Studies on the tillering in the genus Allium. V

Some examples of abnormal leaves and abnormal tillerings observed in the Welsh onion

Abstract

Some examples of abnormal leaves and abnormal tillerings observed in Welsh onion are reported. It may be summarized as follows:
1. Several rare cases where abnormal leaves having two laminae on a leaf sheath were observed in var. Iwatsuki, Kaga-Ippon, Asaki-Kujyo and Matsu-moto-Ippon. These were designated as “di-lamina leaf”. Almost all of these leaves were formed on the second or third node after the first tiller occurred.
As shown in Fig. 5, di-lamina leaves may be di-vided into three fundamental types by the arrange-ment of laminae.
2. When the n-th leaf was dwarf and its develop-ment was very slow, the emerging date of n-th leaf was frequently later than that of (n+1)th leaf in the normal order of emergence.
Examples of such cases were occasionally observed on the first leaf of tillers or new vegetative axil-lary buds.
3. Although the normal tillering bud of Welsh onion generally appears singly on a node, occasional-ly two or more tillering buds appeared on the same node. This abnormal phenomenon was designated as “poly-tillering”.
The poly-tillerings were observed rarely on the nodes of normal leaves, but more frequently on the nodes of di-lamina leaves.
Almost all of these poly-tillerings were formed on the first or second node after the first tiller occurred.
4. Sometimes, the development of tillering bud was so slow that the tiller appeared too late from the leaf sheath of preceding node for the normal tiller. These abnormal tillers may be divided into the following two types:
a) Only the first leaf is dwarf, but the second and subsequent leaves show a normal develop-ment.
b) All leaves of tiller are dwarf.
5. At times the abnormal tillers which developed the first leaf alone were observed. These examples were frequently observed in the last stage of the growing season.