Kiichi Miyake

On a monstrous flower and its linkage in the Japanese morning glory

Summary1.The heart leaf (h) and the “Shishi” form (si) are respectively transmitted as recessives to the normal.2.Owing to the incomplete dominance of the H and Si factors the segregating ratios are each a 1 : 2 : 1.3.About 1.2 per cent. of crossover occurs in a linkage between these two factors. By the convenient nature of incomplete dominance calculation of. linkage was directly made with the self-propagated specimens in the hybrid progeny.4.The percentage of crossover is almost equal in the case both of coupling and repulsion.5.The Si factor represents multiple effects on flower and leaf as well as cotyledon.6.The grasped leaf found in the “Shishi” strain is due to the result of the additional effect of a punched factor (u).

Maternal Transmission of Mutated Plastids in the Japanese Morning Glory

Chlorophyll variegation, which is commonly found in the Japanese morning glory (Pharbitis nil), is transmitted as a simple recessive to the self-green condition. The whitish patches appear somewhat irregularly on the respective leaves of variegated individuals, so that the variegation is regarded as a pattern character. The allelomorphs, normal (self-green) and variegated, are quite constant and no cases of mutations either from normal to variegated or its reverse have come under our notice. In I928 three unexpected variants with variegated leaves incidentally occurred in the hybrid progeny of different crosses, their sister plants being invariably self-green. The variegation of these plants differed in color, namely: I. White; variegation in white. 2. Creamish; at first cream in color and creamish white in the extended leaves. 3. Yellowish; variegated with yellowish color, a little more intense in the young leaves. The white-variegated variant puts out at times green and white branches (fig. I) and also chimerical bud variations with periclinal white-over-green tissues. The results obtained from selfing the flowers of these branches are collected in table I. The albinotic seedlings had short hypocotyls with small cotyledons and perished about two weeks after germination. The green individuals thus segregated bred true to type for generations, while the variegated ones gave rise to three forms in various proportions according to the amount of variegation of the mother plants or of the branches from which the seeds were collected. The slightly variegated branches or individuals gave mostly green seedlings, whereas the highly variegated ones produced mostly albinotic seed-