AECD-3446

values.

-82-

How plants growing in coral sand can be calcium deficient js Somewhat q

an anomaly and certainly warrants further study.

The relative importance of e

cium deficiency and radiation damagein producing the observed symptoms has
not been determined,
MORPHOLOGICAL DEFORMITIES
The most striking morphological deformities were found on Ipomoea Tubs
growing on Engebi Island,

A series of photographs comprising Figures 5, 6,4

9 and 10 shows this species of plant in all degrees of severity in the daformationg
observed,

Figure 5 represents the control, or normal material; Figure 6 shows

areas wherein deformities occurred. These areas have not been fully:covered by
the dense growth of Ipomoea which surrounds them, but have persisted ingrasseg
with stumps of deformed Ipomoea occurring, within the areas.

Figure 7 shows

close-up of the grass and Ipomoea with tumorous growths at the basal nodesof

the stem, Figure 8 is a close-up of the tumorous growths. Figure 9 showsa
fasciation of the stem,

cas

This type of deformity is not rare in nature and should

not be strictly considered as a peculiarity induced by the unusual environmentof :

the "bombed" island, It may occur anywhere and with rather high frequency in semi
plants. Figure 10 shows the most severe deformation. encountered.

There is ex

x

posed on the clubby stem a mass of tymorous growths some of which have regese¥%:
ted rudimentary leaves from the proliferated tissues. How such a deformed plas:
can manufacture sufficient carbohydrate to produce the clubby stem tissue is a8
anomaly,

’

The nature of the injury shown by these plants closely resembles that prev?ES

_ duced, in a numberof species, by an excess of growth hormones or accessory»

growth-stimulatingsubstances, An excess of these substances, above that whieh

:

is required for normal growth, induces such deformities as is shown in the accom’

shows a geranium plant, the stem of which has bees .
severed and the wound smeared with a mixture of indole-3-acetic acid in lanolia e
The same tissue proliferation with partial regeneration of leafy shoots is obs¢

panying Figures,

Figure ui

The similarities in the appearance of the tumorous tisaues on the two species at
plants lead one to suspect a common causal agent,

If the condition in Ipomoss,
I
@

‘Unpublished results of 0, Biddulph.
UNDVERS Try res
UNIV. Gi

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