Comparison of variability in wild Camellia sasanqua Thunberg in connection with possible origin of cultivated variety.

Abstract

A comparative study of variability in the wild Camellia sasanqua was conducted in 69 study sites covered the majority of the natural populations of the species in Japan. Less-disturbed broad-leaved evergreen forests within the study sites exhibited canopy trees of C.sasanqua up to 1Om in height, up to 46cm in DBH (trunk diameter a.t breast height) and average 125 years in age, while well-disturbed forests of either coppice forests or afforested plantations exhibited mostly sapling trees of C. sasanqua up to 2m in height, up to 2cm in DBH and average 10 years in age, which had large stumps up to 75 cm in diameter. All of the plants from the study sites had the same chromosome number of 2n=90 (hexaploid). The burried seeds of the seed bank have never been long-lived and stored for more than a year. Seed germination, recruitment and plant growth of more open habitats, plentifully supplied with light were expected to allow many more modules to develop. However, the seedlings appeared in low relative light intensity of 12.1% br less suffered a constant probability of death within the frst two years. Signficant correlations were seen between mean leaf length and mean petal length, between mean leaf width and mean petal width, between mean leaf area and mean petal area, between mean leaf length and mean leaf width, and between mean petal length and mean petal width. Nevertheless, those quantitative variations in leaf and flower-petal could not be correlated with differences in habitats. Only four variant forms found were as follows: (1) semi-double flower form of a bud variation in the study site No.6, (2) pinkish-white flower form in the study site No.20, (3) larger petal form in the study site No. 64, and (4) deeply crenate-margin leaf form in the study site No.69. No hybrid was seen in cross-combination between the wild C.sasanqua and its cultivars or other sympatric species which were not seasonally isolated. Since the present wild C.sasanqua was highly adapted to morphological uniformity and quantitative constancy and showed no segregation of morphological and quantitative characteristics, it could involve rarely with cultivar occurrence.