Reconsideration for conservation units of wildPrimula sieboldiiin Japan based on adaptive diversity and molecular genetic diversity

Abstract

SummaryPrimula sieboldii E. Morren is a perennial clonal herb that is widely distributed in Japan, but in danger of extinction in the wild. In a previous study, we revealed the genetic diversity of the species using chloroplast and nuclear DNA and used this information to define conservation units. However, we lacked information on adaptive genetic diversity, which is important for long-term survival and, thus, for the definition of conservation units. In order to identify adaptive traits that showed adaptive differentiation among populations, we studied the genetic variation in six quantitative traits within and among populations for 3 years in a common garden using 110 genets from five natural populations from three regions of Japan. The number of days to bud initiation was adaptive quantitative trait for which the degree of genetic differentiation among populations (Q ST ) was considerably larger than that in eight microsatellite markers (F ST ). The relationship between this trait and environmental factors revealed that the number of days to bud initiation was negatively correlated, with the mean temperature during the growing period at each habitat. This suggests that adaptive differentiation in the delay before bud initiation was caused by selective pressure resulting from temperature differences among habitats. Our results suggest that based on adaptive diversity and neutral genetic diversity, the Saitama population represents a new conservation unit.

Identification of effective pollinators of Primula sieboldii E. Morren in a wild habitat in Hiroshima, Japan

“…Corolla tube length differed significantly among five wild populations of P. sieboldii used in previous studies (Yoshida et al, 2008;Yoshida, Honjo, Kitamoto, & Ohsawa, 2009) in a common-garden experiment (Yoshida et al, unpublished), suggesting that these populations have become differentiated as a result of directional natural selection because of different pollinators in each habitat. Thus, we expect that there are not only common insect species, but also unique species that serve as effective pollinators in each habitat.…”

Pollination of Cleisostoma scolopendrifolium (Orchidaceae) by megachilid bees and determinants of fruit set in southern South Korea

“…Based on the zero fruiting rate at the NJ and JD sites, where the orchid population sizes were large, it is expected that the genetic diversity of those orchid populations will decline rapidly unless there is an increase in visits by legitimate pollinator. In a similar situation, the Saitama Primula is in danger of species extinction because the specific pollinator is reported to be absent (Yoshida et al 2009). Therefore, understanding the pollinator's population size and pollination behaviors are of fundamental importance for the conservation of C. scolopendrifolium in Korea.…”

Generation of expressed sequence tags, development of microsatellite and single nucleotide polymorphism markers in Primula sieboldii E. Morren (Primulaceae) for analysis of genetic diversity in natural and horticultural populations

“…Unigene elements that were highly expressed in the WB library may have direct and/or indirect relevance to phenotypic differences in bud initiation for P. sieboldii. Because bud initiation has been reported as an adaptive character for P. sieboldii (Yoshida et al 2009), candidate genes for future research should include those relating to bud dormancy and/or initiation, the control of which is important for plant survival (Horvath et al 2003). The cDNA libraries developed in our study will provide an important resource for future genetic research in P. sieboldii.…”

“…One hundred and forty-six genomic microsatellite markers have been developed for this species (Isagi et al 2001, Ueno et al 2003, 2009b) and used to infer patterns of gene flow (Ishihama et al 2006, Kitamoto et al 2006 and to define appropriate conservation units , Yoshida et al 2009) of the species. Because effective conservation plans are important not only for natural populations but also for breeding materials, estimation of the origin of cultivars ) and genetic analysis of petal traits (Yoshida et al 2008, Yoshioka et al 2005 of this species has been conducted.…”