Y. Higuchi et al., Morphological characteristics of trichomes of primin-secreting and primin-free cultivars in Primula obconica, J JPN S HOR, 68(3), 1999, pp. 614-621
Citations number
10
Categorie Soggetti
Plant Sciences
Journal title
JOURNAL OF THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE
A comparison of the trichome types was made by the Craven test and microsco
pic observation between primin-secreting and primin-free cultivars of Primu
la obconica.
1. All cultivars were classified into two groups according to the lengths o
f trichomes. Group one had trichomes (Fig.1, A similar to D) whose lengths
were 150 mu m or less, whereas group two was represented by those with tric
homes exceeding 1mm (Fig.1, E). Moreover, the trichomes of group one was fu
rther classified into four types from the characteristics of the tips, e.g.
, A : red tip; B : colorless tip; C : yellow tip and D :tip with crystalliz
ed substance (Fig.1, A,B,C and D, respectively).
2. The trichomes of B, C, and D types were observed both on the primin-secr
eting and free cultivars but those of A type were observed only on the prim
in-secreting cultivars. By the Craven test, only the trichome of A type sec
reted primin at its apex.
3. The distribution density of A type trichome (primin-secreting) was highe
r on the basal part of the midrib in leaves and on the calyx and peduncle i
n flower clusters, than in other parts of leaves and newer clusters.
Thus, it should be possible to select primin-free plants by avoiding the pl
ants with red tipped trichomes on midrib of young leaves, calyx and peduncl
e of newer clusters.