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Table 2.

Length and Arm Ratio of the Pachytene Chromosomes in Nipponbare Rice

Chr.no.	Short arm (μm)	n	Long arm (μm)	n	rDNA (μm)	Total length (μm)	Relative length (%)	DNA content (Mb)[ii]	Arm ratio
1	23.39 ± 3.64	50	37.73 ± 5.44	50	—	61.12 ± 8.23	13.24 ± 0.91	56.9 ± 3.9	1.63 ± 0.22
2	19.70 ± 3.30	50	32.75 ± 4.75	50	—	52.45 ± 7.35	11.36 ± 0.77	48.8 ± 3.3	1.68 ± 0.26
3	29.87 ± 4.28	50	26.54 ± 4.10	50	—	56.41 ± 7.56	12.21 ± 0.91	52.5 ± 3.9	0.89 ± 0.08[iii]
4	6.23 ± 0.83	50	31.91 ± 5.18	50	—	38.14 ± 5.80	8.26 ± 0.70	35.5 ± 3.0	5.13 ± 0.60
5	12.46 ± 1.76	50	24.62 ± 3.58	50	—	37.08 ± 4.91	8.05 ± 0.68	34.6 ± 2.9	1.99 ± 0.23
6	19.93 ± 3.13	50	18.44 ± 2.91	50	—	38.37 ± 5.96	8.30 ± 0.64	35.7 ± 2.8	0.93 ± 0.05[iv]
7	12.53 ± 2.06	50	22.16 ± 3.77	50	—	34.69 ± 5.33	7.51 ± 0.69	32.3 ± 3.0	1.78 ± 0.25
8	13.58 ± 1.99	50	18.60 ± 3.11	50	—	32.18 ± 4.54	6.98 ± 0.59	30.0 ± 2.5	1.38 ± 0.20
9	3.88 ± 0.83	50	24.72 ± 3.56	50	3.93 ± 0.78	28.60 ± 4.16[i]	6.21 ± 0.68[i]	26.7 ± 2.9[i]	6.54 ± 1.06[i]
10	6.14 ± 0.94	50	18.60 ± 2.70	50	—	24.74 ± 3.32	5.36 ± 0.38	23.0 ± 1.6	3.07 ± 0.50
11	13.37 ± 2.08	50	17.57 ± 2.81	50	—	30.94 ± 4.45	6.70 ± 0.54	28.8 ± 2.3	1.32 ± 0.18
12	11.65 ± 2.06	50	15.28 ± 2.36	50	—	26.93 ± 4.12	5.83 ± 0.55	25.1 ± 2.4	1.32 ± 0.15

[i] The rDNA section of chromosome 9 was not included in the measurements.

[ii] Estimation of the DNA content of each chromosome is based on the assumption that (1) the haploid genome size of rice is 430 Mb; and (2) the euchromatic and heterochromatic regions contain equal amount of DNA (Mb/μm). Thus, the DNA content will be underestimated for relatively heterochromatic chromosomes and overestimated for relatively euchromatic chromosomes.

[iii] The arm ratio of chromosome 3 is 1.13 ± 0.12 if the current short and long arms are reversed.

[iv] The arm ratio of chromosome 6 is 1.08 ± 0.07 if the current short and long arms are reversed.