Evolution of Chromosome numbers in the Lamiaceae, especially its relation to the Classification and Phylogeny of the Genus Salvia based on the Constituents of Essential Oils.

FUJITA Yasuji

doi:10.18942/bunruichiri.kj00002992147

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Other Title

シソ科における染色体数の進化,特にそのアキギリ属の精油成分による分類および系統との関係
シソカニオケルセンショクタイスウノシンカ , トクニソノアキギリゾクノセイユセイブンニヨルブンルイオヨビケイトウトノカンケイ

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Description

From the view-point of "reduction hypothesis," the author discussed the mode of evolution of the basic chromosome numbers, with special reference to the Lamiaceae (Fig. 1) and proposed the name Proto-polyploidy for n=5→10→15→20, which can be assumed to be the most primitive major polyploidy occurred in plant kingdom. The primary reduction of basic chromosome numbers in the Lamiaceae is stepwise decrease from 11 to 5, originating to the stage of n=20 of this Proto-polyploidy and the secondary reduction occurs after secondary major polyploidy generally in 2x-1 ways. The secondary basic chromosome numbers x_2=19, 17, 13 in Salvia are thus explained as 2×10-1=19, 2×9-1=17, 2×7-1=13 respectively. The highest primary basic number 11 in Salvia may be verified by the abundant occurrence of l-linalool in the oil of S. Sclarea (2n=22). This fact shows Salvia is the most primitive genus in Lamiaceae, though the genus Ajuga is often considered as the most primitive one. A new cubic system of classification of the genus Salvia based on the constituents of the essential oils has been established (Fig. 6). The evolution of basic chromosome numbers in the genus Mentha can be also assumed as 10→9→6.

Journal

Acta Phytotaxonomica et Geobotanica

Acta Phytotaxonomica et Geobotanica 24 (4-6), 113-121, 1970

Japanese Society for Plant Systematics