Summary of map positions of interchanges in chromosomes 1, 3, 9 and 10

2. Summary of map positions of interchanges in chromosomes 1, 3, 9 and 10. Part of this is a repetition of what I sent last year.

Chrom. 1 -

Left of P. An undescribed 1-6 interchange gave the order T-P-sr with 6% crossing over between T and P.
Near P, order uncertain, 1-2b, 1-9c.
Between P and br 1-3a, 1-5b, 1-5c, 1-9a.
Near br 1-3d, 1-7b, 1-7c, 1-9b, 1-10a.
Between br and bm₂ 1-5a, 1-4, 1-7d.

Chrom. 3 -

Chrom. 9 - all tested are beyond waxy.

	% crossing over	No. of backcross plants
1-9a	9.2	239
1-9b	35.4	505
1-9c	12.7	237
2-9a	30.7	505
2-9b	7.5	628
3-9a	3.6	608
4-9a	25.1	426 (2 groups of data 31.0 and 11.6)
4-9b	3.1	193
6-9a	9.5	610
6-9b	3.7	731
8-9b	35.0	141 (data irregular)
9-10	about 3.5 (estimated from combined wx-T and T-R intervals)

Chrom. 10 - crossing over with golden-1 (left of g₁)