1. Inheritance of variegated plant B^v in maize.

In 1939 (Genetics 24:109) we reported a case of a plant that developed fine streaks of color after B pollen was treated with ultra-violet light and applied to lg gl₂b v₄ plants. Treatment of the pollen was made by Dr. L.J. Stadler who first observed the abnormal plant. Cytological examination showed no chromosomal irregularities. Further genetic tests have indicated that this variegation is caused by a variegated B allele which has been designated B^v. Linkage relations of B^v with gl₂ and v₄ are approximately the same as with B.

Segregates of B^vb plants produce only two types B^v and b with an occasional back mutation from B^v to B. Progenies studied were not set up to detect changes from B^v to b. Three point backcross linkage tests gave the following results:

Progeny		48:610	%	48:608	%	48:607
						(F2 not backcross)
Parental	+++	51		47		88
Combinations	gl2bv4	32		30		10
Recombinations		83		77		98
Region 1	+bv4	25		20		19
	gl++	12		12		5
		37	20.9 (19)*	32	19.2 (19)*	24
Region 2	++v4	23		18		21
	gl b+	29		31		14
		52	29.3 (21)	49	29.3 (21)	35
Region 1 & 2	+b+	3		6		12
	gl+v	2		3		1
		5	2.8	9	5.4	13
Solid B		0		0		3
Total		177		167		170

Characters analyzed separately

+	102		91
gl	75	42.4	76	45.6
+=B^v	88		80
b	89	50.3	87	52.1
+	95		96
v4	82	46.3	71	42.5

*Numbers in parenthesis refer to crossover percentage in Cornell Memoir 180.

The crossover percentages correspond fairly close to those listed in Emerson, Beadle and Fraser (Cornell Memoir 180). They are considered to be in agreement when it is thought there was either perhaps sone misclassification or differential mortality of v₄ and gl plants before classification. Plants were classified in the seedling stage and gl+, gl v₄, ++, and +v₄ plants were marked with different colored stakes that were present when the plants were classified for B^v and b in August. It will be noted the proportions of B and b plants approximate the expected proportions rather closely.

The fact that the linkage values of B^v correspond closely to B, also the fact that only the B and b plants occur (as a rule) in segregating populations, lead us to the conclusion that it is the B allele itself causing the variegation and not another gene causing B to mutate.

Occasionally B^v plants produce large sectors that are entirely purple, sometimes including a tassel branch. Pollen from such sectors applied to b plants produces mostly variegated plants, about the same proportion as pollen taken from a variegated sector. (Most of the data on the B^v inheritance are in the files at the Connecticut Experiment Station. They will be assembled and published soon.