1. Blotched leaf.

In June, 1944., a supply of seed of Hawaiian Yellow Field Corn was received from A. J. Mangelsdorf, Hawaii Sugar Planters Association. It was derived from crosses between many tropical and subtropical corns and was extremely variable. Several inbred lines were isolated from it and in these appeared plants showing protogyny, adherence and blotched leaves; the last‑named is discussed here.

Blotching appeared just before tasseling, at about 60 days; the spots were yellow, numerous, evenly scattered over the leaf and later became coalescent. They were not notably elongate; nor were they ever few in number and large in size with a necrotic centre as described by Emerson (Cornell Univ. Agr. Exp. Sta. Mem. 70, 1923). The present gene will be referred to as Bl₃-bl₃.

There was some variation of expression in different cultures but recessivity was complete and classification easy.

Some families segregated also for light red vs. green plant colour (table 1).

Table 1. Segregations

	Red		Green
Parentage	Normal	Blotched	Normal	Blotched
Red‑normals selfed	62	15	18	18
Red‑normal selfed	39	9	‑	‑
Red‑blotched selfed	‑	37	-	10
Green‑blotched selfed	-	-	-	43
Red‑normal x Green‑blotched	16	6	2*	1*
Green‑normal x Green‑blotched	-	-	11	10

* Presumably plants with 'red' genotypes mis‑scored.

Single‑factor segregations are in agreement with expectation; but there is good evidence of coupling linkage (X² = 15.03; crossing over 31.2 � 5.4% by the method of maximum likelihood). Which anthocyanin locus was concerned is not known, but it seems likely that it was R, which would place Bl₃ in the tenth chromosome (Rhoades and Rhoades, Genetics 24: 302, 1939).

Blotched plants seemed to be slightly less vigorous than normals. This impression was supported by measurements of weights of fresh cobs in several families (table 2).

Table 2. Mean weight (gm.) of fresh cobs in segregating families.

Family	Normal	Blotched	Blotched as % of normal
28	113	51	46
25	87	68	79
51	227	118	52
26	108	85	79
21	147	81	55
Means	125	82	66

Differences between families and between the genes were significant at the 1% level.

N. W. Simmonds