Figure 1.
Locations of sampled populations.
(A) Locations of the 63 Castanopsis populations sampled. Numbers correspond to the population numbers in Table S1. The dotted line indicates the coastline of the LGM about 18,000 to 24,000 years ago. (B) Distribution ranges of Castanopsis species and varieties in Japan and surrounding areas.
Figure 2.
Leaf epidermis structure in Castanopsis.
(A) Geographical distribution of leaf epidermis structure. Circle sizes are proportional to sample sizes. (B) Transverse sections of leaves; (i) a leaf taken from a tree growing in Maizuru (population no. 16) has a double epidermal cell layer, (ii) a leaf with a single epidermal cell layer from Ise (No. 48), (iii) intermediate epidermal morphology in a leaf from Hagi (No. 43). Scale bar = 20 µm.
Figure 3.
Distribution of GST values among 63 populations for 32 EST-SSR loci.
Table 1.
AMOVA of genetic variation for Castanopsis and within C. sieboldii and C. cuspidata populations based on 32 EST-SSR markers.
Figure 4.
Distribution of FST values as a function of the within-population heterozygosity based on 32 EST-SSR loci.
Figure 5.
Genetic relationships among the 63 Castanopsis populations over 32 EST-SSR loci.
In total, 1,502 individuals were surveyed in this study. Numbers correspond to the population numbers in Table S1. (A) Neighbor-joining tree based on Nei's genetic distances (DA) and the leaf epidermal type of each population (see Fig. 2). Values in italics are percentages of 1,000 bootstrap replicates supporting the respective nodes. (B) Distribution of cluster memberships at the individual and population levels estimated using STRUCTURE [58].
Figure 6.
Maps of genetic diversity of Castanopsis sieboldii and C. cuspidata populations using GRASS [44].
(A) – (C) Allelic richness, the frequencies of rare alleles and private alleles of C. sieboldii. (D) – (F) Allelic richness, the frequencies of rare alleles and private alleles of C. cuspidata.
Table 2.
Genetic diversity of Castanopsis sieboldii and C. cuspidata populations observed in each district.
Figure 7.
Relationships between the genetic diversity of Castanopsis and the current environmental conditions.
Relationship between allelic richness and latitude for 40 populations of C. sieboldii, and between allelic richness and precipitation in the warmest three months for 16 populations of C. cuspidata var. cuspidata.
Figure 8.
Genetic relationships among the 40 Castanopsis sieboldii populations estimated using STRUCTURE [58].
These data include 937 C. sieboldii individuals on 32 EST-SSR loci. Dotted lines indicate the distributions of clusters revealed by the NJ tree shown in Fig. 5.
Figure 9.
Relationship between geographical distance and Nei's genetic distance (DA) for 32 loci in Castanopsis sieboldii.
The significance of this relationship, which represents the magnitude of isolation by distance, was tested using the Mantel test (C. sieboldii, r = 0.164, P = 0.04; C. sieboldii var. sieboldii, r = 0.105, P = 0.04).