm to long arm were 1.00-0.31.
2) Changes with time in weights of whole plant, leaf and root showed remarkable increase from 42 days after sowing, and then increased gradually from 112 days and showed S type growth curve. Changes in leaf area revealed similar tendency to plant weight, but the increase in bulb weight was very slow.
3) Specific growth rate (SGR) for whole plant weight and leaf weight showed the maximum at 15-28 days after sowing and that of root weight at 29-42 days after sowing. These SGRs corresponded well to each other and decreased gradually to 57-70 days after sowing, the maximum period of SGR in bulb weight, and the latter decreased markedly after the maximum period.
4) Leaf weight ratio (LWR) decreased markedly after the maximum period, 14 days after sowing, to 42 days after sowing and then maintained nearly the same level. Leaf area ratio (LAR) and specific leaf area (SLA) corresponded well to each other and decreased gradually after the maximum period, 43-56 days after sowing, Unit leaf area rate (ULAR) and unit leaf weight rate (ULWR) showed similar tendency.
5) SGR, LAR, LWR, SLA, ULAR and ULWR of each characteristics showed the maximum periods ahead of that of SGR for bulb weight, and then decreased gradually until the maximum period of SGR in bulb weight.
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